Dr Lesley A. Colvin summarises the recent SIGN guideline on the management of chronic, non-malignant pain and explains how thorough assessment can improve outcomes

  • Chronic pain can affect nearly 20% of people at some point in their life
  • The majority of people with chronic pain can be managed in primary care:
    • more complex cases need early access to specialist services
  • Although initially time-consuming, a detailed biopsychosocial assessment is essential for formulating an effective plan of care
  • Supporting patients in self-management is effective
  • Medication for chronic pain should be reviewed at least annually to assess drug efficacy and side-effects:
    • the minimum effective dose should be used
  • Pharmacological management in neuropathic pain is likely to need a very specific approach:
    • regular patient review is required when titrating medication
  • Although strong opioids may be useful in carefully selected patients, a structured approach to management may reduce long-term problems
  • If patients are taking high doses of opioids (>180mg/day morphine equivalent dose), or there is concern about opioid use, the clinician should seek specialist advice
  • Psychological therapies are effective in chronic pain management
  • Exercise should be a key component of any management plan for people with chronic pain.

Chronic pain, that is pain persisting for more than 12 weeks, is common. Most figures indicate that nearly 20% of people will be affected by chronic pain at some point in their lifetime.1,2 Chronic pain is rarely an isolated problem and is often associated with mood disorders and impact on work, relationships, and overall quality of life, with around 5% of sufferers having very severe pain and disability.2,3 There are significant healthcare and social care costs associated with chronic pain, for example back pain alone is estimated to cost the UK around £12 billion a year and account for 4.6 million GP appointments.4,5 A cure for chronic pain is unlikely for most patients, so effective long-term management is important.

The need for a guideline

Provision of specialist pain services is variable and a significant number of patients are unhappy with their treatment.1 The majority of people with chronic pain can, however, be managed effectively in primary care.6 A wide range of management strategies is available, underpinned by an extensive literature. This does, however, create a challenge, because it can be difficult to assess the quality of all the evidence and apply it directly to clinical practice. SIGN’s recent, comprehensive guideline on Management of chronic pain (SIGN 136),7 was published in December 2013 and aims to provide a clinically relevant resource to guide evidence-based treatment (see www.sign.ac.uk/guidelines/fulltext/136/).The hope is that it will improve clinical outcomes, reduce variations in treatment, and be part of the process needed to improve the quality of life of patients with chronic pain.

The scope of the guideline

SIGN 136 is aimed not at pain specialists but at healthcare professionals working in non-specialist settings who are involved in the management of patients with chronic pain.7 A number of areas were excluded:

  • Specialist secondary and tertiary care interventions. These have not been reviewed, although advice about when to refer is given
  • Chronic pain in children. There were several reasons for excluding chronic pain in children, for example, the limited evidence base, which was insufficient for effective use of the SIGN methodology; also treatment options for children are often different from those for adults. A clinical practice guideline for children with chronic pain is currently under discussion
  • Specific review of underlying medical conditions. The impact of chronic pain is often significant, regardless of the underlying cause, so SIGN 136 did not include a review of underlying medical conditions. There are, however, many other SIGN guidelines for conditions where chronic pain is common (e.g. SIGN 121 on Diagnosis and management of psoriasis and psoriatic arthritis in adults8 SIGN 123 on Management of early rheumatoid arthritis,9 and SIGN 107 on Diagnosis and management of headache in adults10).

Limitations of the current evidence—a note of caution

Strict SIGN methodology was followed in the development of SIGN 136, with extensive literature-searching and adherence to defined quality criteria for assessment of clinical studies. It is, however, important to be aware of the potential limitations of clinical trial design and analysis, which may impact on measured treatment effects. There is concern about how best to optimise clinical trial design,11-13 particularly where treatment effect can be overestimated as a result of the statistical analysis technique used. This concern has been raised in many studies of opioids in the treatment of chronic pain.14,15 The result is that even good quality, systematic reviews and meta-analyses, such as those carried out by the Cochrane group,16 may reach conclusions that do not reflect clinical reality. As future trial design improves in line with the Initiative on Methods, Measurement and Pain Assessment in Clinical Trials (IMMPACT),17 the balance of evidence may well change.

