Chapter 46-50

Question 1

Brain stem death

Answer 1

Irreversible coma and apnoea

Question 2

Brain stem anatomy

Answer 2

Extending from upper cervical spinal cord to diencephalon.

Medulla
Pons
Midbrain

Question 3

Functions

Answer 3

1) Conduction of all motor and sensory pathways, EXCEPT olfaction and vision.

2) Autonomic function - respiratory drive, HR, BP, digestion, micturation, sleep

3) Origin of cranial nerve nuclei 3-12

Question 4

Criteria to CONSIDER brain stem death

Answer 4

1. Irreversible cause of brain injury
2. Coma
3. Ventilator dependency - spontaneous ventilation absent or inadequate.

2 doctors, >5 years practice

Question 5

Narcotic/ barbituate/ opiate effect

Answer 5

Directly effect respiratory centre
Weaken effect of elevated CO2 on respiratory drive.

Question 6

Brain stem reflexes fail at what temperature?

Answer 6

32C
Warm >35C before tests conducted

Question 7

Pupillary Reflexes

Answer 7

CN 2+3

Question 8

Corneal reflex

Answer 8

CN 5 and 7

Question 9

Vestibulo-ocular

Answer 9

Slow injection of ice cold water into EAM
3,4,6,7

Question 10

Gag reflex

Answer 10

9 and 10

Question 11

Pyloric stenons

Answer 11

Hypokalaemic hypochloraemic alkalosis

Question 12

NSAIDs MoA

Answer 12

Inhibit COX enzymes, which decrease the synthesis of prostaglandin H2 from arachadonic acid

Question 13

Prostaglandin H2

Answer 13

Converts into further prostaglandins and thromboaxane (causes platelet aggregation and platelet constriction)

Question 14

Paracetamol MoA

Answer 14

Inhibition of prostaglandins centrally (in hypothalamus)
Weak inhibitor of COX 1 and 2

Question 15

NAPQI inactivated by

Answer 15

Glutathione

Question 16

Paracetamol absorbed where

Answer 16

Duodenum

Question 17

Aspirin risk in infancy

Answer 17

Reye Syndrome

Question 18

Poisoned patient with metabolic acidosis…

Answer 18

Calculate Anion gap
Including K+ is 3-11

Question 19

Severe anion gap metabolic acidosis

Answer 19

Classical of ethylene glycol poisoning

Especially if lactate and urea not very elevated

Question 20

Ethylene Glycol

Answer 20

Antifreeze

Severe anion gap metabolic acidosis

Tachypnoea, tachycardia, HTN
Shock, coma, death

Question 21

Treatment of antifreeze

Answer 21

Competitive inhibition of alcohol dehydrogenase

Use ethanol or Fomepizole

Question 22

Paracetamol blood gas

Answer 22

Metabolic acidosis
Lactic acidosis common

Hepatic dysfunction
Derranged INR

Question 23

Salicylates toxicity

Answer 23

Mixed respiratory alkalosis and metabolic acidosis

Hyperventilation first causes respiratory alkalosis
Then ketosis causes metabolic acidosis

Question 24

Causes of raised anion gap metabolic acidosis

Answer 24

MUDPILERS

Question 25

MUDPILERS

Answer 25

Methanol poisoning (Formic acid) Uraemia (check urea) Diabetes (check ketones) Paraldehyde poisoning Isoniazid/ Iron Lactate from hypoxia Ethylene Glycol Rhabdomyolysis (check CK) Salicylate

Question 26

Crossover Design

Answer 26

Single group undergoes more than one intervention in a random order E.g. study relating to relief of symptoms rather than cure. Requires 'wash out' period to allow first intervention to wear off

Question 27

Risk of multiple outcomes

Answer 27

Increase risk of detecting spurious treatment effect