- Email: [email protected]
Assessment of chronic pain: A practice update
International Journal of Orthopaedic and Trauma Nursing (2015) 19, 155–161
International Journal of Orthopaedic and Trauma Nursing www.elsevier.com/locate/ijotn
PRACTICE DEVELOPMENT IN ORTHOPAEDICS AND TRAUMA
Assessment of chronic pain: A practice update It is essential that orthopaedic and trauma practitioners develop and maintain their own skills and knowledge in order to help improve and deliver quality care for patients. The utilisation of research in practice development is an important part of the process for nurses endeavouring to deliver evidence based practice to improve care and service user experience. This series aims to showcase initiatives and innovations in practice development that have transformed delivery of quality care around the world and to provide readers with brief summaries of current thinking in relation to clinical issues that are common features of orthopaedic and trauma nursing practice. The feature will provide readers with a summary of an evidence base with the aim of empowering them to initiate discussion with colleagues and question their own practice. There will be associated CPD activities incorporating self-directed learning that will enhance the series and provide nurses with an opportunity to extend their learning. The International Journal of Orthopaedic and Trauma Nursing invites contributions from clinical staff, educators and students of between 1000 and 2500 words. Items may focus on, but are not restricted to, best practice and practice development initiatives relating to clinical care issues, implementation of research findings and education and development of the workforce in the clinical environment.
Background Pain is defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (Merskey, 1979, p. 250). The IASP (1986, Supplement 3) defines chronic pain as “pain which has persisted beyond normal tissue healing time” which is taken, in absence of other criteria, to be 3 months. The impact of chronic pain on individuals’ lives, their quality of life and their ability to function with activities of daily living can be overwhelming. People may be affected in a number of ways including functional, psychological, emotional, social and economic impacts. This can lead to loss of self esteem and confidence and cause withdrawal from social interactions. It can also affect intimate, personal and sexual relationships. Sleep pattern is frequently disturbed and can subsequently impact on emotional mood, psychological well-being and physical energy http://dx.doi.org/10.1016/j.ijotn.2015.03.004
levels. The experience of chronic pain is also associated with depression. This is recognised as resulting from a reaction to the many disabling effects of the chronic pain experience (Stannard and Booth, 2004). Chronic or persistent pain is a significant problem globally and imposes a high financial burden on healthcare services. For example, according to the British Pain Society, nearly 10 million people (nearly 16% of the population) in the UK suffer pain almost daily, resulting in a major impact on their quality of life (www.britishpainsociety.org.uk). In Australia, chronic pain is reported by 18.6% of adults (Holmes et al., 2012). In the USA, Johannes et al. (2010) estimated that chronic pain was experienced by approximately a third of the population, while in Canada Lynch (2011) reported that 1 in 5 of the population had chronic pain. Chronic musculoskeletal pain presents a management dilemma for the healthcare professional. Polypharmacological treatments are often complex and difficult for patients to manage, with many
156 experiencing adverse effects or some degree of dependence on the pharmacological therapy. Nonpharmacological interventions have varied evidence bases and include complimentary or alternative therapies such as acupuncture, massage, heat/ cryo therapy and visualisation. A biopsychosocial (BSP) model of pain management is promoted by many chronic pain services around the world. The model was first brought to attention by psychiatrist George Engel who discussed the concept of the ‘mind – body’ connection. He theorised that biological, psychological (thoughts, emotions, and behaviours) and social (socioeconomical, socio-environmental and cultural) factors are all part of the way humans function in the context of ill health or disease (Engel, 1977). As chronic pain is so complex and often complicated by other conditions, the aim of this paper is to explore its assessment. Appropriate, holistic and thorough assessment of the patient with chronic pain is central. The assessment process can often be the starting point for helping patients to identify, understand and manage their pain in a more effective manner.
