Shock Flashcards
Define shock
A life-threatening, generalised form of acute circulatory failure with inadequate O2 delivery to, and consequently O2 utilisation by, the cells.
What are the 4 types of shock?
1) Hypovolaemic
2) Distributive
3) Obstructive
4) Cardiogenic
Underlying mechanism in hypovolaemic shock?
Inadequate circulating volume 2ary to fluid loss
- haemorrhage e.g. trauma, AAA, obstetric haemorrhage
- D&V
- DKA
- burns
Underlying mechanism in distributive shock?
Inadequate perfusion 2ary to maldistribution:
- sepsis
- neurogenic shock
- anaphylactic
Underlying mechanism in obstructive shock?
Inadequate cardiac output as a result of mechanical obstruction:
- PE
- tension pnuemothorax
- cardiac tamponade
- acute IVC or SVC obstruction
Underlying mechanism in cardiogenic shock?
Inadequate cardiac output as a result of cardiac failure:
- myocardial infarction
- myocardial contusion
- myocarditis
- late sepsis
- overdose (e.g. beta blockers)
- complete heart block
General presentation of shock?
Very unwell:
- hypotension
- tachycardia
- tachypnoea
- reduced GCS
- possible cardiac arrest
Presentation of patients in hypovolaemic shock?
‘Cold’ shock
- Cold peripheries due to vasoconstriction
- Increased CRT
- May have dry mucous membranes (e.g. if due to dehydration)
Presentation of patients in distributive shock?
‘Warm’ shock
- These patients vasodilate as oppose to vasoconstrict, and are hence often warm with normal CRT
- If infection (sepsis): underlying signs of infection, rigors, high temp, muscle aches, lethargy, drowsiness, reduced GCS
2 key causes of distributive shock?
1) Anaphylaxis
2) Sepsis