Current practice guidelines for ventilatory management advocate protective lung strategies to prevent volutrauma, barotrauma, atelectrauma and biotrauma (3-5). The principles are to use low tidal volumes (Vt) (5-6 ml/kg ideal body weight), maintenance of low mean airway pressures ≤ 30 cmH2O, judicious use of positive end-expiratory pressure (PEEP) with Δ pressure ≤ 18 cmH2O, higher respiratory rates and permissive hypercapnia. This is in direct conflict with the previous “brain-directed” ventilatory strategies that used Vt of 10 ml/kg, high FiO2 and low PEEP or zero end-expiratory pressure. There is proven mortality benefit with the use of low Vt, but permissive hypercapnia may precipitate intracranial hypertension(3,6,7). Animal studies indicate a.