cardiovascular responses to shock

Question 1

what is shock?

Answer 1

an abnormality of the circulatory system resulting in inadequate tissue perfusion and oxygenation

Question 2

describe the pathway of shock

Answer 2

1. shock
2. inadequate tissue perfusion
3. inadequate tissue oxygenation
4. anaerobic metabolism
5. accumulation of metabolic waste products
6. cellular failure

Question 3

describe the pathway of hypovolaemicshock

Answer 3

1. loss of blood volume
2. decreased blood volume
3. decreases venous return
4. decreased end diastolic volume
5. decreased stroke volume
6. decreased cardiac output and decreased blood pressure
7. inadequate tissue perfusion

Question 4

what are the different types of shock?

Answer 4

cardiogenic shock
obstructive shock
distributive shock
hypovolemic shock
vasoactive shock
neurogenic shock

Question 5

describe the pathway of cardiogenic shock

Answer 5

1. decreased cardiac contractility
2. decreased stroke volume
3. decreased cardiac output and decreased blood pressure
4. inadequate tissue perfusion

Question 6

desrieb the pathway of neurogenic shock

Answer 6

1. loss of sympathetic tone to blood vessels and heart
2. massive venous + arterial vasodilatation+ effect on heart rate
3. decreased venous return + decreased SVR (TRP) + decreased heart rate
4. decreased CO and decreased BP
5. inadequate tissue perfusion

Question 7

describe the pathway of vasoactive shock

Answer 7

1. release of vasoactive mediators
2. massive venous + arterial vasodilatation - also increased capillary permeability
3. decreased venous return + decreased SVR (TRP)
4. decreasedd CO + decreased BP
5. inadequate tissue perfusion

Question 8

what is the treatment for shock?

Answer 8

1. ABCDE approach
2. high flow oxygen
3. volume replacement - except for cardiogenic shock
4. call for help early
5. inotropes for cardiogenic shock
6. immediate chest drain for tension pneumothorax
7. adrenaline for anaphylactic shock
8. vasopressors for septic shock
9. treat cause as appropriate

Question 9

causes oh hypovolaemic shock

Answer 9

• haemorrhage (trauma, surgery, GI etc)
• > decreased blood volume = decreased CO
• > circulatory shock
• vomiting, diarrheoa, excessive sweating
• > decreased ECFV
• > decreased blood volume = decreased CO
• > circulatory shock