Constrictive effect of pancuronium on capacitance vessels

The effects of pancuronium 0.08 mg kg-1, metocurine 0.4 mg kg-1 and tubocurarine 0.4 mg kg-1 on vascular tone were studied in 26 patients undergoing open heart surgery during total cardiopulmonary bypass. With a fixed rate of perfusion, arterial pressure is related directly to total peripheral resistance, while the volume of blood remaining in the extracorporeal reservoir is related inversely to vascular capacity, which depends primarily on venous tone. Pancuronium increased the reservoir volume (average of 780 +/- SEM 250 ml (P less than 0.01). We conclude that under certain circumstances pancuronium constricts capacitance vessels in man.