Hypercapnic acidosis transiently weakens hypoxic pulmonary vasoconstriction in anesthetized pigs, without affecting the endogenous pulmonary nitric oxide production

Hypercapnic acidosis is often seen in critically ill patients and during protective mechanical ventilation. Conflicting findings regarding the effect of hypercapnic acidosis on endogenous nitric oxide (NO) production and hypoxic pulmonary vasoconstriction (HPV) have been reported. The aim of this study was to test the effects of hypercapnic acidosis on HPV, and the endogenous NO production in hypoxic and hyperoxic lung regions.