Palliative Care | Medibuddy
15th October 2024

Palliative Care

Introduction

This chapter is not a deep dive into the job, career, philosophy, or inner workings of palliative care but is a brief outline of topics that may be asked about in MRCP based on the curriculum. For a more meaningful exploration, I can recommend ‘With the End in Mind’ by Kathryn Mannix.

Managing pain

Assessing pain and its causes

Key steps when assessing pain, whether or not in a palliative care context, include the following:

  • Characterise each individual pain (there may be more than one) to identify underlying causes
  • Identify reversible causes
  • Explore psychological, social, and spiritual factors
  • Consider using a validated structured pain assessment tool

Characterise each individual pain to identify cause

This involves the usual, familiar steps for assessing pain, including history (SOCRATES) and examination.

Below are some examples of features of different types of pain:

Type of pain Features in the history
Nerve pain Burning, shooting, tingling, hypersensitivity, changes in sensation
Increased intracranial pressure Worse in the mornings and when lying down; nausea
Bone pain Worse on weight bearing or with pressure on the bone
Intestinal colic Wavy/crampy pain
Incident pain For example, associated with moving
Muscle spasm In a specific muscle or over a trigger point

Identify reversible causes

Whilst there are many irreversible causes of pain related to a patient’s underlying conditions, palliative patients also get treatable illnesses that may cause pain. For example, nerve pain could be a manifestation of B12 deficiency and unilateral limb pain could be a deep vein thrombosis.

Principles of pharmacological pain management

Managing pain in palliative care patients is guided by the acuity and the likely cause.

Acute severe pain

  • Aim to relieve this immediately with subcutaneous or intravenous strong opioid medication
  • Give breakthrough dose of opioid (see section on opioid dose calculations)
  • In opioid-naïve patients, consider 5 mg subcutaneous or IV morphine (2.5 mg for elderly or frail patients)

Persistent pain in a non-emergency situation

The WHO (World Health Organisatin) pain ladder, initially developed in 1986, is a stepwise approach for uncontrolled pain. It has been the subject of much debate about its intended use, how effective it is, and whether it is still an appropriate tool. However, it remains widely used as a simple model for acute pain.

  • Step 1. Non-opioids, e.g. paracetamol, NSAIDs ± adjuvant therapies, e.g. tricyclic antidepressants for nerve pain
  • Step 2. Add weak opioids, e.g. codeine ± non-opioid ± adjuvant therapies
  • Step 3. Instead, try strong opioids, e.g. morphine sulphate ± non-opioid ± adjuvant therapies

Managing pain by cause

Below is a table summarising the common causes for pain and how to manage them:

Type of pain Management
Neuropathic pain Underlying cause: e.g. nerve compression – surgery or radiotherapy may be appropriate

Pain ladder – may be mixed pain

Adjuvant: tricyclic antidepressant (e.g. amitriptyline), pregabalin (or gabapentin)

Raised intracranial pressure Underlying cause: e.g. cerebral metastases – consider oncology assessment for radiotherapy

Pain ladder

Adjuvant: trial dexamethasone 8-16 mg and titrate to lowest dose, discontinue if no response

Intestinal colic Underlying cause: e.g. constipation (laxatives) or obstruction (surgical intervention)

Adjuvant: hyoscine butylbromide

Bone pain Underlying cause: e.g. bone metastases – consult oncologist for radiotherapy or bisphosphonates, fracture – consult orthopaedics, malignant hypercalcaemia – rehydration and bisphosphonates

Pain ladder

Adjuvant: hot or cold packs

Pain on movement – breakthrough analgesia 20-30 mins before moving

Muscle spasms Adjuvants: heat pad, massage, transcutaneous electric nerve stimulation, muscle relaxant (benzodiazepines, e.g. diazepam, baclofen)
Spinal cord compression Seek specialist help

16 mg dexamethasone

Use of opioids

Two key principles in opioid management of pain are:

  1. Consideration of the 24-hour total dose and calculation of PRN doses on the basis of this
  2. Conversion from one opioid to another, maintaining equivalent doses

Opioid dose calculations

When working with doses, the first step is to calculate total dose received over 24 h = total regular + total PRN

