Acid Base Imbalance in Dialysis: Risk Factors and Impact on Intradialysis Blood Pressure Changes. Findings from a Single Center Prospective Study in Nigeria

Abstract

Abstract: Introduction: Despite improvements in hemodialysis delivery, acid base imbalance is still common in the dialysis population and it is associated with intradialysis blood pressure changes, dialysis termination, inadequacy and poor treatment outcome. We studied acid base imbalance in maintenance hemodialysis, its determinants and relationship with intradialysis blood pressure changes. Materials & Methods: A prospective study carried out at Babcock University Teaching Hospital, Ilishan-Remo between May 2019 and April 2021 that involved 298 participants who had 1642 hemodialysis sessions. Results: The mean age was 51.44 + 7.31 years, with the females been older than males, P=0.04. The mean predialysis and post dialysis serum bicarbonate were 18.41 ± 3.63 mmol/l and 20.61 ± 6.26 mmol/l (P<0.001). The prevalence of pre and post dialysis metabolic acidosis were 79.0% and 38.3% (P<0.001) and of intradialysis hypotension and hypertension were 19.1% and 25.0% (P=0.02). The risk of intradialysis hypotension was negatively correlated with predialysis bicarbonate while intradialysis hypertension was positively correlated with predialysis bicarbonate. The mean dialysis dose was higher in males (P=0.03). Metabolic acidosis was commoner in elderly and females, and was associated with intradialysis hypotension, dialysis termination and inadequacy. Aging and infrequent dialysis, predicted metabolic acidosis. Conclusion: Metabolic acidosis is common in maintenance hemodialysis, particularly in females, aged and infrequent dialysis, and leads to intradialysis hypotension, dialysis termination, inadequacy and poor treatment outcome. Keywords: Metabolic acidosis, Maintenance hemodialysis, Dialysis dose, Intradialysis hypotension, Intradialysis hypertension, Predialysis bicarbonate, Poor treatment outcome.