Att G.17 VAE

17. Ventilator-Associated Event (IC# 49).pdf

The National Healthcare Safety Network (NHSN)

Att G.17 VAE

OMB: 0920-0666

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Device-associated Events
VAE

Ventilator-Associated Event (VAE)
For use in adult patients (≥ 18 years)
Table of Contents:
Introduction
Settings
Requirements
Definitions
Reporting Instructions
Figures 1-5, VAE Algorithm
Numerator Data
Denominator Data
Data Analyses
References
Appendix of Antimicrobial Agents
VAE Form
Instructions for Completion of VAE Form
Frequently-Asked Questions

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Introduction: Mechanical ventilation is an essential, life-saving therapy for patients with
critical illness and respiratory failure. Studies have estimated that more than 300,000 patients
receive mechanical ventilation in the United States each year [1, 2]. These patients are at high
risk for complications and poor outcomes, including death [1-4]. Ventilator-associated
pneumonia (VAP), sepsis, Acute Respiratory Distress Syndrome (ARDS), pulmonary embolism,
barotrauma, and pulmonary edema are among the complications that can occur in patients
receiving mechanical ventilation; such complications can lead to longer duration of mechanical
ventilation, longer stays in the ICU and hospital, increased healthcare costs, and increased risk of
disability and death. Mortality in patients with acute lung injury on mechanical ventilation has
been estimated to range from 24% in persons 15-19 years of age to 60% for patients 85 years and
older [3].
Surveillance for ventilator-associated events in the National Healthcare Safety Network (NHSN)
has to date been limited to VAP. For the year 2010, NHSN facilities reported more than 3,525
VAPs, and the VAP incidence for various types of hospital units ranged from 0.0-5.8 per 1,000
ventilator days [5]. However, there is currently no gold standard, valid, reliable definition for
VAP, and even the most widely-used VAP criteria and definitions are neither sensitive nor
specific [6-9].
A particular difficulty with many commonly-used VAP definitions, including the NHSN PNEU
definitions (revised in 2002), is that they require radiographic findings of pneumonia. Evidence
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suggests that chest radiograph findings do not accurately identify VAP. The subjectivity and
variability inherent in chest radiograph technique, interpretation, and reporting make chest
imaging ill-suited for inclusion in a definition algorithm to be used for the potential purposes of
public reporting, inter-facility comparisons, and pay-for-reporting and pay-for-performance
programs. Another major difficulty with available VAP definitions is their reliance on specific
clinical signs or symptoms, which are subjective and may be poorly or inconsistently
documented in the medical record. The NHSN PNEU protocol includes multiple definition
pathways and special criteria for selected patient populations (e.g., children,
immunocompromised patients), increasing its complexity.
The limitations of VAP surveillance definitions have implications for prevention. Valid and
reliable surveillance data are necessary for assessing the effectiveness of prevention strategies. It
is notable that some of the most effective measures for improving outcomes of patients on
mechanical ventilation do not specifically target pneumonia prevention [10-13].
In 2011 CDC convened a Working Group composed of representatives of several stakeholder
organizations to address the limitations of the NHSN PNEU definitions and propose a new
approach to surveillance for Ventilator-Associated Events (VAE) for NHSN. The organizations
represented in the Working Group include: the Critical Care Societies Collaborative (the
American Association of Critical-Care Nurses, the American College of Chest Physicians, the
American Thoracic Society, and the Society for Critical Care Medicine); the American
Association for Respiratory Care; the Association of Professionals in Infection Control and
Epidemiology; the Council of State and Territorial Epidemiologists; the Healthcare Infection
Control Practices Advisory Committee’s Surveillance Working Group; the Infectious Diseases
Society of America; and the Society for Healthcare Epidemiology of America.
The VAE surveillance definition algorithm developed by the Working Group is based on
objective, streamlined, and potentially automatable criteria that will intentionally identify a broad
range of conditions and complications occurring in mechanically-ventilated adult patients [14].
There are three definition tiers within the VAE algorithm: 1) Ventilator-Associated Condition
(VAC); 2) Infection-related Ventilator-Associated Complication (IVAC); and 3) Possible and
Probable VAP. Data indicate that streamlined, objective algorithms to detect ventilatorassociated complications (similar to the VAE algorithm) are easily implemented, can make use
of electronic health record systems to automate event detection, and identify events that are
clinically important and associated with outcomes such as ICU and hospital length of stay and
mortality [14,15]. Research to date suggests that most VACs are due to pneumonia, ARDS,
atelectasis, and pulmonary edema [14]. These are all significant clinical conditions that may be
preventable.
Settings: Inpatient locations eligible to participate in VAE surveillance are those in acute care
hospitals, long term acute care hospitals, and inpatient rehabilitation facilities where denominator
data (ventilator and patient days) can be collected for patients ≥ 18 years of age. Such locations
may include critical/intensive care units (ICU), specialty care areas (SCA), step-down units,
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wards, and long term care units. A complete listing of inpatient locations can be found in Chapter
15.
NOTE: It is not required to monitor for VAEs after discharge if a patient is transferred to another
facility while still on mechanical ventilation. However, VAEs discovered within 2 calendar days
of discharge (where the day of discharge is day 1) should be reported to NHSN. No additional
ventilator days are reported.
Requirements: Surveillance for VAE in at least one inpatient location in the healthcare
institution for at least one calendar month as indicated in the Patient Safety Monthly Reporting
Plan (CDC 57.106). The VAE algorithm is only applicable to mechanically-ventilated patients
≥18 years.
Definitions:
VAE: VAEs are identified by using a combination of objective criteria: changes in respiratory
status after a period of stability or improvement on the ventilator, evidence of infection or
inflammation, and laboratory evidence of respiratory infection. The following pages outline the
criteria that must be used for meeting the VAE surveillance definitions (Figures 1-5). To report
VAEs, use the VAE Form (CDC 57.112) and Instructions for Completion found in this chapter.
NOTE: Patients must be mechanically ventilated for more than 2 calendar days to be
eligible for VAE. The earliest day on which VAE criteria can be fulfilled is day 4 of
mechanical ventilation (where the day of intubation and initiation of mechanical
ventilation is day 1). The earliest date of event for VAE (the date of onset of worsening
oxygenation) is day 3 of mechanical ventilation. Line lists of VAE data elements
demonstrating scenarios that meet and do not meet the VAE definitions are presented in
“Frequently-Asked Questions (FAQs)” number (no.) 2 at the end of this chapter.
NOTE: The baseline period of stability or improvement on the ventilator is defined as the
2 calendar days immediately preceding the first day of increased daily minimum PEEP or
FiO2, and must be characterized by ≥ 2 calendar days of stable or decreasing daily
minimum FiO2 or PEEP values (i.e., the daily minimum PEEP or FiO2 on the second day
of the baseline period of stability or improvement must be equal to or less than the daily
minimum PEEP or FiO2 on the first day of the baseline period of stability or
improvement).
EXAMPLE: In the example below, the baseline period is defined by mechanical
ventilation (MV) days 3 and 4 (shaded in light gray), and the period of worsening
oxygenation by MV days 5 and 6 (shaded in darker gray), where the daily minimum FiO2
is ≥ 20 points over the daily minimum FiO2 during the baseline period.

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MV Day
1
2
3
4
5
6

Daily minimum
PEEP (cmH2O)
8
6
5
5
6
6

Daily minimum
FiO2 (%)
100
50
40
40
70
70

VAE

VAC

EXAMPLE: In the example below, there is no VAC, because the FiO2 on MV day 4 is
higher than the FiO2 on MV day 3 (and therefore not stable or decreasing) – even though
the FiO2 on MV days 3 and 4 meets the 20-point threshold when compared with the daily
minimum FiO2 on MV days 5 and 6.
MV Day
1
2
3
4
5
6

Daily minimum
PEEP (cmH2O)
8
6
5
5
6
6

Daily minimum
FiO2 (%)
100
50
35
40
70
70

VAE

No event

NOTE: Patients receiving “rescue” mechanical ventilation therapies (high-frequency
ventilation, extracorporeal membrane oxygenation, and mechanical ventilation in the
prone position) are EXCLUDED from VAE surveillance.
Positive End-Expiratory Pressure (PEEP): According to Stedman’s Medical Dictionary, “A
technique used in respiratory therapy in which airway pressure greater than atmospheric pressure
is achieved at the end of exhalation by the introduction of a mechanical impedance to
exhalation” [16]. In patients on mechanical ventilation, PEEP is one of the key parameters that
can be adjusted depending on the patient’s oxygenation needs, and is typically in the range of 0
to 15 cmH2O. A sustained increase (defined later in this protocol) in the daily minimum PEEP of
≥ 3 cmH2O following a period of stability or improvement on the ventilator is one of two criteria
that can be used in meeting the VAC definition.
Fraction of inspired oxygen (FiO2): The percentage of oxygen in inspired gas. For example, the
FiO2 of ambient air is 21%. In patients on mechanical ventilation, the FiO2 is one of the key
parameters that can be adjusted depending on the patient’s oxygenation needs, and is typically in
the range of 30% to 100%. A sustained increase (defined later in this protocol) in the daily
minimum FiO2 of ≥ 20 points (20 percent) following a period of stability or improvement on the
ventilator is the second of the two criteria that can be used in meeting the VAC definition.
Ventilator: A device to assist or control respiration continuously, inclusive of the weaning
period, through a tracheostomy or by endotracheal intubation.
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NOTE: Lung expansion devices such as intermittent positive-pressure breathing (IPPB);
nasal positive end-expiratory pressure (nasal PEEP); and continuous nasal positive
airway pressure (CPAP, hypoCPAP) are not considered ventilators unless delivered via
tracheostomy or endotracheal intubation (e.g., ET-CPAP).
Episode of mechanical ventilation: Defined as a period of days during which the patient was
mechanically ventilated for some portion of each consecutive day.
NOTE: A break in mechanical ventilation of at least one full calendar day, followed by
reintubation and reinitiation of mechanical ventilation during the same hospitalization,
defines a new episode of mechanical ventilation.
EXAMPLE: A patient is intubated and mechanical ventilation is initiated at 11 pm on
hospital day 1. The patient remains intubated and mechanically ventilated from hospital
days 2-10. The patient is extubated at 9 am on hospital day 11, and remains extubated on
hospital day 12. The patient is reintubated and mechanical ventilation is reinitiated on
hospital day 13. The patient remains intubated and mechanically ventilated from hospital
day 14-18. This patient has had two episodes of mechanical ventilation (days 1-11 and
days 13-18), separated by at least one full calendar day off of mechanical ventilation.
New antimicrobial agent: Defined as any agent listed in the Appendix that is initiated on or after
the third calendar day of mechanical ventilation AND in the 5-day period defined by the 2
calendar days before, the day of, and the 2 calendar days after the onset date of the VAE. The
agent is considered new for the purposes of this definition if it was NOT given to the patient on
either of the 2 days preceding the current start date.
NOTE: There is a qualification to this rule for patients receiving single (i.e. one-time)
doses of vancomycin. If a single dose of vancomycin meets the definition of a new
antimicrobial agent, as above, BUT there is a vancomycin level ≥ 10 mcg/ml during the 2
days preceding the date on which the current single dose of vancomycin was given, then
vancomycin is not considered a new antimicrobial agent.
EXAMPLE: A patient is intubated and mechanically ventilated on hospital day 1 in the
MSICU. Ceftriaxone and azithromycin are started on day 1. After 3 days of improving
respiratory status, the patient’s oxygenation deteriorates on days 4 and 5, with a daily
minimum PEEP that is 4 cmH2O higher than it was on days 2 and 3. Criteria for the VAC
definition are met; the date of the event is day 4. Ceftriaxone is discontinued and
meropenem is begun on day 5. Azithromycin is continued. In this case, meropenem is a
new antimicrobial agent: 1) it was begun on day 5 of mechanical ventilation, and 2)
within the 5-day period around the date of VAE onset (on the day after VAE onset), and
3) it was not given to the patient on either of the 2 days preceding the current start date.
By contrast, ceftriaxone and azithromycin would not be considered new antimicrobial
agents, since they were begun on day 1 of mechanical ventilation.
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The antimicrobial agent must have been given by one of the routes of administration outlined in
Table 1. For further guidance on identification of new antimicrobial agents and on how to
determine whether a new antimicrobial agent was continued for ≥4 days (including special
considerations for patients with renal insufficiency or patients receiving single doses of
vancomycin), refer to FAQs nos. 6-10 at the end of this chapter.
Table 1. Definitions of routes of administration
Route of Administrationa
Intravenous
Intramuscular
Digestive Tract
Respiratory Tract

Definitionb,c
An intravascular route that begins with a vein.
A route that begins within a muscle.
A route that begins anywhere in the digestive tract extending
from the mouth through rectum.
A route that begins within the respiratory tract, including the
oropharynx and nasopharynx.