Regular doses of modified-release (long-acting) preparations should be: (regular + PRN) in 24h
(twice daily) 2
PRN or breakthrough doses should be: (regular + PRN) in 24h
(up to four hourly) 6

Opioid conversions

The following suggested conversion rates between opioids are taken from the Scottish Palliative Care Guidelines. Note that the BNF suggests a dose reduction of 25-50% when switching between opioids if there is a concern of opioid toxicity. The Scottish Palliative Care Guidelines suggest a dose reduction of up to 30% with re-titration when there is a risk of toxicity, in the frail or elderly, or just because the pharmacokinetics are different between drugs.

From To convert to PO morphine
Weak opioid, e.g. codeine, tramadol ÷10
PO oxycodone x2
SC morphine x2
SC diamorphine x3
SC alfentanil x30
Buprenorphine patch Approx. x100, see patches section
Fentanyl patch Approx. x100, see patches section

Table 3 Conversion factors from various opioids to oral morphine

Patches can be difficult to remember, and the above equivalences are approximations. Here are two possible approaches:

  1. Remember how much is equivalent to the smallest patch and multiple up for bigger patches.
    For example:
    Remember, a buprenorphine 5 mcg patch is approximately equivalent to 12 mg morphine in 24 h
    Work out how much a buprenorphine 15 mcg patch is equivalent to by multiplying by 3
    3 x 12 mg = 36 mg morphine in 2 4h
  2. Ensure the time frame and units are consistent, i.e. mg over 24 hours, then use the conversion
    For example: buprenorphine 5 mcg/hr patch
    Total dose in 24 h = 5 mcg x 24 = 120 mcg = 0.12 mg
    Conversion factor to PO morphine (in 24h) = approx. x100
    0.12 mg x 100 = 12 mg/24h PO morphine
Worked example:

A patient is on 30 mg BD of PO modified-release morphine (e.g. MST) and has had 3 PRN doses of 10 mg immediate-release morphine (e.g. Oramorph) over the past 24 hours. He is not able to take anything orally and the decision is made to set up a syringe driver. What dose of morphine should be put in the syringe driver?

Total oral morphine dose over 24 h = total regular + total PRN

= 30 x 2 + 10 x 3

= 60 + 30 = 90 mg

Conversion from oral to subcutaneous route: ÷ 2, 90 ÷ 2 = 45 mg

Answer = 45 mg subcutaneous morphine over 24h

Box 1 Worked example of opioid conversions

Pain management in renal impairment

Opioid accumulation is a potential reversible cause of deterioration (for example becoming drowsy or confused) in palliative patients. Morphine’s active metabolite accumulates in renal failure, and therefore renal function must be taken into account when prescribing. Different opioids are more or less appropriate for patients with renal failure, and when making dose adjustments a balance must be struck between adequate pain control and opioid toxicity.

Drug Notes Prescribing
Morphine To be avoided N/A
Oxycodone Limited accumulation of metabolites in renal failure Consider dose reduction if eGFR <10
Alfentanil Opioid of choice Dose as in normal renal function
Fentanyl Available as patch, sublingual or buccal for incident pain Dose reduction if eGFR <20, do not start in opioid-naïve patients
Buprenorphine Mainly used as a patch Dose reduction if eGFR <10

