Cardiovascular - Shock

Question 1

What is shock?

Answer 1

Abnormality of the circulatory system resulting in inadequate tissue perfusion and oxygenation

Question 2

What is hypovolaemic shock?

Answer 2

Loss of blood volume

Question 3

What is cardiogenic shock?

Answer 3

Decreased cardiac output and decreased blood pressure leading to inadequate tissue perfusion

Question 4

Give some examples of obstructive shock

Answer 4

Cardiac tamponade

Tension pneumothorax

Pulmonary embolism

Severe aortic stenosis

Question 5

How does a tension pneumothorax lead to obstructive shock?

Answer 5

Increased intrathoracic pressure causes decreased venous return leading to decreased end diastolic volume and thus decreased stroke volume

Question 6

What is neurogenic shock?

Answer 6

Loss of sympathetic tone leads to massive venous and arterial dilatation leading to decreased venous return and thus decreased cardiac output

Question 7

Give an example of vasoactive shock. How does it occur?

Answer 7

Anaphylaxis

Release of vasoactivate mediators (e.g. histamine, prostaglandins, bradykinin) causes massive venous and arterial dilatation and increased capillary permeability.

Question 8

In addition to the standard treatments for shock, what additional treatment would be given for cardiogenic shock?

Answer 8

Inotropes

Question 9

In addition to the standard treatments for shock, what additional treatment would be given for septic shock?

Answer 9

Vasopressors

Question 10

Give examples of distributive shock.

Answer 10

Spinal cord injury - neurogenic

Anaphylaxis - vasoactive

Septic shock

Question 11

Up to what blood volume can compensatory mechanisms maintain blood pressure?

Answer 11

until >30% of blood volume is lost