Permissive hypercapnia.

Traditional practice of mechanical ventilation includes tactics to reduce lung injury, such as avoidance of excessive airway pressure, patient distress, and tidal volume. Gas exchange objectives have received priority, however, and a degree of lung injury has been accepted as inevitable. The current trend toward increasing use of permissive hypercapnia is based on the recognition that lung injury induced by mechanical ventilation may be reduced by compensated hypercapnia with few serious adverse effects and contraindications.