Enteral Nutrition Intolerance (EFI)

This study investigates whether the dose of vasopressor medications (drugs that maintain blood pressure in shock) affects gastric emptying during tube feeding in the intensive care unit (ICU). Critically ill patients receiving vasopressors often develop impaired gastric motility, which reduces the effectiveness of enteral nutrition and increases the risk of aspiration. Gastric emptying will be objectively measured using bedside point-of-care ultrasound - a safe, painless imaging method - at three time points: before feeding (T0), at 1 hour (T1), and at 2 hours (T2) after restarting enteral nutrition following a 2-hour fasting period. Patients will be stratified into three groups based on norepinephrine equivalent dose (NEQ): Group 1 (no vasopressor, NEQ=0), Group 2 (low-to-moderate dose, NEQ \>0 to \<0.3 μg/kg/min), and Group 3 (high dose, NEQ ≥0.3 μg/kg/min). The primary outcome is gastric emptying rate (GER = (T0 volume - T2 volume) / 2 hours). Gastroparesis is defined as GER ≤0 mL/hour. Secondary outcomes include antrum cross-sectional area, agreement between ultrasound and aspirated gastric residual volume (Bland-Altman analysis), and enteral nutrition intolerance incidence. A subgroup analysis by shock type (septic, cardiogenic, hypovolemic, obstructive) will also be performed. The study aims to identify the vasopressor dose threshold at which gastric emptying is significantly impaired, and to support the use of bedside gastric ultrasound as an objective, non-invasive monitoring tool for enteral nutrition management in the ICU.

This prospective, observational study evaluates whether serum bicarbonate HCO3 levels can predict enteral nutrition intolerance (EFI) in adult ICU patients.Objective: To determine if lower HCO3 levels correlate with the development of EFI.Design: A 12-month study involving 70 participants at Sultangazi Haseki Training and Research Hospital.Methodology: Patients starting enteral nutrition within 48 hours of admission will be monitored for 72 hours. Daily HCo3 pH, and lactate levels will be recorded from routine morning blood draws.Hypothesis: Lower bicarbonate levels are an independent predictor of EFI development in critically ill patients.