Assessment and care planning

Although a biopsychosocial assessment can be time-consuming, the longer-term benefits it brings to appropriate care-planning usually make it worthwhile. A full assessment may well need to be divided over several consultations. The key points in this process are outlined in the interactive Management of chronic pain pathway for chronic pain assessment, early management and care planning in non-specialist settings, available at www.ckp.scot.nhs.uk/Published/PathwayViewer.aspx?id=609. 18

Diagnosing neuropathic pain

It is particularly important not to miss the diagnosis of neuropathic pain, which requires close attention to the characteristics of the pain. There are a number of validated screening tools for neuropathic pain, although no evidence that their use alters outcome.19,20 Neuropathic pain is a likely diagnosis when the patient:

  • describes the pain as ‘electric shocks’, ‘pins and needles’, or ‘burning’
  • has signs of mechanical allodynia (pain to normally non-painful touch, e.g. brushing the skin with cotton wool)
  • has reduced sensitivity to pin-prick.

Patients with long-term disability

Another important area of assessment is how to identify patients at potential risk of poor outcomes and long-term disability. Although there is limited evidence of effective tools to identify such patients early, the STaRT Back tool (available at www.keele.ac.uk/sbst/) may be useful to stratify what intensity of care individuals with back pain may need.21

Supported self-management

Even in the early stages of a pain condition, patients should be encouraged to self-manage pain and be directed to useful resources (see e.g. www.chronicpainscotland.org).22 Even if other treatments are being considered, self-management may usefully run in parallel. Supported self-management programmes that are run by lay people or patients, and which often have strong educational content, can be effective but some form of interaction is needed with the patient, not just the handing out of advice.7

Drug treatments

A wide range of drugs can be used in the management of chronic pain, often with variable efficacy. Long-term studies are often lacking and this is an identified research gap in the guideline.­7 There are two important points for clinicians to remember regarding pharmacological therapy when managing chronic pain:7

  • regularly review and assess the analgesic benefit of any drug(s), balanced with their side-effects. Patients taking prescribed medication should, as a minimum, be reviewed annually to ensure that they are receiving defined benefit from their medication
  • have a ‘stopping rule’. This perhaps runs hand-in-hand with regular review: if medication is ineffective, or side-effects are not settling and are unacceptable, then the relevant medication should be stopped and a trial of other medications considered, where appropriate.

There is some evidence that combination therapies can be effective (e.g. in neuropathic pain), although further research is needed in this area.23 Further guidance for appropriate prescribing is given in three interactive pathways, available in the SIGN 136 ‘Supporting material’ at www.sign.ac.uk/guidelines/fulltext/136/).7

There are two particularly challenging areas where prescribing for chronic pain can be difficult: neuropathic pain and strong opioids.

Neuropathic pain—a challenge

Neuropathic pain is common, affecting up to 8% of the population and having a very major impact on mood, function, and quality of life.24 The underlying neurobiology changes pain processing such that the effect of standard analgesics (e.g. non-steroidal anti-inflammatory drugs), and even strong opioids, may be unpredictable.25,26 The first step in successful management is correct diagnosis (see ‘Diagnosing neuropathic pain’, above). The interactive Pathway for patients with neuropathic pain in SIGN 136 (Figure 1) provides a pragmatic approach to diagnosis and management.27

Should strong opioids be used for chronic pain?

There is considerable controversy over the use of strong opioids in the management of chronic pain. Used correctly in well selected patients, strong opioids can be very effective analgesics but if used incorrectly, considerable harm may result, including iatrogenic dependence. The majority of studies are short-term, often with very narrow inclusion criteria, which reduces their applicability to the general population of patients with chronic pain. Concerns about long-term effects of opioids include:

  • endocrine function, with menstrual irregularities and reduced libido 28
  • increased risk of:
    • dependence or abuse if the patient has a past history of substance misuse, including alcohol and stimulants29
    • fracture, especially in elderly people.30

Other concerns about possible effects of opioids on the immune system and interaction with cancer neurobiology are as yet unproven and require further study.31,32

