Risk factors of mortality in AAAD patients who had severe postoperative hyperbilirubinemia and received CRRT

Severe acute kidney injury (AKI) and hyperbilirubinemia increase the morbidity and mortality risk in patients undergoing emergency surgery for acute type A aortic dissection (AAAD). Our purpose was to investigate the risk factors of mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and AKI receiving continuous renal replacement therapy (CRRT).

Patients who had severe hyperbilirubinemia and received CRRT after AAAD surgery in our center between January 2015 and December 2018 were retrospectively screened. Univariate and multivariate analyses were performed to identify the risk factors of in-hospital mortality. Kaplan-Meier curves were employed to evaluate the accumulated patient survival proportion.

After screening, 50 patients were included in our present study. The in-hospital mortality was 84%. The univariate logistic analysis showed that preoperative MAP (p = .017) and peak total bilirubin concentration (p < .001) were associated with in-hospital mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and received CRRT. Multivariate logistic regression analysis revealed that the peak bilirubin concentration (odds ratio, 1.050; 95% confidence interval, 1.002-1.101; p = .041) after surgery was the only independent risk factor for in-hospital mortality. The optimal cutoff value of peak bilirubin for predicting in-hospital mortality was 134.4 μmol/L.

AAAD surgery patients with severe hyperbilirubinemia and AKI requiring CRRT had a poor prognosis. Increased postoperative peak bilirubin concentration strongly increased the risk of patient in-hospital mortality. Therefore, these patients should be closely monitored and treated aggressively when possible.