Bicarbonate- versus lactate-buffered solutions for acute continuous haemodiafiltration or haemofiltration

Area of Science:

• Nephrology and Critical Care Medicine
• Renal Replacement Therapy
• Acid-Base Physiology

Background:

• Acute kidney injury (AKI) impairs kidney function, necessitating renal replacement therapies like continuous haemodiafiltration (HDF) and haemofiltration (HF).
• The choice of buffered dialysates (bicarbonate vs. lactate) in HDF/HF impacts acid-base balance and electrolytes, but their comparative benefits and harms in AKI patients are not well-established.

Purpose of the Study:

• To evaluate the benefits and harms of bicarbonate-buffered versus lactate-buffered solutions for HDF or HF in patients with AKI.

Main Methods:

• Systematic review of randomized controlled trials (RCTs) and quasi-RCTs comparing bicarbonate-buffered and lactate-buffered solutions for AKI.
• Searched Cochrane Renal Group's Specialised Register and Chinese Biomedical Literature Database up to January 6, 2015.
• Independent assessment of study eligibility, quality (Cochrane risk of bias tool), and data extraction; results reported as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI).

Main Results:

• Four studies with 171 patients were included; overall study quality was suboptimal with reporting omissions.
• Bicarbonate-buffered solutions were associated with significantly lower serum lactate levels (MD -1.09 mmol/L).
• No significant differences were observed in mortality, serum creatinine, pH, or other key electrolytes. One study suggested fewer cardiovascular events and less hypotension with bicarbonate solutions.

Conclusions:

• Bicarbonate-buffered solutions may offer benefits such as reduced cardiovascular events and lower serum lactate in AKI patients undergoing HDF/HF.
• No significant differences were found for mortality, serum creatinine, or acid-base parameters.
• Primary outcomes like ICU stay, hospital stay duration, and relapse could not be adequately assessed due to study limitations.