Nutritional Needs of the Burn Patient

Joan LeBoeuf, RD, CNSD

UNM Burn Center

Adult & Pediatric Injury

from tragedy… hope!

Topics of Discussion

• Kcal Needs

• Protein Needs

• Micronutrient Supplementation

• Methods of Nutrient Delivery

• Nutritional Monitoring

UNM Burn Center: from tragedy… hope!

Nutrition… A Crucial Component of Care• Hypermetabolism

– Burns=Highest kcal needs than that of any other injury or disease

– Proportional to the extent of the burn injury

• Hypercatabolism– Burns=Highest protein needs– Erosion of lean body mass

• Adequate nutrition = Successful wound healing

Role of Specific Nutrients: Kilocalories

• Kcals– Supplied by carbohydrate, protein, fat– Needed for optimal tissue repair– Required for synthesis of new cells– Sufficient calories is a priority so that protein

will be spared

Determining Kcal Needs• Calculation of energy needs for the burn

patient remains challenging– % TBSA– Degree of burn– Other trauma involved

Determining Kcal Needs• Predictive formulas

– At least 30 formulas have been proposed• Harris-Benedict Equation: adds activity factor and stress factor• Ireton-Jones Equation: accounts for age, weight, gender,

presence of trauma or burn, and ventilatory status

• Kcalories/kg– Used for less severe burns (<20% TBSA)

Determining Kcal Needs• Indirect Calorimetry (Metabolic Cart)

– Considered to be the “gold standard”– An indirect method of calculating energy expenditure

and respiratory quotient using measurements of inspired and expired gas

– Most closely related to actual energy expenditure– Accounts for variability in energy expenditure from

changes in metabolic state

Determining Kcal Needs

– Indirect Calorimetry, continued• Requirements for a valid measurement:

– Hemodynamically stable patient– A cooperative or sedated patient– Period of rest before measurement– FiO2 < 60%– Absence of chest tubes or other sources of air

leak

Role of Specific Nutrients:Protein

– Needed for cell multiplication, collagen and connective tissue formation and increased enzyme activity

– The nutrient most compromised by burn injury– Extensive nitrogen losses, relative to wound size, are

noted in wound exudate and urine– Protein needs

• 20-25% of kcals• 1.5 to 3.0 g/kg

Role of Specific Nutrients:Micronutrients

• Severely burned patients (>20% TBSA) may require micronutrient supplementation due to metabolic changes and increased losses from wounds.– vitamin A, vitamin C, Zinc, multivitamin

• <20% TBSA, a multivitamin alone may be sufficient to meet needs

Micronutrient Guidelines After Thermal Injury

• Adults and Children (>3y, >40 lbs, >20% TBSA)– 1 multivitamin q day– 500 mg ascorbic acid bid– 10,000 IU vitamin A q day**– 220 mg zinc sulfate q day

• **For tube-fed patients, vitamin A supplementation should be discontinued once the feeding formula is administered at a rate that would meet vitamin A requirements.

Micronutrient Guidelines After Thermal Injury• Children (<3y, <40 lbs, >10% TBSA)

– 1 children’s multivitamin q day– 250 mg ascorbic acid bid– 5000 IU vitamin A q day**– 110 mg zinc sulfate q day

• **For tube-fed patients, vitamin A supplementation should be discontinued once the feeding formula is administered at a rate that would meet vitamin A requirements.

Methods of Nutrient Delivery

• Oral Intake– Burns <25% TBSA in older children and adults

and <15% TBSA in young children and infants– High-calorie, high-protein supplements– Modular calorie and protein enhancement of

oral foodstuffs

Methods of Nutrient Delivery

• Enteral Nutrition (EN)– Most burn patients can tolerate a standard

formula– Formula with high nitrogen content – Transpyloric feedings are better tolerated

– EN is preferred to parenteral nutrition (PN)

Methods of Nutrient Delivery• Parenteral Nutrition (PN, TPN, PPN)

– Associated with complications• Intestinal dysmotility• Hepatic steatosis• Septic morbidity• Catheter-related infection

– ASPEN guidelines: limit use of PN to patients in whom EN is contraindicated or unlikely to meet nutritional needs in 4-5 days

Monitoring Nutritional Status

• Body Weight– Weight should be measured regularly– Goal of weight maintenance is within 90%-110% of pre-

burn weight

• Prealbumin– Short half-life of 2-3 days– Reflects recent nutrition intake– Depressed during acute phase response to burn

Monitoring Nutritional Status• Nitrogen Balance

– Evaluates the adequacy of protein intake

– Needs a 24 hour urine collection and a 24 hr UUN lab test

– Nitrogen balance = nitrogen intake - nitrogen losses

Monitoring Nutritional Status• Nitrogen Balance, continued

– Nitrogen intake = protein intake/6.25

– Nitrogen losses =• Urinary nitrogen losses (24 hr UUN)• Other losses from non-urea urinary nitrogen, fecal,

sweat, etc. (3-5 g)• Burn wound nitrogen losses

– <10% open wound = 0.02 g/kg– 11% to 30% open wound = 0.05 g/kg– >30% open wound = 0.12 g/kg

Monitoring Nutritional Status

• Indirect Calorimetry (Metabolic Cart)– Periodic measurements aid in evaluating

adequacy of caloric intake

– Measures resting energy expenditure (REE)• A factor of 10% to 30% added for calorie needs

during PT and wound care

Conclusions

• An aggressive nutrition approach for the burn patient is indicated to:– address hypermetabolism– enhance nitrogen retention– support wound healing– improve survival

References

• ASPEN Board of Directors and the Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. J Parenter Enteral Nutr. 2002;26(suppl):S88-S90.

• Mayes T, Gottschlich MM. Burns and wound healing. In: Gottschlich M, Fuhrman MP, Hammond KA, Holcombe BJ, Seidner, DL, eds. The Science and Practice of Nutrition Support: A Case-based Core Curriculum. Dubuque, Ia: Kendall/Hunt Publishing Co; 2001:391-420.

• Lefton J. Specialized Nutrition Support for Adult Burn Patients. Support Line. 2003;25(4);19-25.

• Trujillo E, Robinson M, Jacobs J. Critical Illness. In: The ASPEN Nutrition Support Practice Manual. Silver Spring, MD: ASPEN; 1998:18-1-18-14.

Questions…

one child burned, is one child too many!

Joan LeBoeuf, RD, CNSD

UNM Burn CenterAdults & Pediatricsfrom tragedy… hope!