Shock

Question 1

What are the types of shock?

Answer 1

1. Hypovolemic
2. Distributive
3. Cradiogenic
4. Mechanical

Question 2

What are the 3 main initial responses to hypovolemic shock?

Answer 2

1. Baroreceptors
2. RAAS
3. Internal transfusion: Increasing the TPR decreases hydrostatic pressure which means more fluid will flow into capillaries

Question 3

What is decompensated shock in hypovolemia?

Answer 3

Decompensated shock is the signs/symptoms experienced when the initial bodily responses to fix shock failed and have become excessive

Question 4

What are the 4 primary signs of decompensated shock?

Answer 4

1. Excessive sympathetic activity: sweaty, clammy, tachycardic
2. RAAS can cause excessive vasoconstriction which leads to a very high TPR: causing cold and clammy peripheries, pallor, weak peripheral pulses and prolonged capillary time
3. Decreased perfusion to the brain
4. Tachypnoea: the body is trying to breathe faster to emit the lactic acid that is forming as a result of decreased perfusion and oxygen

Question 5

What are the causes of mechanical shock?

List 2 major causes, the path of each and what the capillary refill time would be

Answer 5

Failing to fill the ventricles either due to an obstruction or a restriction

Obstruction Eg. A massive, proximal PE can occlude a large pulmonary artery which means…

RV cannot empty ➞ reduced return of blood/filling of left heart ➞ reduced (left) EDV ➞ reduced SV ➞ fall in CO ➞ fall in MABP

Filling restriction Eg Cardiac tamponade where blood/fluid build up in pericardial space restricts filling of the heart, which results in…

Reduced EDV ➞ reduced SV ➞ fall in CO ➞ fall in MABP + high CVP

Capillary refill time would be prolonged as there is more blood in the peripheries that can’t circulate

Question 6

What is Beck’s triad?

Answer 6

A sign of cardiac tamponade: low BP, raised JVP, muffled heart sounds

Question 7

What is the cause of cardiogenic shock? What are some causes and the inevitable outcome?

Answer 7

The heart cannot contract enough to empty the ventricles, could be due to an MI, HF, arrhythmia and causes a reduced SV and CO –> lowering the BP and the CVP

Question 8

What is characteristic of distributive shock and are the two causes?

Answer 8

Profound peripheral vasodilation, anaphylactic shock and septic shock

Question 9

What happens in septic shock and what is the clinical picture?

Answer 9

Bacteria release endotoxins that cause:
1. vasodilation lowering the TPR
2. increased vascular permeability
The Baroreceptors sense this and trigger an increase in HR

Clinical picture: tachycardia, hypotension, warm/red extremities

Question 10

What happens in anaphylactic shock and what is the clinical picture?

Answer 10

A severe allergic reaction causes MAST cells to degranulate abundant histamine causing extreme vasodilation. The hypersensitive reaction can cause increased permeability - leading to laryngeal edema, bronchospasms and difficulty breathing

Clinical picture: tachycardia, hypotension, warm/red extremities, airway inflammation