Shock*

Question 1

what is shock

Answer 1

tissue hypo perfusion due to circulatory failure

Question 2

physio of shock

Answer 2

MAP drops 50-60
slow flow to organs
inadequate perfusion for cellular metabolic requirements (leading to acidosis and lactate formation)

Question 3

what does inadequate perfusion cause

Answer 3

systemic acidosis ph<7.35
micro capillary thrombus with patchy tissue injury and large vessel thrombus with organ infarction
cellular necrosis leads to mortality
in survivors a degree of tissue injury can be irreversible

Question 4

microcirculatory changes in septic shock

Answer 4

capillary blood flow is reduced

intermittent or terminated

Question 5

macrocirculatory changes in septic shock

Answer 5

cutis marmorata - physiological response to cold in neonates

Question 6

immediate impression of shock

Answer 6

mottling
GCS <15 leading to confusion and agitation
UO <0.5ml/kg/h

Question 7

how to confirm shock with lactate levels

Answer 7

> 2mmol/L dx
4 significant mortality
even 0.75 higher than normal carries a worse prognosis

Question 8

cardiogenic shock is what

Answer 8

reduced force of cardiac contraction and stroke volume - reduced CO and MAP

compensatory increase in SVR - cool clammy peripheries

Question 9

cardiogenic shock HR
SV
CO
systemic vascular reisstance

Answer 9

low CO
increase in SVR to compensate
low SV
HR low in some cases

Question 10

rx of cardiogenic shock

Answer 10

arrhythmia/poisoning - HR - drugs/cardioversion/dialysis

MI/cardiomyopathy/valve failure - SV - drugs/PCI/surgery

Question 11

obstructive shock

Answer 11

obstruction of cardiac outflow

evidence of raised JVP and distended neck veins may be prominent

Question 12

why are there distended neck veins in obstructive shock

Answer 12

MAP blocked —> venous back pressure

Question 13

treatment of obstructive shock

Answer 13

trauma/aortic dissection - cardiac tamponade - pericardiocentesis/thoractomy
/surgery

trauma/pleural pathologique - tension pneumothorax - thoracentesis/thoracostomy
/surgery

stasis - PE - anticoagulant/
thrombosis or direct lysis

Question 14

hypovalaemic shock

Answer 14

reduced blood volume
lower venous return to the heart
reduced force of cardiac contraction and CO

Question 15

hypovalaemic shock
CO
SVR
HR
SV

Answer 15

CO may be reduced
SVR increased to compensate - cool clammy peripheries
HR increased to compensate
SV reduced due to low preload

Question 16

treatment of hypovolaemic shock

Answer 16

haemorrhage - temporising measures, find and stop bleeding, cross match blood
dehydration - fluids/electrolytes, unit care, steroids/insulin

Question 17

distributive shock

Answer 17

reduced SVR due to vasodilatation - warm, red peripheries
reduced MAP
increase in CO compensatory

Question 18

treatment of distributive shock

Answer 18

inflammatory - AB noradrenaline, supportive therapy, adrenaline

neurogenic - neurosurgery, support vasopressors