UNVEILING THE EFFECT OF VARYING DIALYSATE BICARBONATE CONCENTRATION ON ACID BASE BALANCE IN HEMODIALYSIS PATIENTS

UNVEILING THE EFFECT OF VARYING DIALYSATE BICARBONATE CONCENTRATION ON ACID BASE BALANCE IN HEMODIALYSIS PATIENTS

Metabolic acidosis, one of the major and fatal complications observed in the dialysis populace, not only leads to a rapid decline in kidney function but also increases morbidity and cardiovascular mortality rates. The study was carried out to discern the effect on immediate post-dialysis acid-base status as well as before the next dialysis by varying dialysate bicarbonate concentration in the dialysis populace. Study design: It was a single-blind crossover clinical trial-based research study.

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This clinical trial comprised 80 patients with chronic kidney disease (CKD) undergoing thrice weekly hemodialysis. Patients were divided into two groups using computer-generated random number tables. Initially, one group was dialyzed with a bicarbonate bath of 30mmol/l, whereas the other group was dialyzed with a bicarbonate bath of 35mmol/l; later patients were crossed over to the other intervention. After the fourth week, blood gas analysis for pH, pCO2, and HCO3 was performed before and after the mid-week (second session of hemodialysis in a week-Wednesday in patients who are getting dialysis on Monday-Wednesday-Friday and Thursday on Tuesday-Thursday-Friday sessions) dialysis session. Pre-dialysis blood samples (3ml) were again obtained immediately before the next session by using the same technique.

Both groups (bicarbonate bath 30mmol/l   and 35mmol/l) had mean values of pre-dialysis arterial pH and HCO3 which were mildly acidotic, which improved after dialysis. There was no statistically significant difference between the two groups in the pre-dialysis pH (p-0.62) and HCO3 (p-0.32). Pre-dialysis pH and HCO3 had a positive correlation with post-dialysis pH (r=0.34, p=0.000), but almost no correlation   between pre-dialysis HCO3 and PCO2 with post-dialysis HCO3- (r=0.0446, p=0.000) and pCO2(r=0.0291, p=0.000). Moreover, pre-dialysis HCO3 had a negative correlation with the increase of intra-dialytic HCO3 after hemodialysis (r=--0.47, p=0.000). The pre-dialysis and post-dialysis difference was negatively correlated with pre-dialysis HCO3. Changes in HCO3, pCO2 and pH level from mid-week post dialysis to next dialysis session pH, pCO2 and HCO3 was also not statistically significant

No dialysate bicarbonate concentration is ideal for the dialysis populace and it has to be tailored to each patient’s need in order to achieve optimum acid-base balance status in such patients.