Incident Pain
An approach to symptom management to guide decision-making in the management of patients with life-threatening illness
Lifestyle changes and non-pharmacological interventions
Incident pain is one type of breakthrough pain, which can be determined as a transient exacerbation of pain that occurs in patients with otherwise stable and adequately controlled baseline pain.
Incident pain is frequently movement-related. It may be:
- Volitional (due to voluntary act) e.g. walking
- Non-volitional (due to involuntary act) e.g. coughing
- Procedural (due to therapeutic intervention) e.g. wound dressing.
Incident pain is usually frequent in occurrence (several times per day), acute in onset, short in duration (median time is 30 minutes) and moderate to severe in intensity.
Management
Assessment
Assessment of incident pain requires a detailed pain history. A patient diary, when appropriate, is useful.
Where possible, the cause of the incident pain should be identified, as well as precipitating factors and the pattern of pain.
Explanation and discussion
Explanation and discussion should include the establishment of realistic treatment goals, with outcomes that are useful or meaningful to the patient e.g. complete pain relief may not be a realistic expectation, but being able to walk without excruciating pain would be achievable.
Underlying cause of incident pain should be treated where appropriate e.g. radiotherapy for bone pain.
Lifestyle changes and non-pharmacological interventions
- Correcting poor posture
- Warming up and stretching
- Adjustment of bending or lifting techniques
- Limiting or pacing physical activities (undertake tasks in small segments, instead of all at once)
Pharmacological interventions
- Optimise (sometimes increase) baseline opioid dose, aiming for a balance between maximal patient activity level and acceptable analgesic side effect profile
- Short-acting opioids, used on an as-needed basis, are the primary treatment of incident pain.
- The problem is that the onset of action of oral short-acting morphine is 30 minutes and duration of action is 4 hours, which lags behind the time course of many episodes of incident pain.
- Therefore, short-acting oral opioids are most effective for predictable incident pain – should be used 30- 60 minutes before a scheduled activity.
- Dose of short-acting opioid determined by individual titration and does not necessarily depend on dose of opioid used for background pain.
- Treatment of unpredictable incident pain is challenging.
- Lipophilic opioids with transmucosal absorption allow for a more rapid onset of action.
Oral transmucosal Fentanyl citrate (OTFC) fits this profile, but is not yet available in South Africa.
- Fentanyl buccal and sublingual tablets are being investigated and have produced positive results.
- Parenteral opioids may sometimes be considered to enable faster onset of action (15-20 minutes for IM or SC morphine, 10-15 minutes for IV morphine)
- Specific drugs such as antitussives, laxatives or anti-spasmodics for non-volitional incident pain
- Inhaled nitrous oxide, ketamine and midazolam may be considered in certain cases of incident pain, although limited evidence is available to support their use.
Reassessment of outcomes
Reassessment of outcomes is necessary to monitor efficiency and tolerability of treatment. Physiotherapy and occupational therapy can assist with lifestyle and physical adjustments. Difficult-to-manage pain problems should be referred to a pain or palliative care specialist, where possible.