Brain swelling after dialysis: old urea or new osmoles?

The pathogenesis of brain swelling and neurological deterioration after rapid hemodialysis (dialysis disequilibrium syndrome) is controversial. The "reverse urea hypothesis" suggests that hemodialysis removes urea more slowly from the brain than from the plasma, creating an osmotic gradien...

Full description

Saved in:
Bibliographic Details
Published inAmerican journal of kidney diseases Vol. 28; no. 1; p. 1
Main Authors Silver, S M, Sterns, R H, Halperin, M L
Format Journal Article
LanguageEnglish
Published United States 01.07.1996
Subjects
Animals
Blood Urea Nitrogen
Blood-Brain Barrier - physiology
Body Water - metabolism
Brain - metabolism
Brain Edema - etiology
Brain Edema - physiopathology
Humans
Osmolar Concentration
Renal Dialysis - adverse effects
Syndrome
Time Factors
Urea - metabolism
Online AccessGet more information

Cover

More Information
Summary:The pathogenesis of brain swelling and neurological deterioration after rapid hemodialysis (dialysis disequilibrium syndrome) is controversial. The "reverse urea hypothesis" suggests that hemodialysis removes urea more slowly from the brain than from the plasma, creating an osmotic gradient that results in cerebral edema. The "idiogenic osmole hypothesis" proposes that an osmotic gradient between brain and plasma develops during rapid dialysis because of newly formed brain osmoles. In this review, the experimental basis for the two hypotheses are critically examined. Based on what is known about the physiology of urea and water diffusion across the blood-brain barrier, and empiric observations of brain solute composition after experimental hemodialysis, we conclude that the "reverse urea hypothesis" remains a viable explanation for dialysis disequilibrium and that rapid reduction of a high urea level in and of itself predisposes to this condition.
ISSN:0272-6386
DOI:10.1016/S0272-6386(96)90124-9