摘要
Objective： Trauma is the leading cause of mortality and morbidity among young age groups in Saudi Arabia and developed countries. This study aimed to evaluate the fall of platelet count in children with traumatic brain injury （TBI） as a potential predictor for clinical severity and outcome. Methods： Totally 74 patients with TBI were admitted to the Pediatric Intensive Care Unit （PICU） of our hospital from the beginning of January 2008 to the end of March 2010 （27 months）. Baseline enrolling criteria were age ≤ 12 years, admission within 4 hours after trauma event, and abbreviated injury scale （AIS）〈3 for extracranial injuries. Injury severity was classified as mild, moderate and severe according to their Glasgow Coma Scale （GCS） scores. Clinical outcomes at discharge were defined as poor （death, severe neurological morbidity） and favorable （moderate disability and good recovery）. Platelet count was taken 2-3 times on the first day after admission and thereafter once daily. The percentage fall of platelet count （PFP） was calculated and taken as an index of change. PFP was considered zero if the platelet count was higher than the initial value. Results： PFP was significantly higher in patients with poor outcomes （mean 56.0%±3.8%, median 55.5%） compared to those with favorable outcomes （mean 25.3%±3.2%, median 20.5%, P〈0.01）. PFP was also closely related to the severity of TBI, GCS score, clinical outcome and length of stay for survivors （P〈0.01 for each）. The frequency of thrombocytopenia was significantly higher in poor outcome patients than in favorable outcome patients （P〈0.05）. The validity of thrombocytopenia as a risk factor to predict poor outcome after TBI was： specificity, 77.4%; odd ratio （OR）, 3.1; relative risk （RR）, 2.15. Receiver operating characteristic （ROC） curve and Youden index showed that the optimum cutoff point of PFP was at 51.5%. Conclusion： PFP is increased with the severity of TBI and it can be taken as a significant independent predicting factor for its outcome as well.
