The treatment of resistant hypotension with ornipressin. A case report

A 50-year-old man underwent emergency aortic valve replacement. He had been treated with five antihypertensive agents before the procedure; this contributed to the development of profound hypotension after induction of anaesthesia. The hypotension did not respond to conventional treatment with an incremental intravenous infusion of phenylephrine HCl, probably due to the direct vasodilator action of the hydralazine group of drugs which renders the peripheral vascular smooth muscle unresponsive to sympathomimetic stimulation. The hypotension did, however, respond rapidly to low-dose infusion of a synthetic vasopressor, ornipressin (POR 8; Sandoz), a drug with a direct action on vascular smooth muscle, especially the capacitance vessels. Ornipressin thus restores vascular smooth-muscle tone even when the integrity of the adrenergic pathways is no longer intact.