Circulatory Shock Flashcards
what is ‘circulatory shock’?
- characterised by significant haemodynamic changes that result in poor tissue perfusion and impaired cell metabolism
- ‘profound haemodynamic and metabolic impairment dir to inadequate tissue perfusion and oxygen delivery’
what are the main categories of shock?
neurogenic/distributive, hypovolaemic, cardiogenic, obstructive, anaphylactic, and septic
explain cariogenic shock
occurs when there is an ‘issue with the pump’, i.e. contractility is impaired. This is likely secondary to heart failure or a myocardial infarction where heart tissue is impaired and therefore the ability of the heart muscle to pump is impaired
*some sources don’t differentiate obstructive shock and cariogenic shock as being seperate conditions
explain obstructive shock
occurs when the heart is prevented from contracting appropriately, often as a result of cardiac tamponade, tension pneumothorax, and pulmonary embolism
*some sources don’t differentiate obstructive shock and cariogenic shock as being seperate conditions
explain neurogenic shock
- primarily associated with CNS control of vasoconstriction/dilation and therefore leads to widespread vasodilation and therefore inadequate organ perfusion
- can be triggered by drugs that lower sympathetic activity or increase parasympathetic activity, or spinal injury
which three types of shock often get grouped together due to similar pathophysiology?
neurogenic, anaphylactic, and distributive
explain anaphylactic shock
anaphylaxis is a severe form of allergic reaction. The activation of immune responses leads to widespread vasodilation, loss of vascular integrity (leaky capillaries), peripheral blood pooling, poor tissue perfusion, and oedema
explain hypovolaemic shock
associated with a loss of blood volume due to a decrease in whole blood, plasma, or interstitial fluid. Often related to haemorrhage (including internal), severe burns, or dehydration (e.g. in uncontrolled diabetes)
what is HAT stand for and what is it’s importance in relation to shock
H - hypotension
A - altered mental status
T - tachypnoea
this pneumonic is used to assist in the recognition of shock
do all variations of shock present in the same way?
no
review and/or explain the clinical snapshot of circulatory shock (cardiogenic/neurogenic/hypovolaemic/anaphylactic/septic)
how would hypovolaemic shock be treated on road?
- primary survey/care
- haemorrhage control (external and internal where possible
- consider O2 if indicated
- establish IV access
- consider fluid therapy
- pain relief
- monitor and prepare for deterioration and arrest
- consider TXA in haemorrhage
- definitive care
What clinical manifestations would you expect to see in a patient presenting with shock?
- hypotension
- increased HR (but not in neurogenic shock)
- weak, thready pulse
- increased respiratory rate, shallow breaths
- decreased bowel sounds (due to shunting of blood to major organs)
- changes to skin appearnace (pallor/flushing depending on type of shock)
in end organ damage
- confusion/lethargy
- decreased urine output
- cold/clammy/mottled skin
- ST elevation
what are the clinical manifestations you would expect to see if a patient in cardiogenic shock?
this is where the pump (heart) is not working, therefore you would expect to see signs and symptoms similar to those in heart failure
- decreased mental status (lack of O2 and potentially glucose delivery)
- pulmonary oedema (backlog of blood into the pulmonary vessels)
- dysrhythmias
- symptomatic hypotension (if the pump isn’t working cardiac output will decrease)
- wheeze or crackles as result of pulmonary oedema
would you administer IV saline to a person in cardiogenic shock if they are presenting with signs of pulmonary oedema?
You would not want to give a patient with pulmonary oedema fluid therapy unless they are symptomatic of hypotension. In this case it may be considered and careful titration would be necessary - I would probably consult someone of higher cliinical ability
