Shock Flashcards
What is the basic underlying pathophysiology of shock?
Inadequate perfusion for cellular metabolic requirements
Inadequate perfusion of tissues results in…(3)
Systemic acidosis
Microcapillary thrombus leading to patchy tissue injury
Cellular necrosis
Immediate signs of tissue hypoperfusion (3)
Altered mental state (GCS lower, agitation, confusion)
Skin mottling
Oliguria
Blood test which confirms shock
High lactate (above 2mmol/l)
Four main aetiologies of shock
Cardiogenic
Obstructive
Distributive
Hypovolaemic
Obvious sign of cardiogenic shock. Why does this happen?
Cold, clammy peripheries. Compensatory increase in vascular resistance to bring up the blood pressure
Causes of cardiogenic shock (3)
Acute MI (wall hypokinesis) Cardiac rhythm (VFib/tachycardia) Poisoning e.g. beta blockers
Obvious sign of obstructive shock
Raised JVP and distended neck veins
Causes of obstructive shock (3)
Cardiac tamponade
Tension pneumothroax
Pulmonary embolus
Haemorrhagic shock:
a) obvious (2)
b) occult (4)
a) trauma, GI bleeding
b) intrathoracic, pelvic fracture, long bone fracture, abdominal viscera
Causes of dehydration (4)
GI losses/lack
Burns
Addisonian crisis
DKA
Immediate management of hypovolaemic shock
Large bore IV access, 250-500ml fluid challenge with 0.9% NaCl
What is the principle behind a fluid challenge?
In a patient with good systolic function, volume expansion should improve the pre-load and hence the stroke volume
Underlying pathophysiology of distributive shock. How does this affect the appearance of the patient?
Reduced vascular resistance. Patient will have warm red peripheries
Causes of distributive shock
Inflammatory (sepsis, allergic)
Spinal cord damage
Spinal and epidural anaesthesia
