Att G9.Dialysis Event

Dialysis Event Protocol

Dialysis Event Protocol
Introduction
In 2011, more than 395,000 patients were treated with maintenance hemodialysis in the United
States. 13 Hemodialysis patients require a vascular access, which can be a catheter, or a graft or an
enlarged blood vessel that can be punctured to remove and replace blood. Bloodstream infections
and localized infections of the vascular access site cause substantial morbidity and mortality in
hemodialysis patients. Hemodialysis vascular access types, in order of increasing risk of infection,
include arteriovenous fistulas created from the patient’s own blood vessels; arteriovenous grafts
typically constructed from synthetic materials; tunneled central lines; and nontunneled central
lines. Other access devices, such as catheter-graft hybrid devices, also exist. Because of frequent
hospitalizations and receipt of antimicrobial drugs, hemodialysis patients are also at high risk for
infection with antimicrobial-resistant bacteria. Measuring and tracking rates of infection and
utilizing this information is an important part of prevention.
Infection prevention information is located at http://www.cdc.gov/dialysis/
Dialysis Event Surveillance
Overview: Each month, facilities report the number of hemodialysis outpatients who were
dialyzed in the facility on the first two working days of the month, using the Denominators for
Dialysis Event Surveillance form. This count is used to estimate the number of patient-months that
there is risk of healthcare-associated infection. Throughout the entire month, any and all
outpatients who receive maintenance hemodialysis at the facility are monitored for three
National Healthcare Safety Network (NHSN)-defined dialysis events, which include IV
antimicrobial starts, positive blood cultures, and evidence of local access site infection. Facilities
use a Dialysis Event form to report the details of each dialysis event that occurred among these
patients. Before data can be reported, facilities must indicate that they are reporting according to
this protocol by saving a Monthly Reporting Plan and selecting “DE.” Completion of an Outpatient
Dialysis Center Practices Survey is required annually.

Setting: Surveillance occurs in outpatient hemodialysis centers. These centers may be attached to
or affiliated with a hospital, but should serve hemodialysis outpatients. If other patients (e.g.,
inpatients, peritoneal dialysis patients) are present, exclude them from Dialysis Event numerator
and denominator reporting.

Population: Hemodialysis outpatients.
• Include transient patients
• Include peritoneal dialysis patients or transplant patients undergoing temporary
hemodialysis

U.S. Renal Data System, USRDS 2013 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage
Renal Disease in the United States, National Institutes of Health, National Institute of Diabetes and Digestive and
Kidney Diseases, Bethesda, MD, 2013. (http://www.usrds.org/adr.htm)

13

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Requirements: Participating facilities are required to report data according to this protocol,
using the NHSN definitions described herein, to ensure data are uniformly reported across
participating facilities. Report available data to NHSN within 30 days to 60 days of the end of the
month for which they were collected. If additional data become available after that period, users
are expected to report the additional information retrospectively to ensure NHSN data are
complete and accurate. This may involve reporting additional dialysis events and/or editing
existing event records.
Event Definitions and Key Terms
Dialysis Event: Three types of dialysis events are reported by users: IV antimicrobial start; positive
blood culture; and pus, redness, or increased swelling at the vascular access site. The following
measures are also generated from the reported data: bloodstream infection (BSI), local access site
infection (LASI), access-related bloodstream infection (ARBSI), and vascular access infection (VAI).

21 day rule: An event reporting rule which reduces reporting of events that are likely to be related to
the same patient problem. The rule is that 21 or more days must exist between two dialysis events of
the same type for the second occurrence to be reported as a separate dialysis event. If fewer than 21
days have passed since the last reported event of the same type, the subsequent event of the same
type is NOT considered a new dialysis event and therefore, it is not reported. The 21 day rule applies
across calendar months. Refer to each event definition for instructions on applying the 21 day rule
for each specific event type.

IV antimicrobial start: Report all starts of intravenous (IV) antibiotics or antifungals administered in
an outpatient setting, regardless of the reason for administration (i.e., include IV antimicrobial starts
unrelated to vascular access problems) and regardless of the duration of treatment. A start is defined
as a single outpatient dose or first outpatient dose of a course. Report all IV antibiotic starts, not just
vancomycin. Do not report IV antiviral starts. Report outpatient starts that are continuations of
inpatient antimicrobial treatment.
•

•
•

21 day rule: There must be 21 or more days from the end of one IV antimicrobial course to
the beginning of a second IV antimicrobial start for two starts to be reported as separate
dialysis events, even if different antimicrobials are used. If IV antimicrobials are stopped for
fewer than 21 days and then restarted, the second start is NOT considered a new dialysis
event and therefore, is not reported.

For outpatient IV antimicrobial starts that are continuations of inpatient antimicrobial
treatment, consider the start day to be the first day of outpatient administration.
Inter-facility patient transfers: If a patient at a dialysis facility has an IV antimicrobial start
and then transfers to another facility (as a transient or permanent patient) where the
antimicrobial is continued, the second facility would report the IV antimicrobial start in
their facility as well.

