Palliative Care AS Flashcards
Analgesic Ladder?
1) Paracetamol + NSAIDs
2) Then weak opioids such as codeine and dextropropoxyphene
3) Strong opioid drugs such as morphine. Analgesia from peripherally acting drugs.
WRSA analgesic ladder - Postop
- Management of acute pain.
= Pain can be acute and severe therefore strong analgesics in combo with local anaesthetic blocks and peripheral acting drugs.
- Second rung on postop ladder is restoration of use of oral route to deliver analgesia.
- Final step is only used peripherally acting agents alone.
Use of local anaesthetics?
Infiltration of wound with long-acting local anaesthetic such as bupivacaine.
Analgesia for several hours.
Further pain relief can be obtained with repeat injections or by infusions via a thin catheter.
Blockade of plexus or peripheral nerves will provide selective analgesia in those parts of the plexus or nerves.
Provide anaesthesia for surgery or specifically postop pain relief.
Spinal anaesthesia?
Surgery for lower half of body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used.
Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea, urinary retention.
Epidural anaesthesia?
Indwelling epidural catheter inserted.
Excellent analgesia. Still preferred option following major open abdo procedure.
Disadvantages = usually for patients confined to bed. Need an indwelling catheter.
May develop an epidural haematoma.
Transversus abdominal plane block?
Technique uses an ultrasound to find the correct muscle plane and local anaesthetic is injected.
diffuses into spinal nerves.
Preferred when there is extensive laparoscopic abdominal procedure.
Examples of strong opioids?
Severe pain arising from deep or visceral structures requires use of strong opioids?
Morphine
- Short half life and poor bioavailability
- Metabolised in liver and clearance is reduced in patients with liver disease.
- SE + Nausea, vomiting, constipation and respiratory depression
Tolerance may occur with repeated dosage.
Pethidine
- Synthetic opioid which is structurally different from morphine but which has similar actions.
- Has 10% potency of morphine.
- Short half life and similar bioavailability and clearance to morphine.
- Short duration of action and may need to be given hourly.
- Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions.
- Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure.
Examples of weak opioids?
Markedly less active than morphine - predictable effects when given orally and is effective against mild and moderate pain.
Management of neuropathic pain?
First line: Amitriptyline or pregabalin
Second line: Amitriptyline and pregabalin
Third line: refer to pain specialist - give tramadol (Avoid morphine)
Diabetic neuropathic pain: Duloxetine.
Opioids in palliative care management?
Offer patients with advanced and progressive disease regular oral modified release or oral immediate release morphine with oral immediate release morphine for breakthrough pain.
If no comorbidities = 20-30mg of MR a day with 5mg morphine for brekthrough pain.
15mg modified release morphine tablets 2xa day with 5mg of oral morphine solution PRN.
Oral modified morphine used in preference to transdermal patches
laxatives prescribed for all patients initiating strong opioids.
Drowsiness is transient and may feel nauseous
Sign guidelines?
Breakthrough dose of morphine is 1/6 the daily dose of morphine.
All patients who receive opioids should be prescribed a laxative.
Opioids should be used with caution in patients with chronic kidney disease. - Alfentanil, bupronorphine and fentanyl preferred.
- Metastatic bone pain may respond to storng opioids, bisphosphonates or radiotherapy.
What to do when increasing dose of opioids?
Increase by 30-50%.
In addition to strong opioids, bisphosphonates, radiotherapy and denosumab may be used.
Transient side effects = nausea, drowsiness.
Persistent = constipaiton.
Conversions between opioids? Oral codeine to oral morphine?
Divide by 10.
Conversions between opioids? Oral tramadol to oral morphine?
Divide by 10 - gives more constipation.
Conversions between opioids? Oral morphine to oral oxycodone
Divide by 1.5-2.
Transdermal fentanyl 12 microgram patch equates to 30mg oral morphine daily.
Transdermal buprenorphine 10 micrograms patch equates to approx 24 mg oral morphine daily.
Conversions between opioids? Oral morphine to subcut morphine?
Divide by 2