Other routes of administration are excluded (e.g., antibiotic locks, intraperitoneal, intraventricular, irrigation, topical).
Definitions per SNOMED Reference Terminology
c
Mapping of standardized terminology for route of administration are provided via the hai-voc spreadsheet.
b

Date of event: The date of onset of worsening oxygenation. This is defined as the first calendar
day in which the daily minimum PEEP or FiO2 increases above the thresholds outlined in the
VAE definition algorithm (i.e., day 1 of the required ≥ 2-day period of worsening oxygenation
following a ≥ 2-day period of stability or improvement on the ventilator).
EXAMPLE: A patient is intubated in the Emergency Room for severe communityacquired pneumonia and admitted to the MICU (day 1). The patient stabilizes and
improves on days 2-5, with a daily minimum FiO2 of 35% on days 4 and 5. On day 6, the
patient experiences respiratory deterioration, and requires a minimum FiO2 of 60% on
days 6 and 7, meeting the criteria for a VAC. The date of the VAC event is day 6.
NOTE: The “date of event” is NOT the date on which all VAE criteria have been met. It
is the first day (of a ≥ 2-day period) on which either of the worsening oxygenation
thresholds (PEEP or FiO2) is met.
Location of attribution: The inpatient location where the patient was assigned on the date of the
VAE, which is further defined as the date of onset of worsening oxygenation.
EXAMPLE: Patient is intubated and ventilated in the Operating Room on hospital day 1,
and then is admitted post-operatively to the SICU on hospital day 1, still on the
ventilator. On hospital day 3, the patient experiences the onset of worsening
oxygenation, manifested by an increase in the daily minimum FiO2 of ≥ 20%. On day 4
(also the 4th day of mechanical ventilation) the patient meets criteria for a VAC. This is
reported to NHSN as a VAC for the SICU.

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EXCEPTION:
Transfer Rule: If a VAE develops on the day of transfer or the day following transfer
from one inpatient location to another in the same facility or to a new facility (where the
day of transfer is day 1), the event is attributed to the transferring location. This is called
the Transfer Rule and examples are shown below:
EXAMPLE: Patient on a ventilator in the SICU who has had improving oxygenation for
3 days is transferred to the MICU, still on the ventilator. On the day of transfer, after the
patient has arrived in the MICU, the patient experiences an acute decompensation,
requiring a 30% increase in FiO2 that persists during the following calendar day. VAC
criteria are met on calendar day 2 in the MICU. Because the onset of worsening
oxygenation occurred on the day of transfer to the MICU, the VAC event is attributed to
the SICU.
EXAMPLE: Patient is extubated in the MICU and transferred to the medical stepdown
unit on hospital day 6. The next day, while in the stepdown unit (day 7), the patient
experiences worsening oxygenation and is reintubated and transferred back to the MICU.
Criteria for VAC are met the next day (day 8). In this case, the day prior to extubation
and the day of extubation (hospital days 5 and 6) count as the required 2-day period of
stability or improvement. The day of reintubation (day 7) and the following day (day 8)
count as the required 2-day period of worsening oxygenation. Because the onset of
worsening oxygenation occurred on the day following transfer out of the MICU, the
event is reported to NHSN as a VAC for the MICU.
EXAMPLE: Patient intubated and mechanically ventilated for 8 days in the MSICU of
Hospital A is transferred for further care on day 8 to the MSICU of Hospital B. The
patient was stable on the ventilator in Hospital A from days 3-8. On the day of transfer,
after arriving in Hospital B (day 1), the patient’s respiratory status deteriorates. The day
after transfer (day 2 in Hospital B), the patient meets criteria for VAC. The date of the
event is day 1 in Hospital B, the first day of the period of worsening oxygenation meeting
VAE PEEP or FiO2 thresholds. The infection preventionist (IP) from Hospital B calls the
Hospital A IP to report that this patient was admitted to Hospital B with a VAC. This
VAC should be reported to NHSN for and by Hospital A, and attributed to the Hospital A
MSICU. No additional ventilator days are reported by Hospital A.
REPORTING INSTRUCTIONS (additional guidance may be found in the FAQs at the end of
this chapter):
 Conducting in-plan VAE surveillance in 2013 means assessing patients for the presence of
ALL events included in the algorithm—from VAC to IVAC to Possible and Probable VAP.
At this time, a unit conducting in-plan VAE surveillance cannot decide, for example, that
only surveillance for VAC (and not for IVAC or possible or probable VAP) will be
performed.
 There is a hierarchy of definitions within VAE:
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o
o
o
o





If a patient meets criteria for VAC and IVAC, report as IVAC.
If a patient meets criteria for VAC, IVAC and Possible VAP, report Possible VAP.
If a patient meets criteria for VAC, IVAC and Probable VAP, report Probable VAP.
If a patient meets criteria for VAC, IVAC, Possible VAP and Probable VAP, report
Probable VAP.
Pathogens may NOT be reported for VAC or IVAC events.
Secondary BSIs may NOT be reported for VAC or IVAC events.
Pathogens may be reported for Possible and Probable VAP events, provided they are isolated
or identified from appropriate specimen types according to the requirements of the algorithm
and are NOT on the list of excluded organisms and culture results:
o Excluded organisms and culture results that cannot be used to meet the Possible or
Probable VAP definitions are as follows: “Normal respiratory flora,” “normal oral
flora,” “mixed respiratory flora,” “mixed oral flora,” “altered oral flora” or other
similar results indicating isolation of commensal flora of the oral cavity or upper
respiratory tract; Candida species or yeast not otherwise specified; coagulasenegative Staphylococcus species; and Enterococcus species, when isolated from
cultures of sputum, endotracheal aspirates, bronchoalveolar lavage, or protected
specimen brushings.
NOTE: ANY organism isolated from cultures of lung tissue or pleural fluid, including
Candida species or yeast not otherwise specified, coagulase-negative Staphylococcus
species or Enterococcus species may be reported as pathogens for Possible or
Probable VAP.



See Table 2 for the required quantitative culture thresholds associated with various specimen
types in the Probable VAP definition. Note that if your laboratory reports semi-quantitative
culture results, you should check with your laboratory to confirm that semi-quantitative
results match the quantitative thresholds noted in Table 2.
Table 2. Threshold values for cultured specimens used in the Probable VAP definition
Specimen collection/technique

Values

Lung tissue
Bronchoscopically (B) obtained specimens
Bronchoalveolar lavage (B-BAL)
Protected BAL (B-PBAL)
Protected specimen brushing (B-PSB)
Nonbronchoscopically (NB) obtained (blind) specimens
NB-BAL
NB-PSB
Endotracheal aspirate (ETA)
cfu = colony forming units, g = gram, ml = milliliter
*Or equivalent semi-quantitative result.
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>104 cfu/g tissue*
>104 cfu/ml*
>104 cfu/ml*
>103 cfu/ml*
>104 cfu/ml*
>103 cfu/ml*
>105 cfu/ml*

Device-associated Events
VAE



Secondary BSIs may be reported for Possible and Probable VAP events, provided that at
least one organism isolated from the blood culture matches an organism isolated from an
appropriate respiratory tract specimen (including respiratory secretions, pleural fluid and
lung tissue).
o In the case where Possible VAP is met with only the purulent respiratory secretions
criterion and no culture is performed, AND there is also a positive blood culture with
a logical pathogen for pneumonia, report as a Possible VAP with a secondary BSI and
report the blood isolate as the pathogen (see Note below).
o In the case where Probable VAP is met with only the histopathology criterion and no
culture is performed, AND there is also a positive blood culture with a logical
pathogen for pneumonia, report as a Probable VAP with a secondary BSI and report
the blood isolate as the pathogen (see Note below).
o In cases where a culture of respiratory secretions, pleural fluid or lung tissue is
performed but is negative or does not grow an organism that matches an organism
isolated from blood, a secondary BSI may not be reported, and the organism isolated
from the blood culture may not be reported as a pathogen for the Possible or Probable
VAP.
NOTE: Candida species or yeast not otherwise specified, coagulase-negative
Staphylococcus species, and Enterococcus species cultured from blood cannot be
deemed secondary to a Possible or Probable VAP, unless the patient was determined
to have Probable VAP based on histopathology results, or unless the organism was
also cultured from pleural fluid or lung tissue.

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Figure 1: Ventilator-Associated Events (VAE) Surveillance Algorithm
Patient has a baseline period of stability or improvement on the ventilator, defined by ≥ 2 calendar days of stable or decreasing daily minimum
FiO2 or PEEP values. The baseline period is defined as the two calendar days immediately preceding the first day of increased daily minimum PEEP
or FiO2.
After a period of stability or improvement on the ventilator, the patient has at least one of the following indicators of worsening oxygenation:
1) Minimum daily FiO2 values increase ≥ 0.20 (20 points) over the daily minimum FiO2 in the preceding two calendar days (the baseline period)
and remain at or above that increased level for ≥ 2 calendar days.
2) Minimum daily PEEP values increase ≥ 3 cmH2O over the daily minimum PEEP in the preceding two calendar days (the baseline period) and
remain at or above that increased level for ≥ 2 calendar days.
Ventilator-Associated Condition (VAC)

On or after calendar day 3 of mechanical ventilation and within 2 calendar days before or after the onset of worsening oxygenation, the patient
meets both of the following criteria:
3

1) Temperature > 38 °C or < 36°C, OR white blood cell count ≥ 12,000 cells/mm or ≤ 4,000 cells/mm .
AND
2) A new antimicrobial agent(s)* is started, and is continued for ≥ 4 calendar days.
*See Appendix for eligible agents.
Infection-related Ventilator-Associated Complication (IVAC)
On or after calendar day 3 of mechanical ventilation and within 2
calendar days before or after the onset of worsening oxygenation,
ONE of the following criteria is met:

On or after calendar day 3 of mechanical ventilation and within 2
calendar days before or after the onset of worsening oxygenation,
ONE of the following criteria is met:

1) Purulent respiratory secretions (from one or more specimen
collections)
 Defined as secretions from the lungs, bronchi, or trachea that
contain >25 neutrophils and <10 squamous epithelial cells per
low power field [lpf, x100].
 If the laboratory reports semi-quantitative results, those results
must be equivalent to the above quantitative thresholds.

1) Purulent respiratory secretions (from one or more specimen
collections—and defined as for possible VAP)
AND one of the following:
5
 Positive culture of endotracheal aspirate*, ≥ 10 CFU/ml or
equivalent semi-quantitative result
4
 Positive culture of bronchoalveolar lavage*, ≥ 10 CFU/ml or
equivalent semi-quantitative result
4
 Positive culture of lung tissue, ≥ 10 CFU/g or equivalent
semi-quantitative result
3
 Positive culture of protected specimen brush*, ≥ 10 CFU/ml
or equivalent semi-quantitative result
*Same organism exclusions as noted for Possible VAP.

2) Positive culture (qualitative, semi-quantitative or quantitative) of
sputum*, endotracheal aspirate*, bronchoalveolar lavage*, lung
tissue, or protected specimen brushing*
*Excludes the following:
 Normal respiratory/oral flora, mixed respiratory/oral flora or
equivalent
 Candida species or yeast not otherwise specified
 Coagulase-negative Staphylococcus species
 Enterococcus species

2) One of the following (without requirement for purulent
respiratory secretions):
 Positive pleural fluid culture (where specimen was obtained
during thoracentesis or initial placement of chest tube and
NOT from an indwelling chest tube)
 Positive lung histopathology
 Positive diagnostic test for Legionella spp.
 Positive diagnostic test on respiratory secretions for
influenza virus, respiratory syncytial virus, adenovirus,
parainfluenza virus, rhinovirus, human metapneumovirus,
coronavirus

6-10
Possible Ventilator-Associated Pneumonia

Probable Ventilator-Associated Pneumonia

Device-associated Events
VAE

Figure 2: Ventilator-Associated Condition (VAC)
Patient has a baseline period of stability or improvement on the ventilator, defined by ≥ 2
calendar days of stable or decreasing daily minimum FiO2 or PEEP values. The baseline
period is defined as the two calendar days immediately preceding the first day of increased
daily minimum PEEP or FiO2.
AND
After a period of stability or improvement on the ventilator, the patient has at least one of
the following indicators of worsening oxygenation:
1) Minimum daily FiO2 values increase ≥ 0.20 (20 points) over the daily minimum
FiO2 in the preceding two calendar days (the baseline period) and remain at or
above that increased level for ≥ 2 calendar days.
2) Minimum daily PEEP values increase ≥ 3 cmH2O over the daily minimum PEEP in
the preceding two calendar days (the baseline period) and remain at or above that
increased level for ≥ 2 calendar days.

