Sedimentation characteristics of leukocytes can predict
bacteremia in critical care patients
Lajos Bogar 1*, Zsolt Molnar 1, Peter Kenyeres 1 and Piroska Tarsoly 1
1 University of Pecs, Hungary
* To whom correspondence should be addressed. E-mail: bogar{at}clinics.pote.hu.
Accepted 9 November 2005
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Abstract |
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Aims: Early detection of blood stream infection can
be lifesaving by initiation of immediate and adequate
measures in critically ill patients. However, the results
of blood culture tests are usually available only 24 hours
after blood sampling. It is obvious that an earlier hint
would provide some advantages for critical care patients
by initiation of immediate and adequate antibiotic
therapy. The aim of this study was to evaluate the ability
of leukocyte count, serum procalcitonin (PCT)
concentration, erythrocyte sedimentation rate (ESR) and
leukocyte antisedimentation rate (LAR) to predict blood
culture result in critical care patients.
Methods: LAR indicates the percentage of
leukocytes crossing the middle line of blood column upward
during one-hour gravity sedimentation. The relevance of
the different parameters was estimated by using
likelihood-ratio test and area under receiver operating
characteristic curves (AUC).
Results: A total of 39 consecutive patients
presenting their first febrile episode were investigated
prospectively. Twenty-three patients had positive, 16 had
negative blood culture results. LAR was significantly
higher in bacteremic patients than in non-bacteremic
patients (p = 0.001) but leukocyte count, ESR and PCT
level failed to present significant differences. Leukocyte
count, PCT and ESR yielded low discriminative values with
the AUCs of 0.66, 0.64 and 0.52, respectively. LAR
provided likelihood-ratio of 3.6 and an AUC of 0.80 (95%
CI, 0.64 to 0.95; p = 0.002).
Conclusions: This study suggests that the simple
LAR test can predict blood culture results and support
urgent treatment decisions in critical care patients at
their first febrile episode.
Key Words:
bacteremia, erythrocyte sedimentation rate, leukocyte, procalcitonin, severe sepsis
