Risk Factors for Negative Blood Cultures in Adult Medical Inpatients – a Retrospective Analysis

Date
2008-10-28
Authors
Ehrenstein, Boris P.
Ehrenstein, Vera
Henke, Christine
Linde, Hans-Jörg
Salzberger, Bernd
Schölmerich, Jürgen
Glück, Thomas
Version
OA Version
Citation
Ehrenstein, Boris P, Vera Ehrenstein, Christine Henke, Hans-Jörg Linde, Bernd Salzberger, Jürgen Schölmerich, Thomas Glück. "Risk factors for negative blood cultures in adult medical inpatients – a retrospective analysis." BMC Infectious Diseases8:148. (2008)
Abstract
BACKGROUND: The identification of clinical factors associated with negative blood cultures could help to avoid unnecessary blood cultures. C-reactive protein (CRP) is a well-established inflammation marker commonly used in the management of medical inpatients. METHODS: We studied the association of clinical factors, CRP levels and changes of CRP documented prior to blood culture draws with the absence of bacteremia for hospitalized medical patients. RESULTS: In the retrospective analysis of 710 blood cultures obtained from 310 medical inpatients of non-intensive-care wards during one year (admission blood cultures obtained in the emergency room were excluded), the following retrospectively available factors were the only independent predictors of blood cultures negative for obligate pathogens: a good clinical condition represented by the lowest of three general nursing categories (OR 4.2, 95% CI 1.8 – 9.5), a CRP rise > 50 mg/L documented before the blood culture draw (OR 2.0 95% CI 1.8–9.5) and any antibiotic treatment in the previous seven days (OR 2.0, 95% CI 1.1–3.5). CONCLUSION: Including the general clinical condition, antibiotic pre-treatment and a substantial rise of CRP into the decision, whether or not to obtain blood cultures from medical inpatients with a suspected infection, could improve the diagnostic yield.
Description
License
Copyright 2008 Ehrenstein et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution 2.0 License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.