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Figure 3: Infection-related Ventilator-Associated Complication (IVAC)
Patient meets criteria for VAC
AND

On or after calendar day 3 of mechanical ventilation and within 2 calendar days before or
after the onset of worsening oxygenation, the patient meets both of the following criteria:
1) Temperature > 38 °C or < 36°C, OR white blood cell count ≥ 12,000 cells/mm3 or
≤ 4,000 cells/mm3.
AND
2) A new antimicrobial agent(s)* is started, and is continued for ≥ 4 calendar days.
*See Appendix for eligible agents.

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Figure 4: Possible Ventilator-Associated Pneumonia (VAP)
Patient meets criteria for VAC and IVAC
AND
On or after calendar day 3 of mechanical ventilation and within 2 calendar days before
or after the onset of worsening oxygenation, ONE of the following criteria is met:
1) Purulent respiratory secretions (from one or more specimen collections)
 Defined as secretions from the lungs, bronchi, or trachea that contain >
25 neutrophils and < 10 squamous epithelial cells per low power field
[lpf, x100].
 If the laboratory reports semi-quantitative results, those results must be
equivalent to the above quantitative thresholds.
OR

2) Positive culture (qualitative, semi-quantitative or quantitative) of sputum*,
endotracheal aspirate*, bronchoalveolar lavage*, lung tissue, or protected
specimen brushing*
*Excludes the following:
 Normal respiratory/oral flora, mixed respiratory/oral flora or equivalent
 Candida species or yeast not otherwise specified
 Coagulase-negative Staphylococcus species
 Enterococcus species

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Figure 5: Probable Ventilator-Associated Pneumonia (VAP)
Patient meets criteria for VAC and IVAC
AND
On or after calendar day 3 of mechanical ventilation and within 2 calendar days before
or after the onset of worsening oxygenation, ONE of the following criteria is met:
1) Purulent respiratory secretions (from one or more specimen collections—and
defined as for possible VAP)
AND one of the following (see Table 2):
 Positive culture of endotracheal aspirate*, ≥ 105 CFU/ml or equivalent semiquantitative result
 Positive culture of bronchoalveolar lavage*, ≥ 104 CFU/ml or equivalent semiquantitative result
 Positive culture of lung tissue, ≥ 104 CFU/g or equivalent semi-quantitative
result
 Positive culture of protected specimen brush*, ≥ 103 CFU/ml or equivalent
semi-quantitative result
*Same organism exclusions as noted for Possible VAP.
OR
2) One of the following (without requirement for purulent respiratory secretions):
 Positive pleural fluid culture (where specimen was obtained during
thoracentesis or initial placement of chest tube and NOT from an indwelling
chest tube)
 Positive lung histopathology
 Positive diagnostic test for Legionella spp.
 Positive diagnostic test on respiratory secretions for influenza virus, respiratory
syncytial virus, adenovirus, parainfluenza virus, rhinovirus, human
metapneumovirus, coronavirus

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VAE

Numerator Data: The Ventilator-Associated Event form (CDC 57.112) is used to collect and
report each VAE that is identified during the month selected for surveillance. The Instructions
for Completion of Ventilator-Associated Event Form includes brief instructions for collection
and entry of each data element on the form. The VAE form includes patient demographic
information and information on the start date and location of initiation of mechanical ventilation.
Additional data include the specific criteria met for identifying VAE, whether the patient
developed a secondary bloodstream infection, whether the patient died, and, where applicable,
the organisms detected and their antimicrobial susceptibilities.
REPORTING INSTRUCTION:
 If no VAEs are identified during the month of surveillance, the Report No Events box must
be checked on the appropriate denominator summary screen, e.g., Denominators for
Intensive Care Unit (ICU)/Other locations (Not NICU or SCA), etc.
Denominator Data: Device days and patient days are used for denominators (see Chapter 16
Key Terms). Ventilator days, which are the number of patients managed with a ventilatory
device, are collected daily, at the same time each day, according to the chosen location using the
appropriate form (CDC 57.117 and 57.118). These daily counts are summed and only the total
for the month is entered into NHSN. Ventilator and patient days are collected for each of the
locations monitored. When denominator data are available from electronic sources (e.g.,
ventilator days from respiratory therapy), these sources may be used as long as the counts are not
substantially different (+/- 5%) from manually-collected counts, validated for a minimum of 3
months.
NOTE: All ventilator days are counted, including ventilator days for patients on mechanical
ventilation for < 3 days, patients on rescue mechanical ventilation therapies, and pediatric
patients who are housed in adult locations where in-plan VAE surveillance is occurring. Patients
with tracheostomies who are undergoing weaning from mechanical ventilation using
tracheostomy collar trials are included in ventilator day counts as long as they spend some
portion of the day on mechanical ventilation at a time that overlaps with the daily time during
which ventilator day counts are performed.
Data Analyses: ***The information that follows regarding the Standardized Incidence Ratio
(SIR) is for informational purposes only, until a baseline period of VAE reporting has been
established.***
The SIR is calculated by dividing the number of observed events by the number of expected
events. The number of expected events, in the context of statistical prediction, is calculated using
VAE rates from a standard population during a baseline time period as reported in the NHSN
Report.
NOTE: The SIR will be calculated only if the number of expected VAEs (numExp) is ≥ 1.

6-15

Device-associated Events
VAE

SIR = Observed (O) VAEs / Expected (E) VAEs
While the VAE SIR can be calculated for single locations, the measure also allows you to
summarize your data by multiple locations, adjusting for differences in the incidence of VAEs
among the location types. For example, you will be able to obtain one VAE SIR adjusting for all
locations reported. Similarly, you can obtain one VAE SIR for all specialty care areas in your
facility.
The VAE rate per 1000 ventilator days is calculated by dividing the number of VAEs by the
number of ventilator days and multiplying the result by 1000. The Ventilator Utilization Ratio is
calculated by dividing the number of ventilator days by the number of patient days. These
calculations will be performed separately for the different types of ICUs, SCAs, and other
locations in the institution.

6-16

Device-associated Events
VAE

References
1) Behrendt CE. Acute respiratory failure in the United States: incidence and 31-day survival.
Chest 2000;118:1100-5.
2) Kahn JM, Goss CH, Heagerty PJ, et al. Hospital volume and the outcomes of mechanical
ventilation. N Engl J Med 2006;355:41-50.
3) Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N
Engl J Med 2005;353:1685-93.
4) Esteban A, Anzueto A, Frutos F, et al. Characteristics and outcomes in adult patients
receiving mechanical ventilation: a 28-day international study. JAMA 2002;287:345-55.
5) Dudeck MA, Horan TC, et. al. National Healthcare Safety Network (NHSN) Report, Data
Summary for 2010, Device-associated Module. Available at
http://www.cdc.gov/nhsn/PDFs/dataStat/2011NHSNReport.pdf.
6) Klompas M. Does this patient have ventilator-associated pneumonia? JAMA 2007;297:158393.
7) Klompas M. Interobserver variability in ventilator-associated pneumonia surveillance. Am J
Infect Control 2010;38:237-9.
8) Klompas M, Kulldorff M, Platt R. Risk of misleading ventilator-associated pneumonia rates
with use of standard clinical and microbiological criteria. Clin Infect Dis 2008;46:1443-6.
9) Zilberberg MD, Shorr AF. Ventilator-associated pneumonia: the clinical pulmonary infection
score as a surrogate for diagnostics and outcome. Clin Infect Dis 2010;51 Suppl 1:S131-5.
10) Girard T, Kress JP, Fuchs BD, et al. Efficacy and safety of a paired sedation and ventilator
weaning protocol for mechanically ventilated patients in intensive care (Awakening and
Breathing Controlled trial): a randomised controlled trial. Lancet 2008;371:126-34.
11) Strøm T, Martinussen T, Toft P. A protocol of no sedation for critically ill patients receiving
mechanical ventilation. Lancet 2010;375:475-80.
12) The Acute Respiratory Distress Syndrome Network. Ventilation with lower tidal volumes as
compared with traditional tidal volumes for acute lung injury and the acute respiratory
distress syndrome. N Engl J Med 2000;342:1301-8.
13) Schweickert WD, Pohlman MC, Pohlman AS, et al. Early physical and occupational therapy
in mechanically ventilated, critically ill patients: a randomised controlled trial. Lancet
2009;373:1874-82.
14) Klompas M, Khan Y, Kleinman K, et al. Multicenter evaluation of a novel surveillance
paradigm for complications of mechanical ventilation. PLoS One 2011;6:e18062.
15) Klompas M, Magill S, Robicsek A, et al. Objective surveillance definitions for ventilatorassociated pneumonia. Crit Care Med;2012, in press.
16) Stedman’s medical dictionary. (28th ed). (2005). Philadelphia: Lippincott, Williams, &
Wilkins.

6-17

Device-associated Events
VAE

Appendix. List of Antimicrobials Agents Eligible for IVAC, Possible and Probable VAP

Antimicrobial Agent

AMIKACIN

Antimicrobial
Antimicrobial
Category
Classa
Anti-influenza M2 ion channel
inhibitors
Antibacterial
Aminoglycosides

AMOXICILLIN

Antibacterial

Penicillins

Aminopenicillin

AMOXICILLIN/
CLAVULANATE
AMPHOTERICIN B

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antifungal

Polyenes

AMPHOTERICIN B
LIPOSOMAL
AMPICILLIN

Antifungal

Polyenes

Antibacterial

Penicillins

Aminopenicillin

AMPICILLIN/
SULBACTAM
ANIDULAFUNGIN

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antifungal

Echinocandins

AZITHROMYCIN

Antibacterial

Macrolides

AZTREONAM

Antibacterial

Monobactams

CASPOFUNGIN

Antifungal

Echinocandins

CEFACLOR

Antibacterial

Cephalosporins

Cephalosporin 2rd generation

CEFADROXIL

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CEFAZOLIN

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CEFDINIR

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFDITOREN

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFEPIME

Antibacterial

Cephalosporins

Cephalosporin 4th generation

CEFIXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFOTAXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFOTETAN

Antibacterial

Cephalosporins

Cephamycin

CEFOXITIN

Antibacterial

Cephalosporins

Cephamycin

CEFPODOXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFPROZIL

Antibacterial

Cephalosporins

Cephalosporin 2rd generation

CEFTAROLINE

Antibacterial

Cephalosporins

CEFTAZIDIME

Antibacterial

Cephalosporins

Cephalosporin with antiMRSA activity
Cephalosporin 3rd generation

CEFTIBUTEN

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFTIZOXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFTRIAXONE

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

AMANTADINE

6-18

Antimicrobial
Subclassa

Device-associated Events
VAE

CEFUROXIME

Antibacterial

Cephalosporins

Cephalosporin 2rd generation

CEPHALEXIN

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CHLORAMPHENICOL

Antibacterial

Phenicols

CIPROFLOXACIN

Antibacterial

Fluoroquinolones

CLARITHROMYCIN

Antibacterial

Macrolides

CLINDAMYCIN

Antibacterial

Lincosamides

COLISTIMETHATE

Antibacterial

Polymyxins

DAPTOMYCIN

Antibacterial

Lipopeptides

DICLOXACILLIN

Antibacterial

Penicillins

DORIPENEM

Antibacterial

Carbapenems

DOXYCYCLINE

Antibacterial

Tetracyclines

ERTAPENEM

Antibacterial

Carbapenems

ERYTHROMYCIN

Antibacterial

Macrolides

ERYTHROMYCIN/
SULFISOXAZOLE

Antibacterial

FIDAXOMICIN

Antibacterial

Folate pathway
inhibitors/
Sulfonamides
Macrocyclic

FLUCONAZOLE

Antifungal

Azoles

FOSFOMYCIN

Antibacterial

Fosfomycins

GEMIFLOXACIN

Antibacterial

Fluoroquinolones

GENTAMICIN

Antibacterial

Aminoglycosides

IMIPENEM/
CILASTATIN
ITRACONAZOLE

Antibacterial

Carbapenems

Antifungal

Azoles

LEVOFLOXACIN

Antibacterial

Fluoroquinolones

LINEZOLID

Antibacterial

Oxazolidinones

MEROPENEM

Antibacterial

Carbapenems

METRONIDAZOLE

Antibacterial

Nitroimidazoles

MICAFUNGIN

Antifungal

Echinocandins

MINOCYCLINE

Antibacterial

Tetracyclines

MOXIFLOXACIN

Antibacterial

Fluoroquinolones

NAFCILLIN

Antibacterial

Penicillins

NITROFURANTOIN

Antibacterial

Nitrofurans

OSELTAMIVIR

Anti-influenza

OXACILLIN

Antibacterial

Neuraminidase
inhibitors
Penicillins

6-19

Penicillinase-stable
penicillins

Device-associated Events
VAE

PENICILLIN G

Antibacterial

Penicillins

Penicillin

PENICILLIN V

Antibacterial

Penicillins

Penicillin

PIPERACILLIN

Antibacterial

Penicillins

Ureidopenicillin

PIPERACILLIN/
TAZOBACTAM
POLYMYXIN B

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antibacterial

Polymyxins

POSACONAZOLE

Antifungal

Azoles

QUINUPRISTIN/
DALFOPRISTIN
RIFAMPIN

Antibacterial

Streptogramins

Antibacterial

Rifampin

RIMANTADINE

Anti-influenza

SULFAMETHOXAZOLE/
TRIMETHOPRIM
SULFISOXAZOLE

Antibacterial

TELAVANCIN

Antibacterial

M2 ion channel
inhibitors
Folate pathway
inhibitors
Folate pathway
inhibitors
Lipo-glycopeptides

