Shock

Question 1

Definitions: shock, septic shock, severe sepsis,

Answer 1

Shock: end-organ dysfunction, circ failure
*UO, lactate, BP, SpO2, INR, bili, plt, Cr)

Septic shock: refractory hypotension

Severe sepsis: organ dysfunction

Question 2

Key equations: CO and MAP

Answer 2

CO = HR x SV (preload, contractility, afterload)

MAP = CO x SVR
MAP = DBP + 1/3PP (pulse pressure)
*MAP >60 for perfusion

Question 3

Classification

Answer 3

hypovolaemic (volume loss e.g. hge, burns, D&V)

distributive (interstitial fluids e.g. sepsis, anaphylaxis)

obstructive (pre/afterload e.g. PE, tamponade, tension PTx)

cardiogenic (primary pump issue e.g. MI, VHD)

Question 4

Clinical features

Answer 4

Portsmouth sign: hypotension + tachycardia
tachypnoea
decreased UO, ATN
altered LOC, confusion
angina, arrhythmia, infarction
GIT impaired motility/absorption

Question 5

management

Answer 5

Lactate (ABG), UO (Catheter), met acid (ABG), U&Es, FBC (Hb), cultures

fluid resus (500-1000mL 0.9% 15-30mins)
*>2L = HDU/ITU for vasopressors (Central line)
oxygen, UO, fluid balance
ABX if ?septic (<1h)
paracetamol (antipyretic)

Question 6

Cardiogenic shock

Answer 6

decreased contractility/SV
hypotension not improved by fluids
pulmonary oedema/high JVP
sweaty but hypothermic

stop fluids and call CCU/ICU - needs inotropes

• HF = blood back into heart
• C-shock = blood not leaving the heart

Question 7

Hypovolaemic shock

Answer 7

fluid loss: low preload (SV)
compensation: ^HR, ^SVR (vasoconstriction)

cold, pale, clammy
sweaty but hypothermic
weak thready pulse, an/oliguria

Question 8

Classes of hypovolaemic shock

Answer 8

class I (750mL; 15%): mild tachyC and tachyP

class II (750-1500mL; 15-30%): mod tachy, CRT, narrow pulse pressure

class III (1500-2000mL; 30-40%) HYPOTENSION, low UO

class IV (2-2.5L; 40-50%) GCS/LOC, profound hypotension

Question 9

Distributive shock

Answer 9

vasodilation: warm but not sweaty
decreased SVR (decreased MAP)
compensatory ^HR

Question 10

Distributive shock types

Answer 10

septic: SIRS + infection;
anaphylaxis: airway, breathing, circulation issues +/- skin and GIT

neurogenic/spinal: BRADYCARDIA, hypotension, arreflexia

Question 11

Obstructive shock

Answer 11

pre/afterload (SV)

compensatory ^HR and SVR (vasoconstriction)

Question 12

MEWS: criteria and response

Answer 12

RR (often first sign of deterioration)
HR
SBP
AVPU
Temp
UO

*3 = urgent medical review
5+ = CCOT review (5-10x mortality risk)

Question 13

Post-op haemorrhage

primary/reactionary/secondary

Answer 13

primary = intra-op/immediate
failed haemostasis

reactionary: within 24h
usually venous

secondary: 1-10 days post-op
usually infection (destroys clots)