Pathophysiology The pathophysiology of pain is complex as both electrical and chemical responses are involved. Although acute pain may initially arise from noxious stimuli such as trauma or infection to tissue, in chronic pain both the peripheral and central nervous systems are implicated. Nociceptors, found in most tissues of the body, are specialised peripheral sensory neurons that respond to noxious stimuli. The 4 stages of the nociceptive process are: • Transduction – myelinated A-delta and unmyelinated C-fibres respond to intense noxious stimuli. This includes mechanical, thermal and chemical noxious stimuli. A-delta fibres transmit ‘fast’ messages associated with acute sharp pain while C-fibres transmit ‘slow’ messages associated with throbbing pain and chronic pain sensations. • Transmission – information is relayed into the dorsal horn of the spinal column. Impulses cross over and are sent via the ascending sensory tracts in the spinal cord to the higher centres of the brain. • Perception – the somatosensory cortex aids the location and interpretation of pain. The conscious awareness of pain is controlled by the
B. Wellington et al. reticular activating and limbic systems and allows the person to be aware of the pain, respond emotionally and take action. Cerebral activity is triggered including discriminative, affective, autonomic and motor responses to the stimuli. • Modulation – direct physiological modulation of pain impulses occurs due to changes in chemicals in the spinal cord and brain. In the dorsal horn of the spinal cord pain sensation may be altered by stimulation of afferent A-beta fibres. From the brain, descending pathways of nerve fibres make inhibitory connections in the dorsal horn and so inhibit nociceptive transmission (Melzack and Wall, 1965). Tissue injury also elicits an inflammatory response (including the release of prostaglandins, cytokines, serotonin and adrenaline) that causes increased excitability. Pro-inflammatory substances (including mast cells, macrophages and neutrophils) increase the efficacy of transduction channels and an exaggeration of the firing threshold and response. However, if there is sustained activation, sensitisation can occur (known as peripheral sensitisation). Changes can occur in the nociceptors which result in heightened responsiveness and a reduced threshold to stimuli. The term ‘central sensitisation’ is used to describe ‘wind-up’ which is a condition of long term potentiation and secondary hyperalgesia. Wind-up is a state where the dorsal horn neuron responses are significantly increased as a result of repetitive stimulation. When the spinal neurons are in this more excitable state, the brain receives a stronger and longer input from a stimulus. Long-term potentiation at individual synapses is thought to be important in the learning and memory of pain. Secondary hyperalgesia can also occur in undamaged tissue adjacent to the area of actual tissue damage and may be due to an increased receptive field and reduced threshold in the dorsal horn (Bridgestock and Rae, 2013). Some of the spinal neurons associated with pain project into the limbic system of the brain and areas of the midbrain that are involved in fear, anxiety and mood and are responsible for the potential activation of autonomic responses (Dickenson, 2013). The key to successful management of chronic pain is accurate assessment by a clinician. This should be based on a broad understanding of the physiological processes. Many approaches have been used to evaluate chronic pain and the next section provides an overview of some of the available assessment tools.
Assessment of chronic pain Table 1
157
Resources for further learning: chronic pain.
Resource
Notes
General resources Engel, G. L. (1977). The need for a new medical model: a challenge for biomedicine. Science, 196, 129–136.
Engel describes the need to move from a biomedical model of care to the framework of care encompassing social, psychological and behavioural aspects of illness.
Holmes, A., Christelis, N. & Arnold, C. (2012). Depression and chronic pain. Medical Journal of Australia Open, 1(4), 17–20.
The authors describe the current approach to the assessment and management of major depression in patients with chronic pain.
International Association for the Study of Pain. Classification of chronic pain. Pain (1986); Suppl 3: S1–S226
Descriptions of chronic pain syndromes and definitions of pain terms. Prepared by the International Association for the Study of Pain
Johannes, C. B., Le, T. K., Zhou, X., Johnston, J. A. & Dworkin, R. H. (2010). The prevalence of chronic pain in United States adults: results of an Internet-based survey. The Journal of Pain, 11(11), 1230–1239.
A cross-sectional, Internet-based survey was conducted in a nationally representative sample of United States (US) adults to estimate the point prevalence of chronic pain and to describe sociodemographic correlates and characteristics of chronic pain
Lynch, M. E. (2011). The need for a Canadian pain strategy. Pain Research & Management: The Journal of the Canadian Pain Society, 16(2), 77.
Pain is undertreated in Canada and there are major problems with access to appropriate care for all types of pain. A national pain strategy addressing educational, clinical and research needs is required.
