Prognostic value of mNUTRIC and nutritional indices, including early change, for ICU mortality in older adults with AECOPD

Abstract Background Malnutrition is common in older adults with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) requiring intensive care unit (ICU) admission and is associated with adverse outcomes. We aimed to evaluate the prognostic value of the Prognostic Nutritional Index (PNI) and its early change (ΔPNI) for predicting ICU mortality and to compare their performance with the modified Nutrition Risk in the Critically Ill (mNUTRIC) score. Methods This single-center retrospective study included 319 older adults (aged ≥ 65 years) with AECOPD admitted to the ICU. PNI was calculated at admission and on day 3, and ΔPNI was defined as the difference between these values. The mNUTRIC score was calculated at admission. The primary outcome was ICU mortality. Discriminative performance was assessed using receiver operating characteristic (ROC) analysis. Independent predictors were identified using multivariable logistic regression, and survival was evaluated using Kaplan–Meier and Cox proportional hazards analyses. Results ICU mortality was 19.8%. The mNUTRIC score demonstrated strong discriminative ability for predicting ICU mortality (AUC 0.852), significantly higher than that of PNI (AUC 0.664; p < 0.0001). In multivariable analysis, the mNUTRIC score remained an independent predictor of ICU mortality (OR 2.50; p < 0.001). Although hypertension was associated with lower mortality in univariate analysis, this association was not confirmed after adjustment for disease severity. In univariate analysis, ΔPNI did not demonstrate significant prognostic value ( p = 0.083), and this was consistent across multivariable logistic regression and Cox proportional hazards analyses. Kaplan–Meier analysis demonstrated significantly poorer survival among patients with high risk (mNUTRIC ≥ 6) (log-rank p < 0.001). In Cox proportional hazards analysis, only mNUTRIC remained independently associated with mortality, whereas neither baseline PNI nor ΔPNI demonstrated an independent association with survival. Conclusion In older adults with AECOPD requiring ICU admission, baseline multidimensional risk assessment using the mNUTRIC score was strongly associated with ICU mortality. Among patients who survived and remained in the ICU until day 3, early changes in PNI did not provide meaningful additional prognostic information beyond the baseline assessment. The lack of prognostic significance of ΔPNI was consistent across ROC, multivariable logistic regression, and Cox survival analyses. The apparent inverse association between hypertension and mortality was largely explained by disease severity. Further prospective studies incorporating direct measures of frailty are needed to validate these findings.