THE METABOLIC RESPONSE TO INJURY

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THE METABOLIC RESPONSE TO INJURY
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INTRODUCTION
Accidental/Deliberate Injury

• Series Of Changes At Site Of Injury Within The
  Body Generally

Restore The Body To Its Pre-injury Condition
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FACTORS MEDIATING THE METABOLIC RESPOSE TO INJURY

• ACUTE INFLAMMATORY RESPONSE
• -Inflammatory cells (macrophages, monocytes,
  neutrophils)
• -Proinflammatory cytokines other inflammatory
  mediators
• ENDOTHELIAL CELL ACTIVATION
• -Adhesion of inflammatory cells
• -Vasodilatation
• -Increased Permeability
• AFFERENT NERVE STIMULATION
• RELEASE OF STRESS HORMONES
• BACTERIAL INFECTIONENDOTOXIN

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SOME CYTOKINES INVOLVED IN THE ACUTE INFLAMMATORY
RESPONSE

• Cytokine Relevant actions
• TNF-a Proinflammatory, release of leukocytes by
  bone marrow, Activation of leukocytes and
  endothelial cells
• IL-1 Fever, T-cell and macrophage activation
• IL-6 Growth and differentiation of lymphocytes,
  activation of Lymphocytes, activation of the
  acute-phase protein response
• IL-10 Inhibits immune function

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URINARY CHANGES DURING THE METABOLIC RESPONSE TO
INJURY

• Reduced urine volume in response to hypovolaemia
  and ADH release.
• Low urinary Sodium and Increased Urinary
  Pottasium excretion due to Aldosterone release
• Increased urinary Nitrogen excretion due to the
  catabolic response to injury.

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CONSEQUENCE OF THE METABOLIC RESPONSE TO INJURY

• Sodium water retention in response to
  Hypovolaemia, Aldosterone ADH release
• Pyrexia for 24-48 hours
• Increase energy expenditure
• Increase glucose fat turnover
• Breakdown of adipose tissue as principal energy
  source
• Catabolism of skeletal muscle to provide amino
  acid for gluconeogenesis hepatic synthesis of
  acute-phase proteins.

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FACTORS MODIFYING THE RESPONSE RESPONSE TO INJURY

• Severity of injury
• Nature of injury
• Infection
• Genetic factors
• Nutritional status
• Coexisting diseases
• Ambient temperature
• Anaesthesia drugs

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ANABOLISM

• Process of regaining weight,restoring skeletal
  muscle mass strength and replenishment of fat
  stores
• Hormones contributing to the process of anabolism
  include insulin,GH,insulin like growth
  factors,androgens 17-ketosteroids.

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METABOLIC RESPONSE TO INJURY

• Discussions

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• How do the acute inflammatory cells,which appear
  at the side of an injury mediate their effects at
  the site of wounding
• Describe the nature of the redistribution of the
  circulation which occurs to maintain central
  blood pressure after severe flood loss.
• Why does the patient lose a considerable amount
  of weight in the few weeks after a severe
  accident? what is the mechanism of this
  weightloss
• In what way does the adrenal cortex become
  involved in the hormonal response to severe
  injury/in what clinical situation or disease will
  this mechanism fail?