Trends in pediatric adjusted shock index predict morbidity and mortality in children with severe blunt injuries.

PURPOSE The utility of measuring the pediatric adjusted shock index (SIPA) at admission for predicting severity of blunt injury in pediatric patients has been previously reported. However, the utility of following SIPA after admission is not well described. METHODS The trauma registry from a level-one pediatric trauma center was queried from January 1, 2010 to December 31, 2015. Patients were included if they were between 4 and 16years old at the time of admission, sustained a blunt injury with an Injury Severity Score≥15, and were admitted less than 12h after their injury (n=286). Each patient's SIPA was then calculated at 0, 12, 24, 36, and 48h after admission and then categorized as elevated or normal at each time frame based upon previously reported values. Trends in outcome variables as a function of time from admission for patients with an abnormal SIPA to normalize as well as patients with a normal admission SIPA to abnormal were analyzed. RESULTS In patients with a normal SIPA at arrival, 18.4% of patients who developed an elevated SIPA at 12h after admission died, whereas 2.4% of patients who maintained a normal SIPA throughout the first 48h of admission died (p<0.01). Among patients with an elevated SIPA at arrival, increased length of time to normalize SIPA correlated with increased length of stay (LOS) and intensive care unit (ICU) LOS. Similarly, elevation of SIPA after arrival in patients with a normal initial SIPA correlated to increased LOS and ICU LOS. CONCLUSIONS Patients with a normal SIPA at time of arrival who then have an elevated SIPA in the first 24h of admission are at increased risk for morbidity and mortality compared to those whose SIPA remains normal throughout the first 48h of admission. Similarly, time to normalize an elevated admission SIPA appears to directly correlate with LOS, ICU LOS, and other markers of morbidity across a mixed blunt trauma population. Whether trending SIPA early in the hospital course serves only as a marker for injury severity or if it has utility as a resuscitation metric has not yet been determined. TYPE OF STUDY Prognostic. LEVEL OF EVIDENCE Level II.