Early urea-to-creatinine ratio to predict ICU-acquired weakness in critically ill patients with sepsis

Abstract Background ICU-acquired weakness (ICUAW) is a serious and common complication of critical illness. Urea-to-creatinine ratio (UCR) reflects protein metabolism and is often used for the assessment of nutritional metabolic status. However, it has not been studied in ICUAW. This study aimed to investigate whether the UCR can predict the development of ICUAW in patients with sepsis. Methods Our retrospective observational study was performed in a university ICU from 2014 to 2021 on a group of adult (≥ 18 years) sepsis patients. We excluded patients who received renal replacement therapy in ICU or transferred from another ICU or the interval between twice upper abdominal CT scans༜5 days. The primary exposures were UCR on day 1, UCR on day 3 minus UCR on day 1(ΔUCR d3-d1). The primary outcome was the onset of ICUAW during hospitalization. We employed multivariate logistic regression models to explore the association between ΔUCR d3-d1 and ICUAW. We calculated the area under the receiver operating characteristic (AUROC) to see the predictive performance of UCR. Results A total of 482 patients were included in the final analysis. The median (IQR) age of the included patients was 62.00 (51.00, 74.00) years, with 350 males and 132 females. Among them, 271(56%) were diagnosed with ICUAW. Compared with the no ICUAW group, the UCR was lower on day 1 (0.09 [0.06–0.12] vs. 0.11 [0.08–0.15], P ≤ 0.001) in the ICUAW group, subsequently, it showed a significant increasing trend. In the ICUAW group, ΔUCR d3-d1 was significantly higher than in the no ICUAW group (2.04 [0.36–3.78] vs. -1.20 [-3.06–0.14], P < 0.001). Multivariate logistic regression analysis showed that ΔUCR d3-d1 was associated with an increased risk of ICUAW (Odds ratio, OR 1.40,95% CI:1.30–1.52). The predictive ability of ΔUCR d3-d1 for predictive ICUAW was 0.78[95% CI 0.74–0.83], adjusted of AUROC remains good (0.78[95% CI 0.75–0.83]). Subgroup analyses showed that in patients ever received neuromuscular blockers, the AUROC of the ΔUCR d3-d1 was significantly higher (0.96[95% CI 0.88–0.99] vs. 0.79[95% CI 0.74–0.83], P < 0.001). Conclusion ΔUCR d3-d1 is independently associated with ICUAW and can predict the development of ICUAW in patients with sepsis.