Table 4 Opioids in renal impairment

References

  • Ashley C, Dunleavy A. The renal drug handbook. Boca Raton, Fl Crc Press; 2019
  • Greater Manchester Health and Social Care Partnership. Palliative Care Pain & Symptom Control Guidelines For Adults [Internet]. 2019 Nov [cited 2022 Feb 13]. Available from: https://www.england.nhs.uk/north-west/wp-content/uploads/sites/48/2020/01/Palliative-Care-Pain-and-Symptom-Control-Guidelines.pdf
  • National Institute for Health and Care Excellence. Palliative cancer care – pain [Internet]. NICE. 2021 [cited 2022 Feb 13]. Available from: https://cks.nice.org.uk/topics/palliative-cancer-care-pain/
  • National Institute for Health and Care Excellence. Prescribing in Palliative Care [Internet]. NICE; 2019 [cited 2022 Feb 13]. Available from: https://bnf.nice.org.uk/guidance/prescribing-in-palliative-care.html
  • NHS Scotland. Choosing and Changing Opioids [Internet]. Scottish Palliative Care Guidelines. 2021 [cited 2022 Feb 13]. Available from: https://www.palliativecareguidelines.scot.nhs.uk/guidelines/pain/choosing-and-changing-opioids.aspx
  • NHS Scotland. Scottish Palliative Care Guidelines – Alfentanil [Internet]. Scottish Palliative Care Guidelines. 2020 [cited 2022 Feb 13]. Available from: https://www.palliativecareguidelines.scot.nhs.uk/guidelines/medicine-information-sheets/alfentanil.aspx
  • NHS Scotland. Scottish Palliative Care Guidelines – Fentanyl Buccal (Effentora) [Internet]. Scottish Palliative Care Guidelines. 2019 [cited 2022 Feb 13]. Available from: https://www.palliativecareguidelines.scot.nhs.uk/guidelines/medicine-information-sheets/fentanyl-buccal-(effentora).aspx
  • World Health Organisation, Cancer pain relief. Geneva: World Health Organization, [Reprint]; 1986.

Managing physical symptoms other than pain

Nausea and vomiting

Nausea and vomiting are common but not always well managed. The underlying cause should always be considered. Mode of delivery is also key: a patient who is actively vomiting is unlikely to benefit from an oral antiemetic.

Main causes of nausea and vomiting, alongside clinical features and management options, are as follows:

Cause and mechanism Clinical picture Antiemetic Other considerations
Chemical and metabolic (inc. opioids and most other drugs)

Chemical stimulation of the chemoreceptor trigger zone (CTZ)

Persistent

Little relief from vomiting

Haloperidol
Metoclopramide
Levomepromazine
NSAIDs – gastroprotect

Antimuscarinics – treat as gastric stasis

HyperCa – consider IV fluids and bisphosphonates

Intracranial disease

Raised ICP

Headache

Altered consciousness

Cyclizine

2nd line levomepromazine

Raised intracranial pressure – consider adding high dose dexamethasone
Vestibular

Stimulation of vestibular nerve of inner ear

Dizziness

Movement related

Cyclizine

Alternatives: hyoscine hydrobromide, cinnarizine, levomepromazine, prochlorperazine

Bowel obstruction – peristaltic failure without colic Intermittent large-volume vomiting

Early satiety

Reflux, hiccups

Minimal nausea until prior to vomiting

Metoclopramide

If high risk of EPSEs – domperidone

Stop drugs that decrease peristalsis, e.g. cyclizine
Bowel obstruction – mechanical or peristaltic failure with colic Cyclizine

Add haloperidol or levomepromazine

Exclude and treat constipation

Avoid prokinetics

Colic – antimuscarinic e.g. hyoscine butylbromide

Large-volume vomiting – hyoscine butylbromide, octreotide

Extrinsic compression – consider dexamethasone

Abdominal or pelvic organ tumour Cyclizine

Anxiety can also be a cause of nausea and vomiting. Management options include cognitive behavioural therapy, benzodiazepines and levomepromazine, and the decision depends very much on the specific clinical context.

Sometimes, the cause of the vomiting is unknown. In this case, levomepromazine is usually the first antiemetic to be trialled. Second-line options include metoclopramide, haloperidol and cyclizine. If these are ineffective, a trial of dexamethasone can be considered.

Pharmacology notes on antiemetics

There are a few things that might cause your pharmacist to come knocking regarding antiemetics.

Long QT: metoclopramide, haloperidol, levomepromazine and domperidone can all prolong the QT interval, increasing the risk of arrhythmias. This is a consideration, especially when a patient is on other medications that may also have this side effect. At the very end of life, the risks of this need to be balanced with the benefits gained from the medications.

Cancelling out: prokinetics (e.g. metoclopramide) and antimuscarinics (e.g. cyclizine) should not be prescribed together as the antimuscarinics will block the prokinetic effect.

