Chapter 42
Medical Nutrition
Therapy for
Metabolic Stress:
Sepsis, Trauma,
Burns, and
Surgery
Metabolic Stress

Sepsis (infection)

Trauma (including burns)

Surgery

Once the systemic response is activated, the
physiologic and metabolic changes that follow
are similar and may lead to septic shock.
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Physiologic and Metabolic Changes
Immediately after an Injury or Burn
ADH, Antiduretic hormone; NH3, ammonia.
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Metabolic Response to Stress

Involves most metabolic pathways

Accelerated metabolism of LBM

Negative nitrogen balance

Muscle wasting
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Ebb Phase

Immediate—hypovolemia, shock, tissue
hypoxia

Decreased cardiac output

Decreased oxygen consumption

Lowered body temperature

Insulin levels drop because glucagon is
elevated.
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Flow Phase

Follows fluid resuscitation and O2 transport

Increased cardiac output begins

Increased body temperature

Increased energy expenditure

Total body protein catabolism begins

Marked increase in glucose production, FFAs,
circulating insulin/glucagon/cortisol
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Hormonal and Cell-Mediated
Response

There is a marked increase in glucose
production and uptake secondary to
gluconeogenesis, and
—Elevated hormonal levels
—Marked increase in hepatic amino acid
uptake
—Protein synthesis
—Accelerated muscle breakdown
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Skeletal Muscle Proteolysis
From Simmons RL, Steed DL: Basic science review for surgeons, Philadelphia, 1992, WB Saunders.
© 2004, 2002 Elsevier Inc. All rights reserved.
Metabolic Changes in Starvation
From Simmons RL, Steed DL: Basic science review for surgeons, Philadelphia, 1992, WB Saunders.
© 2004, 2002 Elsevier Inc. All rights reserved.
Starvation vs. Stress

Metabolic response to stress differs from the
responses to starvation.

Starvation = decreased energy expenditure, use
of alternative fuels, decreased protein wasting,
stored glycogen used in 24 hours

Late starvation = fatty acids, ketones, and
glycerol provide energy for all tissues except
brain, nervous system, and RBCs
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Starvation vs. Stress—cont’d

Hypermetabolic state—stress causes
accelerated energy expenditure, glucose
production, glucose cycling in liver and muscle

Hyperglycemia can occur either from insulin
resistance or excess glucose production via
gluconeogenesis and Cori cycle.

Muscle breakdown accelerated also
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Hormonal Stress Response

Aldosterone—corticosteroid that causes renal
sodium retention

Antidiuretic hormone (ADH)—stimulates
renal tubular water absorption

These conserve water and salt to support
circulating blood volume
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Hormonal Stress
Response—cont’d

ACTH—acts on adrenal cortex to release
cortisol (mobilizes amino acids from skeletal
muscles)

Catecholamines—epinephrine and
norepinephrine from renal medulla to
stimulate hepatic glycogenolysis, fat
mobilization, gluconeogenesis
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Cytokines

Interleukin-1, interleukin-6, and tumor
necrosis factor (TNF)

Released by phagocytes in response to tissue
damage, infection, inflammation, and some
drugs and chemicals
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Systemic Inflammatory Response
Syndrome

SIRS describes the inflammatory response that
occurs in infection, pancreatitis, ischemia,
burns, multiple trauma, shock, and organ injury.

Patients with SIRS are hypermetabolic.
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Diagnosis for Systemic Inflammatory
Response Syndrome (SIRS)

Site of infection established and at least two of the
following are present
—Body temperature >38° C or <36° C
—Heart rate >90 beats/minute
—Respiratory rate >20 breaths/min (tachypnea)
—PaCO2 <32 mm Hg (hyperventilation)
—WBC count >12,000/mm3 or <4000/mm3
—Bandemia: presence of >10% bands (immature
neutrophils) in the absence of chemotherapyinduced neutropenia and leukopenia
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Bacterial Translocation across Microvilli and
How It Spreads into the Bloodstream
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Hypermetabolic Response to Stress—Cause
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000.
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Hypermetabolic Response to Stress—
Pathophysiology
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000.
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Hypermetabolic Response to Stress—
Medical and Nutritional Management
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000. Updated by Maion F. Winkler and
Ainsley Malone, 2002.
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Factors to Consider in Screening an
ICU Patient

ICU medical admission
—Nutritional status, organ function,
pharmacologic agents

Postoperative ICU admission
—Intraoperative complication, nutritional
status, diagnosis, sepsis/SIRS

