23 – Major Trauma Flashcards
What are the 2 phases of physiologic response to trauma?
- Ebb phase: first several hours after surgery
- Flow phase: days to weeks after injury
What are the physiological changes with the stress response to trauma (surgery)?
- Neuroendocrine-metabolic response
o Endocrine response
o Metabolic response - Inflammatory: immune response
What will the duration and progression of the physiological response to trauma vary with?
- Site of injury
- Severity
- Underlying condition of patient
When do you get the greatest stress response? (what type of trauma?)
- Abdominal surgery
- Orthopedic surgery: surgical arthrodesis
When do you get a lesser stress response? (what type of trauma?)
- Simple wound revision: laceration
What are some things to consider with the condition of the patient?
- Age
- Sex
- Concurrent disease processes
o Diabetic
o Cancer
o Immunocompromised - Nutritional status/body condition
Ebb phase: neuroendocrine-metabolic response
- Adrenaline (epinephrine) will be HIGH
o Strengthens sympathetic response
o Mobilizes CHOs and fats - SNS response
o Blood flow to active muscles=increased
o Reduced blood flow to organs NOT used for rapid motor activity (ex. kidneys, GIT)
o Hepatic and muscle lipolysis and glycogenolysis=increase
o Cellular metabolic activity and coagulability of blood=increase
Hypothalamic-pituitary-adrenal (HPA) axis (Ebb phase)
- Adapts and responses
o ACTH rises (return to baseline within 24hrs)
o Cortisol increases (remain increased for at least 7 days)
o GH increases (good initially, but can become hyperglycemic and insulin resistant) - Hypovolemia, hyperosmolarity, increase in AngII
o Release of ADH (urine volume decreases, concentration increases)
o Aldosterone in released
What are the clinical symptoms we will see with the Ebb phase?
- Hypovolemic
- Low perfusion
- Hypothermic
- Acidosis
- Shock
- Pain
What do we need to consider with fear and pain?
- Increased cortisol
- Modulation of pain
o Important in controlling stress response - *control pain early in trauma or surgical patient
o Minimize ‘wind-up’
Metabolic response (Ebb phase)
- Hypermetabolism and hypercatabolism
o Tissue repair and energy sources - Hepatic glycogen stores
o Glucose - Skeletal muscle
o Proteolysis - Fat reserves
o Lipolysis
What are the effects of aldosterone and ADH? (Ebb phase)
- Retention of water and sodium
- Maintenance of blood volume
- Increased vascular tone
- May be protective feature
o Acute loss of plasma volume
What are the clinical symptoms we see with the effects of aldosterone and ADH? (Ebb phase)
- Fluid retention
- Oliguria
- Accumulation of extracellular fluid
Cortisol: pro and con (Ebb phase)
- Pro: critical for recovery
- Con: prolonged secretion can lead to pathologic suppression of the immune response
What is the stress response to surgery? (Ebb phase)
- Innate and cell-mediated adaptive immune system involved
- Excessive production of inflammatory mediators
o Systemic inflammatory response syndrome (SIRS)=no specific
What are cytokines?
- Small proteins
- Mediated and maintain local inflammatory response to tissue damage
- *if balance between pro- and anti- inflammatory cytokines is unregulated than immunodeficiency and sepsis is more likely
What are acute phase proteins?
- Produced by hepatocytes in response to cytokine stimulation
- Response to tissue injury and inflammation
What are the pro-inflammatory cytokines?
- IL-6
- IL-1 beta
- TNF-alpha
- IL-8
What are the anti-inflammatory cytokines?
- IL-4
- IL-10
- Transforming factor-beta
- IL-1 receptor antagonist
- Soluble TNF receptors
- *help reduce magnitude and duration of SIRS response
Flow phase: catabolic period
- Changes in behaviour
- Withdrawal
- Reluctance to move
- Fear
- Anxiety
- Aggression
- Malaise
What are the clinical symptoms of the catabolic period, Flow phase?
- Tachycardia
- Tachypnea
- Hyperthermia
- Hypotension
- Decreased perfusion
- Decreased urine output
- Endotoxemia
- Bacteremia
Flow phase: anabolic period
- Appetite returns
- Body protein is synthesized
- Weight is restored
- Organ function and energy stores
- Metabolic demand reduces
- Water balance restores
- Hormone levels decrease
- Generalized feeling of well-being develops
Who might have a speedy rate of recovery from the stress response?
- Healthy individuals
- No complication
Who might have a prolonged rate of recovery from the stress response?
- Debilitated patients with complications
o Infection
o Prolonged catabolic phase
Modulation of perioperative stress response: anesthetic drugs
- single dose of PROPOFOL: suppresses cortisol concentration (in HUMANS)
- volatile anesthetic agents
o inhibit ACTH, cortisol, catecholamines, and GH
o impair platelet aggregation and clot stability - opioids, alpha 2’s, benzodiazepines
Modulation of perioperative stress response: regional anesthesia, lower limbs
- block endocrine and metabolic response to surgery in lower limbs
- hyperglycemia response is INHIBITED
- *benefits seen alone and in combo with general anesthesia
Modulation of perioperative stress response: regional anesthesia, epidural and spinal anesthesia
- block HPA axis response
o ACTH, cortisol, adrenaline, and GH secretion is impaired - *benefits seen alone and in combo with general anesthesia
Modulation of perioperative stress response: mitigate pain
- Increased metabolic rate
- Pre-emptive analgesia
o More effective than after the fact
o Minimize systemic response - Analgesia: POSITIVE player
Modulation of perioperative stress response: surgical technique
- Minimally invasive surgery
o Reduced hospital stay
o Surgical complication rates reduced
o Decreased in readmittance - Duration of surgery and extent of intraoperative surgical manipulation
o Directly proportional to stress response - Good surgeons follow Halstead’s principles
Why is nutrition and fluid management important?
- INCREASED ENERGY DEMAND
- Accelerated lipolysis
- Accelerated proteolysis
- Amino acids: wound healing and APP
- Glucose: vital organs and wound healing
Nutrition considerations
- Malnutrition and underfeeding
o Risk factors for post-operative complications - Return to feeding ASAP: ideally on their own
What is forced enteral? What are some examples?
- Nutrients to a functional GIT
o Nasoesophageal
o Pharyngostomy
o Esophagostomy
o Gastrostomy
o Eneterostomy
Paraenteral
- Nutrients are provided IV
o Total (TPN): 100% of animal’s nutrient, protein, and caloric requirement
o Partial (PPN): portion of these requirements
Fluid management
- Assess patient’s electrolyte status
- Supplement fluids as necessary
o Potassium
o Sodium
o Chloride
o Calcium
o Magnesium
