The Prognostic Nutritional Index as a predictor of in-hospital mortality in geriatric intensive care patients

Abstract

Aims: This study aimed to evaluate the prognostic value of the Prognostic Nutritional Index (PNI) in predicting in-hospital mortality among geriatric patients admitted to the intensive care unit (ICU). Methods: This single-center, retrospective cohort study included 337 patients aged ≥65 years who were admitted to the ICU between June and December 2024. Patients were divided into two groups based on clinical outcomes: survivors and non-survivors. Demographic data, comorbidities, clinical outcomes, and laboratory values including serum albumin and lymphocyte count were analyzed. PNI was calculated as: PNI=[10×serum albumin (g/dl)]+[0.005×total lymphocyte count (/mm3)]. Statistical analyses included univariate and multivariate logistic regression and receiver operating characteristic (ROC) curve analysis. Results: Among 337 patients, 195 (57.9%) died during ICU stay. PNI scores were significantly lower in non-survivors (p=0.001), with an optimal cut-off value of ≤29.8 (sensitivity: 43.1%, specificity: 90.1%). The area under the ROC curve for PNI was 0.661, indicating limited discriminatory power. Multivariate analysis identified prolonged ICU stay (OR=1.052), elevated WBC (OR=1.044), hypoalbuminemia (OR=2.283), increased urea (OR=1.006), lactate (OR=1.144), sepsis (OR=2.362), and stroke (OR=2.746) as independent predictors of mortality (p<0.05). Conclusion: Low PNI scores are associated with in-hospital mortality in geriatric ICU patients. However, given its low sensitivity and moderate AUC, PNI should not be used as a standalone predictor. Instead, as a simple and cost-effective biomarker, it may serve as a supportive tool alongside other clinical parameters for early risk stratification in geriatric intensive care settings.

Keywords

• Prognostic Nutritional Index
• malnutrition
• geriatric patients
• intensive care unit
• mortality
• albumin
• lymphocyte count

Geriatrik yoğun bakım hastalarında hastane içi mortaliteyi öngörmede Prognostik Beslenme İndeksi

Abstract

Amaç: Bu çalışmanın amacı, yoğun bakım ünitesine (YBÜ) kabul edilen geriatrik hastalarda Prognostik Beslenme İndeksi’nin (PNI) hastane içi mortaliteyi öngörmedeki prognostik değerini değerlendirmektir. Yöntem: Bu tek merkezli, retrospektif kohort çalışmaya, Haziran–Aralık 2024 tarihleri arasında YBÜ’ye kabul edilen ve yaşı ≥65 olan 337 hasta dahil edilmiştir. Hastalar, klinik sonuçlarına göre sağ kalanlar ve eksitus olanlar olmak üzere iki gruba ayrılmıştır. Demografik veriler, eşlik eden hastalıklar, klinik sonuçlar ve serum albümin ile lenfosit sayısı dahil olmak üzere laboratuvar parametreleri analiz edilmiştir. PNI şu formüle göre hesaplanmıştır: PNI = (10 × serum albümin [g/dL]) + (0.005 × toplam lenfosit sayısı [/mm³]) İstatistiksel analizler arasında tek değişkenli ve çok değişkenli lojistik regresyon ile ROC eğrisi analizi yer almıştır. Bulgular: 337 hastanın 195’i (%57,9) YBÜ’deki izlem sürecinde hayatını kaybetmiştir. Eksitus grubunda PNI skorları anlamlı şekilde daha düşüktü (p = 0.001). PNI için optimal kesim değeri ≤29.8 olarak belirlenmiştir (duyarlılık: %43,1, özgüllük: %90,1). ROC eğrisi altında kalan alan (AUC) 0.661 olarak bulunmuş olup bu değer, sınırlı ayırt edici gücü göstermektedir. Çok değişkenli analizde, uzamış YBÜ yatışı (OR = 1.052), yüksek lökosit (OR = 1.044), hipoalbüminemi (OR = 2.283), artmış üre (OR = 1.006), laktat (OR = 1.144), sepsis (OR = 2.362) ve inme (OR = 2.746) mortalitenin bağımsız belirleyicileri olarak saptanmıştır (p < 0.05). Sonuç: Düşük PNI skorları, geriatrik YBÜ hastalarında hastane içi mortalite ile ilişkilidir. Ancak, düşük duyarlılığı ve orta düzeyde AUC değeri göz önüne alındığında, PNI tek başına bir öngörü aracı olarak kullanılmamalıdır. Bununla birlikte, basit ve düşük maliyetli bir biyobelirteç olarak PNI, geriatrik yoğun bakım hastalarında erken risk sınıflandırması ve klinik karar verme süreçlerinde diğer klinik parametrelerle birlikte destekleyici bir araç olarak kullanılabilir.

Keywords

• Prognostik Beslenme İndeksi
• malnütrisyon
• geriatrik hasta
• yoğun bakım ünitesi
• mortalite
• albümin
• lenfosit sayısı

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