MNT for Critical Illness, Burns, and Surgery

inflammatory response

cellular response to stress/injury - usually reversible, extreme/ongoing/ apoptotic at times (nutrition support is crucial)

nutrition on critical illness can impact

metabolic response, prevent oxidative damage, modulate immune response, reduce disease severity, diminish complications

how is good nutrition support achieved

early EN or EEN, meticulous glycemic control, apposite macro- and micronutrient delivery

malnutrition develops when

inadequate supply of nutrients (starvation), body cannot utilize nutrients, needs are higher so they aren’t met (metabolic stress)

metabolic stress does not equal

starvation - body does not react the same way (no adaptation occurs)

types of malnutrition

starvation related, chronic disease related, acute disease or injury related malnutrition

starvation related malnutrition

pure chronic starvation eg anorexia nervosa

chronic disease related malnutrition

organ failure, pancreatic cancer, sarcopenic obesity etc

acute disease or injury related malnutrition

major infection, burns, trauma, closed head injury

traumatic injury

leading cause of death in people 1-46yo and 3rd leading in all age groups

metabolic response to stress

can be from any traumatic event from surgery to sepsis - it is a response to the presence of injured tissue, driven by catabolic hormones and inflammatory markers (degree correlates with severity of injury)

metabolic consequences of stress include

hormone release, acute phase protein synthesis, hypermetabolism, increased reliance on gluconeogenesis, shift in fluid balance, decreased urine output (body’s net goal is higher O2 supply and availability of substrate to active tissue)

phases of stress response

ebb phase and flow phasee

ebb phase

initial 2-48 hours post stress (metabolic shock)

• low BP, cardiac o/p, UOP, temp, O2 consumption, tissue perfusion, and normal/depressed metabolic rate (ALL LOW)

  • risk of: hypovolemia, hypoperfusion, and lactic acidosis

goal of ebb phase treatment

stop bleeding, restore blood flow to organs, and maintain oxygenation of tissuesf

low phase

up to 7 days or more - hypermetabolism and catabolism

• altered immune and hormonal response, acutely liver priority changes from transport proteins to acute phase proteins

• substrates are provided, but poor utilization

  • negative N balance and loss of LBM

important note of flow phase

markers such as prealbumin may not respond to nutrition support

catecholamines

stimulate glycogenolysis (epinephrine and norepinephrine)

aldosterone

retain Na`

cortisol

raises gluconeogenesis, free fatty acid mobilization, protein catabolismg

glucagon

stimulate gluconeogenesis (this and cortisol drive hyperglycemia)

cytokines

proinflammatory proteins released by macrophages in response to shock (interleukin, tumor necrosis factor, c reactive proteins)

• acute phase proteins

acute phase proteins

immunoglobulins, fibrinogen, clotting factors, complement proteins

sepsis

uncontrolled inflammatory response to infection or trauma

systemic inflammatory response syndrome (SIRS)

additional classification of sepsis not necessarily caused by infection, may occur after surgery or trauma such as myocardial infarction

characteristics of sepsis and SIRS

increased WBC, heart rate, respiratory rate, fever or hypothermia — abnormal organ function and hemodynamic instability

medical management of sepsis and SIRS

interventions appropriate for underlying cause eg lung protective ventilation, antibiotics, continuous RRT, glycemic control, etc

why is nutrition support critical

modulates inflammation, spares LBM, supports immune response, supports wound healing, maintains GI and pulmonary mucosal barriers to bacteria

when should EEN be sarted

24-48 hours after admission

MNT goals for trauma

meet energy needs and protein without over or underfeeding

support processes of hypermetabolism and hypercatabolism

is weight gain/loss an objective for an MNT in trauma

NO - overfeeding is detrimental causes retentions, hyperglycemia, hepatic steatosis, and immune dysfunction

nutrition screening in the ICU

screen all patients for nutrition risk using the NRS 2002 NUTRIC screening tools - specific to ICU because they consider inflammation and severity

NUTRIC scoring is different because

it has bases on age (older higher risk), measure organ function, electrolytes, acid/base, and neurological status, and IL-6 measurement for current inflamamtion

some nutrition diagnoses in critical care may include

increased energy expenditure, increased nutrient needs, inadequate protein-energy intake, altered GI function, and impaired nutrient utilization

best way to establish energy needs

indirect calorimetry, but not always available (because VO2 and VCO2 is proportional to energy expenditure)/substrate utilization

respiratory quotient

the ratio of CO2 produced to O2 consumed (VCO2/VO2)

• indicator of substrate utilization, accompanies an IC reading on metabolic cart, and helps determine over or underfeeding

  • <.7 = underfeeding, 0.75-0.90 = normal, >1 = overfeeding

nitrogen balance

compares urinary urea nitrogen output (UUN) with protein intake

N-balance= N intake (g) - [24hr UUN (g) +4]

• + means good, protein greater than losses

• - means bad, protein less than daily losses

  • REMEBER* 6.25g Pro = 1g N so Pro intake(g)/6.25 = N intake (g)

in burn patient the nitrogen balance formula changes to

N balance = nitrogen intake (g) - [24hr UUN (g) +4] x 1.25

• multiple measured losses by 1.25 to account for wound exudate due to burns

ASPEN guidelines for energy in critical care

BMI 20-29= 25-30kcal/kg actual weight

BMI 30-50= 11-14kcal/kg actual body weight

BMI >50= 22-25kcal/kg IBW

ASPEN protein guidelines for critical care

BMI 20-29= 1.2-2gm/kg actual weight

BMI 30-40= 2gm/kg IBW

BMI >40= 2.5gm/kg IBW

macronutrient division in critical care

1. determine protein requirement

2. provide remaining kcal with CHO and fat

   1. CHO needs 100g/d minimum FAT should not exceed 30% of total kcal

Fluid needs

higher N regimens produce increased solute loads for kidneys so they require adequate fluid for excretion

