What are the nutritional requirements for burn patients?

Nutritional Requirements for Burn Patients

Start enteral nutrition within 12-24 hours of burn injury, providing 1.5-2 g/kg/day of protein for adults (up to 3 g/kg/day for children), with energy requirements calculated using the Toronto formula for adults or Schofield formula for children, and supplement with vitamins B, C, D, E and trace elements copper, zinc, and selenium. 1

Timing and Route of Nutrition

• Initiate nutritional support within 12 hours after burn injury, preferably via oral or enteral routes rather than parenteral. 1
• Early enteral nutrition (within 24 hours) decreases muscle protein catabolism, improves wound healing, decreases ICU and hospital length of stay, diminishes rates of sepsis, decreases infectious load, and reduces the risk of Curling ulcer formation. 1
• Patients fed within 24 hours had shorter ICU length of stay (adjusted hazard ratio 0.57) and reduced wound infection risk (adjusted odds ratio 0.28) compared to delayed feeding. 2
• The oral or enteral route is always preferred to parenteral nutrition to attenuate the hypermetabolic response and preserve intestinal mucosal barrier function. 1

Energy Requirements

• Use serial indirect calorimetry as the gold standard for determining energy needs; when unavailable, use the Toronto formula for adults or Schofield formula for children. 1
• Resting metabolic rate reaches up to 180% of basal rate in the first week following thermal injury and remains elevated to 130%-150% at full healing, 120%-140% at 6 months, and 110%-120% at 12 months. 1
• This profound hypermetabolic response can persist for up to 2 years postinjury in severe cases. 1

Protein Requirements

• Provide 1.5-2 g/kg/day of protein for adults and up to 3 g/kg/day for children. 1
• Burn patients oxidize amino acids at a rate 50% higher than baseline, making high protein supplementation critical. 1
• Protein rates exceeding 2 g/kg/day in adults have not demonstrated additional benefits. 1

Carbohydrate and Glucose Management

• Avoid excess carbohydrate provision as it propagates hyperglycemia with subsequent exacerbation of inflammation, muscle breakdown, and excess fat production. 1
• Glucose oxidation increases from 4-5 to 7 g/kg/day after thermal injury, with nearly all burn patients exhibiting some degree of insulin resistance. 1
• Administering insulin can improve lean body mass, bone mineral density, donor site healing, and decrease overall length of stay, though careful monitoring is required to avoid hypoglycemia. 1

Fat Composition

• Low-fat diets are thought to help avoid exaggerated immunosuppression. 1
• While some experts speculate that increasing the proportion of ω-3 fatty acids enhances immunity, reduces hyperglycemic episodes, and decreases ICU stays, a recent systematic review and meta-analysis was unable to appreciate benefit of ω-3 support in burn patients. 1

Glutamine Supplementation

• The role of glutamine supplementation is now being reexamined, with recent high-quality evidence showing no benefit. 1
• A recent international, multicenter RCT found no reduction in time to discharge, no differences in 6-month mortality, hospital length of stay, or incidence of bacteremia when compared with placebo. 1
• However, administration is unlikely to cause harm with similar adverse event rates between groups. 1
• The 2018 ESPEN guidelines recommend additional enteral doses of glutamine in patients with burns involving >20% body surface area, though this recommendation is based on studies with significant design flaws. 1

Micronutrient Supplementation

• Provide early micronutrient supplementation including vitamins B, C, D, and E, along with trace elements copper, zinc, and selenium. 1
• These supplements reflect the high micronutrient requirements of burn patients, which cannot be covered by oral or enteral nutrition alone. 1
• Supplementation of calcium, magnesium, and vitamins A, B-1, B-6, B-12, C, D, and E has been shown to lower the risk for wound infection (30% vs 77.4%), sepsis (13.3% vs 41.9%), and prolonged hospital stay. 1
• Vitamins A, C, and D along with iron, copper, selenium, and zinc improve wound healing and immune function. 1
• Monitor key nutrients closely in major burn patients, particularly those on continuous renal replacement therapy. 1

Common Pitfalls

• Underfeeding is harmful to recovery, especially when it persists for more than 2 weeks. 3
• Severe burn patients often receive only about 70% of prescribed energy and protein, with patients receiving <30% of energy via enteral nutrition having significantly higher 28-day and in-hospital mortality. 3
• Post-pyloric feeding is more efficient than gastric feeding for enteral nutrition tolerance and energy supplementation when enteral feeding intolerance develops. 3
• Majority of severe burn patients need parenteral nutrition supplementation for energy requirements and enteral feeding intolerance. 3