TELITHROMYCIN

Antibacterial

Ketolides

TETRACYCLINE

Antibacterial

Tetracyclines

TICARCILLIN/
CLAVULANATE
TIGECYCLINE

Antibacterial

Penicillins

Antibacterial

Glycylcyclines

TINIDAZOLE

Antibacterial

Nitroimidazoles

TOBRAMYCIN

Antibacterial

Aminoglycosides

VANCOMYCIN

Antibacterial

Glycopeptides

VORICONAZOLE

Antifungal

Azoles

ZANAMIVIR

Anti-influenza

Neuraminidase
inhibitors

Antibacterial

Adapted from CLSI January 2010

6-20

Β-lactam/ Β-lactamase
inhibitor combination

OMB No. 0920-0666
Exp. Date: 01-31-2015
www.cdc.gov/nhsn

Ventilator-Associated Event (VAE)
Page 1 of 4
*required for saving **required for completion

Facility ID:
*Patient ID:
Secondary ID:
Patient Name, Last:
*Gender: F M Other
Ethnicity (Specify):
*Event Type: VAE
Post-procedure VAE: Yes
No
NHSN Procedure Code:
*MDRO Infection Surveillance:

Event #:
Social Security #:
Medicare #:
First:
*Date of Birth:
Race (Specify):
*Date of Event:
Date of Procedure:
ICD-9-CM Procedure Code:

Middle:

□ Yes, this infection’s pathogen & location are in-plan for Infection Surveillance in the MDRO/CDI Module
□ No, this infection’s pathogen & location are not in-plan for Infection Surveillance in the MDRO/CDI Module
*Date Admitted to Facility:
*Location:
Risk Factors
* Location of Mechanical Ventilation Initiation: ______________
*Date Mechanical Ventilation Initiated: __ /__ /_____
Event Details
*Specific Event: □ VAC
□ IVAC □ Possible VAP □ Probable VAP
*Specify Criteria Used:
STEP 1: VAC (≥1 REQUIRED)
†
□
Daily min FiO2 increase ≥ 0.20 (20 points) for ≥ 2 days
†

□ Daily min PEEP increase ≥ 3 cm H2O for ≥ 2 days†

after 2+ days of stable or decreasing daily minimum values.
STEP 2: IVAC

□ Temperature > 38°C or < 36°

□ White blood cell count ≥ 12,000 or ≤ 4,000 cells/mm 3
AND

□ A new antimicrobial agent(s) is started, and is continued for ≥ 4 days
STEP 3: Possible VAP (≥1 REQUIRED)

STEP 3: Probable VAP (≥1 REQUIRED)

□ Purulent respiratory secretions

□ Purulent respiratory secretions‡

‡

(defined as
secretions from the lungs, bronchi, or trachea that
contain >25 neutrophils and <10 squamous
epithelial cells per low power field [lpf, x100], or
equivalent semi-quantitative results)
OR

□ One of the following (qualitative, semi-quantitative
‡

or quantitative):
□ Positive culture of sputum
□ Positive culture of endotracheal aspirate
□ Positive culture of bronchoalveolar lavage
□ Positive culture of lung tissue
□ Positive culture of protected specimen brushing

AND one of the following (meeting quantitative or semi‡
quantitative threshold as outlined in protocol):
□ Positive culture of endotracheal aspirate
□ Positive culture of bronchoalveolar lavage
□ Positive culture of lung tissue
□ Positive culture of protected specimen brushing
OR

□ One of the following results(without requirement for purulent
‡

respiratory secretions), as outlined in protocol:
□ Positive pleural fluid culture
□ Positive lung histopathology
□ Positive diagnostic test for Legionella spp.
□ Positive diagnostic test for viral pathogens

‡

collected after 2 days of mechanical ventilation and within +/- 2 days of onset of increase in FiO2 or PEEP.

*Secondary Bloodstream Infection: Yes No
**Died: Yes No
VAE Contributed to Death: Yes No
Discharge Date:
*Pathogens Identified: Yes No
*If Yes, specify on pages 2-3
Assurance of Confidentiality: The voluntarily provided information obtained in this surveillance system that would permit identification of any individual or institution is collected with a guarantee that it will
be held in strict confidence, will be used only for the purposes stated, and will not otherwise be disclosed or released without the consent of the individual, or the institution in accordance with Sections 304,
306 and 308(d) of the Public Health Service Act (42 USC 242b, 242k, and 242m(d)).
Public reporting burden of this collection of information is estimated to average 25 minutes per response, including the time for reviewing instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the collection of information. An agency may not conduct or sponsor, and a person is not required to respond to a collection of information
unless it displays a currently valid OMB control number. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden
to CDC, Reports Clearance Officer, 1600 Clifton Rd., MS D-74, Atlanta, GA 30333, ATTN: PRA (0920-0666).
CDC 57.112 (Front), v7.1

OMB No. 0920-0666
Exp. Date: 01-31-2015
www.cdc.gov/nhsn

Ventilator-Associated Event (VAE)
Page 2 of 4

Pathogen
#

VANC
Staphylococcus
SIRN
coagulase-negative
(specify): ________________________

_______

Pathogen
#

_______

GENTHL§
SRN

LNZ
SIRN

DOXY/MINO
SIRN

GENTHL§
SRN

LNZ
SIRN

TETRA
SIRN

TIG
S NS N

VANC
SIRN

CIPRO/LEVO/MOXI
SIRN

CLIND
SIRN

DAPTO
S NS N

DOXY/MINO
SIRN

ERYTH
SIRN

GENT
SIRN

OX/CEFOX/METH
SIRN

QUIDAL
SIRN

RIF
SIRN

TETRA
SIRN

TIG
S NS N

TMZ
SIRN

AMK
SIRN

AMPSUL
SIRN

AZT
SIRN

CEFEP
SIRN

CEFTAZ
SIRN

CIPRO/LEVO
SIRN

GENT
SIRN

IMI
SIRN

MERO/DORI
SIRN

PIP/PIPTAZ
SIRN

TMZ
SIRN

TOBRA
SIRN

AMK
SIRN

AMP
SIRN

AMPSUL/AMXCLV
SIRN

AZT
SIRN

CEFAZ
SIRN

CEFTAZ
SIRN

CEFUR
SIRN

CEFOX/CETET
SIRN

CHLOR
SIRN

CIPRO/LEVO/MOXI
SIRN

ERTA
SIRN

GENT
SIRN

IMI
SIRN

TIG
SIRN

TMZ
SIRN

TOBRA
SIRN

AMK
SIRN

AMP
SIRN

AMPSUL/AMXCLV
SIRN

CEFTAZ
SIRN

CEFUR
SIRN

CEFOX/CETET
SIRN

ERTA
SIRN

GENT
SIRN

IMI
SIRN

TIG
SIRN

TMZ
SIRN

TOBRA
SIRN

AMK
SIRN

AMP
SIRN

AMPSUL/AMXCLV
SIRN

CEFTAZ
SIRN

CEFUR
SIRN

CEFOX/CETET
SIRN

ERTA
SIRN

GENT
SIRN

IMI
SIRN

TIG
SIRN

TMZ
SIRN

TOBRA
SIRN

Enterococcus
spp.( specify):
___________

AMP
SIRN

Enterococcus
faecium

Staphylococcus
aureus

_______

Gram-positive Organisms

CIPRO/LEVO/MOXI
SIRN

DAPTO
S NS N

DOXY/MINO
SIRN

TETRA
SIRN

TIG
S NS N

VANC
SIRN

AMP
SIRN

CIPRO/LEVO/MOXI
SIRN

DAPTO
S NS N

QUIDAL
SIRN

STREPHL§
SRN

CHLOR
SIRN
LNZ
SRN

STREPHL§
SRN

VANC
SIRN

Gram-negative Organisms
Acinetobacter
spp. (specify):
____________

Escherichia coli

Enterobacter
spp. (specify):
____________

Klebsiella spp.
(specify):
____________

CDC 57.112 (Back), v7.1

MERO/DORI
SIRN

COL/PB
SIRN
TETRA/DOXY/MINO
SIRN

CEFEP
SIRN

CEFOT/CEFTRX
SIRN
COL/PB
SIRN

PIPTAZ
SIRN

TETRA/DOXY/MINO
SIRN

AZT
SIRN

CEFAZ
SIRN

CEFEP
SIRN

CHLOR
SIRN

CIPRO/LEVO/MOXI
SIRN

MERO/DORI
SIRN

CEFOT/CEFTRX
SIRN
COL/PB
SIRN

PIPTAZ
SIRN

TETRA/DOXY/MINO
SIRN

AZT
SIRN

CEFAZ
SIRN

CEFEP
SIRN

CHLOR
SIRN

CIPRO/LEVO/MOXI
SIRN

MERO/DORI
SIRN

PIPTAZ
SIRN

CEFOT/CEFTRX
SIRN
COL/PB
SIRN

TETRA/DOXY/MINO
SIRN

OMB No. 0920-0666
Exp. Date: 01-31-2015
www.cdc.gov/nhsn

Ventilator-Associated Event (VAE)
Page 3 of 4

Pathogen
#

Gram-negative Organisms (continued)

_______

Serratia
marcescens

Pseudomonas
aeruginosa

_______

AMK
SIRN

AMP
SIRN

AMPSUL/AMXCLV
SIRN

AZT
SIRN

CEFAZ
SIRN

CEFTAZ
SIRN

CEFUR
SIRN

CEFOX/CETET
SIRN

CHLOR
SIRN

CIPRO/LEVO/MOXI
SIRN

ERTA
SIRN

GENT
SIRN

IMI
SIRN

TIG
SIRN

TMZ
SIRN

TOBRA
SIRN

AMK
SIRN

AZT
SIRN

CEFEP
SIRN

IMI
SIRN

MERO/DORI
SIRN

_______

Stenotrophomonas
maltophilia

Pathogen
#

Fungal Organisms
Candida spp.

ANID
SIRN

_______

(specify):

Pathogen
#

Other Organisms

____________

Organism 1
(specify)

_______

____________
Organism 1
(specify)

_______

____________
Organism 1
(specify)

_______

____________

CEFEP
SIRN

CEFOT/CEFTRX
SIRN
COL/PB
SIRN

MERO/DORI
SIRN

PIPTAZ
SIRN

TETRA/DOXY/MINO
SIRN

CEFTAZ
SIRN

CIPRO/LEVO
SIRN

COL/PB
SIRN

GENT
SIRN

PIP/PIPTAZ
SIRN

TOBRA
SIRN

MICA
S NS N

VORI
S S-DD R N

LEVO
SIRN

TETRA/MINO
SIRN

TICLAV
SIRN

TMZ
SIRN

CASPO
S NS N

FLUCO
S S-DD R N

FLUCY
SIRN

ITRA
S S-DD R N

_______
Drug 1
SIRN

_______
Drug 2
SIRN

______
Drug 3
SIRN

_______
Drug 4
SIRN

_______
Drug 5
SIRN

______
Drug 6
SIRN

______
Drug 7
SIRN

______
Drug 8
SIRN

______
Drug 9
SIRN

_______
Drug 1
SIRN

_______
Drug 2
SIRN

______
Drug 3
SIRN

_______
Drug 4
SIRN

_______
Drug 5
SIRN

______
Drug 6
SIRN

______
Drug 7
SIRN

______
Drug 8
SIRN

______
Drug 9
SIRN

_______
Drug 1
SIRN

_______
Drug 2
SIRN

______
Drug 3
SIRN

_______
Drug 4
SIRN

_______
Drug 5
SIRN

______
Drug 6
SIRN

______
Drug 7
SIRN

______
Drug 8
SIRN

______
Drug 9
SIRN

Result Codes
S = Susceptible I = Intermediate R = Resistant NS = Non-susceptible S-DD = Susceptible-dose dependent N = Not tested
§
GENTHL and STREPHL results: S = Susceptible/Synergistic and R = Resistant/Not Synergistic

