Starch or Saline After Cardiac Surgery: A Double-Blinded Randomized Controlled Trial

Abstract

Background: Despite decades of investigation, the balance of clinical risks and benefits of fluid supplementation with starch remain unresolved. Patient-centered outcomes have not been well explored in a “real-world” trial in cardiac surgery. Objective: We sought to compare a starch-based fluid strategy with a saline-based fluid strategy in the cardiac surgery patient. Design: A pragmatic blinded randomized controlled trial comparing starch-based with saline-based fluid strategy. Setting: A large tertiary academic center in London Ontario between September 2009 and February 2011. Participants: Patients undergoing planned, isolated coronary revascularization. Measurements: Serum creatinine and patient weight were measured daily postoperatively. Methods: Patients were randomized to receive 6% hydroxyethyl starch (Voluven) or saline for perioperative fluid requirements. Fluid administration was not protocolized. Co-primary outcomes were incidence of acute kidney injury (AKI) and maximum postoperative weight gain. Secondary outcomes included bleeding, transfusion, inotropic and ventilator support, and fluid utilization. Results: The study was prematurely terminated due to resource limitations. A total of 69 patients (19% female, mean age = 65) were randomized. Using RIFLE criteria for AKI, “risk” occurred in 12 patients in each group (risk ratio [RR] = 1.0; 95% confidence interval [CI] = 0.5-1.9; P = 1.00), whereas “injury” occurred in 7 of 35 (20%) and 3 of 34 (9%) of patients in the starch and saline groups, respectively (RR = 2.3; 95% CI = 0.6-8.1; P =.31). Maximum weight gain, bleeding and blood product usage, and overall fluid requirement were similar between groups. Limitations: The study had to be prematurely terminated due to resource limitations which led to a small sample size which was not sufficiently powered to detect a difference in the primary outcomes. Conclusions: This pragmatic double-blinded randomized controlled trial revealed a number of interesting hypothesis-generating trends and confirmed the feasibility of undertaking a logistically complex trial in a pragmatic fashion.