PAIN

(see Bone Pain, Central Pain, Liver Pain, Nerve Pain, Pain Pathways, Pain Threshold, Pelvic Pain)

Pain in cancer patients can be:

«  Many cancer patients assume they will get severe pain and are relieved to learn that 30% of cancer patients do not get pain.

The best clinical classification of cancer pain is:

1. Continuous cancer pains (visceral or soft tissue) which usually respond well to opioid analgesics.

2. Variable cancer pains which tend to respond poorly to opioid analgesics.

   • Bone pain

   • Nerve pain

   • Pleuritic pain

   • Colic (see Intestinal Obstruction)

3. Incidental pains not caused by the cancer, which need specific treatments.

   • Tension headache

   • Anal fissure

   • Reflux esophagitis

   • Osteoarthritis

   • Angina

   • Renal colic

   • Treatment-related (scar pain, neuropathy)

«  Cancer pain is relatively easy to control in about 85% of patients. About 15% of patients need specialist knowledge or techniques.

«  The aim of pain control is an alert, pain-free patient.

I. Pain assessment — The clinician must decide what type of pain it is in order to institute the correct management. The purpose of assessment (usually history and physical examination suffices) is to consider the likely cause of each pain. (In one survey 34% of patients had more than 4 different pains.)

«  The main purpose of the initial assessment is to assess the CAUSE and not the severity of the pain. Estimating severity of pain is only useful in monitoring response to treatment.

The body chart is a useful tool in assessing a patient’s pains. Since pain is a wholly subjective symptom, it can be difficult to convey information about it. Poor communication can cause poor pain control. A body chart makes the problem more visible and helps to improve communication. Ideally it is filled in by the patient with the doctor or nurse (or preferably both) present. It emphasizes that patients often have more than one pain, and it encourages analysis of the likely cause of each pain (visceral, bone, nerve, pleuritic, colic, incidental), which improves management.

The patient’s initial description may be enough to suspect the type of pain:

• “Aches all the time.” — visceral

• “Worse when I move” — bone

• “Burning, stabbing” — nerve

• “Worse when I breathe” — pleuritic

• “Comes and goes” — colic

Some questions usually help to clarify the diagnosis:

• Where is it?

• What is it like?

• Does it spread?

• What makes it worse?

• What improves it?

• Does it come and go?

• Is it severe?

These questions need to be asked about each pain.

A detailed analgesic history is essential both to assess the cause (bone and nerve pains usually respond poorly to opioid analgesics) and to help with appropriate prescribing of analgesia later.

• Which drugs tried?

• Dose actually taken?

• Did it help? For how long?

• Interval between doses?

• Side-effects?

• Reason for stopping?

II. Management options:

1. Morphine (or other opioid)

2. Co-analgesic drugs

3. Radiotherapy (for bone pain)

4. Nerve block

5. Physical methods

6. Psychological methods

1. Visceral and soft tissue pains respond well to the correct dose of morphine (or other opioid).

«  There is no known opioid drug superior to morphine. (see Morphine)

2. Co-analgesic drugs may be required when morphine is not effective or only partially effective:

• NSAIDs for bone pain

• Steroids for nerve compression pain

• Tricyclics for nerve pain (burning)

• Anti-convulsants for nerve pain (stabbing)

• Anti-spasmodics for colic

• Antibiotics for cellulitis

3. Palliative radiotherapy is the treatment of choice for bone pain. (see Bone Pain)

4. About 7% of patients with cancer pain benefit from a nerve block. (see Nerve Blocks)

5. Physical methods of pain relief include:

• Heating pad

• Local injections (steroids, local anesthetic)

• Skin traction (see Fractures)

• TENS (see TENS)

• Massage

6. Psychological methods of pain relief are important, particularly for the few patients whose pain (most commonly nerve pain) can be reduced but not abolished. (see Nerve Pain, Pain Threshold)

III. Monitoring pain control — The key to effective pain control is constant reassessment (at least daily) and modification of treatment until the patient is pain-free.

The best measurement of the severity of pain is the patient’s verbal report. The difficulty is that often different professional carers need to assess pain control at different times, and are not present together with the patient to listen to his description of the pain.

There are several methods of recording the patient’s own assessment:

1. Verbal description

2. Pain score

3. Visual analog scale

1. Verbal descriptions can be used (none, mild, moderate, severe, excruciating), and the patient is asked to supply or check off the appropriate word.

2. The patient can be asked to give a pain score from 0 to 10, and the number is recorded by carers on the patient’s chart.

3. A visual analog scale can be used. The patient puts a mark on a horizontal line which reads “no pain at all” at one end, and “worst pain imaginable” at the other. Since nurses have the most contact with patients, it is a good idea for these assessments to be recorded by the nurses on the team.

The Happy Face-Sad Face scale (a variation of the visual analog scale) is a useful tool in assessing pain in younger children.

Indirect assessment of severity of pain is by:

• Observing behavior

• Observing mobility

• Asking about sleep

• Reviewing analgesic requirements

The patient with severe pain is less able to carry on with normal activities of daily living, less able to be independent, less able to concentrate, may have disturbed sleep due to pain, and needs escalating doses of analgesics.

Good communication among physicians, nurses and other members of the team is essential. One reason why pain control is often achieved more quickly in a hospice setting than in a hospital is because, in a good hospice program, the doctor and nurse in charge discuss the treatment plan of each patient at least once a day.

The author and publisher have taken precautions to ensure that the information in this book is error-free. However, readers must be guided by their own personal and professional standards of good practice in evaluating and applying recommendations made herein. The contents of this book represent the views and experience of the author, and not necessarily those of the publisher.