[Nosocomial diarrhea in the intensive care unit: incidence and risk factors]

Nosocomial diarrhea seems to be common at intensive care units, although its epidemiology be poorly documented in Brazil.

To determine the incidence and risk factors of diarrhea among adult patients admitted to intensive care units.

Four hundred and fifty five patients were prospectively included during the period between October 2005 and October 2006. Demographic, clinical and biochemical data as well as aspect and number of bowel movements were recorded on a daily basis until discharge from the unit.

Diarrhea occurred in 135 (29.5%) patients, lasting 5.4 days average. The time of its onset in according to admission was 17.8 days and similar cases of diarrhea during the same period were recorded in 113 (83.7%) patients. In a multivariate analysis through the logistics regression model, only the number of antibiotics (OR 1.65; I.C. 95% = 1.39-1.95) and the number of days of antibiotic therapy (OR 1.16; I.C. 95% = 1.12-1.20) were statistically associated with the diarrhea occurrence. Each day added of antibiotic therapy, raised in 16% the risk of diarrhea (I.C. 12% to 20%), while the addition of one more antibiotic to the scheme, increased the chances of occurring diarrhea in 65% (I.C. 39% to 95%).

The incidence of nosocomial diarrhea in intensive care units is high (29.5%). The main risk factors for its occurrence were number of prescribed antibiotics and duration of the antibiotic therapy. Besides the enteric precautions, judicious and limited prescription of antimicrobians probably will reduce the occurrence of diarrhea at this unit.