Increased risk of mortality in severe traumatic brain injury with improper ventilation

Brain Scan with Highlighted Spot

Hyperventilation (with a mechanical ventilator or a manual bag valve mask, for instance) can be a life-saving treatment in the early stages of traumatic brain injury. Although hyperventilation can reduce intracranial pressure and reduce mortality rates, improper ventilation can lead to adverse outcomes.

A recent study considered the hyperventilation guidelines from the Brain Trauma Foundation and determined how much improper use could affect in-hospital mortality. They found the following:

  1. Hypocarbia/hyperventiliation and hypercarbia/hypoventilation administered after traumatic brain injury increased the risk of in-hospital mortality.
  2. Normocarbia administered after traumatic brain injury decreased the risk of in-hospital mortality.

Hypo- and hypercarbia (carbon dioxide pressure that is too low or too high) that occurs early in treatment (pre-hospital trauma care) can actually induce secondary brain damage. Normocarbia (normalized carbon dioxide pressure) should therefore be the goal in early trauma management. It was suggested that, rather than indiscriminate administration of hyperventilation, only patients with signs of brainstem herniation and elevated intracranial pressure should be treated.

Dumont DM, Visioni AJ, Rughani AI, et al. Inappropriate prehospital ventilation in severe traumatic brain injury increases in-hospital mortality. Journal of Neurotrauma. (April 2010).