Serum Bilirubin Levels and Mortality Risk: Evaluation of Prognostic Use in a High-Risk Intensive Care Population

Öz

Background: Serum bilirubin serves as a crucial biomarker for liver function and may reflect the severity of systemic inflammatory responses in critically ill patients. This study aims to assess the prognostic significance of serum bilirubin levels in predicting mortality among high-risk patients admitted to the emergency intensive care unit (EICU). Materials and Methods: In this retrospective cohort study, an evaluation was conducted on high-risk patients admitted to the EICU between January 2020 and December 2022. The patients were grouped based on 28-day mortality outcomes. Serum bilirubin levels, along with other clinical and laboratory parameters, were recorded and examined using multivariable logistic regression and receiver operating characteristic (ROC) curve analysis. Results: The most common comorbidities were Chronic Obstructive Pulmonary Disease (COPD) (80.2%) and sepsis (67.2%). Multivariate analyses identified hypertension (OR=4.165, p=0.004), sepsis (OR=8.459, p<0.001), chronic kidney disease (OR=3.910, p=0.009), and total bilirubin levels (OR=1.605, p=0.036) as independent risk factors for mortality. ROC curve analysis demonstrated that a total biliru-bin cutoff value of 1.75 mg/dL provided 86.4% sensitivity and 60.0% specificity in predicting mortality. AUC was calculated to be 0.761, indicating that bilirubin levels possess significant power in distinguis-hing between surviving and died patients. Conclusions: Elevated serum bilirubin levels have been identified as an independent predictor of morta-lity in critically ill patients. This finding suggests that bilirubin levels can serve as a reliable indicator in prognostic evaluations within the EICU setting, thereby contributing to more effective management of the patients' treatment process.

Anahtar Kelimeler

• bilirubin
• mortality
• intensive care unit
• prognostic marker
• sepsis

Serum Bilirubin Düzeyleri ve Mortalite Riski: Yüksek Riskli Yoğun Bakım Popülasyonunda Prognostik Kullanımının Değerlendirilmesi

Öz

Amaç: Serum bilirubin, karaciğer fonksiyonunun önemli bir biyobelirteci olup, kritik hastalarda sistemik inflamatuar yanıtın şiddetini yansıtabilir. Bu çalışma, yoğun bakım ünitesine (YBÜ) kabul edilen yüksek riskli hastalarda serum bilirubin düzeylerinin mortaliteyi öngörmedeki prognostik önemini değerlendir-meyi amaçlamaktadır. Materyal ve Metod: Bu retrospektif kohort çalışmasında, Ocak 2020 ile Aralık 2022 tarihleri arasında yoğun bakım ünitesine (YBÜ) kabul edilen yüksek riskli hastalar değerlendirilmiştir. Hastalar, 28 günlük mortalite sonuçlarına göre gruplandırılmıştır. Serum bilirubin düzeyleri ile diğer klinik ve laboratuvar parametreleri kaydedilmiş ve çok değişkenli lojistik regresyon ile alıcı işletim karakteristiği (ROC) eğrisi analizi kullanılarak incelenmiştir. Bulgular: En sık görülen komorbiditeler Kronik Obstrüktif Akciğer Hastalığı (KOAH) (%80,2) ve sepsis (%67,2) olarak tespit edilmiştir. Çok değişkenli analizlerde hipertansiyon (OR=4,165, p=0,004), sepsis (OR=8,459, p<0.001), kronik böbrek hastalığı (OR=3,910, p=0,009) ve toplam bilirubin düzeyleri (OR=1,605, p=0,036) mortalite için bağımsız risk faktörleri olarak belirlenmiştir. ROC eğrisi analizi, 1,75 mg/dL’lik toplam bilirubin kesim değerinin mortaliteyi öngörmede %86,4 duyarlılık ve %60,0 özgüllük sağladığını göstermiştir. Eğri altında kalan alan (AUC) 0,761 olarak hesaplanmış ve bilirubin düzeylerinin sağ kalan ve ölen hastalar arasında anlamlı bir ayrım gücüne sahip olduğu gösterilmiştir. Sonuç: Artmış serum bilirubin düzeyleri, kritik hastalarda mortalite için bağımsız bir öngördürücü olarak tanımlanmıştır. Bu bulgu, bilirubin düzeylerinin yoğun bakım ortamında prognostik değerlendirmelerde güvenilir bir gösterge olarak kullanılabileceğini ve hastaların tedavi sürecinin daha etkin yönetilmesine katkı sağlayabileceğini ortaya koymaktadır.

Anahtar Kelimeler

• bilirubin
• mortalite
• yoğun bakım ünitesi
• prognostik belirteç
• sepsis

Kaynakça

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