The SIGN 136 interactive Pathway for using strong opioids in patients with chronic pain (see www.ckp.scot.nhs.uk/Published/PathwayViewer.aspx?id=608)33 provides a clear pathway for initial assessment and discussion through to treatment and monitoring for patients taking opioids for chronic pain. The current advice is that where patients are on large doses of opioids (>180mg/day of morphine-equivalent dose), or there is concern about rapid dose escalation, specialist advice should be sought.7

Figure 1: Pathway for patients with neuropathic pain
Pathway for patients with neuropathic pain
  • SNRI= serotonin-adrenaline reuptake inhibitors
  • SIGN website. SIGN 136. Management of chronic pain. Pathway for patients with neuropathic pain. Reproduced by kind permission. The full version of this pathway is available at: www.ckp.scot.nhs.uk/Published/PathwayViewer.aspx?id=610 (accessed 5 June 2014).

When should psychological therapies be considered?

There is good quality evidence for the efficacy of psychologically-based pain management programmes, although the treatment effect drops over time.34–36 Access to such programmes is often variable, and other options that may be considered include strategies to modify the physiological response to pain, such as progressive relaxation or electromyogram (EMG) biofeedback.37,38 The effect of clinician and patient interaction can have a major impact on behaviour. This is perhaps not surprising, given the subjective nature of pain perception, but is illustrated well in a volunteer neuroimaging study. A painful burn stimulus was used to induce pain under conditions where volunteers received a potent intravenous opioid, and the effect on analgesia of altering expectation was studied. The analgesic effect was almost completely reversed by using negative expectation.39 This is a good example of how our interaction with patients may dramatically alter the effect of treatment.

The role of exercise in chronic pain management

Exercise is good for you—it’s official! There is high quality evidence for the benefits of exercise in chronic pain, and a key recommendation in SIGN 136 is that exercise in any form (either formal exercise classes, or even just daily housework) should be encouraged; however, giving advice to exercise without any additional explanation or support is unlikely to be effective. Some sort of interaction, be it face-to face, by post, or electronically, is better than simply handing out a leaflet.40 There are a number of different approaches that can be used to encourage and support patients to exercise:7

  • exercise sessions with direct supervision
  • exercises tailored to individuals, in a group setting
  • written information or internet-based resources can be useful, with self-help materials providing some reduction in pain, perceived disability, and stress.41 For some useful links, see www.chronicpainscotland.org22
  • combined programmes between group and home settings.

Short-term relief of back pain may be achieved by use of manual therapy (e.g. manipulation or mobilisation).42

Do complementary therapies have a role?

The evidence for complementary therapies is limited, so no key recommendations were made in SIGN 136. There was, however, evidence that TENs, and also low level laser therapy, may be useful. There is also evidence for the efficacy of acupuncture on short-term pain relief for patients with chronic low back pain or osteoarthritis.7,43,44 The place of acupuncture in the longer-term management of chronic pain needs to be carefully considered, as evidence here is limited.

Conclusion

Chronic pain is a significant problem and there has until now been no evidence-based clinical guideline available. SIGN 136 provides such a resource, with linked signposting to other useful resources for both healthcare professionals and patients. In particular, the three pathways on clinically challenging areas are designed to be used in day-to-day clinical practice. It is hoped that by optimising management, SIGN 136 will help to improve the lives and outcomes for patients with chronic pain.

  • SIGN 136 provides useful algorithms for the assessment of and treatment for chronic pain that could form the basis of local care pathways
  • Commissioners should consider how best to support GPs in undertaking biopsychosocial assessments, as these assessments take longer than the usual time available in consultations:
    • a community specialist nurse service would be helpful here; otherwise, educational support should be provided as a minimum to help GPs distinguish between neuropathic and non-neuropathic pain
  • Local formularies should identify analgesic agents that can be used and their acquisition costs and provide guidelines for their use prior to any specialist referral
    • costs for some agents (e.g transdermal opioid patches) can vary considerably between similar products
  • Prescribers should always be aware of the possibility of dependence and abuse with both opioid (e.g. morphine, tramadol) and non-opioid (e.g. pregabalin and, surprisingly, amitriptyline45) agents.
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