Abstract:

Objective To investigate the relationship between serum uric acid increase and acute kidney injury (AKI) after cardiac surgery. Methods The clinical data and follow-up data of patients undergoing cardiac surgery were collected, and patients were divided into elevated uric acid group and non-elevated uric acid group according to pre-operative serum uric acid. The prevalences of AKI, severity of AKI and outcomes in two groups were retrospectively analysed, and the relationship between the incidence of AKI and serum uric acid increase was evaluated by multivariate Logistic regression analysis. Results After cardiac surgery, 328 of 1 056 patients (31.1%) developed AKI. There were significant differences in the prevalences of AKI between elevated uric acid group and non-elevated uric acid group (49.3% vs 26.0%, P<0.001). The duration of ICU stay was longer, and the survival was lower in elevated uric acid group than in non-elevated uric acid group (P<0.001 and P=0.001). After adjustment for age, pre-operative renal function, left ventricular insufficiency, combined surgery, operation time and post-operative circulation volume insufficiency, multivariate Logistic regression analysis revealed that pre-operative serum uric acid increase was an independent risk factor of AKI after cardiac surgery (OR=1.97, 95%CI 1.22-3.18, P=0.006). Conclusion Pre-operative serum uric acid increase may be associated with incidence of AKI after cardiac surgery, and the former may be an independent risk factor of the later.

Key words: acute kidney injury, cardiac surgery, uric acid, risk factors