Does pre-hospital ventilation effect outcome after significant brain injury?

Traumatic brain injury has a devastating impact on society, utilizing many resources and disproportionately affecting the young. Recent evidence demonstrates the early care of the brain injured patient impacts patient outcomes. While prevention of systolic hypotension and hypoxia are mainstays of prehospital management of the injured patient ventilatory management performed in the prehospital environment has recently been shown to impact outcomes. Hypocapnea from hyperventilation has been shown in several trials to cause deleterious effects from cerebral vasoconstriction and ischemia. The importance of balancing the prevention of both hypocapnea and hypercapnea has led to the idea of a target ventilation range for arterial carbon dioxide tension, the ideal way to achieve this balance in the prehospital setting remains elusive. This article reviews the background, physiologic effects, impact on outcomes, and implications for prehospital care of prehospital ventilation.