Hydroxyethyl Starch 130/0.42 Effect’s on Renal Function in Patients After Cardiac Surgery: A Retrospective Cohort Analysis

Background: Fluid management is an everyday challenge in intensive care units worldwide. Data from recent trials suggest that the use of hydroxyethyl starch leads to a higher rate of acute kidney injury and mortality in septic patients. Evidence on the safety of hydroxyethyl starch used in postoperative cardiac surgery patients is lacking Methods: The aim was to determine the impact of postoperatively administered hydroxyethylstarch 130/0.42 on renal function and 90-day mortality compared to with or without balanced crystalloids in patients after elective cardiac surgery. A retrospective cohort analysis was performed including 2245 patients undergoing elective coronary artery bypass grafting or, aortic valve replacement, or a combination of both between 2015 - 2019. Acute kidney injury was defined according to the ‘kidney disease improving global outcomes’ criteria. Multivariate logistic regression yielded adjusted associations of postoperative hydroxyethyl starch administration with acute kidney injury during hospital stay and 90-day mortality. Linear mixed-effects models predicted trajectories of estimated glomerular filtration rates over the postoperative period to explore the impact of dosage and timing of hydroxyethyl starch administration.Results: A total of 1009 patients (45.0 %) suffered from acute kidney injury. Significantly less acute kidney injury of any stage occurred in patients receiving hydroxyethyl starch compared to patients receiving only crystalloids for fluid resuscitation (43.7 % vs. 51.2 % p=0.008). In multivariate analysis, the administration of hydroxyethyl starch showed a protective effect (OR 0.89 95% confidence interval (CI) (0.82-0.96)) which was less prominent in patients receiving only crystalloids (OR 0.98, 95% CI (0.95-1.00)). No association between hydroxyethyl starch and 90-day mortality (OR 1.05 95% CI (0.88-1.25)) was detected. Renal function trajectories were dose-dependent and biphasic and hydroxyethyl starch could even slow down the late postoperative decline of kidney function.Conclusion: This study showed no association between hydroxyethyl starch and the postoperative occurrence of acute kidney injury and may add evidence to the discussion about the use of hydroxyethyl starch in cardiac surgery patients. In addition, hydroxyethyl starch administered early after surgery in adequate low doses might even prevent the decline of the kidney function after cardiac surgery.