Effect of dihydroergotamine on leg blood flow during combined epidural and general anaesthesia and postoperative deep vein thrombosis after cholecystectomy

The effects of dihydroergotamine (DHE) on the circulation of the leg during combined epidural and general anaesthesia were studied to determine if DHE would enhance leg blood flow and prevent postoperative deep vein thrombosis in a double‐blind trial of 40 elderly female patients subjected to cholecystectomy. Central and big toe temperature, arterial blood pressure, heart rate, calf volume and arterial inflow of the leg by electrical impedance plethysmography and the venous outflow by Doppler method were measured. DHE 0.5 mg subcutaneously reduced the volume of the leg, i.e. increased the electrical impedance, probably due to venous vasoconstriction. Simultaneously the need for etilefrine hydrochloride was reduced. No significant changes in the pulsatile inflow of the leg or the outflow were detected. Deep vein thrombosis (DVT) was detected by fibrinogen uptake test in five patients (three in DHEH and two in the control group) and verified by ascending phlebography in four patients. Intraoperative characteristics in patients with postoperative DVT were tachycardia (P°0.001), enhanced need for etilefrine (P°0.01) and a more rapid increase in big toe temperature (P°0.05) after induction of epidural analgesia, compared with patients without DVT. Femoral vein flow velocity remained at the preinduction level, whereas pulsatile arterial inflow slightly increased. Together with a low basal impendance of the leg, the changes were indicative of a more intense vasodilatation, probably leading to stagnant flow and development of postoperative deep vein thrombosis.