Drug Codes:
AMK = amikacin

CEFTRX = ceftriaxone

ERYTH = erythromycin

MICA = micafungin

AMP = ampicillin

CEFUR= cefuroxime

FLUCO = fluconazole

MINO = minocycline

AMPSUL = ampicillin/sulbactam

CETET= cefotetan

FLUCY = flucytosine

MOXI = moxifloxacin

AMXCLV = amoxicillin/clavulanic acid

CHLOR=
chloramphenicol

GENT = gentamicin

OX = oxacillin

STREPHL = streptomycin –
high level test
TETRA = tetracycline
TICLAV = ticarcillin/clavulanic
acid
TIG = tigecycline

ANID = anidulafungin

CIPRO = ciprofloxacin

AZT = aztreonam

CLIND = clindamycin

GENTHL = gentamicin –high
level test
IMI = imipenem

PIP = piperacillin

TMZ =
trimethoprim/sulfamethoxazole
TOBRA = tobramycin

CASPO = caspofungin

COL = colistin

ITRA = itraconazole

PIPTAZ = piperacillin/tazobactam

VANC = vancomycin

CEFAZ= cefazolin

DAPTO = daptomycin

LEVO = levofloxacin

QUIDAL = quinupristin/dalfopristin

VORI = voriconazole

CEFEP = cefepime

DORI = doripenem

LNZ = linezolid

RIF = rifampin

CEFOT = cefotaxime

DOXY = doxycycline

MERO = meropenem

CEFOX= cefoxitin

ERTA = ertapenem

METH = methicillin

CEFTAZ = ceftazidime

CDC 57.112 (Back), v7.1

PB = polymyxin B

OMB No. 0920-0666
Exp. Date: 01-31-2015
www.cdc.gov/nhsn

Ventilator-Associated Event (VAE)
Page 4 of 4

Custom Fields
Label
______________________
_______________________
_______________________
_________________________
_________________________
_________________________
_________________________
Comments

CDC 57.112 (Back), v7.1

____/____/____
_____________
_____________
______________
______________
______________
______________

Label
_______________________
_______________________
_______________________
_______________________
_______________________
_______________________
_______________________

____/____/_____
______________
______________
______________
______________
______________
______________

Device-associated Events
VAE

Instructions for Completion of Ventilator-Associated Event Form
Data Field
Facility ID #
Event #
Patient ID #
Social Security #
Secondary ID #
Medicare #
Patient Name
Gender
Date of Birth
Ethnicity
Hispanic or Latino
Not Hispanic or Not
Latino
Race
Event Type
Date of Event

Post-procedure VAE
Date of Procedure
NHSN Procedure Code

ICD-9-CM Procedure Code

Instructions for Data Collection
The NHSN-assigned facility ID will be auto-entered by the computer.
Event ID number will be auto-entered by the computer.
Required. Enter the alphanumeric patient ID number. This is the
patient identifier assigned by the hospital and may consist of any
combination of numbers and/or letters.
Optional. Enter the 9-digit numeric patient Social Security Number.
Optional. Enter the alphanumeric ID number assigned by the facility.
Optional. Enter the patient’s Medicare number.
Optional. Enter the last, first, and middle name of the patient.
Required. Check Female, Male, or Other to indicate the gender of the
patient.
Required. Record the date of the patient birth using this format:
MM/DD/YYYY. Only patients ≥18 years are eligible for VAEs.
Optional.
If patient is Hispanic or Latino, check this box.
If patient is not Hispanic or not Latino, check this box.
Optional.
Check all the boxes that apply to identify the patient’s race.
Required. VAE.
Required. The date of onset of worsening oxygenation (i.e., day 1 of
the ≥ 2-day period of worsening oxygenation, according to the VAE
PEEP or FiO2 criteria). Enter date using this format:
MM/DD/YYYY.
Optional. Check Y if this event occurred after an NHSN-defined
procedure but before discharge from the facility; otherwise, check N.
Conditionally required. If Post-procedure VAE = Y, then enter the
date the procedure was done.
Conditionally required. Answer this question only if this patient
developed the VAE during the same admission as an operative
procedure. Enter the appropriate NHSN procedure code.
NOTE: A VAE cannot be “linked” to an operative procedure unless
that procedure has already been added to NHSN. If the procedure was
previously added, and the “Link to Procedure” button is clicked, the
fields pertaining to the operation will be auto-entered by the
computer.
Optional. The ICD-9-CM code may be entered here instead of (or in
addition to) the NHSN Procedure Code. If the ICD-9-CM code is
entered, the NHSN code will be auto-entered by the computer. If the
NHSN code is entered first, you will have the option to select the
appropriate ICD-9-CM code. In either case, it is optional to select the
ICD-9-CM code. Only those ICD-9-CM codes identified in Table 1

6-25

Device-associated Events
VAE

Data Field

MDRO Infection
Surveillance

Date Admitted to Facility

Location

Risk Factors: Location of
Mechanical Ventilation
Initiation

Risk Factors: Date
Mechanical Ventilation
Initiated

Instructions for Data Collection
of the Surgical Site Infection Event Chapter (Chapter 9 of NHSN
Manual: Patient Safety Component Protocol) are allowed.
Required. Check Y if the event is a Possible or Probable VAP AND if
one of the following pathogens is reported AND if the pathogen is
being followed for Infection Surveillance in the MDRO/CDI Module
in that location as part of your Monthly Reporting Plan: MRSA,
MSSA (MRSA/MSSA), VRE, CephR-Klebsiella, CRE-E. coli, CREKlebsiella, MDR-Acinetobacter. If the pathogen for Possible or
Probable VAP happens to be an MDRO but your facility is not
following the Infection Surveillance in the MDRO/CDI Module in
your Monthly Reporting Plan, check N for this question. Check N if
the VAE specific event is VAC or IVAC, since pathogens cannot be
reported for these events.
Required. Enter date patient admitted to facility using this format:
MM/DD/YYYY. An NHSN Inpatient is defined as a patient whose
date of admission to the healthcare facility and the date of discharge
are different calendar days. When determining a patient’s admission
dates to both the facility and specific inpatient location, the NHSN
user must take into account all such days, including any days spent in
an inpatient location as an “observation” patient before being
officially admitted as an inpatient to the facility, as these days
contribute to exposure risk. Therefore, all such days are included in
the counts of admissions and patient days for the facility and specific
location, and facility and admission dates must be moved back to the
first day spent in the inpatient location.
Required. Enter the inpatient location to which the patient was
assigned when the VAE was identified (i.e., day 1 of the ≥ 2-day
period of worsening oxygenation). If the VAE develops in a patient
within 2 days of transfer from a location (where the day of transfer is
day 1), indicate the transferring location, not the current location of
the patient.
Required. Enter the location in which the current episode of
mechanical ventilation was initiated (the episode associated with the
VAE). If this episode of mechanical ventilation was initiated in
another facility or by mobile emergency services, enter the code you
have mapped to “Location Outside Facility” (see Chapter 15, page
20) or Mobile Emergency Services/EMS (Chapter 15, page 14) as
appropriate. An episode of mechanical ventilation is defined by the
number of consecutive days during which the patient was
mechanically ventilated. A period of at least 1calendar day off the
ventilator, followed by reintubation, defines a new episode of
mechanical ventilation.
Required. Enter the date that the current episode of mechanical
ventilation was initiated (the episode associated with the VAE). Use
this format: MM/DD/YYYY. An episode of mechanical ventilation is
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Device-associated Events
VAE

Data Field

Event Details: VAE
Specific Event

Event Details:
Specify Criteria Used
Event Details: Secondary
Bloodstream Infection

Event Details:
Died
Event Details:
VAE Contributed to Death
Event Details:
Discharge Date
Event Details:
Pathogen Identified

Instructions for Data Collection
defined by the number of consecutive days during which the patient
was mechanically ventilated. A period of at least 1 calendar day off
the ventilator, followed by reintubation, defines a new episode of
mechanical ventilation.
Required. Check one: Ventilator-Associated Condition (VAC),
Infection-related Ventilator-Associated Complication (IVAC),
Possible Ventilator-Associated Pneumonia (Possible VAP), Probable
Ventilator-Associated Pneumonia (Probable VAP).
Required. Check each of the elements that were used to identify this
VAE.
Required. Check Y if there is a culture-confirmed bloodstream
infection (BSI) and a related Possible or Probable VAP, otherwise
check N. Note that secondary BSI must be checked N if the event is a
VAC or IVAC.
Required. Check Y if patient died during the hospitalization,
otherwise check N.
Conditionally required. If the patient died, check Y if the VAE
contributed to death, otherwise check N.
Optional. Date patient discharged from facility.
Required. This field will be auto entered by the computer as N for
VAC and IVAC (for which pathogens cannot be reported) and as Y
for Possible and Probable VAP. Specify pathogens on reverse form.
For specified Gram-positive, organisms, Gram-negative organisms, or
other organisms, Pathogen #:
Up to three pathogens may be reported. If multiple pathogens are
identified, enter the pathogen judged to be the most important cause
of infection as #1, the next most as #2, and the least as #3 (usually
this order will be indicated on the laboratory report). If the species is
not given on the lab report or is not found on the NHSN drop down
list, then select the “spp” choice for the genus (e.g., Bacillus cohnii
would be reported as Bacillus spp.).
Antimicrobial agent and susceptibility results:
Conditionally required if Pathogen Identified = Y.
• For those organisms shown on the back of an event form,
susceptibility results are required only for the agents listed.
• For organisms that are not listed on the back of an event form,
enter a susceptibility result for at least one antimicrobial agent,
even if that result is “Not Tested”.
Circle the pathogen’s susceptibility result using the codes on the

6-27

Device-associated Events
VAE

Data Field

Instructions for Data Collection
event forms.
Additional antimicrobial agents and susceptibility results may be
reported for up to a total of 20 agents.

Custom Fields

Comments

Optional. Up to 50 fields may be customized for local or group use in
any combination of the following formats: date (MMDDYYY),
numeric, or alphanumeric.
NOTE: Each Custom Field must be set up in the Facility/Custom
Options section of the application before the field can be selected for
use.
Optional. Enter any information on the event.

6-28

Device-associated Events
VAE

VAE FREQUENTLY-ASKED QUESTIONS
1) When should I use VAE? Are there circumstances in which I should still use PNEU?
 The VAE algorithm is ONLY applicable to mechanically-ventilated adult patients ≥18
years.
 The VAE algorithm is NOT applicable to neonatal or pediatric patients (<18 years).
 VAE surveillance may be conducted for mechanically-ventilated adult patients housed in
any type of unit in acute care and long-term acute care hospitals and inpatient
rehabilitation facilities, including adults who are housed in units that predominantly care
for pediatric patients.
 Patients who are receiving rescue mechanical ventilation (e.g., high-frequency
ventilation, extracorporeal membrane oxygenation, mechanical ventilation in the prone
position) are not eligible for VAE surveillance.
 In 2013, in-plan surveillance for ventilator-associated PNEU may still be conducted for
neonatal and pediatric patients ONLY.
 In 2012 and 2013, the PNEU definitions are still available for those units seeking to
conduct off-plan PNEU surveillance for mechanically-ventilated adults or non-ventilated
adults or children.
2) I am having difficulty visualizing how to arrange the VAE data elements to facilitate easy
identification of events. Can you provide some additional guidance?
 For units in which VAE surveillance will be conducted manually, we recommend that
you organize the necessary data elements in a table or spreadsheet to assist in identifying
VAEs. There are a number of different ways in which to organize the data – you may
consider limiting your spreadsheet to just include the minimum PEEP and FiO2 values,
and then, if a VAC event is identified, utilize other data sources to gather information on
the data elements included in the IVAC, Possible VAP, and Probable VAP definitions.
Alternatively, you may choose to include columns for all data elements (from VAC
through Probable VAP) in a single spreadsheet.
NOTE: Keep in mind that the baseline period of stability or improvement on the
ventilator is defined as the 2 calendar days immediately preceding the first day of
increased daily minimum PEEP or FiO2, and must be characterized by ≥ 2 calendar days
of stable or decreasing daily minimum FiO2 or PEEP values (i.e., the daily minimum
PEEP or FiO2 on the second day of the baseline period of stability or improvement must
be equal to or less than the daily minimum PEEP or FiO2 on the first day of the baseline
period of stability or improvement).
EXAMPLE: In the table below, the data elements used to meet VAC, IVAC and Possible
VAP definitions are organized in a fashion that facilitates identification of an event,
highlighted in the shaded region. In this example, MV days 3 and 4 constitute the
baseline period, with stable minimum PEEP of 5 cmH2O on each day. On MV days 5 and
6, the daily minimum PEEP is 8 cmH2O, which meets the VAC criterion for worsening
6-29

Device-associated Events
VAE

oxygenation. If we scan across the table, we can see that the IVAC temperature/white
blood cell count criterion is not met (there are no temperatures < 36°C or > 38°C, and no
white blood cell counts ≤ 4,000 cells/mm3 or ≥ 12,000 cells/mm3) – so even though the
patient was started on a new antimicrobial agent and continued on that agent for 4
calendar days, IVAC is not met. Therefore, this event would be reported as a VAC, with
the date of event being MV day 5.
Patient

MV Day

PEEPmin

FiO2min

Tempmin

Tempmax

WBCmin

WBCmax

Abx

Specimen

Polys / Epis

Organism

VAE

100

37.1

37.6

4.3

None

36.8

37.2

4.6

None

37.0

37.9

5.4

None

36.5

37.3

9.2

Yes

36.3

36.9

8.4

Yes

ETA

≥ 25 / ≤ 10

Mixed flora

VAC

37.2

37.5

8.5

8.8

Yes

37.8

37.9

7.6

Yes

MV = mechanical ventilation. PEEPmin = Daily minimum PEEP. FiO2min = Daily minimum FiO2. Tempmin = Daily minimum temperature. Tempmax = Daily
maximum temperature. WBCmin = Daily minimum white blood cell count. WBCmax = Daily maximum white blood cell count. Abx = antimicrobial agents. Polys
/ epis = Polymorphonuclear leukocytes and squamous epithelial cells from respiratory specimen.

