burns & nutrition

8/3/2019 Burns & Nutrition

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BURN P ATIENTS

DR. S.M.T AHIR.

A SSOCIATE PROFESSOR

DEPARTMENT OF PLASTIC & BURN

SURGERY.LUMHS. J AMSHORO.



NUTRITION SUPPORT IN

BURN P ATIENT Although our topic of discussion

is nutrition support in burn

patients, one can never everrealizes its significance without

having an idea of metabolic

derangements in burn patients.



The body can be divided into twocompartments. Lean body mass(LBM) makes up about 75% of body

weight and contains three quarterswater and all the protein and mineralin the body.

The fat mass makes up about 25% of

body weight and contains all the fat(water free).



The LBM is maintained by an action of

the anabolic hormones, growth hormone,

testosterone and insulin.

Adequate protein intake is of course

required for sufficient substrate needed by

the protein synthesis pathway.



As noted, lean mass contains all the body muscle,organ structure, skin collagen and circulatingproteins. Over half of the body·s protein is present inmuscle. About 50-100 grams of muscle continually brokendown and re-synthesized each day. In health, the rate of

loss and synthesis is equal, with a net zero nitrogen (N)balance. With increased anabolism muscle gain, isincreased with a nitrogen gain. With burn injury, there isa net loss.

The fat mass component is a pure energy store withno significant metabolic role except to provide fatty

acids for fuel when needed and for storing fatproduced by excess calorie intake.



METABOLIC RESPONSE TO STARVATION.

Decrease in metabolic rate

Protein sparing with minimal use

for energy

Increased use of fat (ketones) for

Energy

Generation of glucose via lactate

Recycling.



THE ´STRESS RESPONSEµ

CAUSED BY A BURN. The effects of a burn or trauma differ from those of simple

starvation due to activation of the ´stress responseµ, a neural andendocrine response, which accelerates the loss of lean tissue andinhibits adaptation. A significant alteration in normal metabolicactivity occurs.

The host response to injury (afferent arc) is an amplification of

the ´fright-flight responseµ. Major burn, activates a veryabnormal hormonal response, in large part due to neuro-activation of the pituitary adrenal axis, led by a marked increasein catecholamines and cortisol, (efferent arc). These changesproduce a profound hypermetabolic-catabolic state. Humangrowth hormone and testosterone levels decrease, leading to adecrease in anabolic drive and a further increase in catabolism.

The degree of hypermetabolism and catabolism from any insult isdependent on the degree of injury.



Major burn always create an extreme state of

physiologic stress.

No other single insult results in such an

accelerated rate of tissue catabolism, loss of leanbody mass, and depletion of energy and protein

reserves.



Multiple factors contribute to thepostburn hypermetabolic response.

Increased levels of catecholamines

Glucagon and Cortisol Increased body temperature

Extent and depth of burn wound

Infectious complications :

All have been reported to to increasemetabolic rate



A SSESSMENT OF NUTRITIONAL NEEDS

Energy (caloric) needs

Protein needs

Nutrient mix

Water needs

Micronutrient needs



GOAL OF NUTRITION SUPPORT

The goal of nutrition support in patientswith burns is to replace nutrient lossesand provide adequate nutrients to

promote wound healing and energy andnitrogen balance.

Assessing metabolic and nutritionneeds,and monitoring the effectiveness of nutrition intervention are essentialcomponents of nutrition support of theburn patient



A DULT FORMULA Curreri formula : most widely known

formula, this is the best in estimatingpeak energy expenditure, but may lead to

overfeeding during non-peak times. ( 25 kcal x pre-burn weight(kg) + (40 kcal

x TBS)

TBS= Total body surface area burned. For

burns over 50% TBS a constant of 50%should be used to prevent overestimation



PEDIATRIC FORMULA Pediatric formulas: Formulations of age

dependant formulas that reflect the amount of

calories needed to maintain weight for burns

with more than 25% of the body surface area.



FORMULAS THAT REFLECT C ALORIES

Age Formula

0-1 year 2,100 kcal/m2 BSA/day +

1,000 kcal/m2 BSA burned/day

2-12 years 1,800 kcal/m2 BSA /day +

1,300 kcal/m2 BSA burned/day

13-18 years 1,500 kcal/m2 BSA day +

1,500 kcal/m2 BSA burned /day

BSA- body surface area burned ,m2-meters squared



PROTEIN As with adults protein needs are based on

LBW . When fluid retention is suspectedpre burn weight is used.

Children <1 year= 3 to 4 gm protein/ kgLBW.

Children and adolescents 1.5 to 2.5 gmprotein/kg LBW

Children and adults with wound size of more than 10% total body surface(TBSA),protein should comprise 20% of the totalcaloric requirements



PROTEIN. For children younger than 1 year of age,

conservative recommendation 3 g to 4 g protein

per kilogram can be given

Some authors still recommend a high proteinintake of 20% with close monitoring for tolerance



F ATControversy exists over how much fat

should be given to burn patients.

