The Impact of Platelets on the Progression of Traumatic Intracranial Hemorrhage

Background: The purpose of this study was to analyze the association of the initial platelet count with mortality and progression of intracranial hemorrhage (ICH) in blunt traumatic brain injured (TBI) patients. Methods: All blunt trauma patients with severe TBI admitted from January 2006 to December 2007 were retrospectively identified. Patients with a chest, abdomen, or extremity AIS score >3 were excluded to minimize the impact of concomitant injuries on the outcomes of the patients. All brain computed tomography scans were reviewed to analyze ICH progression. Discrete platelet cutoff values were entered into a multiple regression model to detect critical thresholds associated with ICH progression and mortality. Results: Of 626 TBI patients, 310 (49.5%) had a minimum of two brain computed tomography scans and were able to have ICH progression evaluated. Patients with platelets <175,000/mm(3) had a significantly increased risk for ICH progression (OR [95% CI]: 2.09 [1.07-4.37]; adjusted p = 0.043). ICH progression was associated with increased need for craniotomy (OR [95% CI]: 3.27 [1.28-8.33]; adjusted p = 0.013) and mortality (OR [95% CI]: 3.41 [1.11-10.53]; adjusted p = 0.033). A platelet count <100,000/m(3) was an independent predictor for mortality (OR [95% CI]: 9.5 [1.3-71.4]; adjusted p = 0.029). Conclusion: A platelet count <100,000/mm(3) is associated with a ninefold adjusted risk of death, and a platelet count <175,000/mm(3) is a significant predictor of ICH progression. The impact of early correction of the admission platelet count warrants further validation.