What are the guidelines for enteral feeding in Intensive Care Unit (ICU) patients?

Guidelines for Enteral Feeding in ICU Patients

Enteral nutrition (EN) should be provided to all ICU patients who are not expected to resume a full oral diet within 3 days, and should be initiated within 24-48 hours of ICU admission in hemodynamically stable patients with functioning gastrointestinal tracts. 1, 2

Indications and Timing

• All ICU patients who are not expected to be on a full oral diet within 3 days should receive nutritional support 1
• Early EN (within 24-48 hours of ICU admission) is recommended for hemodynamically stable critically ill patients with functioning gastrointestinal tracts 1, 2
• Oral diet should be preferred over EN or PN in critically ill patients who are able to eat 1
• EN should be initiated rather than delaying nutritional support or using early parenteral nutrition (PN) 1

Route of Administration

• Use the enteral route in patients with functioning gastrointestinal tracts 1
• There is no significant difference in efficacy between jejunal versus gastric feeding in most critically ill patients 1, 2
• For patients with high gastric residuals or feeding intolerance, consider post-pyloric feeding 3
• Consider intravenous administration of prokinetic agents (metoclopramide or erythromycin) in patients with enteral feeding intolerance 1

Energy and Protein Requirements

• During the acute and initial phase of critical illness, energy supply should be limited to 20-25 kcal/kg body weight/day to avoid overfeeding 1
• During the anabolic recovery phase, energy provision should be increased to 25-30 kcal/kg body weight/day 1
• For severely malnourished patients, provide EN up to 25-30 kcal/kg body weight/day 1
• Low-dose protein (max 0.8 g/kg/day) should be provided during the early phase of critical illness, while a protein target of >1.2 g/kg/day could be considered during the rehabilitation phase 4

Progression and Monitoring

• No general amount can be recommended as EN therapy must be adjusted to the progression/course of the disease and gut tolerance 1
• Start at low rates and increase gradually over days until requirements are met 2, 3
• Monitor for feeding intolerance (high gastric residuals, vomiting, abdominal distension, diarrhea) 2, 4
• Monitor for refeeding syndrome by daily measurement of plasma phosphate; a phosphate drop of 30% should be managed by reduction of enteral feeding rate and high-dose thiamine 4

Supplemental Parenteral Nutrition

• Avoid additional PN in patients who tolerate EN and can be fed approximately to the target values 1
• Consider supplemental PN in patients who cannot reach their target nutrient intake with EN alone, particularly after 3-7 days of inadequate EN 1, 5
• In case of contraindications to oral and EN, PN should be implemented within three to seven days 1
• Early and progressive PN can be provided instead of no nutrition in case of contraindications for EN in severely malnourished patients 1

Formula Selection

• Whole protein formulas are appropriate for most patients as no clinical advantage has been shown for peptide-based formulas 1, 2
• There is no general indication for immune-modulating formulas in patients with severe illness or sepsis and an APACHE II Score >15 1
• Glutamine supplementation should be considered in patients suffering from burns or trauma 1

Common Pitfalls to Avoid

• Delaying nutritional support beyond 48 hours in eligible patients 2, 6
• Overfeeding during the acute phase (>25 kcal/kg/day) may worsen outcomes 1, 2
• Abandoning EN due to feeding intolerance rather than implementing strategies to improve tolerance 2, 4
• Failing to monitor for refeeding syndrome, especially in malnourished patients 2, 4
• Providing excessive energy during the early phase of critical illness 1

Benefits of Early Enteral Nutrition

• Early EN is associated with reduced infectious complications compared to early PN (RR 0.50, CI 0.37,0.67) 1, 2
• EN leads to shorter ICU stays (RR -0.73, CI -1.30,0.16) and hospital stays (RR -1.23, CI -2.02,0.45) compared to PN 1, 2
• Very early EN (within 6 hours of ICU admission) has been shown to be feasible and safe in appropriate patients 7
• Early EN may help maintain gut integrity and prevent intestinal permeability 1, 5