Dialysis disequilibrium syndrome

Abstract

The dialysis disequilibrium syndrome is a rare but serious complication of hemodialysis. Despite the fact that maintenance hemodialysis has been a routine procedure for over 50 years, this syndrome remains poorly understood. The signs and symptoms vary widely from restlessness and headache to coma and death. While cerebral edema and increased intracranial pressure are the primary contributing factors to this syndrome and are the target of therapy, the precise mechanisms for their development remain elusive. Treatment of this syndrome once it has developed is rarely successful. Thus, measures to avoid its development are crucial. In this review, we will examine the pathophysiology of this syndrome and discuss the factors to consider in avoiding its development.

Fig. 1

A schematic diagram of the blood brain barrier. a The endothelial cell of the microvasculature has tight junctions that prevent paracellular movement of solute and water. Thus, it is the true blood brain barrier [14]. (Reproduced from [37], with permission). b In the presence of hypertonicity, the astrocyte cell–cell junction is no longer intact. This will allow a more rapid entry of water into the brain tissue. (Reproduced from [37], with permission)

Fig. 2

Urea concentration gradients between the cerebrospinal fluid (CSF) and blood in patients undergoing hemodialysis. Vertical arrows represent the difference in the urea concentrations between the blood and CSF, horizontal axis represents the initial blood urea concentration. As can be seen, the patients with higher initial blood urea concentrations had larger post-dialysis blood–CSF urea gradients. (Reproduced from [15] with permission)