Bicarbonate and Other Buffer Therapies in Acute Metabolic Acidosis: A Systematic Review and Meta-Analysis

The aim of this study was to perform a systematic review and meta-analysis on the effect of buffering therapies on clinical outcomes in adult patients with acute metabolic acidosis.

Searches were conducted in Embase, Cochrane, and PubMed for randomised clinical trials comparing a buffering therapy to either placebo, no buffering therapy, or another buffering therapy in adult patients with acute metabolic acidosis. Two assessors independently reviewed trials for relevance, extracted data, and assessed risk of bias using the Cochrane Risk of bias 2 tool. Meta-analyses were performed using fixed-effect models. The certainty of evidence was assessed using the GRADE methodology.

Fifteen manuscripts representing 14 trials were included. Most trials were conducted in critically ill patients (4 trials; n = 1064), in patients with out-of-hospital cardiac arrest (3 trials; n = 1426), or in patients with intraoperative acidosis (3 trials; n = 136). In most trials, the intervention was bicarbonate. Risk of bias was assessed as moderate for most trials. In ICU patients with acute kidney injury, buffering therapy probably has no large effect on survival outcomes (low certainty), but likely reduces the use of renal replacement therapy and the rate of bloodstream infections (moderate certainty). Buffering therapy likely does not have an effect on survival outcomes in patients with out-of-hospital cardiac arrest (very low to low certainty).

Buffering therapy in ICU patients with acute kidney injury likely has beneficial effects on the use of renal replacement therapy, but probably no effect on survival outcomes. Similarly, no effects were found for survival outcomes in patients with out-of-hospital cardiac arrest.

This systematic review with meta-analysis presents an up to date and trustworthy synthesis of evidence concerning buffer therapy in acute metabolic acidosis, largely focused in the critical care context.