Gut health, feeding & nutrition
Gastrointestinal tract: gut health in burn patients
Maintaining gut integrity is an important part of general care for burn patients.
The gut is a potential reservoir of potentially pathogenic microorganisms. Risks include the development of mucosal atrophy and increased intestinal permeability, which provides a route for bacterial translocation.
Gastric stasis occasionally occurs and may be related to opiate medication. Gastric ulceration is reported, especially in patients with extensive burns. Intestinal stasis is unusual and may be an early sign of sepsis.
Enteral feeding for burn patients
The most important way to prevent gastrointestinal complications is to establish early enteral feeding. This attenuates villous atrophy, protects the gastric mucosa and preserves gut function.
It is usually safe to commence feeding within a few hours of injury.
Practical tips for enteral feeding
Patients with burns of more than 20% TBSA may require supplemental tube feeding.
Ideally: place a post-pyloric tube either via the nasal route or via a gastrostomy.
Alternatively: place a double lumen nasogastric tube (to monitor gastric retention).
As the stomach can be emptied mechanically, patients do not need to fast pre-operatively.
Nutrition in burn patients
Burn patients require additional nutritional support. Following a burn injury, there are significant changes in metabolism:
- Energy loss in the form of evaporative heat loss
- Catabolism induced by the hypermetabolic response
- Loss of proteins and minerals via wound exudate
- Weight loss
Malnutrition weakens the immune system and impairs wound healing. Therefore, it is important to provide nutritional support during the acute phase of recovery.
Nutrition therapy describes how to provide nutrients to support nutrient intake.
Patients who are able to eat and drink but do not consume enough protein or calories on their own can take additional nutrients orally, such as fortified food or oral nutritional supplements.
If resources permit, nutrients can also be provided via enteral tube-feeding, especially for patients with significant burn injury (>20% TBSA).
Gastric tubes are useful in burn patients
An additional advantage of a gastric tube is it can be used to empty the patient’s stomach manually. This keeps pre-operative fasting to a minimum.
Commence feeding within 12 hours of injury, and gradually advance it over a day or two until the goal intake of caloric requirements is reached. When nutritional therapy is started, it is mandatory to monitor nutrient intake and, if possible, consult a dietician, to minimize risks, such as overfeeding or gastrointestinal or mechanical problems.
Gastric stasis and retention occur occasionally and may cause nausea, therefore feeding might have to be reduced temporarily. Domperidon (Motilium) may be useful for reducing nausea. If resources permit, introducing a post-pyloric tube usually solves the problem.
Avoid parenteral nutrition (provision of sterile intravenous fluids containing the full spectrum of nutritional needs) unless all other means fail.
In low and middle-income countries (LMICs), specialized nutritional support can be challenging due to limited resources. If resources do not permit enteral tube feeding, meet the patient’s protein and caloric needs orally as soon as possible. A multimodal approach to nutrition can include appointing a (nutritional) nurse or volunteers to help feed the incapacitated patient, educating caregivers about the importance of adequate nutrient intake and encouraging them to stay with the patient to assist with nutrition.
Some patients with extensive burn injury may develop dysphagia due to oral thrush. The risk is increased in patients receiving antibiotics. Oral thrush can be treated with nystatin.
Caloric requirements
Patients with burns covering more than 20% TBSA should receive a high protein and calorie diet to meet their energy needs.
International Society for Burns Injuries (ISBI) guidelines
Adults should receive 1.5-2 grams of protein per kilogram of body weight per day. Children should receive 3 grams per kilogram of body weight per day.
Examples of sources of dietary protein are meat, poultry, eggs and dairy products. Keep periods of fasting (e.g. pre-operatively) to a minimum.
You can use the Harris Benedict Equation + 1% extra per % TBSA burned as a guide to estimate caloric needs. Free calculators are available online for practical use of the Harris Benedict Formula, such as:
Harris Benedict Formula (modified) to calculate resting energy expenditure
| Adjusted formula | |
|---|---|
| Men | BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5 |
| Women | BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161 |
Harris Benedict Equation example
A 40-year-old adult male, 80 Kg, height 180 cm with 30% TBSA burned.
BMR = (10 x 80)
+ (6.25x 180)
– (5 x 40) + 5
= 800
+ 1,125 – 200 + 5
= 1730
Actual requirement = 1730 + 30% = 1730 + 519 = 2249 Kcal per day
Nutritional supplements for burn patients
Compose the burn patient’s diet with care.
Patients require daily supplementation of vitamins (B, C and D). Trace elements are rapidly depleted in burn patients, including copper, iron, selenium and zinc. These trace elements are important for wound healing, so supplementation may be useful. There is also evidence to support supplementing glutamine.
It is safe to administer twice the recommended dosage of proprietary supplements.
Support for good nutrition
Hyperglycemia is a risk factor in intensive care patients, so the aim is to maintain normoglycemia during the hypermetabolic phase. Insulin inhibits gluconeogenesis, diminishes proteolysis and stimulates fatty acid synthesis. Insulin therapy requires intensive monitoring and risks hypoglycemia. Anabolic steroids may increase lean body mass and improve wound healing, though there are risks associated with the use of anabolic steroids in children.