Razi Journal of Medical Sciences

  Current, lung protection strategy possesses some degree of hypercapnia and hypoxia. Permissive hypercapnia and hypoxia may attenuate the complications of mechanical ventilation in neonates. Adapting this approach and thorough understanding of the biopathologic effects of hypercapnia and hypoxia could prevent mechano-trauma and air leak syndromes. This helps protecting the lung and inflammatory organs lessening inflammatory damages, inflammatory cascade and prostaglandins at the presence of endotoxins, inflammatory cells and bacteria. In addition, allowing normal versus supra normal values of oxygen and reduction of oxygen toxicity could diminish the free radical related illness (e.g., respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD)).This article reviews the pathophysiologic effects of hypercapnia and hypoxia, principals of oxygen delivery and tissue consumptions, clinical applications of permissive hypercapnia and permissive hypoxia and concerns when such approaches are decided.