Impact of nosocomial infections on clinical outcome and resource consumption in critically ill patients

Abstract

Objective: Nosocomial infections still present a major problem in intensive care units (ICUs), accounting for prolonged ICU and hospital stays and worsened outcomes. There exist differences in the literature regarding the impact of nosocomial infections on attributable mortality and resource consumption. The aim of this study was to observe these effects in a large cohort of critically ill patients.

Patients and settings: Thirty-four Austrian ICUs participated in the study by documenting all nosocomial infections from 1 June to 30 November 2003 according to the Hospital in Europe Link for Infection Control through Surveillance (HELICS) protocol.

Measurements and results: Of 2,392 patients with a length-of-stay (LOS) >2 days, 683 (28.6%) developed at least one nosocomial infection. The most common infection was pneumonia (n = 456), followed by central venous catheter (CVC) infections (n = 101). Risk-adjusted mortality rates (standardized mortality ratios) were significantly increased for infected patients [0.91 (0.83-0.99) vs. 0.68 (0.61-0.74)]. Significant attributable risk-adjusted mortality was found for patients with pneumonia, combined infections (both 32%) and CVC-related infections (26%). LOS in the ICU increased significantly for all infections.

Conclusions: We conclude that significant attributable mortality for several nosocomial infections exists in a large cohort of critically ill patients, with the highest impact occurring in those with microbiologically diagnosed pneumonia and combined infections. All infections were associated with an increased resource consumption. Effective infection control measures could improve both clinical outcome and proper and effective use of ICU resources.