EXAMPLE: In the table below, by scanning across the data elements, you can see that there are
no periods in which there is a stable, 2-day baseline period followed by a 2-day period where the
PEEP or FiO2 are increased 3 cmH2O or 20 points over baseline. On MV days 2 and 3, the PEEP
values are 7 cmH2O and 6 cmH2O respectively, and then increase to 9 cmH2O on MV days 4 and
5 – but the difference between day 4 or day 5 and day 2 is only 2 cmH2O, rather than the required
3 cmH2O. Also, the gradual increase in FiO2 from the time of initiation of mechanical ventilation
means that there are not two days on which the FiO2 is at least 20 points higher on the 2 previous
days. Therefore, although the temperature and white blood cell counts exceed the required
thresholds for IVAC on several occasions, and the patient appears to have received a new
antimicrobial agent for several days in the setting of a positive blood culture, the VAC definition
is not met, and so no VAE is reported.

6-30

Device-associated Events
VAE

Patient

MV Day

PEEPmin

FiO2min

Tempmin

Tempmax

WBCmin

WBCmax

Abx

Specimen

Polys / Epis

Organism

VAE

37.1

37.6

4.3

None

36.8

37.2

4.6

None

37.0

37.9

5.4

None

36.5

37.3

9.2

None

36.3

36.9

8.4

None

ETA

≥ 25 / ≤ 10

Mixed flora

37.2

37.5

8.5

8.8

None

37.8

37.9

7.6

None

38.2

38.4

10.5

11.9

Yes

Blood

S. aureus

38.5

38.9

12.7

Yes

37.4

38.1

12.9

Yes

37.2

37.9

9.4

Yes

37.3

37.5

9.5

Yes

37.2

37.8

8.2

Yes

37.0

37.7

8.6

Yes

3) Is there a hierarchy of reporting for VAE? How do I know whether to report a VAC, an
IVAC or a Possible or Probable VAP?
 Conducting in-plan VAE surveillance in 2013 means assessing patients for the presence
of ALL events included in the algorithm—from VAC to IVAC to Possible and Probable
VAP. At this time, a unit participating in in-plan VAE surveillance cannot decide, for
example, that only surveillance for VAC (and not for IVAC or Possible or Probable
VAP) will be performed.
 There is a hierarchy of definitions within VAE:
o If a patient meets criteria for VAC and IVAC, report as IVAC.
o If a patient meets criteria for VAC, IVAC and Possible VAP, report Possible
VAP.
o If a patient meets criteria for VAC, IVAC and Probable VAP, report Probable
VAP.
o If a patient meets criteria for VAC, IVAC, Possible VAP and Probable VAP,
report Probable VAP.
4) How do I determine the duration of a VAE? Can a patient have more than one VAE during a
hospitalization?
 Patients may have multiple VAEs during a single hospitalization. The event period is
defined by the 14-day period that starts on the date of onset of worsening oxygenation.
VAE criteria met during that 14-day period are attributed to the current VAE.
EXAMPLE: Patient is intubated and mechanical ventilation is initiated in the MICU (day
1). The patient is stable during the following 3 calendar days (days 2 through 5). On days
6 and 7 the patient’s minimum daily FiO2 is elevated more than 20 points over baseline,
6-31

Device-associated Events
VAE

therefore meeting the VAC FiO2 threshold. The VAC episode is defined by the period
encompassing days 6 through 19 (14 days, starting on day 1 of worsening oxygenation,
which in this case is day 6). If the patient were to experience a period of stability or
improvement on the ventilator on days 18 and 19, followed by another 2-day period of
worsening on days 20 and 21, a new VAE would be reported, since the second period of
worsening oxygenation has occurred more than 14 days after the start of the initial period
of worsening oxygenation.
5) Sometimes patients are intubated, extubated, and reintubated several times during a single
hospitalization. How do I define an episode of mechanical ventilation, and can a VAE occur
in a patient who has recently been extubated?
 An episode of mechanical ventilation is defined as a period of days during which the
patient was mechanically ventilated for some portion of each consecutive day during the
period.
EXAMPLE: A patient is intubated and mechanically ventilated on hospital day 1. The
patient remains on mechanical ventilation from hospital day 2 through 12 noon on
hospital day 6. At noon on hospital day 6, the patient is extubated. The patient remains
extubated on hospital day 7, and is then reintubated on hospital day 8. In this case, the
first episode of mechanical ventilation is defined by days 1 through 6. Since the patient
was extubated on day 6 and remained extubated for a full calendar day on day 7, the reintubation of the patient on day 8 defines the start of a second episode of mechanical
ventilation. See figure, below.
Hosp Day No.
MV Episode

1
1

2
1

3
1

4
1

5
1

MV Day No.

6
1
6—extubated
at noon

7
--

8
2

9
2

10
2

1--reintubated

1 full calendar day off mechanical ventilation, followed by
reintubation, defines a new episode of mechanical
ventilation antimicrobial agent must be given to meet

EXAMPLE: A patient is intubated and mechanically ventilated on hospital day 1. The
patient remains on mechanical ventilation from hospital day 2 through hospital day 6 at
12 noon. At noon on hospital day 6, the patient is extubated. The patient is reintubated at
9 pm on hospital day 7, and remains intubated and mechanically ventilated till 2 pm on
day 10. The patient is extubated at 2 pm on day 10 and remains extubated until hospital
discharge on day 15. In this case, there is only a single episode of mechanical ventilation,
defined by days 1 through 10, because the patient was extubated on day 6 but reintubated
the next calendar day (day 7). See figure, below.
Hosp Day No.
MV Episode

1
1

2
1

3
1

4
1

5
1

MV Day No.

6
1
6—extubated at
noon

7
1
7—reintubated
at 9 pm

8
1

9
1

10
1
10—extubated
at 2 pm

Patient was reintubated on the calendar day following extubation (days 6-7). Because there is not 1
calendar day off mechanical ventilation, there is only 1 episode of mechanical ventilation.

6-32

Device-associated Events
VAE



A VAE can occur in a patient who has been extubated and is then reintubated, subject to
the amount of time the patient was off the ventilator, as noted in the examples below.
EXAMPLE: A patient is intubated and mechanically ventilated on hospital day 1. The
patient remains on mechanical ventilation from hospital day 2 through 12 noon on
hospital day 6. At noon on hospital day 6, the patient is extubated. The patient remains
extubated on hospital day 7, and is then reintubated on hospital day 8. In this case,
because the patient has been extubated for 1 full calendar day (day 7), the “VAE clock”
starts over with reintubation on hospital day 8. To meet VAE during this second episode
of mechanical ventilation, the patient would have to have at least two days of stability or
improvement and at least two days of worsening oxygenation on the ventilator; therefore,
the earliest date on which the patient could meet VAE criteria would be hospital day 11
(stable or improving settings on days 8 and 9, increased ventilator settings on days 10 and
11). The VAE event date would be reported as day 10—the first day of worsening
oxygenation meeting VAE criteria. See figure, below.

Hosp Day No.
MV Episode

1
1

2
1

3
1

4
1

5
1

MV Day No.

VAE Criterion

6
1
6—extubated
at noon

7
--

8
2
1-reintubated
Day 1 of
stability or
improvement

9
2

10
2

11
2

Day 2 of
stability or
improvement

Day 1 of
worsening
oxygenation

Day 2 of
worsening
oxygenation

EXAMPLE: A patient is intubated and mechanically ventilated on hospital day 1. The
patient remains on mechanical ventilation from hospital day 2 through 12 noon on
hospital day 6, when the patient is extubated. The patient is reintubated at 9 pm on
hospital day 7. In this case, there is no “new” episode of mechanical ventilation, since
there was not a full, ventilator-free calendar day. Therefore, the period of worsening
oxygenation may be determined to have started on day 7, the day of reintubation, as long
as PEEP or FiO2 criteria are met. PEEP and FiO2 data from hospital days 5 and 6
(through the time of extubation) may be used to determine whether a period of stability
and improvement occurred, and these data may be compared to PEEP and FiO2 data
obtained from the time of reintubation on day 7 and beyond to determine whether at least
2 days of worsening oxygenation occurred. The earliest that the patient could meet VAE
criteria would be day 8 (assuming stable or improving ventilator settings on days 5 and 6,
and two days of worsening oxygenation meeting criteria on days 7 and 8). The VAE
event date would be reported as day 7—the first day of worsening oxygenation meeting
VAE criteria. See figure, below.

6-33

Device-associated Events
VAE

Hosp Day No.
MV Episode

1
1

2
1

3
1

4
1

5
1

MV Day No.

5
Day 1 of
stability or
improvement

VAE Criteria

6
1
6—extubated
at noon
Day 2 of
stability or
improvement

7
1
7—reintubated
at 9 pm
Day 1 of
worsening
oxygenation

8
1

9
1

10
1

Day 2 of
worsening
oxygenation

6) What antimicrobial agents are included in the IVAC definition?
 See the Appendix for a list of the antimicrobial agents eligible for consideration in the
IVAC definition (as well as the possible and probable VAP definitions).
 See Table 1 for eligible routes of administration.
7) How do I figure out if an antimicrobial agent is “new” for the IVAC definition?
 A new antimicrobial agent is defined as any agent listed in the Appendix that is initiated
on or after 3 days of mechanical ventilation AND in the 5-day period defined by the two
days before, the day of, and the two days after the onset date of the VAE. The agent is
considered new for the purposes of this definition if it was NOT given to the patient on
either of the 2 days preceding the current start date. The agent must be administered via
one of the routes listed in Table 1. See the figure below:
MV Day No.
VAE Criterion

7
Onset (day 1) of worsening
oxygenation meeting VAE PEEP
or FiO2 thresholds

8
Day 2 of worsening oxygenation
meeting VAE PEEP or FiO2
thresholds

5-day period during which the first dose of a new antimicrobial agent
must be given to meet requirements of IVAC definition

NOTE: There is a qualification to this rule for patients receiving single (i.e., onetime) doses of vancomycin. If a single dose of vancomycin meets the definition of
a new antimicrobial agent, as above, BUT there is a vancomycin level ≥ 10
mcg/ml during the 2 days preceding the date on which the current single dose of
vancomycin was given, then vancomycin is not considered a new antimicrobial
agent.
EXAMPLE: If a one-time dose of vancomycin is given to a patient on the VAE
onset date (which is the day of onset of worsening oxygenation meeting VAE
criteria, in this case MV day 7), and was not given to the patient during the 2
previous days (MV days 5 and 6), and there is no serum vancomycin level
reported during the 2 previous days (MV days 5 and 6), then vancomycin is
considered a new antimicrobial agent (see figure below). See FAQ no. 10 for
guidance about how to determine when a patient has received at least 4
consecutive days of vancomycin therapy, when vancomycin is being given as
single doses and not on a regular dosing schedule.

6-34

Device-associated Events
VAE

MV Day No.
VAE Criterion

4
--

Antimicrobial
agent

None

5
Day 1 of
stability or
improvement

6
Day 2 of
stability or
improvement

None

7
Day 1 of
worsening
oxygenation
Single dose of
vancomycin
ordered and
administered

8
Day 2 of
worsening
oxygenation

None

Single dose of
vancomycin
ordered and
administered

A single dose of vancomycin is ordered and administered to the patient within the
period defined by the two days before, the day of, and the two days after the VAE onset
date. Note that no vancomycin was given in the 2 preceding days, and there is no
vancomycin level reported, so vancomycin is a “new” antimicrobial agent for the
purposes of the VAE definition.

