Hydroxyethyl starch and change in renal function in patients undergoing coronary artery bypass graft surgery

Background. Several case reports and clinical lore have suggested that exposure to the colloid hydroxyethyl starch may impair renal function, but few studies have systematically addressed this issue, and several have produced conflicting results. We sought to study the question in a formal analysis of postoperative change in renal function in patients undergoing coronary artery bypass graft (CABG) surgery. Methods. We identified 238 consecutive patients who underwent CABG surgery at a large academic medical center. Glomerular filtration rate (GFR) was estimated using the Cockroft-Gault formula at baseline as well as on postoperative days 3 and 5. Linear regression analysis was used to study the relation between changes in GFR and intraoperative hydroxyethyl starch administration. Multivariate models controlled for potential demographic, clinical, and surgery-related confounders. Results. Hydroxyethyl starch use was independently associated with a reduction in GFR on both postoperative days 3 and 5, with GFR declining by 7.2 mL/min/1.73 m(2) on day 3 per unit of hydroxyethyl starch administered (95% CI, 1.7 to 12.7; P = 0.012), and by 6.6 mL/min/1.73 m(2) on day 5 (95% CI, 1.2 to 11.9; P = 0.018). Conclusion. Intraoperative use of hydroxyethyl starch may be associated with modest impairment in renal function in patients undergoing CABG surgery. Randomized clinical trials will be necessary to confirm these findings and to further investigate their clinical implications.