Background: The incidence and risk factors for the development of thrombocytosis after trauma have not been well established. Although it has been suggested that the occurrence of this sequela may be associated with adverse events, there are also limited data regarding outcomes of patients developing posttraumatic thrombocytosis. The objective of this study was to determine the incidence of, risk factors for, and sequela of posttraumatic thrombocytosis.
Methods: A retrospective review of all trauma intensive care unit (ICU) admissions between July 1998 and December 2005 identified patients with early (< or = 7 days), late, and no thrombocytosis. Bivariate analysis was used to compare the clinical and demographic characteristics with outcomes between the three patient groups.
Results: A total of 3,484 patients were admitted to the ICU during the 7-year study period. After exclusions, the study population consisted of 3,286 patients. The overall incidence of thrombocytosis was 18.7%; early thrombocytosis was found in 72 patients, and late thrombocytosis was identified in 542 patients. All complications examined were significantly higher in patients with thrombocytosis. Overall, the venous thromboembolic rate was 2.4%; for patients with thrombocytosis it was 4.6% compared with 1.9% in patients without thrombocytosis. Overall mortality was 15.4%, but was significantly lower in patients with thrombocytosis (3.8% vs. 18.1%, p < 0.0001). Independent risk factors for the development of thrombocytosis included obesity, laparotomy, blunt injury, Injury Severity Score > 16, mechanical ventilation, Chest Abbreviated Injury Score > 3, and tachycardia.
Conclusion: Thrombocytosis is a common finding among patients with trauma admitted to the ICU. The occurrence of both early and late thrombocytosis is associated with significantly higher rates of complications, particularly venous thromboembolism. However, patients developing posttraumatic thrombocytosis may have a significantly lower mortality compared with those without this sequela of injury.