EXAMPLE: A one-time dose of vancomycin is given to a patient on the VAE
onset date (which is the day of onset of worsening oxygenation meeting VAE
criteria, in this case MV day 7), and was not given to the patient during the 2
previous days (MV days 5 and 6). However, because there is a serum vancomycin
level ≥ 10 mcg/ml during the 2 days preceding the date on which the current
single dose of vancomycin was given, vancomycin is NOT considered a new
antimicrobial agent. See figure, below. Also, see FAQ no. 10 for guidance about
how to determine when a patient has received at least 4 consecutive days of
vancomycin therapy, when vancomycin is being given as single doses and not on
a regular dosing schedule.
MV Day No.
VAE Criterion

5
Day 1 of
stability or
improvement

-Antimicrobial
agent

Single dose
of
vancomycin
ordered and
administered

Serum
vancomycin
level=
20 mcg/ml

6
Day 2 of
stability or
improvement

7
Day 1 of
worsening
oxygenation

None

Single dose of
vancomycin
ordered and
administered

8
Day 2 of
worsening
oxygenation

None

Single dose of
vancomycin
ordered and
administered

A single dose of vancomycin is ordered and administered to the patient within the period defined by the two
days before, the day of, and the two days after the VAE onset date. Note that no vancomycin was given in
the 2 preceding days—BUT because there is a serum vancomycin level ≥ 10 mcg/ml in the 2 preceding days,
vancomycin does NOT qualify as a new antimicrobial agent.

EXAMPLE: If meropenem is given to a patient on the VAE onset date (which is the day
of onset of worsening oxygenation meeting VAE criteria, in this case MV day 7), and
was not given to the patient during the 2 previous days (MV days 5 and 6), then
meropenem is considered a new antimicrobial agent (see figure below). Note that the
patient is also receiving ceftriaxone, and receives doses during the 5-day period around
the onset of worsening oxygenation (first dose during the 5-day period was on MV day
5). However, because ceftriaxone was given to the patient the day before the 5-day period
(on MV day 4), ceftriaxone does not count as a new antimicrobial agent for the purposes
of the IVAC definition.
6-35

Device-associated Events
VAE

MV Day No.
VAE Criterion

4
--

Antimicrobial
agent

Ceftriaxone

5
Day 1 of
stability or
improvement

6
Day 2 of
stability or
improvement

7
Day 1 of
worsening
oxygenation

8
Day 2 of
worsening
oxygenation

Ceftriaxone

Meropenem

First dose of meropenem during the 5-day period around the onset of worsening
oxygenation. Note that no meropenem was given in the 2 preceding days, and so
meropenem is a “new” antimicrobial agent for the purposes of the VAE definition.

8) I have figured out that a new antimicrobial agent was given to the patient. How do I
determine whether it was continued for 4 days?
 Any doses of any new antimicrobial agent (or agents) given on 4 consecutive days count
as 4 days of new antimicrobial therapy and therefore meet the antimicrobial criterion.
Note that there is no requirement that the same new antimicrobial agent be given on 4
consecutive days—as long as there are 4 consecutive days of new antimicrobial therapy
(consisting of one or more agents), the antimicrobial criterion is met.
EXAMPLE: In the figure below, meropenem would meet the antimicrobial
criterion of the IVAC definition because at least one dose was given on 4
consecutive days.
MV Day No.
VAE Criterion

1
--

Antimicrobial
agent

Ceftriaxone

2
Day 1 of
Stability or
improvement
Ceftriaxone

3
Day 2 of
stability or
improvement
Ceftriaxone

4
Day 1 of
worsening
oxygenation
Meropenem

5
Day 2 of
worsening
oxygenation
Meropenem

Meropenem

Meropenem is given on each of 4 consecutive days, with the
first dose given during the 5-day period around the onset of
worsening oxygenation.

EXAMPLE: In the figure below, the 3 drugs shown in bold lettering all qualify as
new antimicrobial agents, and therefore the antimicrobial criterion of IVAC is
met, since the patient is given 4 consecutive days of new antimicrobial agents.

MV Day No.
VAE Criterion

1
--

Antimicrobial
agent

Ceftriaxone

2
Day 1 of
Stability or
improvement
Ceftriaxone

3
Day 2 of
stability or
improvement
Ceftriaxone

4
Day 1 of
worsening
oxygenation
Meropenem

5
Day 2 of
worsening
oxygenation
Imipenem

Piperacillin/
tazobactam

A new antimicrobial agent is given on each of 4 consecutive days,
and the first dose of a new antimicrobial agent was given during
the 5-day period around the onset of worsening oxygenation.

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9) There are many patients in my ICU with renal insufficiency and/or who are receiving
hemodialysis. These patients may receive certain antimicrobial agents on an infrequent
dosing schedule (for example, every 48 hours). How do I determine whether they have
received 4 consecutive days of new antimicrobial therapy?
 Review the patient’s Medication Administration Record (MAR). If any new
antimicrobial agents are given on a dosing schedule that is less frequent than once per
day (for example, one dose every 48 or 72 hours) then you will count 1 day of therapy for
each day of the dosing interval.
EXAMPLE: The patient is being given levofloxacin every 48 hours, as shown in
the figure below. The first dose of levofloxacin was given on MV day 6, during
the 5-day period around the onset of worsening oxygenation, and was not given in
the 2 previous days—so levofloxacin counts as a new antimicrobial agent. You
will count one day of antimicrobial therapy for each day of the dosing interval, so
that there are a total of 6 days of levofloxacin therapy starting on MV day 6
through MV day 11. The IVAC antimicrobial criterion is therefore met.
MV Day No.
VAE Criterion

Antimicrobial
agent

None

6
Day 1 of
stability or
improvement
Levofloxacin 1
dose every 48
hours
(Day 1)

7
Day 2 of
stability or
improvement
Day 2 of
levofloxacin

8
Day 1 of
worsening
oxygenation
Levofloxacin
1 dose every 48
hours
(Day 3)

9
Day 2 of
worsening
oxygenation
Day 4 of
levofloxacin

Levofloxacin
1 dose every
48 hours
(Day 5)

Day 6 of
levofloxacin

Levofloxacin qualifies as a new antimicrobial agent, and one day of levofloxacin
therapy is counted for each day of the dosing interval (which is every 48 hours in this
case). Since 6 days of therapy were given, the IVAC antimicrobial criterion is met.

10) What if the patient is being given one-time doses of vancomycin? How do I take that into
account when using the IVAC surveillance definition?
 Make sure that vancomycin qualifies as a new antimicrobial agent (see FAQ no. 6).
 If vancomycin is a new antimicrobial agent, a second dose of vancomycin given within 4
days following the first dose (where the day the first dose is given is day 1) meets the
IVAC antimicrobial criterion.
EXAMPLE: A patient is given a single dose of vancomycin 1 gram IV MV day 5.
Since vancomycin was started on or after day 3 of mechanical ventilation, and no
vancomycin was administered on MV days 2, 3 or 4, vancomycin qualifies as a
new antimicrobial agent. A second, single dose of vancomycin 1 gram IV is
administered on MV day 8. This meets the IVAC antimicrobial criterion.

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MV Day No.
VAE Criterion

2
--

3
--

Antimicrobial
agent

None

4
Day 1 of
Stability or
improvement
None

5
Day 2 of
stability or
improvement
Vancomycin 1
gram IV x 1
dose

6
Day 1 of
worsening
oxygenation
None

7
Day 2 of
worsening
oxygenation
None

Vancomycin 1
gram IV x 1
dose

None

Vancomycin is given on 2 days during the 4-day period starting on the
first day of vancomycin—meeting the IVAC antimicrobial criterion.

EXAMPLE: A patient is given a single dose of vancomycin 1 gram IV on MV
day 5. No vancomycin was administered on MV days 2-4 and so vancomycin
qualifies as a new antimicrobial agent. A second, single dose of vancomycin 1
gram IV is administered on MV day 6. This also meets the IVAC antimicrobial
criterion.
MV Day No.
VAE Criterion

2
--

3
--

Antimicrobial
agent

None

4
Day 1 of
Stability or
improvement
None

5
Day 2 of
stability or
improvement
Vancomycin 1
gram IV x 1
dose

6
Day 1 of
worsening
oxygenation
Vancomycin 1
gram IV x 1
dose

7
Day 2 of
worsening
oxygenation
None

None

Vancomycin is given on 2 days during the 4-day period starting on the first day
of vancomycin—meeting the IVAC antimicrobial criterion.

11) Can I report pathogens or secondary BSIs for VAC and IVAC?
 Pathogens may NOT be reported for VAC or IVAC events.
 Secondary BSIs may NOT be reported for VAC or IVAC events.
EXAMPLE: A patient hospitalized and mechanically-ventilated in the MICU for
14 days develops worsening oxygenation following a 7-day period of stability on
the ventilator. VAC criteria are met on hospital day 15 (stable ventilator settings
on days 12 and 13, increased ventilator settings on days 14 and 15). The onset
date is day 14. The white blood cell count is noted to be 15,500 cells/mm3 on day
14. Meropenem and vancomycin are begun on day 15, administered through the
patient’s right-sided central line, which was inserted on ICU admission. The
antibiotics continue to be administered on day 18, meeting IVAC criteria.
Endotracheal aspirate cultures done on days 15 and 16 grow scant upper
respiratory flora. A blood culture collected on day 15 is positive for Klebsiella
oxytoca. There are no other signs or symptoms of infection. This patient should be

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reported as having an IVAC and a central line-associated BSI. The BSI cannot be
reported as secondary to the IVAC event.
12) Can I report pathogens for Possible and Probable VAP?
 Pathogens may be reported for Possible and Probable VAP events, provided they are
isolated or identified from appropriate specimen types according to the requirements of
the algorithm and are NOT on the list of excluded organisms and culture results:
o Excluded organisms and culture results that cannot be used to meet the
Possible or Probable VAP definitions are as follows: “Normal respiratory
flora,” “normal oral flora,” “mixed respiratory flora,” “mixed oral flora,”
“altered oral flora” or other similar results indicating isolation of commensal
flora of the oral cavity or upper respiratory tract; Candida species or yeast not
otherwise specified; coagulase-negative Staphylococcus species; and
Enterococcus species, when isolated from cultures of sputum, endotracheal
aspirates, bronchoalveolar lavage, or protected specimen brushings.
NOTE: When Candida species or yeast not otherwise specified, coagulase-negative
Staphylococcus species or Enterococcus species are isolated from cultures of lung tissue
or pleural fluid, these organisms may be reported as Possible or Probable VAP
pathogens.


See Table 2 for the required quantitative culture thresholds associated with various
specimen types in the Probable VAP definition. Note that if your laboratory reports semiquantitative culture results, you should check with your laboratory to confirm that semiquantitative results match the quantitative thresholds noted in Table 2.

