Initial hematocrit predicts the use of blood transfusion in the pediatric trauma patient

Purpose: Initial hematocrit (Hct) is generally not considered a marker of acute blood loss because it is assumed that physiologic response of fluid conservation to hemorrhage is delayed. We challenged this idea by theorizing that admission Hct correlates with conventional signs of shock and predicts the use of blood transfusion during resuscitation of pediatric trauma patients.

Methods: Data from 1928 pediatric admissions (<18 years) at a Level I trauma center (2000-2012) were compared using standard statistical analyses and logistic regression modeling to identify factors associated with blood transfusion during initial trauma resuscitation.

Results: Overall mortality rate was 3.5%, with a transfusion rate of 10.7%. Factors significantly associated with transfusion were initial Hct, Glasgow Coma Score, base deficit, and injury severity score (all p<0.001). Initial Hct is a stronger predictor for transfusion (area under receiver operator curve (AUC: 0.728) compared to age-specific tachycardia (AUC: 0.689), age-specific hypotension (AUC: 0.673), and altered mental status (AUC: 0.654)). On multivariate analysis, initial Hct was an independent predictor (OR [95% CI]: 2.94 [1.56, 5.52]) along with hypotension (6.37 [2.95, 13.8]), base deficit (4.14 [1.38, 12.4]), and tachycardia (3.07 [1.62, 5.81]).

Conclusions: Initial Hct correlates significantly with conventional signs of shock and is a strong independent predictor for blood transfusion with better predictability than other clinical factors.