Marked decrease in arterial oxygen tension associated with continuous intravenous nifedipine administration.

Intravenous nifedipine was administered to treat arterial hypertension in a 54-year-old woman presenting for removal of a meningioma. A marked decrease in arterial oxygen tension occurred during the nifedipine infusion. Inhibition of hypoxic pulmonary vasoconstriction by nifedipine is discussed.