Serum Bicarbonate and Enteral Feeding Intolerance in Adult ICU: A Prospective Clinical Trial

Inclusion criteria

• Adult patients aged 18 and older.
• Patients started on enteral nutrition (EN) within the first 48 hours of their intensive care unit admission.
• Patients predicted to remain in the intensive care unit for at least 72 hours.
• Patients (or their legal representatives) who have provided consent to participate in the study.

Exclusion criteria

• Patients under the age of 18.Individuals who are currently pregnant or breastfeeding.
• Patients with gastrointestinal (GI) perforation, active GI bleeding, or mechanical bowel obstruction.
• Patients who have undergone major abdominal surgery (e.g., esophagectomy, gastrectomy) within the last month.
• Patients receiving total parenteral nutrition (TPN) or those who are only fed orally.
• Patients requiring specialized enteral formulas (e.g., diabetic, renal, immunomodulatory, elemental, or semi-elemental) due to clinical necessity.
• Patients with a known diagnosis of diabetes or those with HbA1c >6.5 requiring a diabetic enteral formula.
• Patients with terminal-stage malignancy or those requiring specific enteral nutrition protocols.
• Patients with advanced (Child-Pugh C) liver failure.
• Patients with chronic kidney failure requiring dialysis.
• Patients with diabetic ketoacidosis, severe metabolic asidozis, or those requiring initial bicarbonate replacement.
• Patients who are brain dead or in the palliative care stage.