Welcome to the 2016 National Healthcare Safety
Network Quick Learn series. These CDC presentations
are an educational resource for healthcare facilities working to
prevent Healthcare Associated Infections, or H-A-Is.
In this session, we’ll review definition changes to the
National Healthcare Safety Network, or NHSN,
patient safety component for 2016.
CDC reviews and makes changes to NHSN infection definitions
for several reasons.Definitions are sometimes updated in
response to user feedback and to remain current with diagnostic
practices. NHSN strives to be receptive and
responsive to concerns from those who apply the definitions.
If a definition needs to be changed, NHSN works
to ensure data elements comprising the definition can be collected,
that the change is objective and can be applied consistently,
and that it’s based on published scientific findings.
For 2016, there are fewer changes than last year. Some
changes affect multiple NHSN modules. The other
changes affect the definitions of bloodstream infection, or B-S-I,
intra-abdominal infection, and pneumonia. Here are
the changes that affect more than one NHSN surveillance module:
First, newer, non-culture based diagnostic
laboratory testing that provides specific organism
identification is used more frequently in patient care settings.
As a result, NHSN accepts these tests for
many of the 2016 infection definitions.
One example is a polymerase chain reaction, or PCR
test, which identifies organisms present in
patient specimens. A blood specimen with Klebsiella pneumonia
identified by PCR could be used to meet the laboratory confirmed
bloodstream infection, or LCBI, criteria.
Second, there are some new pathogen exclusions for 2016
infection definitions and protocols. Some
fungal pathogens, rarely implicated in H-A-Is, are
excluded from the NHSN organism list.
Excluded genera are limited to Blastomyces,
Histoplasma, Coccidioides, Paracoccidioides,
Cryptococcus, and Pneumocystis. Finally,
results of laboratory tests performed on specimens collected from
patients after they have been documented as brain dead and being
supported for organ donation purposes can no longer be used
to meet any NHSN infection definitions.
The following changes are specific to BSI surveillance.
NHSN is removing Salmonella organisms as BSI pathogens.
It is highly unlikely that Salmonella organisms would
cause a primary bloodstream infection. For that reason,
these organisms are excluded as primary BSI pathogens.
The next change is that there are two exceptions
in which a patient may meet the CLABSI definition, but
not have a CLABSI reported. The first exception
involves patients whose medical record contains documentation
that the patient was observed or suspected of injecting into their own
intravascular lines during the LCBI infection window period, or IWP.
This behavior must be
documented in the patient’s medical record and the documentation
must occur during the three days before, the day of, or
the three days after the positive blood culture collection.
The second exception is a patient who has a central line, but who
also has an infected noncentral-line vascular access site,
OR has an infected central line site which was not accessed
during the hospitalization. In this case
there must be BOTH an organism identified in a blood specimen,
AND purulence from the access site which tests positive for
at least one matching organism in the blood. The pus
from the access site must be collected during the LCBI IWP.
In both exceptions, if a facility reports the
BSI to NHSN, the data field central line
should be marked No. If additional blood tests
are positive for organisms after the BSI repeat infection timeframe
additional documentation would be necessary to
exclude the BSI as a CLABSI on the same grounds.
In 2016, an additional criterion is added to
intra-abdominal infection, or I-A-B, criteria.
If a patient has an abscess or other evidence of I-A-B
on gross anatomic or histo-pathologic exam and
an organism from the list included here is identified in the blood,
the patient meets the criterion for I-A-B.
The list includes organisms belonging to the following genera:
Bacteroides, Candida, Clostridium,
Enterococcus, Fusobacterium,
Peptostreptococcus, Prevotella,
Veillonella, and organisms from the
Enterobacteriaceae family. If this
I-A-B is not a surgical site infection, the elements must occur
within the IWP. Also, the culture
or microbiologic testing must be performed for purposes
of clinical diagnosis or treatment and not
active surveillance. An example is when a patient is taken
to the operating room and an intra-abdominal infection is identified.
The infection is documented in the medical record, but no
cultures are collected from the intra-abdominal space and blood
specimens test positive for Enterococcus faecium.
In this case, the IAB criterion would be met.
The previous NHSN I-A-B criterion 3b,
which included two signs or symptoms of infection,
plus the identification of organisms from blood
and an imaging test evidence of infection, is now modified.
The organisms identified in the blood must now contain
at least one of the organisms we just identified for the new
I-A-B criterion. These changes provide consistency
for the I-A-B criteria while more accurately identifying
intraabdominal infections with secondary bloodstream infections.
Positive tests from bronchial alveolar lavage
or protected specimen brushing procedures
are now allowed as elements of the infection criterion for
pneumonia, or PNU-3. This is in addition to
sputum and endotracheal aspirate tests that identify
microorganisms. Positive tests from these sites are more
specific than those from sputum or endotracheal aspirate,
and therefore should be interchangeable in the criterion.
A matching positive test for Candida species from blood
and from one of these sites during the pneumonia infection window period
fulfills the laboratory portion of the PNU-3 criterion.
For more information about the NHSN protocol and
definitions, visit C-D-C-dot-gov-slash-N-H-S-N.
Questions can be e-mailed to N-H-S-N@C-D-C-dot-gov.