Management of mechanical ventilation in brain injury: hyperventilation and positive end-expiratory pressure

The study intended to make a critical review on use of pulmonary hyperventilation maneuvers and the different positive end-expiratory pressures applied to traumatic brain injury patients. As a reference were used publications in English, Spanish and Portuguese, contained in the following databases: MedLine, SciELO and LILACS, from 2000 to 2007, we included all studies about the use of pulmonary hyperventilation maneuvers and the different positive end-expiratory levels used for adult patients with brain injury at acute or chronic stage. Thirty one trials were selected, 13 about pulmonary hyperventilation, as prophylaxis, prolonged or optimized and 9 shows the levels of positive end-expiratory pressures used, ranging from 0 to 15 cmH2O. The prophylactic hyperventilation maneuver in the first 24 hours can lead to an increase of cerebral ischemia; the prolonged hyperventilation must be avoided if intracranial pressure did not increase; however optimized hyperventilation seems to be the most promising technique for control of the intracranial pressure and cerebral perfusion pressure; the rise of the positive end-expiratory pressure, up to 15cmH2O, can be applied in a conscientious form aiming to increase arterial oxygen saturation in lung injury.