Date post: | 15-Jul-2015 |
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NUTRITION OF THE BURNED PATIENT
Prepared by
Rania Hassan Abdel Hafiez
Effects of Burn on the Body
Extensive inflammatory response Rapid fluid shifts and accumulation. Hypermetabolic state Muscle protein catabolism Decrease cardiac output because of increased
capillary permeability and vasodilation. Heat loss Increased blood glucose levels Burn Shock
Nutrition Therapy Goals
Promote wound healingMaintain lean body massRestore fluid levels
Hypermetabolism
Catecholamines, cortisol, and other glucocorticoids are increased in burn victims due to the stress state of the body causing a hypermetabolic response.
Epinephrine and norepinephrine increase 10-fold in people with burns greater that 30-40%.
Hypermetabolic state lasts 9-12 months after a burn.
Glucose Metabolism
Accelerated gluconeogenesis, glucose oxidation and plasma clearance of glucose
Blood glucose levels increase due to insulin resistance and breakdown of glycogen stores
Glucagon excretion by the liver increases initially after the burn and slows down as wound heals
Muscle Protein Catabolism
Protein catabolism increases in burn patients leading to protein losses of 260 mg protein/kg/hr.
Catabolic hormones counteract the effect of insulin; as a result, blood sugar levels rise, and protein synthesis and lipogenesis are inhibited. Growth hormone is similarly antagonized and less effective.
In this environment, skeletal muscle is the major obligatory fuel. (compare to starvation)
Role of Specific Nutrients:
Kilocalories 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, continuedRequirements for a valid measurement:
Hemodynamically stable patientA cooperative or sedated patientPeriod of rest before measurementFiO2 < 60%Absence of chest tubes or other sources of air leak
Table 1: Nutrition Support for Burn Injuries
Stressors Stress Factors
Activity factor
Confined to bed 1.2
Out of bed 1.3
Injury factor
Minor operation 1.2
Skeletal trauma 1.3
Major surgery 1.4
Sepsis 1.6
Burn factor Stress Factors
20% TBSA 1.2
20–25% TBSA 1.6
25–30%TBSA 1.7
30–35% TBSA 1.8
35–40% TBSA 1.9
40% TBSA 2.0
Table 1 Use of the modified Harris-Benedict equations to estimateresting energy expenditureMen: BEE=(66.47+13.75W+5.0H-6.76A)x(Activity Factor)x(Injury and/or Burn Factor)Women: BEE=(655.1+19.56W+1.85H-4.68A)x(Activity Factor)x(Injury and/or Burn Factor)
W=weight in kg; H=height in cm; A=age in years.
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
Protein Requirements
Amino acids are important for collagen synthesis for wound healing
Maintaining visceral protein is important for organ function especially for immune systems Maintaining intercostal muscles and the
diaphragm is imperative for respiratory efficiency
1.4-2.2 g/kg protein requirement for burns Urinary nitrogen losses increase with severity of
the burn injury Trauma patient may lose 20-25 g of lean body
nitrogen daily
Protein Requirement cont…
Protein requirement estimate: Combine 24-hour urinary nitrogen loss, 2 to 4 g
of nitrogen for fecal loss and 4 to 5 g/d for anabolism.
Convert each gram of nitrogen to 6.25 g of protein.
Patients are likely to miss feedings if in surgery frequently so should be given high protein formulas between surgeries Be aware of uremia- increase free water
Generally 20-25% of calories from protein
Lipid requirements
Lipid stores are critical for long-term fuel after major thermal burns
Fat oxidation is higher in hypermetabolic patients than in normal patients
Fat consumption should not exceed 30% of the diet to avoid diarrhea
Beneficial because Fat is a more concentrated form of energy Vegetable oils contain essential fatty acids and
fat soluble vitamins Help with infection
Carbohydrate Requirements
Carbohydrate metabolism is significantly affected in burn patients Gluconeogenesis from Alanine and other AAs are
elevated Carbohydrates are good sources for protein
sparing especially for nitrogen retention High carbohydrates can contribute to
hyperglycemia in which case a diet can be altered to increase fat in the diet
Recommended 60% of the calories from CHO, not surpassing 400g/d or1600 kcal/d
Vitamin C
Needed for edema prevention Involved in collagen synthesis for wound
healing Aid in immune functioning
Vitamin A
Needed for immune function Epithelialization 5000 IU of Vitamin A per 1000
cal of enteral feeding is recommended
Vitamin D and Calcium
Burns cause an impairment in the metabolism of Vitamin D
Burn patients are more susceptible to fractures so calcium and vitamin D should be administered
Calcium- 1000 mg daily Vitamin D- 200-400 IU daily
Maintain serum 25-hydroxy vitamin D level of 30-60 ng/Ml
Zinc and Copper
Zinc and copper deficiencies have been seen in burn patients most likely from tissue breakdown and urinary excretion.
Supplementation is recommended for patients
Conditionally essential amino acids
Glutamine
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
Conclusions
An aggressive nutrition approach for the burn patient is indicated to: address hypermetabolism enhance nitrogen retention support wound healing improve survival
Adequate nutrition
Successful wound healing
He has too much food to eat
Thank you