Unexpected haemodynamic instability associated with standard bicarbonate haemodialysis.
BACKGROUND
The bicarbonate concentration in dialysis fluids for intermittent haemodialysis usually is between 32 and 35 mmol/l. The severity of chronic metabolic acidosis secondary to end-stage renal failure is very variable, however, so that in some patients pre-dialysis acidosis is overcorrected. This study aimed to analyse haemodynamic tolerances to metabolic alkalosis during intermittent haemodialysis.


METHODS
In this randomized controlled trial with a single blind, cross-over design, we used dialysis liquids with two different bicarbonate concentrations, 32 (modality A) and 26 (modality B) mmol/l, and in 26 patients, 468 dialysis sessions, compared blood pressure, heart rate, incidence of hypotension and the frequency of corrections required with saline or hypertonic glucose infusions.


RESULTS
The results of intradialytic haemodynamic monitoring for modalities A and B, respectively, were: lowest systolic blood pressure 120.8+/-20.8 vs 124.3+/-20.6 mmHg (P < 0.01); mean systolic blood pressure 138.5+/-23.8 vs 144.6+/-24.8 mmHg (P < 0.001); and highest heart rate 73.5+/-12.0 vs 75.8 +/- 12.9 (NS); with modality A, patients had more dialysis sessions with hypotensive episodes (5.55 vs 1.7%, P < 0.05) and required more saline or hypertonic glucose infusions (20.9 vs 13.7% of the dialysis sessions, P < 0.05).


CONCLUSIONS
Mild metabolic alkalosis resulting from standard bicarbonate haemodialysis (32 mmol/l) may induce symptomatic hypotension. While normalizing chronic metabolic acidosis is desirable, reducing bicarbonate concentrations should be considered in cases of significant alkalaemia or otherwise untreatable haemodynamic instability.
Gabutti
Luca
L
Department of Nephrology, Ospedale la Carità, Locarno, Switzerland. luca.gabutti@eoc.ch
Ferrari
Nicola
N
Giudici
Giacomo
G
Mombelli
Giorgio
G
Marone
Claudio
C
D000328:Adult; D000368:Aged; D000471:Alkalosis / Q000139:chemically induced*; D001639:Bicarbonates / Q000009:adverse effects* / Q000032:analysis; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D015312:Hemodialysis Solutions / Q000009:adverse effects* / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012720:Severity of Illness Index; D016037:Single-Blind Method
D001639:Bicarbonates; D015312:Hemodialysis Solutions