Association between fentanyl use and mortality during prehospital emergency anaesthesia in traumatic brain injury – a retrospective cohort study

Fentanyl is commonly used as an adjuvant in prehospital emergency anesthesia to reduce the sympathetic response caused by laryngoscopy. It is widely employed in patients with traumatic brain injury, a group considered particularly vulnerable to both rises and falls in blood pressure during anesthesia. Currently, there is a lack of data on the overall impact of fentanyl use on mortality in TBI patients during prehospital anesthesia. We performed a retrospective cohort study to assess the effects of using fentanyl as an anesthetic adjuvant during prehospital intubation of patients with traumatic brain injury. We collected data on patients intubated between January 2014 and December 2022 by a single helicopter emergency medical service unit and included patients diagnosed with traumatic brain injury. The primary outcome was death before discharge. The secondary outcomes were (a) exiting the favorable blood pressure zone of 130–180mmHg, and (b) a change in blood pressure of either 10% or 20% after intubation. A logistic regression model was used to control the effects of confounding variables. We identified a total of 423 patients, 353 of whom received fentanyl as an anesthetic adjuvant and 70 did not. In the logistic regression model use of fentanyl was a significant predictor for lower mortality (OR 0.376, 95% CI 0.172–0.823, p = 0.014). There was no significant difference in the number of patients exiting the favorable blood pressure zone. There were fewer episodes of 10% and 20% increases (18% and 9% vs. 41% and 27%) but also more episodes of decreases (48% and 33% vs. 30% and 19%) in blood pressure in the fentanyl group ( p < 0.05). The use of fentanyl as an anesthetic adjuvant during prehospital emergency anesthesia of patients with traumatic brain injury was associated with lower mortality before hospital discharge. Substantial baseline differences suggest that treatment selection may partly explain this finding.