It is well-known that acute renal failure is often caused by hemolysis. Its possible causes may be free-hemoglobin (F-Hb), stroma freed from destroyed red blood cell, and their combined action. Especially, a great amount of F-Hb is liable to flow out during extracorporeal circulation. The plasma fractionation using a membrane has so far been applied to remove F-Hb (1). The molecular weight, of F-Hb of 68,000 which is nearly equal to that of albumin has made it still difficult to separate F-Hb effectively.

Recently, we have developed an adsorbent that is capable of selectively removing F-Hb and succeeded in obtaining its high adsorption performance.