Reduction of hypoxic pulmonary vasoconstriction during diethyl ether anaesthesia in the dog.

The activity of the pulmonary vasoconstrictor response to alveolar hypoxia was assessed by measuring the redistribution of pulmonary blood flow in response to the ventilation of one lung with nitrogen. The vasoconstrictor response was depressed during the administration of 5% diethyl ether but returned when the ether was withdrawn. It is suggested that depression of the hypoxic vasoconstrictor mechanism may be one cause of the increased alveolar-arterial Po2 difference noted during ether anaesthesia.