Postoperative 20% albumin vs standard care and acute kidney injury after high-risk cardiac surgery (ALBICS): study protocol for a randomised trial

BACKGROUND: Acute kidney injury (AKI) is a common complication of cardiac surgery. Factors such as cardiopulmonary bypass, aortic cross-clamping and surgical stress may precipitate renal hypoperfusion and ischaemia, inflammation and oxidative stress are associated with development of AKI. Albumin’s pharmacological properties and widespread availability have the potential to mitigate these factors. However, the effect of albumin on cardiac surgery-associated AKI is unknown. OBJECTIVE: To evaluate the impact of postoperative 20% albumin infusion on kidney function after high-risk cardiac surgery. METHODS: We designed an open-label, multicentre, randomised controlled trial—the ALBICS study (ALBumin Infusion and acute kidney injury following Cardiac Surgery). A total of 590 patients undergoing high-risk cardiac surgery (combined procedure or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)) will be enrolled into the study and randomly allocated to receive a postoperative 20% albumin infusion or standard care in a 1:1 ratio, stratified by centre and baseline renal function. The study fluid will be administered upon arrival in intensive care for 15 h. Patients will be followed up until 28 days after surgery or until discharge from the hospital. The primary outcome is the proportion of patients who develop AKI in both groups. Secondary outcomes to be measured are proportions of AKI stage II and III, 28-day mortality, mechanical ventilation time and length of stay in intensive care and hospital. CONCLUSION: This trial aims to determine if a postoperative infusion of concentrated albumin reduces the risk of AKI following high-risk cardiac surgery. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12619001355167. Registered on 03 October 2019—retrospectively registered. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378383.