Shock

Question 1

What are the 4 types of shock?

Answer 1

Hypovolaemic, Cardiogenic, Obstructive, & Distributive

Question 2

What is shock?

Answer 2

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

Question 3

How does shock lead to cellular failure?

Answer 3

Inadequate tissue perfusion -> inadequate tissue oxygenation ->anaerobic metabolism -> accumulation of metabolic waste products -> cellular failure

Question 4

Causes of inadequate tissue perfusion

Answer 4

Loss of blood volume, sudden severe impairment of heart function, physical obstruction to circulation, excessive vasodilation and abnormal distribution of blood flow

Question 5

Cause of Hypovolaemic shock

Answer 5

Loss of blood volume
Haemorrhagic e.g.trauma, surgery, GI haemorrhage
+
Non-haemorrhagic e.g. vomiting, diarrheoa, excessive sweating -> Decreases extracellular fluid volume (increase in plasma))
This decreases blood volume -> decreases cardiac output -> circulatory shock (decrease in MAP)

Question 6

During haemorrhagic shock how long can compensatory mechanisms maintain blood pressure?

Answer 6

Until about >30% of blood volume is lost

Question 7

What are the vitals for class I haemorrhagic shock

Answer 7

Blood loss (ml) - up to 750
Blood Loss (%blood volume) - up to 15
Pulse rate (per min) <100
Blood pressure - normal
Pulse Pressure (mmHg) - normal or increased
Respiratory rate (per min) 14-20
Urine output (ml/hour) >30
Central nervous system/mental status - slightly anxious

Question 8

What are the vitals for class II haemorrhagic shock

Answer 8

Blood loss (ml) 750-1500
Blood Loss (%blood volume) 15-30
Pulse rate (per min) 100-120
Blood pressure - normal
Pulse Pressure (mmHg) - decreased
Respiratory rate (per min) 20-30
Urine output (ml/hour) 20-30
Central nervous system/mental status mildly anxious

Question 9

What are the vitals for class III haemorrhagic shock

Answer 9

Blood loss (ml) 1500-2000
Blood Loss (%blood volume) 30-40
Pulse rate (per min) 120-140
Blood pressure - decreased
Pulse Pressure (mmHg) - decreased
Respiratory rate (per min) 30-40
Urine output (ml/hour) 5-15
Central nervous system/mental status - anxious,confused

Question 10

What are the vitals for class IV haemorrhagic shock

Answer 10

Blood loss (ml) >2000
Blood Loss (%blood volume) >40
Pulse rate (per min) >140
Blood pressure - decreased
Pulse Pressure (mmHg) - decreased
Respiratory rate (per min) >35
Urine output (ml/hour) - negligible
Central nervous system/mental status - confused,lethargic

Question 11

Causes of cardiogenic shock

Answer 11

Sudden severe impairment of cardiac function - heart suddenly unable to pump sufficient blood to provide adequate tissue perfusion e.g. severe heart attack (severe acute MI), decreased cardiac contractility

Question 12

Causes of distributive shock

Answer 12

Excessive vasodilation and abnormal distribution of blood flow. Neurogenic e.g. spinal cord injury and Vasoactive e.g. septic shock, anaphylactic shock

Question 13

Causes of obstructive shock

Answer 13

Physical obstruction to circulation either into or out of the heart e.g. cardiac tamponade, tension pneumothorax, pulmonary embolism, severe aortic stenosis

Question 14

What is the pathway of Hypovolaemic shock

Answer 14

Loss of blood volume -> decreased blood volume -> decreased venous return -> decreased end diastolic volume -> decreased stroke volume -> decreased cardiac output and decreased blood pressure -> inadequate tissue perfusion

Question 15

What is the pathway of cardiogenic shock

Answer 15

Decreased cardiac contractility -> decreased stroke volume -> decreased cardiac output and decreased blood pressure -> inadequate tissue perfusion

Question 16

What is the pathway of tension pneumothorax: obstructive shock

Answer 16

Increased nitrate or acid pressure -> decreased venous return -> decreased end diastolic volume -> decreased stroke volume -> decreased cardiac output and decreased blood pressure -> inadequate tissue perfusion

Question 17

What is the pathway of neurogenic shock

Answer 17

Loss of sympathetic tone to blood vessels and heart -> massive venous and arterial vasodilation, effect on heart rate -> decreased venous return and decreased systemic vascular resistance (TPR), decreased heart rate (unlike other types of shock) -> decreased cardiac output and decreased blood pressure -> inadequate tissue perfusion

Question 18

What is the pathway of vasoactive shock

Answer 18

Release of vasoactive mediators -> massive venous and arterial vasodilation-also increased capillary permeability -> decreased venous return and decreased Systemic vascular Resistance (TPR) -> decreased cardiac output and decreased blood pressure ->inadequate tissue perfusion

Question 19

What are the treatments of sock?

Answer 19

ABCDE approach
High flow oxygen
Volume replacement (except for cardiogenic shock)
Call for help early
Treat cause as appropriate

Question 20

What effect does an increase/decrease in cardiac contractility have on the frank-starling curve

Answer 20

Increase contractility (excercise) - curve shifts to left and higher
Decreased contractility (heart failure) - shifts right and down
Cardiogenic shock (decrease contractility a lot) - shifts very right and down (doesn’t plateau, is arc shaped)

Question 21

Treatment for cardiogenic shock and what can do you?

Answer 21

Inotropes for cardiogenic shock
No volume replacement

Question 22

Treatment for tension pneumothorax

Answer 22

Immediate chest drain for tension pneumothorax

Question 23

Treatment for anaphylactic shock?

Answer 23

Adrenaline for anaphylactic shock

Question 24

Treatment for septic shock

Answer 24

Vassopressors for septic shock