Editing Stress response


== "Ebb" (first 24 hours) ==

* Surges in catecholamine, cortisol and aldosterone
* Tachycardia
* Tachypnoea
* Vasoconstriction
* Decreased cardiac output
* Decreased oxygen consumption
* Lower basal metabolic rate
* '''Increased sodium and water retention'''
* Shunting of blood from periphery to vital organs
* Acute phase protein production

== "Flow" (peaks at 48-72 hours) ==

* Secretion of catecholamines, ADH, cortisol, insulin, glucagon, growth hormone
* Enhanced proteolysis and lipolysis mobilises carbon sources for gluconeogenesis (catabolism)
** Skeletal muscle not spared
* Explosive metabolic and immune activity
* Tissue repair
* Enhanced enzymatic function
* Tachycardia and tachypnoea
* Peripheral oedema
* Fever
* Hyperglycaemia
* Leucocytosis
* Increased oxygen consumption
* Increased CO2 production
* Increased minute ventilation
* Elevated metabolic rate
* Negative nitrogen balance

== Then anabolic state ==

* High insulin, growth hormone etc
* '''Oedema reabsorbed, brisk diuresis'''
* Decrease in serum ions as they move into cells, and therefore need replacement

== Other points to note ==

* Liver hypoperfusion (often see cholestasis of critical illness as a marker of secondary liver hypoperfusion)
* Gut translocation (secondary to reduced splanchnic blood flow causing ischaemia-reperfusion-mediated gut injury)
** Enteral feeding supports gut integrity (maintains mucosal mass, stimulates epithelial cell proliferation, maintains villus height, promotes production of brush border enzymes, stimulates blood flow)
* Opioids likely impact stress response - immune cells express opioid receptors!
* Influence of neuroimmune axis is pretty poorly understood
* Muscle wasting - mediated by lack of anabolic factors, and increase in catabolic factors e.g. cortisol, combined with critical illness. Particularly bad in ventilated/septic patients. Strategies for prevention:
*

[[Category:Peri-op medicine]]