Intro week

Question 1

Fluid and electrolyte requirements for 24hr period:

• Fluid
• Sodium
• Chloride
• Glucose

Answer 1

Fluid - 25-30ml/kg
Sodium - 1mmol/kg
Potassium - 1mmol/kg
Chloride - 1mmol/kg
Glucose - 50-100g/day

Question 2

Fluid requirement for abnormal distribution (e.g. heart failure)

Answer 2

20-25ml/kg/day

Question 3

Appropriate opioid use

3 situations + 1 inappropriate

Answer 3

Acute pain
Cancer pain
End of life

Chronic pain = inappropriate

Question 4

Non-opioid responsive pain:

• Bone
• Nerve compression
• Oedema, inflammation

Answer 4

Bone - NSAID +/- opioid +/- bisphosphonate

Nerve compression - steroid

Question 5

Opioid resistant pain:

• Muscle pain/spasm
• Neuropathic

Answer 5

Muscle - relaxant

Neuropathic - TCA/anticonvulsant

Question 6

WHO pain ladder

Answer 6

Step 1 = non-opioid
Step 2 = weak opioid
Step 3 = strong opioid + non-opioid

Question 7

Step 2/weak opioid examples

Answer 7

Codeine
Tramadol
Buprenorphine

Question 8

Step 3/strong opioid examples

Answer 8

Morphine
Diamorphine
Fentanyl (25mcg/hr patch = 60-90mg PO orphan)
Oxycodone (10mg po = 20mg po morphine)
Alfentanil (1mg SC = 30mg po morphine)

Question 9

Codeine clearance mechanism

Answer 9

Renal

Question 10

Codeine:oral morphine ratio

Tramadol:oral morphine ratio

Answer 10

10:1 i.e. 10x less potent than morphine

240mg codeine = 24mg morphine
100mg = 10mg morphine

Question 11

Morphine preparations

Answer 11

Immediate release (prescribe in mg):

• Oral morphine (oramorph)
• Sevredol tablets

Sustained release
- Most preparations 12 hourly (e.g. MST/zomorph)

Question 12

Breakthrough dose calculation

Answer 12

24hr dose, divided by 6

Question 13

Opioid naive patients

Answer 13

Immediate release liquid morphine (oramorph)
Usually start 2.5-5mg po 4 hourly regularly for 24-48 hours + same dose prn
After 24 hours, consider increasing dose by 1/3rd
No maximum dose

Once a dose relieves the pain:

• Add up total 24hr morphine usage
• Then convert to moprhine sulphate sustained release oral (usually bd prep)

Give pro/breakthrough dose of immediate release
- 1/6 of 24hr dose

Question 14

Starting morphine

Answer 14

• Assess number of breakthrough doses needed and change regular dose accordingly
• Do not mix opioids (exceptions - alfentanil, fentanyl SC/patch, butrans patch)
• Caution in renal/liver impairment

Question 15

Unwanted effects of opioids

Answer 15

Constipation -> prescribe laxative
Drowsiness -> usually resolves, lower dose
Nausea -> usually resolves, anti-emetic

Question 16

Signs of opioid toxicity

Answer 16

Sedation
Confusion
Hallucinations
Myoclonic jerks
Pinpoint pupils
Coma