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Positive blood culture: Report all positive blood cultures from specimens collected as an outpatient
or collected within one calendar day after a hospital admission. One calendar day after hospital
admission includes positive blood cultures collected on the day of or the day following admission to
the hospital. Positive blood cultures meeting the criteria above should be reported regardless of
whether or not a true infection is suspected or whether the infection is thought to be related to
hemodialysis.
•

•

21 day rule: There must be 21 or more days between positive blood cultures for each
positive blood culture to be considered a separate dialysis event, even if organisms are
different. If positive blood cultures occur less than 21 days apart, the second positive blood
culture is NOT considered a new dialysis event and therefore, is not reported. However, if
different organisms grow from these subsequent positive blood cultures, add the new
organisms to the reported event.

Suspected source of the positive blood culture: indicating one of four suspected sources of a
positive blood culture is required.
o

o

o

o

Vascular access: Choose “Vascular access” if there is objective evidence of vascular
access infection and the vascular access is thought to be the source of the positive
blood culture.

A source other than the vascular access: Choose “A source other than the vascular
access” if either (a) or (b) is true:
a) a culture from another site (e.g., infected leg wound, urine) shows the same
organism found in the blood and the site is thought to be the source of the
positive blood culture.
b) there is clinical evidence of infection at another site which is thought to be the
source of the positive blood culture, but the site was not sampled for culture.

Contamination: Choose “Contamination” if the organism isolated from the blood
culture is thought by the physician, infection preventionist, or nurse manager to be a
contaminant. Contamination is more likely if the organism is a common commensal
and is isolated from only one of several blood cultures. Examples of common
commensals include: diphtheroids [Corynebacterium spp., not C. diphtheriae];
Bacillus spp. [not B. anthracis]; Propionibacterium spp.; coagulase-negative
staphylococci [including S. epidermidis]; viridans group streptococci; Aerococcus
spp.; and Micrococcus spp.
Uncertain: Choose “Uncertain” only if there is insufficient evidence to decide among
the three previous suspected source categories.

Pus, redness, or increased swelling at the vascular access site: Report each new outpatient episode
where the patient has one or more symptoms of pus, greater than expected redness or greater than
expected swelling at any vascular access site, regardless of whether the patient received treatment
for infection. Pus is always reportable. Report redness or swelling if it is greater than expected and
suspicious for infection. Indicate the vascular access site(s) where the symptom(s) occurred.
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•

21 day rule: There must be 21 or more days between the onset of one episode and the onset
of a second episode of pus, redness, or increased swelling at a vascular access site to be
considered separate dialysis events. If an episode of pus, redness, or increased swelling at a
vascular access site resolves and then recurs within 21 days of the first onset, the recurrence
is NOT considered a new dialysis event and therefore, is not reported.

Measure Definitions
o
o

o

o

Bloodstream infection (BSI): Any positive blood culture.

Access-related bloodstream infection (ARBSI): Positive blood culture with the suspected
source reported as the vascular access or uncertain.

Local access site infection (LASI): Pus, redness, or increased swelling of the vascular access
site and access-related bloodstream infection is not present.
Vascular access infection (VAI): Either a local access site infection or an access-related
bloodstream infection.

Vascular Access Types
Consider all vascular accesses for hemodialysis and all central venous catheters that are present at
the time of the event in Dialysis Event reporting, even if they are not used for dialysis and even if they
are abandoned/non-functional.
•

•

•
•

Nontunneled central line: a central venous catheter that is fixed in place at the point of
insertion and travels directly from the skin entry site to a vein and terminates close to the
heart or one of the great vessels, typically intended for short term use.

Tunneled central line: a central venous catheter that travels a distance under the skin from
the point of insertion before entering a vein, and terminates at or close to the heart or one of
the great vessels (e.g., Hickman® or Broviac® catheters 14).
Graft: a surgically created connection between an artery and a vein using implanted material
(typically synthetic tubing) to provide a permanent vascular access for hemodialysis.

Fistula: a surgically created direct connection between an artery and a vein to provide
vascular access for hemodialysis.
o

•

14

Buttonhole: a cannulation technique where a blunt needle (cannula) is inserted into
the fistula at the same location each time using an established track. Report the way
in which a patient is primarily cannulated.

Other access device: includes catheter-graft hybrid vascular access devices, ports, and any
other vascular access devices that do not meet the above definitions. Do not use this field to

Use of trade names and commercial sources is for identification only and does not imply endorsement.

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report vascular accesses that are grafts, central venous catheters or fistulas. Do not use this
field to report peritoneal dialysis accesses.
o

Catheter-graft hybrid: a subcutaneous surgical implant with both a catheter and a
graft component that provides blood flow directly from the target artery to the heart,
bypassing the patient’s central venous system (e.g., HeRO® vascular access device 15).

REPORTING INSTRUCTIONS
NHSN forms and/or the definitions in this protocol should be used to collect required data. Each
form has a corresponding table of instructions.

Complete a Survey Annually: Upon enrollment and annually thereafter, complete the Outpatient
Dialysis Center Practices Survey (CDC 57.500). After enrollment, the data for the dialysis survey
should be collected and reported in February.