13) Can I report secondary BSIs for Possible and Probable VAP?
 Secondary BSIs may be reported for Possible and Probable VAP events, provided that the
organism isolated from the blood culture matches an organism isolated from an
appropriate respiratory tract specimen (including respiratory secretions, pleural fluid and
lung tissue).
o In the case where Possible VAP is met with only the purulent respiratory
secretions criterion and no culture is performed, and there is also a positive blood
culture with a logical pathogen for pneumonia, report as a Possible VAP with a
secondary BSI and report the blood isolate as the pathogen (see Note below).
o In the case where Probable VAP is met with only the histopathology criterion and
no culture is performed, AND there is also a positive blood culture with a logical
pathogen for pneumonia, report as a Probable VAP with a secondary BSI and
report the blood isolate as the pathogen (see Note below).
o In cases where a culture of respiratory secretions, pleural fluid or lung tissue is
performed but is negative or does not grow an organism that matches an organism
isolated from blood, a secondary BSI may not be reported, and the organism
isolated from the blood culture may not be reported as a pathogen for the Possible
or Probable VAP.
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Device-associated Events
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NOTE: Candida species or yeast not otherwise specified, coagulase-negative
Staphylococcus species, and Enterococcus species cultured from blood cannot be deemed
secondary to a Possible or Probable VAP, unless the patient was determined to have
Probable VAP based on histopathology results, or unless the organism was also cultured
from pleural fluid or lung tissue.
EXAMPLE: Patient hospitalized and mechanically ventilated in the MICU for 14 days
develops worsening oxygenation following a 7-day period of stability on the ventilator.
VAC criteria are met on hospital day 15 (stable ventilator settings on days 12 and 13,
increased ventilator settings on days 14 and 15). The onset date is day 14. The white
blood cell count is noted to be 15,500 cells/mm3 on day 14. Meropenem and vancomycin
are begun on day 15, administered through the patient’s right-sided central line (inserted
on ICU admission). The antibiotics continue to be administered on day 18, meeting
IVAC criteria. Endotracheal aspirate specimens collected on days 15 and 16 grow heavy
Klebsiella oxytoca. Endotracheal aspirate quality is not reported. A blood culture
collected on day 15 is positive for K. oxytoca. This patient should be reported as having a
Possible VAP with a secondary BSI due to K. oxytoca.
EXAMPLE: Patient hospitalized and mechanically ventilated in the MICU for 14 days
develops worsening oxygenation following a 7-day period of stability on the ventilator.
VAC criteria are met on hospital day 15 (stable ventilator settings on days 12 and 13,
increased ventilator settings on days 14 and 15). The onset date is day 14. The white
blood cell count is noted to be 15,500 cells/mm3 on day 14. Meropenem and vancomycin
are begun on day 15, administered through the patient’s right-sided central line (inserted
on ICU admission). The antibiotics continue to be administered on day 18, meeting
IVAC criteria. A thoracentesis is performed on day 15 at the patient’s bedside using
aseptic technique. Pleural fluid is sent for culture and grows Candida albicans. A blood
culture collected on day 16 is positive for C. albicans. This patient should be reported as
having a Probable VAP with a secondary BSI due to C. albicans.
EXAMPLE: Patient hospitalized and mechanically ventilated in the MICU for 14 days
develops worsening oxygenation following a 7-day period of stability on the ventilator.
VAC criteria are met on hospital day 15 (stable ventilator settings on days 12 and 13,
increased ventilator settings on days 14 and 15). The onset date is day 14. The white
blood cell count is noted to be 15,500 cells/mm3 on day 14. Meropenem and vancomycin
are begun on day 15, administered through the patient’s right-sided central line (inserted
on ICU admission). The antibiotics continue to be administered on day 18, meeting
IVAC criteria. An endotracheal aspirate collected on day 15 is a good quality specimen,
with ≥ 25 neutrophils and ≤ 10 squamous epithelial cells per low power field, and grows
Candida albicans (qualitative result). A blood culture collected on day 16 is positive for
C. albicans. This patient should be reported as having a Possible VAP, with no pathogen
reported and no secondary BSI. The positive blood culture for C. albicans may need to be
reported separately as a central line-associated bloodstream infection if no other primary
source of infection meeting an NHSN HAI definition is identified.
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14) Can I only report pathogens if they are isolated in cultures of appropriate specimens? What
about pathogens identified by non-culture-based diagnostic testing?
 Probable VAP is the only VAE definition that incorporates results of non-culture-based
microbiological diagnostic testing. For Probable VAP, pathogens that are grown in
culture OR that are identified as a result of other laboratory testing (e.g., antigen testing,
PCR, immunohistochemistry, etc.) should be reported. Do not limit reporting to just those
organisms isolated in culture. For example, influenza A identified by polymerase chain
reaction (PCR) in a patient meeting probable VAP criteria should be reported as a
pathogen for that event.
15) The “Probable VAP” criteria include “positive diagnostic tests” for Legionella species, and
selected viruses. What kinds of diagnostic tests can be used to meet the definition?
 Diagnostic testing practices may vary from facility to facility and change over time as
better tests are developed. Listed here are some examples of diagnostic tests for specific
pathogens included in the Probable VAP definition. Positive results of these tests may be
used in meeting the Probable VAP definition. Your facility may use other testing
methods; positive results obtained using these methods may also be appropriate for use in
meeting the Probable VAP definition. If you have a question regarding a diagnostic test
method, check with your laboratory.
 For Legionella species, positive results of any of the following, performed on the
appropriate specimen: urinary antigen, Legionella-specific respiratory culture, paired
serology (4-fold rise in titer between acute and convalescent specimens), direct
fluorescent antibody stain, immunohistochemistry stain, or nucleic acid detection assays
(such as PCR) performed on a respiratory specimen.
 For respiratory viruses (influenza, respiratory syncytial virus [RSV], parainfluenza
viruses, human metapneumovirus, coronaviruses, rhinoviruses and adenovirus), positive
results for any of the following:
o Performed on an appropriate respiratory specimens – PCR or other viral
nucleic acid detection methods, antigen detection methods, including rapid
tests, viral cell culture, or
o Performed on appropriate pathologic specimens – immunohistochemical
assays, cytology, microscopy, or
o Performed on appropriately timed paired sera (acute and convalescent) –
serological assays demonstrating seroconversion or a significant rise in
antibody titer.
16) What about pneumonitis that occurs in a mechanically-ventilated patient and is determined to
be due to herpes simplex virus (HSV) or cytomegalovirus (CMV)? Can these infections be
reported as VAEs?
 In most cases pneumonitis due to HSV and CMV represents reactivation of a latent
infection, and therefore would not be considered healthcare-associated, according to the
NHSN definition of a healthcare-associated infection.

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17) Are there any culture results or microorganisms that CANNOT be used to meet the Possible
and Probable VAP definitions?
 The following pathogens and culture results may NOT be used to meet the definitions
and may NOT be reported as causes of Possible or Probable VAP when they are obtained
from cultures of sputum, endotracheal aspirates, bronchoalveolar lavages or protected
specimen brushings:
o Culture results reported as “Normal respiratory flora,” “normal oral flora,”
“mixed respiratory flora,” “mixed oral flora,” “altered oral flora” or other similar
results indicating isolation of commensal flora of the oral cavity or upper
respiratory tract.
o Candida species or yeast not otherwise specified
o Coagulase-negative Staphylococcus species
o Enterococcus species
NOTE: These organisms are excluded because they are common upper respiratory tract
commensals, colonizers or contaminants, and are unusual causes of VAP. Their exclusion
from the surveillance definitions should NOT be used in clinical decision-making
regarding patient treatment. Providers must independently determine the clinical
significance of these organisms isolated from respiratory specimen cultures and the need
for treatment.
NOTE: When Candida species or yeast not otherwise specified, coagulase-negative
Staphylococcus species or Enterococcus species are isolated from cultures of lung tissue
or pleural fluid, these organisms may be reported as Possible or Probable VAP
pathogens.


When sputum, endotracheal aspirate, bronchoalveolar lavage or protected specimen
brushing culture results are mixed and contain one or more of the excluded pathogens in
addition to one or more non-excluded pathogens, the culture may be used to meet the
Possible or Probable VAP definition (depending on whether a qualitative, semiquantitative or quantitative culture was performed, and whether the semi-quantitative or
quantitative cfu/ml thresholds were met) BUT only the non-excluded pathogen(s) should
be reported.
EXAMPLE: Patient intubated and mechanically ventilated in the MSICU meets IVAC
criteria on day 8 of mechanical ventilation. On the day after the onset of worsening
oxygenation, an endotracheal aspirate is collected. The gram stain shows ≥ 25 neutrophils
and ≤ 10 squamous epithelial cells per low power field, and the culture grows “heavy
Staphylococcus aureus” and “heavy Candida albicans.” This patient should be reported
as having a Probable VAP due to Staphylococcus aureus – as long as the semiquantitative result “heavy” is equivalent to the quantitative threshold of ≥ 105 cfu/ml for
endotracheal aspirates. Candida albicans from the endotracheal aspirate culture is not
reported, because it is an excluded result.

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18) What about pleural fluid cultures and lung tissue cultures? Can I report any pathogen isolated
from a lung tissue culture, or from a pleural fluid culture, assuming the specimen was
obtained during thoracentesis or at the time of chest tube insertion?
 Any pathogen cultured from lung tissue, when that lung tissue was obtained during an
open lung biopsy, video-assisted thoracoscopic surgery, or via other transthoracic or
transbronchial biopsy approach, may be reported.
 Any pathogen cultured from pleural fluid, when that fluid was obtained during
thoracentesis or at the time of initial chest tube insertion, may be reported.
19) How are “purulent respiratory secretions” defined?
 Purulent respiratory secretions used to meet Possible and Probable VAP definitions are
specifically defined as:
o Defined as secretions from the lungs, bronchi, or trachea that contain > 25
neutrophils and < 10 squamous epithelial cells per low power field [lpf, x100].
o If the laboratory reports semi-quantitative results, those results must be
equivalent to the above quantitative thresholds. You should check with your
laboratory to be certain that the semi-quantitative results match the
quantitative thresholds noted above.
20) What is the definition of “positive lung histopathology” that can be used to meet the Probable
VAP definition?
 If the lung tissue specimen was obtained via open lung biopsy, video-assisted
thoracoscopic surgery, or via other transthoracic or transbronchial biopsy approach, it is
eligible for consideration in meeting the Probable VAP definition.
 Histopathological findings that can be used to meet the possible and probable VAP
definitions include:
o Abscess formation or foci of consolidation with intense neutrophil
accumulation in bronchioles and alveoli;
o Evidence of lung parenchyma invasion by fungi (hyphae, pseudohyphae or
yeast forms);
o Evidence of infection with the viral pathogens listed in FAQ no. 14 based on
results of immunohistochemical assays, cytology, or microscopy performed
on lung tissue.
21) I am still having trouble understanding the time frame that defines a VAE. Can you explain
what is meant by this statement that appears in the algorithm: “On or after calendar day 3 of
mechanical ventilation and within 2 calendar days before or after the onset of worsening
oxygenation”?
 The intent of these criteria is to determine whether a VAC is due to an infectious process
(IVAC) and/or pneumonia (Possible or Probable VAP) by looking for corroborating
inflammatory and infectious signs at the time of VAC onset. The criterion, “on or after
calendar day 3” is intended to exclude inflammatory and infectious signs present on the
first two days of mechanical ventilation because they are more likely to be due to preexisting conditions than ventilator-acquired complications. The criterion, “within 2
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Device-associated Events
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calendar days before or after the onset of worsening oxygenation,” is intended to identify
infectious and inflammatory signs that arise at the same time as VAC and may therefore
point to the cause of the VAC.


The figures below illustrate the time frame that defines a VAE. The event date is the first
day of worsening oxygenation, defined by the PEEP and FiO2 thresholds outlined in the
algorithm. The event date defines the time frame within which all other criteria must be
met. In the examples below, the shaded area defines the period in which IVAC criteria
(temperature or white count abnormalities, plus a new antimicrobial agent started and
continued for at least 4 days) must be met, and in which Possible or Probable VAP
criteria must be met.
NOTE: Keep in mind that VAE criteria must be met based on specimens collected or
antimicrobial agents started after day 2 of mechanical ventilation.
EXAMPLE 1: When the onset date of the VAE occurs early in the course of mechanical
ventilation (e.g., day 3 or 4 of mechanical ventilation), the period in which certain
inflammatory and infectious criteria are sought for IVAC and possible or probable VAP
is shorter, because the first 2 days of mechanical ventilation are excluded from the
normal 5 day window surrounding the day of increased ventilator support.

MV Day No.
Worsening oxygenation

Temperature abnormality or
white blood cell count
abnormality
Antimicrobial agent
Purulent respiratory secretions,
positive culture, positive
histopathology

1
--

2
Day 1 of
Stability or
improvement

3
4
5
6
Day 2 of
Day 1 of
Day 2 of
stability or
worsening
worsening
improvement
oxygenation
oxygenation
An abnormal temperature or white blood cell count, according to
the algorithm parameters, must be documented within this shaded
period
New agent must be started on any day within this shaded period,
and then continued for at least 4 days
Specimen must be collected on any day within this shaded
period

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Device-associated Events
VAE

EXAMPLE 2: When the onset date of the VAE occurs later in the course of mechanical
ventilation, the period in which certain criteria must be met is a day longer, because the
patient has already been on mechanical ventilation for more than 3 days and therefore
inflammatory and infectious signs arising anywhere in the full 5-day window surrounding
the day of increased ventilator settings can count towards IVAC and possible or probable
VAP.
MV Day No.
Worsening oxygenation

Temperature abnormality or
white blood cell count
abnormality
Antimicrobial agent
Purulent respiratory secretions,
positive culture, positive
histopathology

10
--

11
Day 1 of
Stability or
improvement

12
Day 2 of
stability or
improvement

13
Day 1 of
worsening
oxygenation

14
Day 2 of
worsening
oxygenation

An abnormal temperature or white blood cell count, according to the algorithm
parameters, must be documented within this shaded period
New agent must be started on any day within this shaded period, and then continued
for at least 4 days
Specimen must be collected on any day within this shaded period

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File Type	application/pdf
File Title	6 Ventilator-associated Pneumonia (VAP) Events
Subject	Information on Ventilator-associated pneumonia events
Author	CDC/OID/NCEZID/DHQP
File Modified	2012-06-07
File Created	2012-06-07