Removal of morphine with the new high-efficiency and high-flux membranes during haemofiltration and haemodialfiltration.

We present three critically ill patients with severe renal failure who required haemofiltration or haemodiafiltration, with high-efficiency or high-flux membranes, while receiving an intravenous infusion of morphine. We show that despite the very high ultrafiltrability/diffusability of free morphine, only 1-3% of the total amount of infused morphine is removed in 24 h. This is in marked contrast to haemodialysis where, owing to much higher dialysate flow rate, a significant quantity of free morphine is removed.