Predictors of positive blood cultures in critically ill patients: a retrospective evaluation.

Autor: Previsdomini M; Intensive Care Unit, Ospedale Regionale Bellinzona e Valli, Bellinzona, Switzerland. marco.previsdomini@eoc.ch, Gini M, Cerutti B, Dolina M, Perren A
Jazyk: angličtina
Zdroj: Croatian medical journal [Croat Med J] 2012 Feb 15; Vol. 53 (1), pp. 30-9.
DOI: 10.3325/cmj.2012.53.30
Abstrakt: Aim: To identify predictors of bacteremia in critically ill patients, to evaluate the impact of blood cultures on the outcome, and to define conditions for breakthrough bacteremia despite concurrent antibiotic treatment.
Methods: A descriptive retrospective study was performed over a two-year period (2007-2008) in the medico-surgical Intensive Care Unit (ICU) of the San Giovanni Hospital in Bellinzona, Switzerland.
Results: Forty-five out of 231 patients (19.5%) had positive blood cultures. Predictors of positive blood cultures were elevated procalcitonin levels (>2 µg/L, P<0.001), higher severity scores (Simplified Acute Physiology Score II>43, P=0.014; Sequential Organ Failure Assessment >4.0, P<0.001), and liver failure (P=0.028). Patients with bacteremia had longer hospital stays (31 vs 21 days, P=0.058), but their mortality was not different from patients without bacteremia. Fever (t>38.5°C) only showed a trend toward a higher rate of blood culture positivity (P=0.053). The rate of positive blood cultures was not affected by concurrent antibiotic therapy.
Conclusions: The prediction of positive blood culture results still remains a very difficult task. In our analysis, blood cultures were positive in 20% of ICU patients whose blood was cultured, and positive findings increased with elevated procalcitonin levels, liver failure, and higher severity scores. Blood cultures drawn >4 days after the start of antibiotic therapy and >5 days after surgery could detect pathogens responsible for a new infection complication.
Databáze: MEDLINE