Priapism associated with the use of intravenous fat emulsion: case reports and postulated pathogenesis.

During the 8 years since inception of a home total parenteral nutrition program in 35 male patients 2 suffered priapism related temporally to the weekly intravenous infusion of 20 per cent fat emulsion. Fat emulsions have been shown to cause hypercoagulability, capillary thrombosis and fat embolus in in vivo and in vitro experiments. Autopsies of patients treated with intravenous fat emulsion have revealed capillary engorgement and fat embolus with associated organ infarction. We postulate that fat emulsions may cause priapism in these patients. Because of the more frequent occurrence of priapism in this small subset of patients we now recommend that 1) patients be informed of this potential complication before hyperalimentation is begun, 2) the less concentrated 10 per cent emulsion should be used twice weekly, rather than the 20 per cent emulsion weekly, and should be infused during at least 4 hours, and 3) the fat emulsion should be added to other components of the intravenous regimen, when possible, to dilute the fat and prolong its administration time.