The goal of this observational study is to determine the relationship between the nutritional profile of critically ill patients diagnosed with COVID-19 and disease severity, prognosis, and survival, to assess the ability to meet nutritional goals, EN complications, and reasons for discontinuation and postponement of feeding.

The main questions aim to answer are the relationship between the duration of EN initiation and Prognostic Nutritional Index (PNI) score, neutrophil-lymphocyte ratio (NLR), oxygenation status, MV, ICU, and length of hospital stay, overall mortality, and whether nutritional goals were met, EN complications, and reasons for discontinuation and postponement.

Nutritional support is a crucial component of managing critically ill patients. The prognostic impact of early enteral nutrition (EN) in critically ill COVID-19 patients is largely unknown. The study aimed to determine the relationship between the nutritional profile of critically ill patients diagnosed with COVID-19 and disease severity, prognosis, and survival, to assess the ability to meet nutritional goals, EN complications, and reasons for discontinuation and postponement of feeding. Methods: This retrospective study was conducted with adult intensive care unit (ICU) patients diagnosed with COVID-19 and receiving mechanical ventilation (MV) and EN. The demographic, clinical, biochemical, and nutritional data of the patients were obtained from the patient's files and the hospital database. The initiation time, route, method, product type, amount, and duration of feeding were recorded, and the daily intake of energy, protein, pulp, and water were calculated. The nutritional requirements of the patients were defined, and achievement of targets, EN complications, and reasons for discontinuation and postponement were recorded. Patients were divided into two groups: early EN (EEN) if the feeding was initiated within the first 48 hours after MV and late EN (LEN) if 48 hours or later. The research outcomes are to determine the relationship between the duration of EN initiation and Prognostic Nutritional Index (PNI) score, neutrophil-lymphocyte ratio (NLR), oxygenation status, MV, ICU, and length of hospital stay, overall mortality, and whether nutritional goals were met, EN complications, and reasons for discontinuation and postponement.

Inclusion Criteria:

• patients diagnosed with COVID-19
• aged 19 years and older
• on MV
• receiving only enteral tube nutrition

Exclusion Criteria:

• patients with an inflammatory disease
• myocardial infarction, collapse, and circulatory shock within the last 6 months
• hemodynamic instability
• embolism and stroke
• presence of unspecified coma
• renal disease
• cancer with a mortality rate of more than 50% within 6 months
• allogeneic bone marrow transplantation within 5 years
• enteral nutrition was contraindicated
• patients with allergic reactions to the enteral formula
• patients who received antioxidant supplements during feeding
• patients who received tube feeding supplemented with immunonutrition agents
• patients whose data could not be accurately retrieved

This retrospective study was conducted in a 3rd line ICU. The study included adult patients diagnosed with COVID-19, aged 19 years and older, on MV, and receiving enteral tube nutrition.