Can patients on vasopressors (vasoactive medications) have an oral diet order?

Enteral Nutrition in Patients on Vasopressors

Patients on vasopressors can safely receive oral diet or enteral nutrition when they are adequately resuscitated (normalized lactate) and on low to moderate doses of vasopressors (norepinephrine <0.3 μg/kg/min), but should avoid full nutritional support when on high-dose vasopressors (≥0.3 μg/kg/min). 1

Vasopressor Dose Considerations

The safety of enteral nutrition in patients on vasopressors depends primarily on:

1. Vasopressor dose threshold:

   • Safe: Norepinephrine <0.3 μg/kg/min in adequately resuscitated patients 1
   • Caution needed: Norepinephrine ≥0.3 μg/kg/min 1

2. Resuscitation status:

   • Enteral nutrition should be initiated only after adequate resuscitation (normalized lactate) 1
   • Unresuscitated hemodynamic instability is a contraindication to enteral feeding 1

Clinical Decision Algorithm

1. Assess hemodynamic stability:

   • Is the patient adequately resuscitated? (normalized lactate)
   • Is the vasopressor dose stable or decreasing?
   • Is the dose <0.3 μg/kg/min of norepinephrine (or equivalent)?

2. If YES to all above:

   • Proceed with enteral nutrition
   • Start with trophic feeding (low-dose nutrition) and advance as tolerated
   • Monitor for signs of feeding intolerance

3. If NO to any of the above:

   • Delay full enteral nutrition
   • Consider low-dose trophic feeding (6 kcal/kg/day with 0.2-0.4 g/kg/day protein) 1
   • Reassess frequently as patient stabilizes

Monitoring During Enteral Nutrition with Vasopressors

• Abdominal examination for distension or tenderness
• Gastric residual volumes (if applicable)
• Signs of bowel ischemia:
  • Unexplained abdominal distension
  • Gastrointestinal bleeding
  • Worsening metabolic acidosis
  • Increasing vasopressor requirements

Important Considerations

• Risk of non-occlusive mesenteric ischemia (NOMI): Occurs in <1% of critically ill patients, but mortality is high when it occurs 1
• Avoid early high-dose feeding: The Nutrirea-3 trial showed increased ICU length of stay by one day in patients on vasopressors who received full nutrition compared to low-dose nutrition 1
• Hemodynamic instability: In patients with uncontrolled shock, enteral nutrition should be withheld and gradually recommenced upon stabilization 1

Special Situations

• Post-operative patients: Enteral nutrition can be safely initiated in most post-operative patients, including those with an open abdomen 1
• Prone positioning or ECMO: These are not contraindications to enteral nutrition 1
• Acute mesenteric ischemia: Patients with suspected acute mesenteric ischemia should not receive enteral nutrition 1

Pitfalls to Avoid

• Overlooking signs of feeding intolerance: Monitor for abdominal distension, high gastric residuals, or worsening metabolic parameters
• Aggressive advancement of feeding rates: Gradually increase feeding rates as hemodynamic status improves
• Ignoring changes in vasopressor requirements: If vasopressor needs increase, reassess the appropriateness of continued enteral feeding

By following these guidelines, clinicians can safely provide enteral nutrition to most patients requiring vasopressor support while minimizing the risk of intestinal ischemia and other complications.