The objective of this investigation was to assess the predictive capacity of the NUTRIC Score and NRS-2002, separately or combined, in forecasting hospital, 28-day and 3-month mortality in patients with respiratory failure admitted to the intensive care unit.

Malnutrition is a significant and widespread issue amongst hospitalized patients. Its prevalence is higher in critically ill patients who are admitted to Intensive Care Units (ICUs). Nutritional screening aims to estimate the probability of both positive and negative outcomes in patient treatment based on nutrition-related factors, and whether nutritional therapy can have a positive effect. The Nutritional Risk Score-2002 (NRS-2002) and Nutritional Risk Score in Critically Ill Patients (NUTRIC) are commonly used for nutritional risk assessment in critically ill patients. However, there is currently insufficient evidence in the literature to determine which scale should take precedence in the nutritional care protocol of critically ill patients with respiratory failure. Furthermore, there are no studies demonstrating the sensitivity of these scales varies based on the type of respiratory failure. This study aims to examine the effectiveness of the NUTRIC Score and NRS-2002, alone or combined, in predicting hospital, 28-day, and 3-month mortality in critically ill patients admitted to the intensive care unit with respiratory failure. Do the NUTRIC Score and NRS-2002 provide sufficient accuracy or is there a distinction when utilised singularly or together in forecasting mortality rates within the hospital, 28-day and 3-month time frames? Additionally, is there a defined threshold for predicting mortality in patients with respiratory failure when using the NUTRIC Score and NRS-2002 either by themselves or in conjunction? Does the efficacy of these prediction tools differ based on the type of respiratory failure?

Inclusion Criteria:

• All patients aged 18 and over
• Admission to the intensive care unit due to respiratory failure (respiratory distress is included in the complaints of patients when admitted to the intensive care unit).

Exclusion Criteria:

• Patients diagnosed with neurodegenerative diseases (Alzheimer's disease and other dementia diseases, Parkinson's disease, Prion disease, Motor neuron diseases, Huntington's Disease, Spinocerebellar ataxia, Spinal muscular atrophy)
• Pregnant patients
• Patients with a length of stay in the ICU of less than 72 hours
• Patients in the terminal period who were diagnosed with malignancy and whose treatment process was terminated due to lack of response to treatment.

All adult patients (aged ≥18) admitted to the Intensive Care Units at the Anesthesiology and Reanimation Clinic of Ankara Atatürk Sanatorium Training and Research Hospital with respiratory distress, who remain in ICU for over 72 hours and meet the study criteria, are included.