2. Definition of Pain
‘An unpleasant sensory and emotional
experience associated with actual or potential
tissue damage, or described in terms of such
damage’ (International Association for the Study of Pain)
‘whatever the experiencing person says it is,
existing whenever he says it does’ (Margo McCaffrey ,
1968)
6. Drug Relative potency to Oral
Morphine
Oramorph (4hourly) 1
MST (12hourly) 1
IM Morphine 2
Sc Morphine 2
Diamorphine 3
Oxycodone 2
Fentanyl 150
Hydromorphone 7.5
Tramadol 0.2
7. Prescribing
• Starting dose for morphine 10mg 4 hourly
(2.5-5mg in frail/elderly)
• The same dose (10mg) is PRN dose (1/6th
of
total daily dose)
• Increase incrementally over days until
patient’s pain controlled
8. Case 1
• Mrs K, a 50 year old lady with breast cancer
and pain from bone metastases
• Currently on Cocodamol 30/500, 2 tablets,
QDS.
• Pain not controlled
• What should you do?
9. Case 1 Answers
• Pain not controlled so need to go up WHO
pain ladder
• Add in strong opiate.
• Starting dose Oramorph 10mg 4hourly and
PRN Oramorph 10mg.
• Consider antiemetics and laxatives
• Titrate dose up gradually until pain controlled
10. Prescribing
• When daily morphine requirements are stable
can convert 4hourly morphine into modified
release form
• Same total daily dose given but split into 2
doses rather than 6.
• I.e Oramorph 10mg 4hourly is equivalent to
MST 30mg 12hourly.
• PRN dose remains the same (10mg Oramorph)
11. Case 2
• Mrs K’s pain is finally controlled with
Oramorph 30mg. She does not like taking so
many tablets.
• What do you do?
12. Case 2 answer
• Change to modified release morphine e.g.
MST.
• Dose is total daily amount of oramorph split
into 2 doses 12 hours apart
• MST 90mg 12hourly and PRN Oramorph 30mg
13. Prescribing if patient unable/unwilling
to swallow
• IM morphine – divide total daily dose of oral morphine
by 2. Then split between 6 daily doses (4hourly).
– E.g Oramorph 10mg 4hourly is equivalent to IM Morphine
sulphate 5mg 4hourly.
• IM Diamorphine- better for palliative care patients
because more soluble so given in smaller volume than
morphine sulphate.
– Divide total daily dose by 3 and split into 6 daily doses.
– E.g. Oramorph 15mg 4hourly becomes Diamorphine 5mg
4hourly. (Comes in 5, 10, 30,100 and 500mg ampules)
14. Case 3
• Mrs K becomes more weak and unwell, she
can no longer swallow, but she is distressed by
her pain. She is still prescribed MST 90mg
12hourly and PRN Oramorph 30mg.
• What should you do?
15. Case 3 Answer
• Needs parenteral route for pain relief
• IM Morphine sulphate 15mg 4hourly (90x2/2
into 6 doses) and PRN IM Morphine sulphate
15mg
Or
• IM Diamorphine 10mg 4hourly (90x2/3 into 6
daily doses) and PRN IM Diamorphine 10mg
16. Syringe drivers
• Diamorphine can also be given sc so can be
put in a syringe driver
• Divide total daily dose oral morphine by 3
• E.g. Oramorph 10mg 4hourly is equivalent to
20mg Diamorphine over 24hours in syringe
driver.
17. Case 4
• Mrs K is cachetic and the regular IM injections
are difficult to do. She is currently prescribed
IM diamorphine 10mg 4hourly and PRN
Diamorphine 10mg.
• What should you do?
18. Case 4 answer
• Set up a syringe driver
• Total daily dose of diamorphine put into
syringe driver and infused over 24hours.
• Diamorphine 60mg over 24hours in syringe
driver (10x6)
• PRN Diamorphine 10mg IM
• Consider adding any other necessary drugs to
syringe driver e.g. Antiemetics.
Editor's Notes
Subjective
Multidimensional- sensory - nociception
- affective, relates to mood –distracted feel less pain when stub toe etc..
- cognitive therefore potentially if have impaired emotional centres in brain may not experience pain in same way
2nd definition great but if there is limited communication available e.g. Cognitive impairment then this does not help!
Post-op #NOF surgery start at Step 3
Morrison and Siu, 2000
76% of patients rated pain after hip surgery as moderate or severe, therefore should be receiving opiate medication according to WHO ladder. If cognitively impaired patients experience pain in the same way then also would have moderate/severe pain.
Adjuvant means something like NSAID
Mild opiate e.g. codeine
Step 3 – Should be going in with a combination of all these drugs.
BUT:
NSAIDS – GI problems particulary bad in elderly. The incidence of gastrointestinal bleeding from NSAIDs is nearly twice as high in patients over 65 as in younger patients. Elderly may already have some renal impairment. Need to monitor renal dysfunction as well as bp and heart failure due to fluid retention. Therefore use with caution in elderly.
Paracetamol high dose = >2g/24hrs for older adults (4g/24hrs normally)
Opioids – many different routes of admin
- mild but common s/e in elderly is constipation, always co-prescribe with laxative.
- rare but severe s/e is respiratory depression
Other options :
PCA – IV opioids, but not suitable for patients with cognitive impairment as don’t associate pushing button with relieving pain.
Epidural- continuous epidural anaesthesia. Can use LA, opiates or combination.
Foss, 2005. RCT showed that continuous epidural after hip fracture surgery reduced pain on active movement without problems with motor blockade compared to IV morphine. However did not influence overall rehab outcome as other s/e such as hypotension, nausea and exhaustion which prevented physiotherapy.
Regional anaesthesia. Often used pre-operatively so patients can be moved in bed easily without pain. If used post-op can give pain relief for a number of hours. May prevent physio if continued and associated with other complications such as nerve injury and the need for catherisation.
Foss et al, 2005. Double blind RCT. 1st trial on hip fracture patients, most of previous evidence for elective hip replacements. Compared continuous epidural anaesthesia with conventional IV opioid nurse controlled pain relief and a placebo epidural.
Post-op epidural analgesia with LA and low-dose morphine provided superior pain control during dynamic exercise in patients who underwent surgery for hip fracture
Motor blockade not a problem. Patients were significantly less restricted by pain in their ability to perform basic functions without motor blockade.
However, overall ability to perform basic mobility functions independently was not significantly improved, potentially because of other confounding limiting factors, such as nausea and exhaustion, that impeded physical function despite the absence of pain.
Study excluded patients with a cognitive impairment.
Future studies with multimodal rehabilitation are required to establish whether superior analgesia can be translated into enhanced rehabilitation and reduced morbidity in hip fracture patients.
So...less pain with epidural but may not influence rehab outcome because of side effects.
