164 Influence of Time to Transport to a Higher Level Facility on the Clinical Outcomes of US Combat Casualties With Traumatic Brain Injury: A Multicenter 7-Year Study

Abstract

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is associated with mortality rates as high as 30%. Patients with TBI are at high risk for secondary injury and need to be transported to definitive care expeditiously. However, the physiologic effects of aeromedical evacuation are not well understood and may compound these risks. It is unknown if combat TBI patients may benefit from early versus delayed aeromedical evacuation. The aim of this study was to evaluate the impact of transport timing out of theater via CCATT to a higher-level facility on the clinical outcomes of combat casualties with TBI. We performed a retrospective record review of patients with TBI who were evacuated out of theater by Critical Care Air Transport Teams (CCATT) from January 2007 to May 2014. Data abstractors collected flight information, laboratory values, vital signs, procedures, and clinical in-flight assessments. Outcomes were obtained from the Department of Defense Trauma Registry (DoDTR). Time to transport was defined as the time (in days) from injury to CCATT evacuation out of combat theater. We calculated descriptive statistics and constructed multivariable regression models to determine the association between time to transport and clinical outcomes. We examined the records of 438 patients transported via CCATT from a Role III facility to Landstuhl Regional Medical Center (LRMC). For analyses we categorized patients into three groups: those transported in one day or less (n=165, 38% of the sample), two days (n=163, 37%), and three days or more (n=110, 25%). Multivariable logistic regression models indicated that patients with longer time to transport (ie, two days, or three or more days) had 50% lower odds of being discharged on a ventilator and were twice as likely to return to duty or be discharged home, even after adjusting for demographics, injury severity, and injury type. Additionally, patients transported in three or more days were 70% less likely to be ventilated at discharge with a GCS of 8 or lower and had 28% lower odds of mortality when compared to those transported in one day or less. In patients with moderate to severe TBI, a delay in aeromedical evacuation out of the combat theater was associated with lower odds of mortality and ventilation at discharge and a higher likelihood of discharge to home and return to duty dispositions.