Renal Outcome in Patients Undergoing Cardiac Surgery Using Cardiopulmonary Bypass

Introduction

Renal dysfunction is a significant variable in determining the outcome of surgery, such as cardiopulmonary bypass graft and valvular replacement, used to treat cardiovascular diseases. In Saudi Arabia, the incidence of renal failure and diabetes is higher than in most western populations. Our aim is to determine the renal outcome of patients who underwent cardiac surgery at King Faisal Cardiac Center from 2014 to 2017.

Methods

This a retrospective cohort study using a non-probability consecutive sampling technique for selection of the study population to assess the renal outcome in cardiac surgery patients using cardiopulmonary bypass from May 2014 to June 2017 in King Faisal Cardiac Center, Jeddah. Patients older than 18 years of age undergoing cardiac surgery, with available data, were included. Categorical variables were summarized by percentages and frequencies, and continuous variables by means and standard deviations, or medians and interquartile ranges if their distributions were skewed. Logistic regression was done with post-op renal impairment as the dependent variable and pre-op renal dysfunction, age, gender, smoking status, diabetes, hypertension, dyslipidemia, and cardiopulmonary bypass time as independent variables.

Results

Our sample size included 244 patients who underwent cardiac surgery in this study period; their mean age was 60.5 (SD =7.5) with a mean body mass index (BMI) of 28.62 (SD=5.19). Among our population, 73% (n = 179) were males and 27% (n =66) were females. Two percent (2%) of patients (n = 5) died within 30 days, 4% of patients (n = 10) with temporary dialysis, 8% of patients (n = 19) with postoperative renal dysfunction, and no patients with permanent dialysis. The data showed a significant relationship between levels of creatinine preoperatively and postoperative renal dysfunction (p-value = 0.0001, OR=1.05, 95% CI of 1.031 to 1.064).

Conclusion

The main predictor of poor renal outcomes for cardiac surgery is preoperative creatinine. While other factors, such as age, gender, body mass index, cardiopulmonary bypass time, diabetes, hypertension, and dyslipidemia, did not show any risk to the postoperative renal outcome.