Objective  Cardiac surgery-associated acute kidney injury is a common and serious complication of cardiac surgery. Albumin solution is a commonly administered fluid in cardiac surgery patients; the role of albumin in preventing cardiac surgery-associated acute kidney injury is unclear. The objective of this systematic review and meta-analysis was to evaluate the impact of perioperative albumin compared with other fluid regimens on the risk of acute kidney injury in cardiac surgical patients undergoing cardiopulmonary bypass.

Methods  A systematic search was performed of MEDLINE^®, Embase, CINAHL, and Cochrane Central Register of Controlled Trials databases, and the Australian New Zealand Clinical Trials Registry, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, and ISRCTN registries. Randomized trials of adult patients undergoing on-bypass cardiac surgery comparing albumin-containing solutions with any other fluid regimen given perioperatively were included. Trials comparing fluids used only for bypass priming were excluded. Data extraction, risk of bias, and certainty of evidence were assessed in duplicate by independent reviewers. A Bayesian framework was the primary statistical approach, with a secondary frequentist approach. The primary outcome was perioperative acute kidney injury, defined as the period from surgery until hospital discharge. Secondary outcomes were all-cause mortality at longest follow-up, intensive care unit length of stay, hospital length of stay, proportion of patients requiring renal replacement therapy postoperatively, duration of mechanical ventilation postoperatively, and duration of vasopressor support postoperatively.

Results  Fourteen randomized trials, including 3,304 adults, were included in the analysis. Seven trials contributed data to the primary outcome. Four trials had an overall low risk of bias across all domains and outcomes. The pooled estimated risk ratio for acute kidney injury with albumin solutions was 1.09 (95% credible interval 0.86 – 1.34, tau = 0.12; I2 = 31.5%), with a 18.3% posterior probability of reduced acute kidney injury. There were no significant subgroup effects or differences in secondary outcomes.

Conclusion  Among patients undergoing on-bypass cardiac surgery, the use of albumin solutions is unlikely to reduce the risk of acute kidney injury. Other interventions need to be considered for this condition.