Association between traumatic brain injuries and ketamine infusion side effects following combat injury

Introduction: Ketamine is a vital component for acute pain management in emergency trauma care for both civilian and military hospitals. This preliminary analysis examined whether combat-injured US service members sustaining traumatic brain injuries (TBI) experienced increased odds of ketamine side effects compared with those without TBI.

Methods: This preliminary analysis included combat-injured service members, ages ≥18 years with documented pain scores during the 24 hours before and 48 hours after receiving an intravenous ketamine infusion at Walter Reed National Military Medical Center (WRNMMC) between 2007 and 2014. Logistic regression modeling examined the association between TBI and ketamine side effects (eg, hallucinations, nightmares, dysphoria, nausea, decreased oxygen saturation) during hospitalisation.

Results: Of the 77 patients, 62% presented with a documented TBI. Side effects were documented for 18.8% of those without TBI and 24.4% of those with TBI. Analyses were unable to find evidence against the null hypothesis with the current sample size, even when adjusting for injury characteristics and preinfusion opioid doses (adjusted OR=0.90 (95% CI 0.26 to 3.34), p=0.87).

Conclusion: In this small sample of combat-injured service members, we were unable to detect a difference in ketamine-related side effects by documented TBI status. These hypothesis-generating findings support the need for future studies to examine the use of intravenous ketamine infusions for pain management, and subsequent care outcomes in patients who experience polytraumatic trauma inclusive of TBI.