Prehospital intubation in patients with severe traumatic brain injury: a review

Traumatic brain injury (TBI) is a global health burden, with an incidence of 874-1005/100 000. It is a leading cause of morbidity and mortality in all ages. TBI is a heterogeneous entity, with a variety of definitions. Treatment starts at a prehospital level and aims to prevent secondary injury. Airway management is vital to prevent hypoxia, hypercapnia, and aspiration which could contribute to secondary injuries. In some systems, it is current practice to perform endotracheal intubation in the prehospital setting to secure the airway and permit controlled ventilation, as opposed to using basic maneuvers and adjuncts with supplemental oxygen. This study aims to review the effect of prehospital tracheal intubation on mortality and functional outcome in adult and pediatric patients with severe TBI compared with patients not intubated in the prehospital setting. A digital literary search of four databases using variations of the terms 'Endotracheal Intubation', 'Laryngeal Mask Airway', and 'Traumatic Brain Injury" included reports up to 31 March 2023. Of 7242, 33 studies were included. The overall risk of bias was moderate to serious. Nine studies noted an increase in mortality associated with prehospital intubation, four studies demonstrated a significant decrease in mortality and five studies reported poorer functional outcomes using various scales. Only three reports, including the only randomized controlled trial (RCT), showed improved functional outcomes with prehospital intubation. In eight studies, the prehospital intubation cohort had significantly more severe injuries. The majority of studies showed no effect on or increased mortality, and no significant association with functional outcome in patients with severe TBI who underwent prehospital intubation. However, all but one were retrospective and with a moderate to serious risk of bias. The cause of the mortality increase is uncertain and possibly a result of more severe injuries in the prehospital intubation group. The single available RCT reported improved functional outcomes with prehospital intubation but has yet to be replicated. The current evidence for prehospital intubation is uncertain in either direction, and there is a need for new prospective research, ideally with uniform outcome measures and the application of up-to-date intubation practices in the prehospital field.