Mortality in intensive care: The impact of bacteremia and the utility of systemic inflammatory response syndrome


      • We assessed the outcome of bacteremia in an intensive care unit using matching by propensity scores.
      • Intensive care unit patients with bacteremia had higher mortality and length of stay than controls.
      • We also assessed the relationship between systemic inflammatory response syndrome criteria and blood culture result in an intensive care unit.
      • There was no relationship between systemic inflammatory response syndrome and blood culture status.
      • A decision rule tool based on systemic inflammatory response syndrome criteria met cannot predict blood culture result.


      The purpose of this study was to determine the impact of bacteremia on intensive care unit (ICU) mortality and to develop a bacteremia prediction tool using systemic inflammatory response syndrome (SIRS) criteria.


      Patients included those aged >18 years who had blood cultures taken in the ICU from January 1, 2011-December 31, 2013. Eligible patients were identified from microbiology records of the Glasgow Royal Infirmary, Scotland. Clinical and outcome data were gathered from ICU records. Patients with clinically significant bacteremia were matched to controls using propensity scores. SIRS criteria were gathered and used to create decision rules to predict the absence of bacteremia. The main outcome was mortality at ICU discharge. The utility of the decision tools was measured using sensitivity and specificity.


      One hundred patients had a clinically significant positive blood culture and were matched to 100 controls. Patients with bacteremia had higher ICU mortality (odds ratio [OR], 2.35; P = .001) and longer ICU stay (OR, 17.0 vs 7.8 days; P ≤ .001). Of 1,548 blood culture episodes, 1,274 met ≥2 SIRS criteria (106 significant positive cultures and 1,168 negative cultures). There was no association between SIRS criteria and positive blood cultures (P = .11). A decision rule using 3 SIRS criteria had optimal predictive performance (sensitivity, 56%; specificity, 50%) but low accuracy.


      ICU patients with bacteremia have increased mortality and length of ICU stay. SIRS criteria cannot be used to identify patients at low risk of bacteremia.

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