Shock

Question 1

Causes of shock

Answer 1

Blood loss - hypovolaemic
Heart fails - cardiogenic
Blockage of blood flow - obstructive
Vessel distended - vasogenic

Question 2

Causes of hypovolaemic shock

Answer 2

• Haemorrhage
  
  • Trauma
  • GI bleed
  • Ectopic pregnancy
  • Ruptured AAA/TAA
• Fluid loss
  
  • Diarrhoea
  • vomitting
  • Burns
  • Polydipsia
    
    • DKA
    • DI
  • Third spacing

Question 3

Mechanisms behind cardiogenic shock

Answer 3

• Reduced contractility
• Arrhthmia
  
  • Bradycardia → decreased HR therefore CO
  • Tachycardia → decreased preload → decreased CO
• Reduced compliance
• Valvular incompetence
  
  • Reduced forward floe

Question 4

Clinical conditions causing cardiogenic shock

Answer 4

• MI
• Myo/pericarditis
• AF/SVY/VT
• Complete heart block
• Valvulopathies
  
  • Mitral regurg
  • Aortic stenosis
• Drug overdose
  
  • CA antagonsit
  • Betablocker

Question 5

What can cause obstructive shock?

Answer 5

• Cardiac tamponade
• Tension pneumothorax
• Pulmonary embolism
• Coarctation of aorta
  
  • First month life when PDA closes
• Air embolus
• Aortocaval compression

Question 6

How does obstruction cause shocl

Answer 6

• Inflow obstruction
  
  • Reduced preload, reducd Stroke vol
• Outflow
  
  • Increased afterload → reduced stroke vol

Question 7

What causes vasogenic shock?

Answer 7

• Adrenal insufficiency
• Spinal cord injuryb
• Anaphylaxis
• SIRS/Sepsis
• Drug overdose
  
  • Ca antagonists
  • Propofol

Question 8

Mechanism of vasogenic shock

Answer 8

• Capacitance vessels
  
  • Reduced preload causes reduced stroke volume
• Resistance vessels
• SVR decreases - increase CO + decrease MAP, redistribution of blood flow may cause cellular hypoperfusion

Question 9

How to treat anyphylactic shock

Answer 9

Call for help
Epinephrine 500mcg IM
Hydrocortisone
Chlorphenamine

Question 10

Treatment for sepsis/septic shock

Answer 10

3 in

• Oxygen
• Fluids
• IV antibiotics - early and effective

3 out

• Bloods
• Lactate
• Urine output

Question 11

What curve determines Mean Arterial Pressure

Answer 11

Frank-sterling = Stroke volume against preload

Question 12

How to calculate mean arterial pressure

Answer 12

CO x SVR
CO= HR X SV

Question 13

Management for shcok

Answer 13

A to E
Oxygen
IV fluids - fluid challenge
Time is tissue

Question 14

What is a fluid challenge

Answer 14

• 250-500ml 0.9% NaCl or Hartmans
• Over no more than 15 mins
• Assess for respsonse and side effects
• Repeat if appropriate
• If 2L and no improvement get more helpn