Week 5 - Shock & Hypertension

Question 1

What is shock?

Answer 1

• condition where circulatory system cannot provide adequate blood supply to vital organs
• results when MAP decreases
• MAP = HR x HV x TPR
• decrease of any of them will result in shock

Question 2

What are the types of shock?

Answer 2

hypovolemic
- loss of blood or plasma
- SV decreases
cardiogenic
- very low cardiac output
- SV and/or HR decreases
vasogenic
- septic or anaphylactic
- TPR decreases
neurogenic
- neural
- TPR decreases

Question 3

What is non-haemorrhagic hypovolemic shock?

Answer 3

• caused by loss of water or plasma
• from diarrhoea/ cholera
• excessive urinary loss
• burn injuries causing plasmas to travel to surface
• loss of blood volume decreases CO
• treat by fluid replacement

Question 4

What is haemorrhagic hypovolemic shock?

Answer 4

• caused by blood loss
• from external/internal injury
• loss of blood volume decreases CO
• treat by stopping bleeding and then fluid replacement
• classified from class I (normal healthy state) to class IV (pre-terminal and requiring of immediate intervention)

Question 5

What is cardiogenic shock?

Answer 5

• caused by infarction (heart attack) or fibrillation
• or other heart pathologies
• heart is weakened
• becomes an ineffective pump
• lower stroke volume decreases cardiac output
• underlying cause needs to be treated
• no fluid as it would cause fluid overload

Question 6

What is septic vasogenic shock?

Answer 6

• caused microorganisms
• bacteria release toxins
• damage enodthelial cells
• excessive vasodilation and inflammation
• underlying cause needs to be treated

Question 7

What is anaphylacsis vasogenic shock?

Answer 7

• caused by extreme hypersensitivity reaction
• excessive vasodilation decreases resistance
• airway needs to be maintained

Question 8

What is neurogenic shock?

Answer 8

• caused spinal cord injury or drugs
• defective vasoconstrictor tone
• decreased resistance
• underlying cause needs to be treated

Question 9

What is the short term compensatory mechanism?

Answer 9

• baroreceptor reflex
• increases MAP after detecting a decrease
• in the aortic arch and carotid sinus
• does not correct problem

Question 10

What is the long-term compensatory mechanism of shock?

Answer 10

• increased thirst
• hormonal renal regulation of blood volume
• hormonal regulation of MAP via epinephrine

Question 11

What is irreversible shock?

Answer 11

• compensatory mechanisms are not sufficient because too much blood has been lost
  hypotheses
• hypoxia builds up vasodilator substances
• localised vasodilation preferred over general vasocontriction
• metabolic acidosis
• anaerobic metabolism leads to lactic acid build up
• impairs enzyme activity
• cannot produce ATP
• kidney malfunction
• electrolyte imbalance
• cardiac arrhythmias
• myocardial toxic factors released from hypoxia
• weakens heart
• intravascular clotting