[Thrombocytopenia in a surgical intensive care unit: incidence, risk factors and effect on outcome]

To determine the incidence of thrombocytopenia in a surgical intensive care unit (ICU), the risk factors associated with it, and its effect on patient outcome.

During a 6-month period, all patients admitted to the surgical intensive care unit were studied prospectively. The factors associated with thrombocytopenia were evaluated by univariate and multivariate analysis.

The study included 112 patients with a mean age of 50+/-18 years and a mean SAPS II (Simplified Acute Physiology Score) of 25+/-19: 41 developed thrombocytopenia (incidence=36,6%). Risk factors associated with it in the univariate analysis were high SAPS II, high organ dysfunction score, invasive intravascular catheters, sepsis, septic shock, and bleeding. After multivariate logistic regression analysis, only 3 independent risk factors remained for thrombocytopenia: bleeding (OR=11.9; 95% CI: 3.3-43.6; p<0.001), sepsis (OR=4.1; 95% CI: 1.3-11.7; p=0.013) and SAPS II>20 (OR=2.8; 95% CI: 1.0-7.8; p=0.042). Although mortality was higher in patients with than without thrombocytopenia , this difference was not statistically significant (41% versus 31%, p=0.26). Survival was similar in both groups, according to the Kaplan-Meier survival curve.

Thrombocytopenia is common in surgical ICUs. Bleeding and sepsis are the major risk factors. In this study, thrombocytopenia was not an independent factor of poor vital outcome in these critically ill patients.