• use standard guidelines, but adjust for fever, GI losses, warm ambient temp, beds with airflow, or fluid restricted diseases

• monitor urine output, serum electrolyte balance, and edema signs

fluid calculations

• 30-35mL/kg

• 1mL/kcal of enteral intake

• 100mL/kg for 1st 10kg, 50mL/kg for next 10kg + 25mL/kg for remaining weight

• 1500mL/m2 total body surface area

stressed pts may need what extra vit/min

ascorbic acid, Zn, selenium, vit E, K (or less), PO4, and Mg

thiamin, niacin, and other B vits may be needed if more aggressive

if pt at risk for aspiration or gastroparesis use what tube feed

jejunal tube - continue with trickle feedings at 10-20kcal/hr

what formulas are appropriate in most cases

standard polymeric formulas, use other disease specific only if needed - monitor glucose and avoid overfeeding

glucose goal in the ICU

140-180mg/dL

what to reserve PN for

pts NPO >7 days, malnourished pts who cannot use EN, pts who cannot meet needs EN alone, may surgery will prevent initiation of EN

arginine

vasodilator, may have increased needs during stress

glutamine

preferred energy source for enterocytes (maintains intestinal barrier), reduces cytokine levels, and may have increased needs during stress

labs headed for normal ranges during recovery phase

serum glucose, urine nitrogen losses, acute phase respondents, O2 consumption, fever and WBC count

trauma considerations for feedings

• utilize EEN with a high protein polymeric formula

• may benefit from volume based EN

• consider an immune-modulating EN formula with arginine and omega 3s

• provide 20-35 kcal/kg/d (lower in ebb, higher in flow)

when does REE peak

over 4-5 days, remains high for 9-12 days, begins to decrease after - remaining elevated for 21 days

how much protein can patients lose in 21 days

16%, 65% comes from skeletal muscle

what are burn injuries

caused by exposure to heat, chemicals, radiation, or electricity

may extend beyond skin and into muscle and bone

classified by depth and %

eschar

necrotizing tissue with appearance of dark leathery skin

TBSAB

total body surface area burned

full thickness burn

destroys epidermis and dermis

s/s black, leathery, translucent, mottled, and dry appearance

partial thickness burn

destroys superficial or deep dermis

s/s red, tender, blistered, wet, or weeping

superficial (1st degree) burns

epidermis only

heal in a few days ontheir own

partial thickness (2nd degree) burns

damage epidermis and dermis

very painful

takes weeks to heal

may require excision and debridement

full thickness (3rd degree) burns

damage the epidermis, dermis, and subcutaneous tissue, and possibly muscle and organs

loss of nerve endings so less painful

require surgical intervention eg wound debridement and grafting

functions of skin

protection from infection and injury

prevention of loss of body fluid

regulation of body temperature

sensory contact with the environment

complications of burn injuries

hypermetabolism

hypothermia

fluid loss from the wound

sepsis and infection

organ dysfunction (renal, cardio, respiratory)

electrical burn - cardiac sequela

smoke inhalation

metabolic response to ebb phase in burns

focus on fluid resuscitation and restoring organ function

flow phase metabolic response to burn

hypermetabolism can last up to 2 years

can lose up to 20% LBM in weeks post injury

focus on healing and wound closure

wound management

dressings, irrigation

debridement and grafting may be necessary in the early stages of wound care

debridement

removal of necrotic, infected, or foreign material from wound

types of debridement

surgical, mechanical, enzymatic

possible nutrition diagnoses

increased energy expenditure, increased nutrient needs, impaired nutrient utilization, altered nutrition-related lab valuesbe

best way to determine energy reqs for adults is

indirect calorimetry, but can use IBW for obesity

also curreri formula

curreri formula

kcal = (25kcal x kg usual body wt) + (40kcal x %TBSAB)

*only %TBSAB up to 50% max

*may be best during peak phase

• could overfeed beyond that

determining calories for children

-indirect calorimetry is the best

< 30% TBSAB use DRI for kcal per age group

> 30% TBSAB use galveston equation

BSA

body surface area

BSAB

body surface area burned

key anabolic hormone in burns

insulin - slows gluconeogenesis and LBM catabolism

protein is best utilized when

CHO is abundant

what can build up in the liver and decrease immune function in burn victims

fats - low fat feedings are recommended

parkland formula for fluid restriction

children: 3-4ml/kg/%BSA/24 hours

adults: 4ml/kg/%BSA/24 hours

Day 1: provide ½ of calculated needs within first 8hr, then provide remaining over 16hre

electrolytes in burn pts

provided based on serum and urine data in conjunction with fluid needs

minerals and trace elements in burns pts

provide DRI

may supplement additional vit c, zn, vit e, vit a, selenium for wound healing

small bowel is tolerated better in burn pts because

ileus in burns

may use oxandrolone to help

maintain LBM and promote healing (anabolic steroid) in those with >15% TBSA

continue nutrition support in burn patient until patient can meet

>60% of nutritional needs orally

impact of surgery on nutrition

npo status

post operative ileus r/t anesthesia

poor intake r/t pain meds

hypermetabolic response to injury/stress

wound healing

surgery and malnutrition =

higher mortality and morbidity (more susceptible to infection and poor wound healing)

pre-operative nutrition support is recommended

old practice for pre op nutrition

fast for 12 hoursn

ew practic for pre op nutrition

no solids for 5 hours before

clear liquids within reason up to 2 hours beforepo

post op nutrition

early and aggressive post op nutrition is within 24 hours of sx

start high protein oral intake ASAP

if EN is needed, feed within 24 hours

consider immune enhancing formulas (supplement PN if needed)