2025 Southeastern Residency Conference

Title: Tolerability of Enteral Nutrition in ICU Patients Receiving Vasopressors 

Authors: Micah A. McKinnie, Megan Langley, Jana Mills 

Background/Purpose: Critically ill patients are often faced with malnutrition and are thought to require more high-protein and calorie-dense diets. Due to favorable mortality outcomes, implementation of enteral nutrition within 24-48 hours of ICU admission is recommended for critically ill patients who cannot receive an oral diet. However, studies have shown that patients in the ICU are unlikely to receive the amount of nutrition they were initially prescribed. One contributing factor is the practice of delaying or pausing enteral nutrition for patients on high or increasing doses of vasopressors due to the risk of serious complications, such as ischemic or necrotic bowel. The lack of strong evidence has led to an ongoing debate about whether patients requiring ongoing vasopressors should receive enteral nutrition. As more evidence regarding the safety of initiating early enteral nutrition in patients on vasopressors emerges, there is potential for a professional consensus to be made. This may allow for a greater portion of the nutritional needs to be met in these critically ill patients. This retrospective single-center chart-review study seeks to explore further if patients receiving vasopressors exhibit a decreased tolerance to enteral feedings, resulting in an inability to achieve adequate nutrition.  
 
Methods: A retrospective review was conducted to identify patients admitted to the ICU from January 2024 through August 2024. Patients included in the study were at least 18 years old, on mechanical ventilation for at least 24 hours, admitted to the ICU for greater than 72 hours, and had a consult for enteral nutrition during their ICU stay. Patients were excluded if they were on vasopressors for less than 24 hours, were placed on end-of-life care, underwent GI surgery, or had other contraindications to enteral nutrition. Patients were subdivided into either the treatment group (vasopressors for at least 24 hours) or the control group (no vasopressors) to compare the primary outcome of the average percent of daily caloric goals met. Secondary outcomes included the average daily rate of vasopressors, the median time patients received enteral nutrition, the median time of interruption, and incidences of suspected intolerance to enteral feeding. Data was collected for the total course of the prescribed enteral feeding while in the ICU, or until vasopressors were discontinued (if applicable).  
 
Results: The average percent of caloric goals met while in the ICU was 46.7% for the vasopressor group and 56.9% for the control group. The vasopressor group was found to have both a lower median time receiving enteral nutrition (3 days vs 5 days, p-value 0.002) and a lower median time of enteral nutrition interruption (26 hours vs 45 hours, p-value 0.003). Incidences of suspected intolerance occurred in 28.2% of the vasopressor group and 7.7% of the control group. The median vasopressor rate during the study period was 0.072mcg/kg/min norepinephrine equivalents, and the median vasopressor rate at the time of suspected intolerance was 0.158mcg/kg/min norepinephrine equivalents. 
 
Conclusions: Mechanically ventilated patients requiring vasopressors in the ICU tended to receive a lower percentage of caloric goals through enteral nutrition than those not requiring vasopressors. Regardless of vasopressor use, this patient population was generally underfed while in the ICU. However, the clinical significance of these findings needs further exploration, and prospective research may be beneficial.