Solute mass balance during isovolaemic high volume haemofiltration.
OBJECTIVE
To evaluate the effect of changing the amount of pre-dilution replacement fluid on the sieving coefficient (SC) and mass transfer of small solutes during isovolaemic high-volume haemofiltration (HVHF).


METHODS
Prospective interventional study in the intensive care unit of a tertiary university hospital.


METHODS
Eight patients with septic shock.


METHODS
Isovolaemic HVHF (6 l/h of replacement fluid) was performed. The proportion of replacement fluid delivered in pre-filter was altered to progressively decrease it from 6 to 0 l/h. Samples were simultaneously taken from the "pre-filter", "post-filter" and ultrafiltrate (UF) sampling ports.


RESULTS
Sodium, potassium, chloride, total calcium, total magnesium, phosphate, total CO(2), urea, creatinine and glucose concentrations were measured in each sample. The sieving coefficients of chloride, total CO(2), phosphate, urea and glucose were higher than 1 in most pre-dilution states. The sieving coefficients of sodium, potassium, calcium, magnesium, total CO(2) and urea decreased significantly with decreasing pre-dilution fluid rate. The sieving coefficients of chloride and glucose increased with decreasing pre-dilution fluid rate. There was a significant mass gain of sodium and glucose under all pre-dilution conditions. Mass chloride gains decreased with decreasing pre-dilution rates and changed into chloride loss during 6 l/h of post-dilution. Decreasing pre-dilution improved urea and creatinine mass removal.


CONCLUSIONS
Small solute SC and mass transfer during isovolaemic HVHF are significantly affected by the proportion of replacement fluid administered pre-filter. Isovolaemic HVHF is neither isonatraemic nor isochloraemic.
Uchino
Shigehiko
S
Department of Intensive Care, Austin & Repatriation Medical Centre, Heidelberg, 3084 Victoria, Australia.
Cole
Louise
L
Morimatsu
Hiroshi
H
Goldsmith
Donna
D
Ronco
Claudio
C
Bellomo
Rinaldo
R
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002118:Calcium / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D002712:Chlorides / Q000032:analysis; D003404:Creatinine / Q000032:analysis; D018592:Cross-Over Studies; D004573:Electrolytes / Q000032:analysis; D005260:Female; D005440:Fluid Therapy; D015312:Hemodialysis Solutions / Q000032:analysis*; D006440:Hemofiltration / Q000379:methods*; D006801:Humans; D008274:Magnesium / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000032:analysis; D011446:Prospective Studies; D012772:Shock, Septic / Q000628:therapy*; D012964:Sodium / Q000032:analysis; D014508:Urea / Q000032:analysis
D001786:Blood Glucose; D002712:Chlorides; D004573:Electrolytes; D015312:Hemodialysis Solutions; D002245:Carbon Dioxide; D014508:Urea; D012964:Sodium; D003404:Creatinine; D008274:Magnesium; D011188:Potassium; D002118:Calcium