Complete Monthly Reporting Plans: The Monthly Reporting Plan (CDC 57.501) is used by NHSN
facilities to inform CDC that they are committed to following the NHSN surveillance protocol, in its
entirety, for each data type selected on the plan. These data are referred to as “in-plan.” A Monthly
Reporting Plan must be completed before data can be entered into NHSN for that month.

 To indicate the facility is reporting in accordance with this protocol, save a Monthly
Reporting Plan with the “DE” checkbox selected for the ‘outpatient hemodialysis clinic’
location, under the Events section, for each month that the facility is participating in Dialysis
Event Surveillance.

Do not select “No NHSN Reporting this Month.” Selection of this checkbox indicates the facility did
not follow any NHSN Dialysis Component surveillance protocols that month (e.g., the facility was
closed that month).
Report Denominator Data Monthly: The denominators are counts of patients by vascular
access type used to estimate the number of patient-months considered at risk for dialysis
events. To report denominator data, each month, report the number of hemodialysis
outpatients with each vascular access type who received hemodialysis at the center during the
first two working days of the month on the Denominators for Dialysis Event Surveillance form
(CDC 57.503).
Report all hemodialysis outpatients, including transient patients. Exclude non-hemodialysis
patients and exclude inpatients. Report denominator data each month, regardless of whether
any dialysis events occur. Count each patient only once; if the patient has multiple vascular
accesses, record that patient once, reporting only their vascular access with the highest risk of
infection (note: this might not be the vascular access currently in use for dialysis).
HIGHER
INFECTION
RISK

15

Nontunneled
Central
Lines

Tunneled
Central
Lines

Other
Access
Devices

Grafts

Fistulas

LOWER
INFECTION
RISK

Use of trade names and commercial sources is for identification only and does not imply endorsement.

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See tables of instructions for an explanation of each field of the Denominators for Dialysis Event
Surveillance form.
Working Days: The first two “working days” of the month should provide the opportunity to
capture all regularly scheduled shifts and patients.
•

•
•
•

For example, if a facility dialyzes patients 6 days a week, Monday through Saturday, and the
first day of the month falls on a Sunday, then Monday and Tuesday would be the first two
working days of the month for that facility.
Sun
Mon
Tues
Wed
Thurs
Fri
Sat
1
2
3
4
5
6
7
Facility
Working
Working
closed
day 1
day 2
For facilities that provide nocturnal hemodialysis, working days should include nocturnal
hemodialysis patients.

Working days are shift/schedule dependent – the actual patient census is not a criterion for
determining a working day.
If the facility was closed the entire month, do not complete a denominator form.

Report Numerator Data Monthly: The numerators are the number of dialysis events that occur
during a defined time period. To report numerator data, complete one Dialysis Event form (CDC
57.502) per occurrence of event(s) among all patients who received hemodialysis at the facility
during that month. If there are no dialysis events to report, access that month’s denominator form
to “Report No Events.”

Report Events: Any patient who receives outpatient hemodialysis treatment at your facility is
monitored for dialysis events, even if they were not counted on the denominator form. Include
transient patients at your facility who have a dialysis event. Complete a Dialysis Event form only if a
hemodialysis outpatient has one or more of the following:
 IV antimicrobial start
 Positive blood culture
 Pus, redness, or increased swelling at the vascular access site
See tables of instructions for an explanation of each field of the Dialysis Event form.

Multiple Dialysis Events: If multiple dialysis events occur together, as a part of the same patient
problem, they should be reported on the same Dialysis Event form. For example, if a patient has a
positive blood culture and begins IV antimicrobials, these two events would be recorded together
on one form. When reporting multiple dialysis events together, the “date of event” is always the
date that the first event occurred. Refer to dialysis event definitions for the 21 day rule. Do not
report unrelated dialysis events on the same form.

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Event Type
IV antimicrobial start

Positive blood culture

Pus, redness or increased swelling at
vascular access site
Combination

Date of Event Criterion
Date of first outpatient dose of an antimicrobial course
Date of specimen collection
Date of onset

Earliest date of the three types

Report No Events: Each dialysis event type needs to be accounted for every month. Either (a) the
event type is reported on one or more Dialysis Event forms, or (b) the “report no events” box for
that event type is checked on the Denominators for Dialysis Event Surveillance form to confirm that
no events of that type occurred during the month.
Data Analyses
Dialysis event rates are stratified by vascular access type and expressed per 100 patient-months.
Rates are calculated by dividing the number of events by the number of patient-months and
multiplying the result by 100. CDC calculates aggregate pooled mean rates for each event type by
combining rates from all participating facilities. Facilities can compare their rates with the
aggregate rates using NHSN analysis rate table or run chart output options. Facilities are strongly
encouraged to analyze the data they report and provide regular feedback to staff about patient
outcome event rates.
𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟 =

𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 (𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛)
× 100
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃-𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀ℎ𝑠𝑠 (𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑)

Reporting Resources
Data collection and reporting resources are available on the NHSN Dialysis Event website:
http://www.cdc.gov/nhsn/dialysis/dialysis-event.html.

Please direct questions to the NHSN Helpdesk at [email protected] and include “dialysis” in the subject
line.

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