title: Fall of platelet count in children with traumatic brain injury: is it of value?
abstract: 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 less than or equal to 12 years, admission within 4 hours after trauma event, and abbreviated injury scale (AIS) less than 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 less than 0.01). PFP was also closely related to the severity of TBI, GCS score, clinical outcome and length of stay for survivors (P less than 0.01 for each). The frequency of thrombocytopenia was significantly higher in poor outcome patients than in favorable outcome patients (P less than 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%.
  
  
  CONCLUSIONS
  PFP is increased with the severity of TBI and it can be taken as a significant independent predicting factor for its outcome as well.
authors.affiliation: Department of Pediatric Intensive Care Unit, King Fahad Hofuf Hospital, Hofuf, Saudi Arabia.
authors.forename: Hosam-Mustafa
authors.initials: HM
authors.lastname: Kamal
authors.forename: Habeeb
authors.initials: H
authors.lastname: Sammou
authors.forename: Ahmad-Adnan
authors.initials: AA
authors.lastname: Mardini
authors.forename: Ahmad
authors.initials: A
authors.lastname: Zaitoni
mesh_terms: D000058:Accidental Falls; D001930:Brain Injuries; D002648:Child; D015600:Glasgow Coma Scale; D006801:Humans; D010976:Platelet Count; D012307:Risk Factors