Brain swelling during dialysis: A randomized trial comparing low-flux hemodialysis with pre-dilution hemodiafiltration .
Osmotic changes in plasma are assumed to cause cerebral swelling in hemodialysis patients. We investigated the acute effect of low-flux hemodialysis (HD) (removal of small molecules) and pre-dilution hemodiafiltration (pre-HDF) (additional removal of larger molecules) on cerebral compartment volumes using quantitative magnetic resonance imaging (MRI) in chronic uremic patients. Twelve patients underwent a session of HD and pre-HDF in a randomized crossover study with equal ultrafiltration. MRI was performed immediately before and after dialysis. A linear correlation was found between changes in gray matter and plasma osmolarity (HD: r2= 0.83; HDF: r2= 0.73) but not between changes in white matter volume and plasma osmolarity (HD: r2= 0.02; HDF: r2= 0.004). Total brain volume increased by 1.8 ± 1.7% (18.7 ± 17.4 mL) (mean ± SD) during HD and 2.0 ± 0.9% (22.3 ± 10.7 mL) during pre-HDF. Gray matter volume increased: HD 3.8% (from -3.6 to 9.7) and pre-HDF 4.2% (from -2.8 to 14.3). White matter volume did not change significantly. Reduction ratio of urea (molecular weight (MW) 0.06 kDa) (HD: 68%; pre-HDF: 69.7%) and β2-microglobulin (MW 11.7 kDa) (HD: -13.7%; pre-HDF: 67.2%) separated the treatments. This study showed that HD and pre-HDF caused equal acute cerebral swelling of the grey matter. This appeared to be driven by small solute change in plasma interacting linearly with gray matter volume regardless of additional removal of larger molecules or ultrafiltration. .
Niels
N
Johansen
Krista Dybtved
KD
Kjaergaard
Christian Daugaard
CD
Peters
Michael
M
Pedersen
Bente
B
Jespersen
Jens Dam
JD
Jensen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000209:etiology*; D018592:Cross-Over Studies; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects*; D014508:Urea / Q000097:blood
D014508:Urea