Lecture 28: Shock and Hemorrhage

Question 1

Circulatory shock occurs when

Answer 1

The blood pressure falls so low that adequate blood flow to the tissues can no longer be maintained

Question 2

Four types of circulatory shock

Answer 2

1. Hypovolumic
2. Vasogenic
3. Cardiogenic shock
4. Neurogenic

Question 3

Hypovolemic shock is induced by

Answer 3

A fall in blood volume

Question 4

Four ways hypovolemic shock can occur

Answer 4

1. Hemorrhage
2. Burns
3. Trauma and surgery
4. Severe diarrhea and vomiting

Question 5

What’s the most common cause of hypovolumic shock

Answer 5

hemorrhage

Question 6

What happens during hemorrhage

Answer 6

• Decreases the filling pressure of the circulation
• Decreased venous return
• Decreased cardiac output
• Shock

Question 7

What happens during burns

Answer 7

• Loss of plasma in exudate from damaged tissue
• Loss in blood volume with little to no change in rbc concentration
• hemocencentration
• Increased blood viscosity
• Increased afterload on heart
• Loss of plasma volume
• Decreased venous return, decreased cardiac output

Question 8

Exudate

Answer 8

A fluid with a high content of protein and cellular debris which has escaped from blood vessels and has been deposited in tissues or on tissue surfaces

Question 9

Hemoconcentration

Answer 9

Increase in the proportion of formed elements in the blood, as a result of a decrease in its fluid content

Question 10

Surgery and trauma shock can occur without the hemorrhage because

Answer 10

Contusion of the body can damafe capillaries enough to allow excess loss of plasma into tissues

Question 11

Two types of vasogenic shock

Answer 11

1. Septic shock

2. Anaphylaxis

Question 12

Septic shock

Answer 12

• Endotoxin released by invading bacteria stimulates nitric oxide release by macrophages
• Thought to contribute to the severe hypotension characteristic of septic shock

Question 13

Anaphylaxis

Answer 13

• Severe allergic reaction to an antigen

- Release in a large amount of histamine

Question 14

Histamine promotes

Answer 14

• Profound vasodilation

- Increased permeability of capillaries which promotes protein and fluid loss, resulting in edema

Question 15

Cardiogenic shock

Answer 15

Blood flow to tissues is no longer adequate to meet resting metabolic demands

Question 16

Cardiogenic shock is most commonly due to

Answer 16

extensive infarction of the left ventricle

Question 17

Why is cardiogenic shock sometimes called congested shock?

Answer 17

Associated with congestion of lungs

Question 18

Neurogenic shock

Answer 18

Produced by loss of vascular tone due to inhibition of the normal tonic activity of the sympathetic vasoconstrictor nerves
-Often caused by brain/spinal cord injury and deep excruciating pain

Question 19

Five effects of shock

Answer 19

1. Decreased metabolism
2. Muscular weakness
3. Decreased body temperature
4. Impaired mental function
5. Reduced renal function

Question 20

Usually a patient can continue to live for only a few hours if the cardiac output falls to as low as

Answer 20

40% below normal

Question 21

One of the earliest symptoms of shock is

Answer 21

muscular weakness

Question 22

Why is there reduced renal function in shock?

Answer 22

Diminishes urine output because of decreased filtration of fluid into Bowman’s capsule, due to a decrease in glomerular pressure