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Human Disease > Shock > Flashcards

Flashcards in Shock Deck (23):
1

What is shock?

An abnormal circulatory state in which tissue blood flow is reduced. Causes cellular hypoxia

2

What is cardiac output?

HR x SV

3

How does shock lead to lactic acidosis?

Reduced cellular oxygenation
Anaerobic metabolism
Lactic acidosis (reduced pH)

4

What are the 2 types of shock?

Haemorrhagic
Non haemorrhagic

5

What is haemorrhagic shock?

Hypovolaemia - Low blood volume when bleeding
Loss of fluid from intravascular space

6

What is non haemorrhaigc shock?

Cardiogenic
Septic
Anaphylactic
Nerurogenic (spinal)

7

Where does blood sit normally?

42 L total
1/3 in interstitial fluid
2/3 in cells
3L in plasma

8

What does haemorrhagic shock lead to?

Reduced venous return
Reduced cardiac output
Baroreceptor response (at bifurcation of carotid)
Increased SVR

9

Other than bleeding, what are other causes of hypovolaemia?

GI losses- sever diarrhoea
Burns
Diabetic ketoacidosis

10

What are the aims of shock management?

Resolve lactic acidosis
Prevent tissue ischaemia
Optimise CO
Maintain BP

11

How do we manage shock?

ABC
Support physiology
1) Inotropes improve myocardial performance and maintain perfusion pressure to keep blood flow to the organs
2) Vasopressors increase SVR and maintain mean arterial pressure

12

What is cardiogenic shock?

Non - haemorrhagic shock
Pump failure via either myocardial damage or abnormal contraction
1) Myocardial damage - MI (IHD), myocarditis, trauma
2) Abnormal contraction - LA, anti arrythmic drugs, beta blockers, caridac tamponade when fluid is in the pericardium and the heart cant pump

13

How do we improve cardiogenic shock?

Give chronotropes - increase rhythmic activity

14

What is septic shock?

Non haemorrhagic shock
Systemic response to infection

15

What is an endotoxin?

Released from gram -ve bacteria

16

What is an exotoxin?

Released from gram +ve bacteria

17

What is the process of septic shock?

Endo / exo toxin released
Cytokines released
Metabolites and free radicals

18

What does septic shock cause?

Hypotension
Increased blood lactate
Altered end organ perfusion - low urine output, altered CNS, clotting disorders, metabolic disorders

19

How do you manage septic shock?

support physiology
antibiotics
eliminate source

20

What is anaphylactic shock?

Non haemorrhaigc shock
exposure to allergen, mast cells, histamine, complement cascade, systemic effects

21

How do you manage anaphylactic shock?

adrenaline, O2, fluids, corticosteroids, antihistamines, beta 2 agonists

22

What is neurogenic shock?

Non haemorrhaigc shock
Loss of normal sympathetic activity
Due to trauma, drugs, tumor of spinal cord

23

What does neurogenic shock cause?

Vasomotor paralysis below level of injury
Decreased peripheral vascular resistance
Blood pools in capillary beds
Reduced venous return, CO and BP