Shock

Question 1

Cardiac physiology

Answer 1

HRxSV = CO

SV = preload, contractility, afterload

Preload - capacitance, volume status and difference between mean venous systemic pressure and right atrial pressure

Question 2

Cardiogenic shock

Answer 2

Cardiac tamponade, myocardial infarction, blunt injury

Question 3

Cardiac tamponade

Answer 3

Use FAST

but echo is the best test

Question 4

Neurogenic shock

Answer 4

Hypotension without tachycardia or cutaneous vasoconstriction

Question 5

Failure to respond to fluid therapy

Answer 5

Ongoing haemorrhage or neurogenic dysfunction

Question 6

Classes of haemorrhage

Answer 6

Base excess increases as amount of haemorrhage increases

0 - -2

• 2 - -6
• 6 - -10
• 10 or less

Class I (<15%): No signs
Class II (15-30%): Maybe increased HR, but decreased pulse pressure
Class III (31-40%) and above (40% and more): everything changes

Question 7

Confounding factors

Answer 7

Age
Severity
Time lapse
Pre hospital fluid therapy
Medications used for chronic conditions

Soft tissue injury - oedema and blood loss –> hard to estimate and often underestimated

Question 8

Vascular access

Answer 8

rate of flow is proportional to the fourth power of the radius of the cannula AND is inversely related to its length

Question 9

Elderly patient

Answer 9

Poor response to catecholamines with age
Atherosclerosis
Beta blockers can mask tachycardia

Reduced pulmonary compliiance
Glomerular and tubular senescence

Question 10

Medications

Answer 10

NSAID
Beta blocker
Long term diuretics