Extrapyramidal side effects: avoid dopamine antagonists (in particular metoclopramide and haloperidol) in those at increased risk of extrapyramidal side effects, e.g. patients with Parkinson’s disease. Domperidone does not cross the blood-brain barrier and so is safe in patients with Parkinson’s disease.

Breathlessness

Reversible causes should always be considered and treated if present – for example, furosemide for pulmonary oedema, blood transfusions for anaemia, etc.

Non-pharmacological management techniques include use of a fan, opening a window, keeping the room cool, breathing techniques, posture and repositioning, encouragement to exercise and adaptation of the environment (e.g. setting up single-floor living or a micro-environment) to make living with breathlessness whilst carrying out daily activities easier.

Pharmacological management options include the following:

  • Low-dose strong opioid (immediate-release preparation)
  • Benzodiazepine if associated with acute anxiety (short-term use)
  • Bronchodilator if partial airway obstruction, e.g. compressing tumour
  • Oxygen may be considered in symptomatic hypoxia or in specific cases such as pulmonary hypertension, but there is limited evidence otherwise

Noisy secretions

Often, noisy secretions cause more distress to relatives than to the patient themselves. NICE guidelines recommend treatment if they are causing distress to the patient or to their carers.

Infection should be considered as a possible reversible cause.

The main conservative measure is to reposition the patient onto one side with their upper body elevated.

Pharmacological management options include:

  • Glycopyrronium bromide
  • Hyoscine butylbromide
  • Hyoscine hydrobromide (although this may cause sedation or confusion)

It is important to monitor and treat side effects – dry mouth, delirium, sedation – and to consider stopping medications if the side effects outweigh the benefits.

Constipation

Common causes of constipation in the palliative care context include drugs, direct effects of the disease and secondary effects of the disease.

When initiating a drug likely to cause constipation (e.g. an opioid), a pre-emptive prescription of a stimulant laxative (e.g. senna) should be considered.

Reversible contributing factors include diet, dehydration, environment (particularly privacy and bedpan use), haemorrhoids or fissures and local tumour.

Management includes:

  • Stimulant laxative (senna)
  • Addition of a stool softener if needed – osmotic (lactulose, macrogol) or stool-softening laxatives (docusate)
  • Consider rectal treatments if the rectum is full:
    • Soft loading – bisacodyl or sodium citrate
    • Hard loading – glycerol

Although phosphate enemas are commonly used, NICE guidelines advise to avoid them as they cause water and electrolyte imbalances.

Rectal interventions should not be carried out on those on chemotherapy who may be neutropenic, those with thrombocytopenia, and those with rectal or anal disease.

Terminal restlessness

Common causes of delirium should be considered and ruled out if needed: infection, drugs, anaemia, constipation, urinary retention, etc.

Conservative measures include reassurance, orientation with clocks and written messages, encouraging friends and family to be around, and ensuring the patient has their glasses and/or hearing aids if appropriate.

Medical management includes midazolam.

References

Prognosis and the dying patient

Accurately estimating prognosis can be difficult, and some patients surprise us with their trajectories. Reflecting on the time frame over which changes are happening can be an effective way of explaining their prognosis – e.g. if they have found that they have become worse each month, week or day, they may have in the region of months, weeks or days left respectively.

At the very end of life, there are patterns to dying, and recognising these can be helpful to allow us to care for our patients at the end of their lives:

  • Day-to-day changes
  • Reduced physical activity – reduced mobility, becoming weaker and more fatigued, sleeping more, bed bound
  • Reduced mental activity – reduced cognition, communication, reduced consciousness
  • Reduced intake – food, fluids, and medications
  • Terminal agitation
  • Peripheral cyanosis, mottled skin, cool to touch
  • Breathing changes – apnoea or cheynes-stokes breathing

Anticipatory medications are often prescribed to manage some of the symptoms that we can predict may arise in the last days of life. These are subcutaneous medications to tackle pain (e.g. morphine), agitation (e.g. midazolam), secretions (e.g. glycopyrronium bromide), and nausea (e.g. haloperidol), and are prescribed or provided in advance to minimise any delays if they are needed. They are not to hasten the journey to death but are to make it as comfortable as possible.

References

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