Analgesia

Question 1

What is porphyria variegate?

Answer 1

Genetic disorder. Deficiency in any enzyme in haem biosynthetic pathway. Accumulation of haem intermediaries.

Question 2

How confirm porphyria variegate diagnosis?

Answer 2

Test urine Ala and PBG

Question 3

Name 3 triggers porphyria variegate

Answer 3

• Drugs: barbiturates!, diazepam, ketorolac, phenytoin, birth control pills, sulfonamides
• stress (give midazolam premed)
• hypoglycaemia
• sunlight
Dehydration (fluid load 10% dextrose with electrolytes)

Question 4

Treatment porphyria variegate attack? (4)

Answer 4

• Stop precipitating drug
• hydrate with 10% dextrose-saline infusion
• treat symptoms: pain, seizure (midazolam), ht, tachy
• haem arginate official treatment

Question 5

Which agents are definitely safe in porphyria variegate? (9)

Answer 5

• Succinylcholine
• Atropine
• neostigmine
• pancuronium
• nitrous oxide
• procaine
• meperidine (pethidine)
• fentanyl
• morphine

Regional anaesthesia, ketamine, etomidate controversial.
Thiopentone absolute contraindication!!

Question 6

Which analgesic targets secondary hyperalgesia with andromic release of substance p?

Answer 6

Capsaicin

Question 7

Which 3 analgesics target NMDA receptors?

Answer 7

• Ketamine
• magnesium.
Dextromethorphan
Nitrous oxide
Xenon

Question 8

Which 2 analgesics target GABA receptors?

Answer 8

• Pregabalin
• gabapentin

Question 9

Which 2 analgesics target descending alpha 2 pathway?

Answer 9

• Clonidine
• Dexmedetomidine

Question 10

Name an opioid receptor antagonist

Answer 10

Naloxone

Question 11

Which opioids target mu receptor in brain, brainstem and spinal cord and what effects do they have? (5)

Answer 11

Analgesia, euphoria, respiratory depression, constipation
•Morphine
• fentanyl
• met-enkephalin
. B-endorphin

Question 12

Which opioids target kappa receptor in brain, brainstem, hypothalamus and spinal cord and what effects do they have? (3)

Answer 12

Spinal analgesia, sedation, dysphoria
• morphine
• oxycodone

Question 13

Which opioids target delta receptor in telencephalon and spinal cord and what effects do they have? (3)

Answer 13

Analgesia, antidepressant, dependence
-leu-enkephalin
-B-endorphin

Question 14

When should opioid be prescribed?

Answer 14

Only for severe pain because most potent analgesics

Question 15

Name 3 long acting opioids

Answer 15

-morphine (longest)
-tramadol
-pethidine

Question 16

Name 2 medium acting opioids

Answer 16

Fentanyl
Sufentanyl
Take 3-5 minutes, work for 30-60 minutes

Question 17

Name a short acting opioids

Answer 17

Alfentanil
1 minute onset, very potent, last about 10 minutes

Question 18

Name an ultra short acting opioids

Answer 18

Remifentanil. 3 minutes and fastest onset of 2 min

Question 19

Name 6 side effects cox2 inhibitors and NSAIDs

Answer 19

-renal impair
-gastric ulceration
-inhibit platelet aggregation (thrombosis)
-bronchoconstriction
-fluid retention
-PDA closure fetus
COX2 specific increase risk MI

Question 20

Name 4 NSAIDs that have Full COX 1 and 2 inhibition

Answer 20

Full COX 1 and 2 inhibition
-aspirin (irreversible)
-ibuprofen
-diclofenac
-naproxen
-indomethacin

Question 21

Name 3 NSAIDs with preferential COX2 and partial 1inhibition

Answer 21

Nimesulide
Meloxicam
Etodolac

Question 22

Name 3 NSAIDs with primary COX2 and minimal 1inhibition

Answer 22

Etoricoxib
Celecoxib (sulfonamide)
Rofecoxib

Question 23

Name 3 NSAIDs with weak COX2 and 1inhibition

Answer 23

Paracetamol
5-ASA (mesalazine)
sulfasalazine

Question 24

Similarity between mivacurium and cocaine.

Answer 24

Both metabolised by buteryl cholinesterase

Question 25

Analgesic agent of choice for trauma patients with gross hypovolaemia?

Answer 25

Opioids and paracetamol NSAIDs contraindicated!

Question 26

Which 2 receptors does morphine target?

Answer 26

Mu and kappa opioid receptors

Question 27

Which analgesic agent is deleterious for the shocked hypovolaemic patient?

Answer 27

Ketorolac (NSAID)

Question 28

Describe the WHO pain ladder.

Answer 28

Multimodal step-up approach! 1. Non opioid: paracetamol 2. NSAID 3. Weak opioid: tramadol codeine 4. Strong opioid morphine Can give adjuncts with these eg ketamine, dexmedetomidine, regional,steroids (gabapentin- chronic pain)

Question 29

Which analgesic is good to give with TIVA infusion?

Answer 29

Remifentanil • ultra short acting • doesn't build up in body: organ independent breakdown

Question 30

Which analgesic agents are good for short airway procedures eg bronchoscope?

Answer 30

Alfentanyl • good intubation response, very potent • short acting, last about 10 minutes

Question 31

Which analgesic is best to use for induction and intra-op acute pain?

Answer 31

Fentanyl and sufentanyl

Question 32

Give example of multimodal analgesia in a patient undergoing hysterectomy

Answer 32

• Fentanyl: preop and intra-op boluses . Regional: tap • paracetamol • morphine o, 1 mg/kg every 4 hours towards end surgery and post-op (patient controlled best, give 1 mg every 5-6 minutes) • NSAIDs post op if candidate

Question 33

Dose fentanyl?

Answer 33

1 ug/kg (0,001 mg)

Question 34

Dose sufentanyl?

Answer 34

0,1 ug/kg (0,0001 mg)

Question 35

Analgesic opioid of choice in asthmatics?

Answer 35

Pethidine (meperidine) Synthetic opioid so less bronchospasm

Question 36

Side effect tramadol?

Answer 36

Very pro-emetic

Question 37

Name 5 side effects naloxone

Answer 37

• tachycardia • hypertension • myocardial ischaemia • cardiac failure • pulmonary oedema

Question 38

Name 3 side effects flumazenil

Answer 38

Arrhythmia, ht, convulsions

Question 39

Atropine class/moa? NB

Answer 39

Antmuscarinic. Antagonise ach and work on exocrine glands to decrease secretions, smooth muscle (bronchoditation), cardiac (tachy), CNS

Question 40

Cox 1 vs cox 2? (2)

Answer 40

• Cox 1 generates prostaglandins involved in protection gi mucosa vs prostaglandins that mediate inflammation and pain all over body • Inhibitors more gastric side effects and bleeding risk vs less

Question 41

Name 8 side effects morphine

Answer 41

Morphine Myosis Out of it (sedation) Respiratory depression Pneumonia (aspiration) Hypotension Infrequency (constipation, urinary retention ) Nausea emesis

Question 42

Which fibres are responsible for the transmission noxious stimuli? (2)

Answer 42

= elicit tissue damage and activate nociceptors. AKA pain. • C fibres ! • A delta fibres

Question 43

Flumazenil class?

Answer 43

Selective GABA A receptor antagonist (Antag Benzo)