Adequate intravenous (IV) fluid administration is essential during and after cardiac surgery to restore circulating blood volume and improve end-organ tissue perfusion. Clinical decisions about which fluid type to use, when to use it, and in what patient populations continue to be made in the absence of consensus recommendations or practice guidelines. This uncertainty has fueled the long-standing "great fluid" debate, which evolved from a colloid-crystalloid debate after recognition of potential harm associated with synthetic colloid use among critically ill patients and among patients undergoing cardiac surgery, making albumin the colloid of choice. 1 Clinical equipoise surrounding using albumin or balanced crystalloids in cardiac surgery persists, perpetuating wide practice variation in fluid replacement strategies. Putative protective effects of albumin on endothelial glycocalyx and microvascular integrity, reduced platelet consumption, and prevention of acute kidney injury are mainly derived from preclinical or small clinical studies or extrapolated from different critically ill patient populations but have not been substantiated by high-quality evidence of its greater clinical benefit or safety profile compared with balanced crystalloid solutions in patients undergoing cardiac surgical procedures.In this issue of JAMA, Pesonen and colleagues 2 report findings from the ALBICS (Albumin in Cardiac Surgery) trial and add a persuasive argument to the albumin-crystalloid debate. In this single-center, randomized, double-blind, pragmatic, superiority trial involving 1386 patients undergoing cardiac surgery with cardiopulmonary bypass, patients were randomized in a 1:1 ratio to receive either 4% albumin solution (n = 693) or Ringer acetate (n = 693) for both cardiopulmonary bypass priming fluid and perioperative IV volume replacement (intraoperative and up to 24 hours postoperatively).The authors reported no significant difference in the 90-day incidence of major adverse events (MAEs; ≥1 of the following: death, myocardial injury, acute heart failure, resternotomy, stroke, arrhythmia, bleeding, infection, or acute kidney injury) between the albumin and Ringer groups (257 of 693 patients [37.1%] vs 234 of 693 patients [33.8%]; P = .22) and total serious adverse events (SAEs) (40.8% vs 45%, P = .13), respectively.Exploratory analyses of individual components of the composite primary outcome revealed a lower incidence of myocardial injury (3.9% vs 8.9%; relative risk [RR], 0.44; 95% CI, 0.28-0.68; P < .001) but conversely higher incidence of bleed-