Enteral formulations for adults usually

have 25% to 30% of total caloriesPediatrics enteral formulations 50% of

total calories

For enterally fed patients 10% to 15% of

non-protein calories should be fromlipid,with 5% from linoleic acid



C ARBOHYDRATEFor adults glucose should be provided up

to a rate of 5 mg/kg/min enterally ,for

approximately 60% of total calories.

For enterally fed children carbohydratesshould provide between 50% and 55% of

total calories, unless signs on intolerance

are observed



W ATER NEEDS. Water is a very essential nutrient as water is

required to transport nutrients and remove byproducts from cell metabolism in addition to itseffect on maintaining cardiovascular stability.

Optimum macronutrient intake in the absence of inadequate fluid will lead to poor nutrientprocessing and can accentuate the degree of dehydration.

Water requirements per nutrient intake = 1cc of water per calorie



THE PROBLEM POST BURN WATER LOSS.

Loss of skin integrity produces a massive loss of water fromthe wound surface (till wound closure)

Hypermetabolism increases urinary output (water losses)2 to 3 fold above normal.

Gastrointestinal losses can be severe with presence of

diarrhea Water loss increases with wound exposure

Increases with increase in temperature (10% per degree)

Averages 2-4 liters/day in adult with major burn

Water Loss can be estimated: ml/hr = (25 + %TBS Burn xM2 body weigh

To keep up with Losses Decrease Loss by:

Wound Occlusion Dressing (50%)



MICRONUTRIENTSConservative protocols are recommended

for vitamin and mineral supplementation.

Beyond the RDA additional amounts are

recommended for Vitamin A

Vitamin C

Water soluble vitamins

Potassium, Phosphorus



FEEDING MODALITIES Criteria for selecting the method of nutrition

support include: age, percentage and location of

burn, gastro-intestinal function, fluid balance,

liver and renal function, respiratory status,

previous nutritional status, and the surgical

plan.



FEEDING MODALITIES A high protein, high calorie diet is

indicated for the patient who is able to

eat. Oral nutrition supplements should be

used to meet nutritional requirements.Small frequent meals which are nutrient

dense are required to meet nutrient needs

during recovery



TUBE FEEDING An oral diet during the day supplemented

with nocturnal feeds is indicated.

If full nutrition support is required, the

enteral route is preferred over TPN inorder to increase gut blood, preserve gutfunction, maintain mucosal integrity,decrease the incidence of metabolicimbalances, eliminate the risks of infection, and decrease the cost of nutrientdelivery.



ENTERAL FEEDINGDespite concerns for post burn ileus,

immediate intra gastric feeding after burninjury (within 6 to 24 hours) has been

shown to be safe and effective. Initiation of enteral feeding within 48

hours may significantly reduce length of stay.

A reduction in the hyper metabolicresponse has also been seen with earlyenteral feeding due to prevention of excessive secretions of hormones.



ENTERAL TUBE FEEDINGSPediatric:The starting hourly rate should

be 1 ml to 2 ml/kg, and the volume of feeding should increase 5 ml to 15 ml

every 8, 12, or 24 hours . Adult: The rate should start at 10 ml to 40

ml/hr. Volume can be increased in 20 to 25ml increments every 8,12, or 24 hoursdepending on patient tolerance.

Residual gastric volume should bechecked every 4 hours when gastricfeedings are given.



Withholding continuous enteral feedings

is a common practice due to frequent

surgical procedures. When duodenal

feedings were delivered with monitoringintra-operative feedings were reported to

be well tolerated

Special enteral formulas designed for

burn patients do not exist.



Commercial infant formulas are utilizedwhen aggressive nutrition support isneeded

A 20 kcal/30 ml can be made morecalorically dense(24 to 30 kcal/30 ml) withglucose polymer

For children ages 9 months through 10years, isotonic products with a higher

density product can be used.Modular protein supplement can be added

to commercial formulas to increase theprotein content .



Increased mortality has been associated

with the use of TPN in severely burned

patients.

Therefore TPN should be limited to onlyto those patients whose gut is not

functioning

Extreme short bowel, enteric fistulas,

severe pancreatitis, and prolonged ileus

are examples of TPN



NUTRITION A SSESSMENT P ARAMETERS

Recommended assessment measurements

include body weight , laboratory analyses,

nitrogen balance, and nutritional intake

records.Weight: initial weights are difficult to

assess. Fluid resuscitation performed in

the first 48 to 72 hours results in

significant increase in body weight



CONCLUSION Appetite, mental status, wound healing,

and pulmonary function should bemonitored to aid in day-to-day nutritional

adjustments.Thus burn injuries have important

ramifications from a nutritionalperspective.

Close attention to the increased needs fornutrients is warranted to ensure adequateintake is provided .

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