OPIODS

Question 1

What is hyperalgesia?

Answer 1

It is an increased sensitivity to pain

Question 2

What is life threatening about opioids?

Answer 2

They can cause respiratory depression

Question 3

What is acute pain?

Answer 3

• Pain that is of recent onset and is less than 6 weeks.

- Usually resolves with healing

Question 4

What is chronic pain?

Answer 4

• Pain that is is present for more than 3 months

- outlasts the potential for healing

Question 5

How does depolarisation happen in the dorsal horn of the spinal cord?

Answer 5

Th nerve free endings(nociceptors) being stimulated cause depolarisation and then an impulse is generated

Question 6

What type of pain do delta fibres transmit?

Answer 6

-sharp, well-localised pain followed by a dull and persistent pain via the C-fibres

Question 7

What inflammatory markers are released?

Answer 7

• potassium
• serotonin
• hitamine
• substance P
• cytokines
• prostaglandins
• nitric oxide

Question 8

What favourable effects of opioids do we want?

Answer 8

• analgesia
• euphoria, tranquility
• synergism
• cardiovascular effects
• respiratory depression

Question 9

What is the function of opiods on the vagal nuclei?

Answer 9

It causes decreased heart rate and vasodilation(eg. if the surgeon opens up the patient and starts messing in there, the patient won’t have tachycardia and increased heart rate

Question 10

What can you do to reverse respiratory depression caused by opiods?

Answer 10

• provide oxygen
• mechanical ventilation
• naloxone to reverse however very short acting(around 0 minutes)

Question 11

What are the things we can do to prevent respiratory depression?

Answer 11

1. Decrease the dose of analgesia
2. monitor the patients closely
3. provide mechanical ventilation
4. provide multimodal analgesia

Question 12

Which drugs are lipophillic and hydrophillic?

Answer 12

1. morphine-hydrophilic

2. fentanyl-lipophilic

Question 13

Why do we need to give an infusion after a bolus of fentanyl?

Answer 13

-fentanyl is short acting and so we need to infuse it over time to ensure the patient does not feel pain during

Question 14

What is morphine terminated by?

Answer 14

elimination

Question 15

What is fentanyl terminated by?

Answer 15

redistribution

Question 16

What drugs are categorised as the first step/simple analgesics?

Answer 16

1. paracetamol
2. NSAIDS
3. Codeine

Question 17

What drugs are categorised as the second step/moderate analgesics?

Answer 17

1. Tramadol

2. Higher dose of codeine

Question 18

What drugs are categorised as severe pain analgesics?

Answer 18

1. morphine

2. fentanyl

Question 19

What are the most NB factors regarding paracetamol?

Answer 19

• acts centrally and peripherally via the COX-3 enzyme
• no anti-inflammatory effects
• anti-pyretic
• possible hepatic necrosis and failure(give N-acetylcysteine to protect from liver damage

Question 20

What is the onset of action and duration of action for paracetamol?

Answer 20

1. onset: 30 minutes

2. duration: 2-5 hours

Question 21

What is perfalgan?

Answer 21

-It is a IV form of paracetamol that has an onset of duration of 5-10 minutes

Question 22

Where do NSAIDS work?

Answer 22

1. COX-1 and COX-2

Question 23

What are the effects of NSAIDS on thromboxane production?

Answer 23

1.

Question 24

What are the effects of NSAIDS on thromboxane production?

Answer 24

1. reduced platelet aggregation and risks of bleeding

Question 25

What are the side effects of NSAIDS?

Answer 25

1. gastric irritation 2. bronchospasm 3. renal dysfunction 4. platelet dysfunction 5. hepatotoxicity 6. myocardial dysfunction

Question 26

What is the dosage of Ibuprofen?

Answer 26

200-400 mg orally 8 hourly

Question 27

What is the dosage of codeine?

Answer 27

30-60 mg orally 4-6 hourly | -available as a syrup or tablet

Question 28

What is the additional mechanism of tramadol?

Answer 28

-it inhibits noradrenaline and serotonin(5-HT) at the presynaptic nerve endings

Question 29

What are the side effects of pethidine?

Answer 29

- originally intended as an anti-cholinergic | - can produce dry mouth, tachycardia, convulsions, hyperpyrexia, coma,

Question 30

What is the dosage of morphine that adults and children can get IV and IM?

Answer 30

1. 0,1-0,2 mg.kg 4-6 hourly | oral dose is double the parenteral

Question 31

How much do we titrate morphine intra-operatively?

Answer 31

1-5mg IV

Question 32

How much more is fentanyl more lipid soluble than morphine?

Answer 32

600 times

Question 33

What is the onset of action and duration of action of fentanyl?

Answer 33

1. onset: 3-4 minutes | 2. duration: 30-40 minutes

Question 34

How does fentanyl help with LMA/ETT insertion?

Answer 34

It relaxes the laryngeal reflexes

Question 35

What is the difference between fentanyl ,alfentanil and sufentanil?

Answer 35

sufentanil and alfentanil are short acting when given as boluses -alfentanil is particularly good at inhibiting the effect of increased BP and HR

Question 36

Remifentanil?

Answer 36

-ultra-short acting opiate as a result of rapid metabolism by non specific plasma and tissue esterases

Question 37

What is naloxone?

Answer 37

- acts on all the pain receptors | - can cause pulmonary oedema, arrythmias, hypertension

Question 38

What does NSAIDS work on?

Answer 38

Cox 2+3

Question 39

What does paracetamol work on?

Answer 39

COX 1+2

Question 40

What are the intra-op signs of pain?

Answer 40

1. Hypertension because of sympathetic stimulation 2. FRC decreases 3. FEV1 decreases 4. Hyperglycaemia