Development and validation of prognostic nomogram for cirrhotic patients with acute kidney injury upon ICU admission

Abstract

This study aims to develop and validate a prognostic nomogram that accurately predicts the short-term survival rate of cirrhotic patients with acute kidney damage (AKI) upon ICU admission. For this purpose, we examined the admission data of 3060 cirrhosis patients with AKI from 2008 to 2019 in the MIMIC-IV database. All included patients were randomly assigned to derivation and validation cohorts in a 7:3 ratio. The derivation cohort used the least absolute shrinkage and selection operator (LASSO) regression model to identify independent predictors of AKI. A prognostic nomogram was constructed via multivariate logistic regression analysis in the derivation cohort and subsequently verified in the validation cohort. Nomogram's discrimination, calibration, and clinical utility were evaluated using the C-index, calibration plot, and decision curve analysis (DCA). A total of 2138 patients were enrolled in the derivation cohort, with a median follow-up period of 15 days, a median survival time of 41 days, and a death rate of 568 patients (26.6%). The cumulative survival rates at 15 and 30 days were 75.8% and 57.5%, respectively. The results of the multivariate analysis indicated that advanced AKI stage, use of vasoactive drugs, advanced age, lower levels of ALB, lower mean sBp, longer INR, and longer PT were all independent risk factors that significantly influenced the all-cause mortality of cirrhosis patients with AKI (all p < 0.01). The C-indices for the derivation and the validation cohorts were 0.821 (95% CI 0.800-0.842) and 0.831 (95% CI 0.810-0.852), respectively. The model's calibration plot demonstrated high consistency between predicted and actual probabilities. Furthermore, the DCA showed that the nomogram was clinically valuable. Therefore, the developed and internally validated prognostic nomogram exhibited favorable discrimination, calibration, and clinical utility in forecasting the 15-day and 30-day survival rates of cirrhosis patients with AKI upon admission to the ICU.

Keywords: Acute kidney injury; Intensive care unit; Model; Nomogram; Prognosis.