Etiology and clinical relevance of elevated platelet count in ICU patients : Aretrospective analysis.

Abstract

Thrombocytosis is acommon phenomenon in critically ill patients. Although thrombocytosis is an independent risk factor for complications, it does not seem to influence mortality in intensive care (ICU) patients. Our investigation aimed to evaluate the etiological and clinical relevance of aplatelet count greater than 450× 109/l in ICU patients. Patients admitted for aminimum of 4days to an interdisciplinary ICU during a45-month period were enrolled in this retrospective observational study. Thrombocytopenic patients (platelet count <150× 109/l in at least one measurement) were excluded. The study patients were divided into two groups: thrombocytosis group (thrombocytes >450× 109/l in at least one measurement) and control group (thrombocytes= 150- 450× 109/l during ICU stay). Univariate and multiple regression analysis were used to determine the influence of severe co-morbidities on the development of thrombocytosis and the association of elevated platelet count with thrombotic embolism, length of stay (LOS) in ICU, and mortality. Atotal of 307 patients were analyzed, of whom thrombocytosis was observed in 119 cases. Independent risk factors for the development of thrombocytosis included SIRS, mechanical ventilation, and acute bleeding. Increasing age reduced the risk of thrombocytosis. Thromboembolism occurred in 16patients (13.4%) with an elevated platelet count and only in nine patients (4.7%) with physiological platelet values (OR: 3.1; 95% CI: 1.3-7.2; p= 0.009). Mean duration of LOS was significantly longer in patients with thrombocytosis (25.2 vs.11.7 days, p< 0.0001). Elevated platelet count showed anegative correlation with ICU mortality (OR: 0.32; 95%-CI: 0.12-0.83; p= 0.019). In our retrospective analysis the occurrence of thrombocytosis in acohort of interdisciplinary ICU patients was associated with a higher rate of complications and longer LOS in the ICU. Despite these findings, thrombocytosis seems to reduce mortality in critical ill patients.