Shock

Question 1

What is shock?

Answer 1

A syndrome where tissue perfusion is inadequate for the tissue’s metabolic requirements

Question 2

What causes hypovolaemic shock?

Answer 2

Loss of plasma or blood volume

= acute haemorrhage, severe dehydration, burns)

Question 3

How does hypovolaemia affect cardiac output?

Answer 3

Volume depletion → reduced SVR → reduced pre-load → decreased CO

Question 4

What causes cardiogenic shock?

Answer 4

Pump failure due to reduced contractility, heart rate, or stroke volume

= MI, cardiomyopathies, valvular issues).

Question 5

What is the mortality rate in cardiogenic shock after MI involving >40% of the LV?

Answer 5

> 75%

Question 6

How do CO and perfusion differ in distributive shock?

Answer 6

CO may increase, but perfusion is poor due to regional differences and impaired oxygen extraction

Question 7

What causes distributive shock?

Answer 7

Disruption of vascular autoregulation and profound vasodilation

= sepsis, anaphylaxis)

Question 8

Name causes of obstructive shock

Answer 8

(1) PE
(2) air/fat/amniotic embolism tamponade
(3) tension pneumothorax

Question 9

What endocrine disorders can cause shock?

Answer 9

(1) Severe hypothyroidism
(2) Addisonian crisis
(3) Thyrotoxicosis (can lead to A Fib)

Question 10

What is the common end pathway of shock?

Answer 10

Cellular ischemia triggers inflammatory mediators → vasoconstriction, oedema, cytotoxic damage

Question 11

Name key inflammatory mediators in shock

Answer 11

Cytokines, TNF-alpha, nitric oxide, platelet-activating factor, lysosomal enzymes

Question 12

How does nitric oxide contribute to vascular reactivity loss in shock?

Answer 12

Inflammatory pathways induce iNOS → 1000x NO increase → smooth muscle relaxation, vasodilation

Question 13

What is a common feature of all types of shock?

Answer 13

Hypotension

Question 14

What are signs of cardiogenic shock?

Answer 14

Myocardial failure signs:
(1) chest pain
(2) fatigue
(3) SOB
(4) oedema

Question 15

How is hypovolaemic shock present?

Answer 15

Pale, cold skin, prolonged capillary refill

Question 16

What are the signs of distributive shock in sepsis vs anaphylaxis?

Answer 16

Sepsis: Pyrexia, vasodilation, rapid capillary refill.

Anaphylaxis: Erythema, bronchospasm, profound vasodilation

Question 17

What is the gold standard for measuring cardiac output in shock?

Answer 17

Thermodilution with a pulmonary artery catheter

Question 18

What surrogate markers assess perfusion?

Answer 18

Blood pressure, consciousness, urine output, lactate levels

Question 19

What is the first step in managing shock?

Answer 19

ABCDE approach and wide-bore IV access

Question 20

How is a fluid challenge administered?

Answer 20

300-500 mL over 10-20 minutes, with targets like ↑MAP, ↓HR, or ↑urine output

Question 21

Which drug is a low-dose beta-adrenergic agonist and high-dose alpha-agonist?

Answer 21

Adrenaline

Question 22

What drugs are used for vasoconstriction in severe shock?

Answer 22

(1) Noradrenaline
(2) Vasopressin
(3) Dopamine
(4) Dobutamine

Question 23

What are the mechanical options for cardiogenic shock?

Answer 23

Balloon pumps

Question 24

Why is “de-resuscitation” important?

Answer 24

To remove excess fluid after resolving shock, using diuretics, dialysis, or spontaneous means

Question 25

What are the types of shock?

Answer 25

Hypovolaemic (blood loss)
Septic (severe systemic infections)
Anaphylactic
Cardiogenic (poor cardiac output)
Neurogenic
Anaphylactic shock

Question 26

A 30-year-old man comes into the emergency department. His blood pressure is 80/60 mmHg, and his heart rate is 105 bpm. He is pale and cool. On auscultation, crackles can be heard at both bases.

What kind of shock is this?

Answer 26

Cardiogenic shock

Question 27

What is the blood loss in millilitres for (1) Class 1 shock
(2) Class 2 shock
(3) Class 3 shock
(4) Class 4 shock

Answer 27

(1) <750 mL
(2) 750-1500mL
(3) 1500-2000mL
(4) >2000mL

Question 28

What percentage of blood loss is associated with;
(1) Class 1 shock
(2) Class 2 shock
(3) Class 3 shock
(4) Class 4 shock

Answer 28

(1) <15%
(2) 15-30%
(3) 30-40%
(4) >40%

Question 29

At what pulse rate does
(1) Class 1 shock
(2) Class 2 shock
(3) Class 3 shock
(4) Class 4 shock
occur?

Answer 29

(1) <100
(2) >100
(3) >120
(4) >140

Question 30

How does blood pressure change in Class’s I - IV shock?

Answer 30

I - normal
II - normal
III - decreased
IV -decreased

Question 31

> 35 resp rate indicates what class shock?

Answer 31

IV

Question 32

What are the symptoms associated with class I - IV shock?

Answer 32

Class I - normal
Class II - anxious
Class III - confused
Class IV - letsargic

Question 33

A 32-year-old man is admitted to hospital following a road traffic accident. Initial assessment reveals extensive pelvic injury. The patient is drowsy and speaking incoherently.

A set of observations are performed during initial resuscitation:
Heart rate 128 bpm Blood pressure 83/68 mmHg Respiratory rate 36 /min Oxygen saturations 98% on room air Temperature 36.5 °C

What stage of hypovolaemic shock is the patient most likely to be in?

and why?

Answer 33

Stage 3

= The patient has all the features of stage 3 shock, confusion, tachycardia, hypotension, tachypnoea and reduced pulse pressure

Question 34

A 29-year-old man is admitted to the emergency department having been stabbed in the right flank. On examination, he is mildly anxious, with a heart rate of 110 bpm, blood pressure of 130/65mmHg, RR 25 with normal urine output.

What likely class of haemorrhagic shock is this patient presenting with?

and why?

Answer 34

Class II

= Class II haemorrhagic shock describes an estimated blood loss of 750-1500ml (15-50%). The heart rate is typically 100-120 BPM. Blood pressure remains normal. The respiratory rate is typically 20-30/min. Urine output is slightly low i.e. 20-30ml/hr. The patient may appear mildly anxious