Haemodialysis Disequilibrium

Abstract

The size of the abnormal urea gradient between C.S.F. and plasma produced by haemodialysis is proportional to the concentration of plasma urea at the beginning of dialysis, and this abnormal gradient persists for approximately 24 hours after the termination of dialysis. The delay in removal of urea from C.S.F. is associated with a change in the osmolality gradient between C.S.F. and plasma. This results in the passage of water into C.S.F., with consequent symptoms due to an increase in intracranial pressure. It has also been demonstrated that haemodialysis creates a disturbance in equilibration of uric acid, creatinine, inorganic phosphorus, and bicarbonate between C.S.F. and blood. It is therefore suggested that haemodialysis be performed at low levels of biochemical disturbance, for short periods of time, and at frequent intervals so that minimal biochemical disturbances be opened up between C.S.F. and blood and the dialysis disequilibrium syndrome be prevented. © 1964, British Medical Journal Publishing Group. All rights reserved.