Sedation as a risk factor for intensive care unit-acquired infections

Abstract

Sedative and analgesic drugs are routinely and heterogeneously used in mechanically ventilated patients. Several epidemiologic studies suggested a relationship between sedation and intensive care unit (ICU)-acquired infections. Sedation may promote infection, a common complication in the ICU, associated with a high morbidity, mortality, and cost. Prolongation of exposure to risk factors for infection, microaspiration, gastrointestinal motility disturbances, and microcirculatory effects are the main mechanisms by which sedation may favour infection in the critically ill patients. Experimental evidence based on both human and animal studies suggests that sedatives and analgesics may alter the immunologic response to exogenous stimuli. Clinical studies comparing different sedative agents do not provide evidence to recommend the use of a particular agent to reduce the rate of ICU-acquired infection. However, sedation strategies aiming to reduce the duration of mechanical ventilation including daily interruption of sedatives or nursing-implementing sedation protocols should be promoted.