Burn or trauma admission
—Type of trauma, extent of injury, GI
function
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Glutamine Metabolism
NH2, Amine; NH3, ammonia.
From Simmons RL, Steed DL: Basic science review for surgeons, Philadelphia, 1992, WB Saunders.
© 2004, 2002 Elsevier Inc. All rights reserved.
Interpretation of Burn Classification Based on
Damage to the Integument
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Nutritional Care Goals for Burned Patients
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Energy Requirements

Use Ireton-Jones calculation for estimated
energy expenditures.
EEE = estimated energy expenditure (kcal/day)
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Energy Requirements —cont’d
EEE = 1784 – 11(A) + 5(W) + 244(G)
+ 239(T) + 804(B)
A = age
W = weight (kg)
G = gender (female = 0 male = 1)
T = diagnosis of trauma (absent = 0, present = 1)
B = diagnosis of burn (absent = 0, present = 1)
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Energy Requirements —cont’d

Corrective factors for stress: BEE x 1.35 =
skeletal trauma

BEE x 1.6 = major sepsis

BEE x 2.0 = severe thermal trauma
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Protein or Nitrogen
Requirements

1.2 to 1.5 g protein/kg BW
for anabolism mild or moderate stress

Nitrogen requirement estimated from
energy requirements
—Estimate energy needs
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Protein or Nitrogen
Requirements—cont’d

For burn patients
— <10% open wound = 0.02 g nitrogen/kg/day
— 11% to 30% open wound = 0.05 g
nitrogen/kg/day
— >31% open wound = 0.12 g nitrogen/kg/day
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Protein or Nitrogen
Requirements—cont’d

Glutamine is beneficial.

BCAAs also important for better nitrogen
retention (valine, leucine, and isoleucine),
but not necessarily in burn patients.

Check TF or TPN solutions.
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Identify Malnutrition



Marasmus
Somatic proteins depleted
Immune function compromised
Visceral proteins normal or moderately depleted
Kwashiorkor: common in stressed patients!
Somatic proteins normal or moderately depleted
Immune function compromised
Visceral proteins depleted
PCM
All measures depleted
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Vitamins, Minerals, Trace Elements

No specific guidelines

May be extra B-complex, potassium,
magnesium, phosphorus, zinc, vitamin C

Monitor electrolytes by serum levels.
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Surgery

Well nourished patient tolerates surgery better
than poorly nourished patient

When possible, replete before surgery

TF or TPN as needed

Postoperative: introduce solid food when GI
tract is ready, perhaps sooner than in the past
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Multiple Organ System Dysfunction

MODS

Lung failure

Liver failure

Intestinal failure

Kidney failure

Hematologic and cardiac failure

CNS changes occur at any time
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Traumatic Brain Injury

Head injury

Huge hypermetabolic response—brain is so
glucose dependent

Rapid loss of LBM can occur

Glasgow Coma Scale—state of consciousness

Energy needs = 40% over BEE

Protein = 1.5 to 2.2 g/kg BW
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Major Body Burns

Severe insult—skin as protective organ can no
longer prevent infectious agents from invading
the body

Fluid and electrolytes most essential

Wound management depends on depth and
extent of injury—check staging

Wound healing can only occur in anabolic state
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Major Body Burns—cont’d

Maximum glucose load is 7 mg/kg/min, above
which glucose is not used and causes
lipogenesis

Hyperglycemia, dehydration, and respiratory
difficulty can result from excess glucose.

Omega-3 fatty acids are useful; give lipid at
15% to 20% of kcal

Structured lipids (some MCT, some LCT) may
improve hepatic protein synthesis.
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Major Body Burns—cont’d

Protein losses occur from urine, wounds,
healing process, and increased gluconeogenesis

20% to 25% kcal as protein needed

Check renal function and fluid balance

BCAAs have no effect in burned patients

Arginine seems to be needed

Glutamine enhances bactericidal ability in
neutrophils
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Major Body Burns—cont’d

Estimation of wound nitrogen losses
–10% open wound = 0.02 g N/kg/day
– 11% to 30% open wound = 0.05 g N/kg/day
– More than 31% open wound = 0.12 g
N/kg/day
– Check nitrogen balance studies to find best
guess of needs
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Vitamins and Minerals

Vitamin C for collagen synthesis and immune
function—maybe use 500 mg 2x daily
(remember tissues saturate at 200 mg)

Vitamin A for epithelialization (5000 IU per
1000 kcal of TF)

Minerals: low Na, Ca, Mg, PO4, Zn, Fe can
occur—monitor carefully

Zn and Fe are bacterial nutrients; use caution
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Summary

This level of nutrition intervention is highly
specialized!

Critical care—not for everyone

Must monitor patient status carefully
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