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Device-associated Module
Dialysis Events

Dialysis Event (DE)
Introduction:
In 2008, >350,000 patients were being treated with maintenance hemodialysis in the
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United States. Hemodialysis patients require a vascular access, which can either be a
catheter or a graft or an enlarged blood vessel that can be punctured to remove and
replace blood. Bloodstream infectious and localized infections of the vascular access site
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are common in hemodialysis patients. The vascular access types, ordered according to
increasing risk of infection, include arteriovenous fistulas created from the patient’s own
blood vessels; arteriovenous grafts often 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 at high risk for infection with
antimicrobial-resistant bacteria.
Settings:
Surveillance will occur in outpatient hemodialysis centers. These centers may be
attached to or affiliated with a hospital, but should serve hemodialysis outpatients.
Population: The population for Dialysis Event surveillance is hemodialysis outpatients.
Requirements:
A minimum of 6 months of Dialysis Event (DE) surveillance among hemodialysis
patients receiving treatment at an outpatient hemodialysis facility, as indicated in the
Patient Safety Monthly Reporting Plan (CDC 57.106). Monthly report of patient
census information for the first 2 working days of each month, as indicated in the
Denominators for Outpatient Dialysis form (CDC 57.119). Annual completion of the
Outpatient Dialysis Center Practices Survey (CDC 57.104).
Definitions:
IV antimicrobial start: Include all outpatient IV antimicrobial starts, not just IV
vancomycin starts and not just starts for vascular access problems. There must be 21 or
more days from the end of the first IV antimicrobial start to the beginning of a second IV
antimicrobial start for two starts to be considered separate dialysis events. If IV
antimicrobials are stopped for less than 21 days and then restarted, the second start is
NOT considered a new dialysis event.
Positive blood culture: Include all positive blood cultures collected as an outpatient or
collected within 1 calendar day after a hospital admission. The date of a blood culture
result is based on the date the blood specimen was collected, not the date the laboratory
reported the result. There must be 21 or more days between positive blood cultures for
each positive blood culture to be considered a separate dialysis event. If positive blood

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cultures occur less than 21 days apart, the second positive blood culture(s) is NOT
considered a new dialysis event.
Pus, redness, or increased swelling at the vascular access site: Include each new episode
where the patient has one or more symptoms of pus, redness or increased swelling at a
vascular access site. There must be 21 or more days between the onset of a first and
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, the recurrence is NOT
considered a new dialysis event.
The following specific types of DEs are determined with a computer algorithm from
reported data.
Local access site infection: Pus, redness, or swelling of the vascular access site and
bloodstream infection was not present.
Access-related bloodstream infection: Blood culture positive with suspected
source identified as the vascular access site or uncertain.
Vascular access infection: Either local access site infection or access-related bloodstream
infection.
REPORTING INSTRUCTIONS:
Reporting multiple dialysis events for a single patient:
Dialysis Event surveillance definitions include IV antimicrobial start; positive blood
culture; and pus, redness, or increased swelling at the vascular access site. If multiple
dialysis events occur together, as a part of the same patient problem, they should be
reported as one dialysis event. For example, if a patient has a positive blood culture and
has an IV antimicrobial start, these two events would be recorded together as one dialysis
event. When reporting multiple dialysis events together, always use the date from the first
event that occurred. Refer to Dialysis Event definitions for the 21 day rule.
Suspected source of the positive blood culture:
When reporting a positive blood culture, indicating the suspected source of the positive
blood culture is required.
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

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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 head nurse to be a
contaminant. Contamination is more likely if the organism is a common
commensal and is isolated from only one blood culture.
 Examples of some common commensals include:
o diphtheroids (Corynebacterium spp., not C. diphtheria)
o Bacillus spp. (not B. anthracis)
o Propionibacterium spp.
o coagulase-negative staphylococci (including S. epidermidis)
o viridans group streptococci
o Aerococcus spp.
o Micrococcus spp.
Uncertain: Choose “Uncertain” only if there is insufficient evidence to decide among the
three previous suspected source categories.
Numerator Data:
For each patient with an IV antimicrobial start; positive blood culture; or pus, redness,
or increased swelling at the vascular access site, participating dialysis centers will
complete one Dialysis Event form (CDC 57.109) (see Definitions). The Instructions for
Completion of Dialysis Event form (Patient Safety Component Manual, Chapter 14
Tables of Instructions, Tables 9 and 2a) includes brief instructions for collection and
entry of each data element on the form.
Denominator Data:
The number of chronic hemodialysis patients with each access type who received
hemodialysis at the center during the first two working days of the month is recorded on
the Denominators for Outpatient Dialysis Form (CDC 57.119). These data are used to
estimate the number of patient-months. Only hemodialysis outpatients are included. Each
patient is counted only once; if the patient has multiple vascular accesses, record that
patient once reporting their highest risk vascular access type only. The Instructions for
Completion of Denominators for Outpatient Dialysis (Patient Safety Component Manual,
Tables of Instructions, Table 10) includes brief instructions for collection and entry of
each data element on the form.
Data Analyses:
The numbers of various dialysis events are tabulated, and rates of these events per 100
patient-months are calculated by dividing the number of dialysis events by the number
of patient-months and multiplying the result by 100. These rates are stratified by
vascular access type and compared to the pooled mean rate of all centers combined.

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1

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Stevenson KB, Adcox MJ, Mallea MC, Narasimhan N, Wagnild JP. Standardized surveillance
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hemodialysis center. Infect Control Hosp Epidemiol 2000;21:200-3.
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Tokars JI, Light P, Anderson J, Miller E, Parrish J, Armistead N, et al. A prospective study of
vascular access infections at seven outpatient hemodialysis centers. Am J Kidney Dis
2001;37:1232-40.
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Kaplowitz LG, Comstock JA, Landwehr DM, Dalton HP, Mayhall CG. A prospective study of
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Control Hosp Epidemiol 1988;9:534-41
7

Tokars J, Stein G, Frank M, the Dialysis Surveillance Network. The influence of blood culture
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for Healthcare Epidemiology of America, Salt Lake City, UT, April 2002.

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