Merskey, H. (1979) Pain terms: a list with definitions and notes on usage recommended by the IASP subcommittee on taxonomy. Pain, 6, 249–252
• See www.iasp-pain.org
RNAO (Registered Nurses’ Association of Ontario (2013) Clinical Best Practice Guidelines. Assessment and Management of Pain. 3rd Ed. www.rnao.ca/bpg/ guidelines/assessment-and-management-pain
The guideline contains recommendations for best nursing practices in the assessment and management of pain for Registered Nurses in Canada. This guideline is endorsed by the International Association for the Study of Pain.
Stannard, C. & Booth, S. (2004). Pain 2nd Ed. Elsevier Churchill Livingstone: Edinburgh.
This book is generally about the management of chronic pain associated with cancer and non malignant disease. It contains chapters on functional imaging, opioid medication and neurostimulation.
Wood, S. (2008) Assessment of pain http://www.nursingtimes.net/nursing-practice/ specialisms/pain-management/assessment-of-pain/ 1861174.article
A useful introduction to pain assessment tools that provides basic information for nurses in everyday clinical activity
http://www.britishpainsociety.org.uk/
The British Pain Society has a membership of over 1,400 and is involved in all aspects of pain and its management through the work of the Council.
http://www.iasp-pain.org/Education/Content.aspx ?ItemNumber=1698
The following pain terminology is updated from “Part III: Pain Terms, A Current List with Definitions and Notes on Usage” (pp. 209–214) Classification of Chronic Pain, Second Edition, IASP Task Force on Taxonomy, edited by H. Merskey and N. Bogduk, IASP Press, Seattle, ©1994.
www.wongbakerfaces.org
Wong Baker Faces scale is a self-assessment scale, so the patients need to be able to understand the instructions and select a face that illustrates the pain they are experiencing. It should never be used with unresponsive patients or to compare the patient’s face to the scale to determine the level of pain. (continued on next page)
158 Table 1
B. Wellington et al. (continued)
Resource
Notes
Reviews of the evidence and literature Carnes, D., Homer, K. E., Miles, C. L., Pincus, T., Underwood, M., Rahman, A. & Taylor, S. J. (2012). Effective delivery styles and content for selfmanagement interventions for chronic musculoskeletal pain: a systematic literature review. The Clinical Journal of Pain, 28(4), 344–354.
The objective of the study was to report the evidence for effectiveness of different self-management course characteristics and components for chronic musculoskeletal pain
Eldridge, S., Spenser, A., Pincus, T., Rahman, A., Bremner, S. A., Underwood, M. R. & Diaz-Ordaz, K. (2014). OP21 Effectiveness and cost-utility of a group self-management support intervention (COPERS) for people with chronic musculoskeletal pain: a randomised controlled trial. Journal of Epidemiology and Community Health, 68(Suppl 1), A13–A14.
The authors evaluated a new and innovative, theoretically grounded self-management support intervention for chronic musculoskeletal pain.
Hogg, M. N., Gibson, S., Helou, A., DeGabriele, J. & Farrell, M. J. (2012). Waiting in pain: a systematic investigation into the provision of persistent pain services in Australia. Med J Aust, 196(6), 386–90.
The aim of this systematic investigation was to document and describe persistent pain management in outpatient services in Australia
Nicholas, M., Molloy, A., Tonkin, L. & Beeston, L. (2011). Manage Your Pain. Souvenir Press: London.
This book explains practical and positive ways in which your patients can manage and adapt to a life with chronic pain. It includes chapters for older people, pacing, exercises and treatments.
Reid, K. J., Harker, J., Bala, M. M., Truyers, C., Kellen, E., Bekkering, G. E. & Kleijnen, J. (2011). Epidemiology of chronic non-cancer pain in Europe: narrative review of prevalence, pain treatments and pain impact. Current Medical Research & Opinion, 27(2), 449–462.
Pan-Europe epidemiological data about chronic noncancer pain were obtained using systematic review principles in searching and summarising results.
Smith, B. H., Hardman, J. D., Stein, A., & Colvin, L. (2014). Managing chronic pain in the non-specialist setting: a new SIGN guideline. British Journal of General Practice, 64(624), e462-e464.
This guides you through the rationale and process of developing the SIGN guideline.
Tan, T., Barry, P., Reken, S. & Baker, M. (2010). Pharmacological management of neuropathic pain in non-specialist settings: summary of NICE guidance. BMJ: British Medical Journal, 707–709.
This summarises the most recent recommendations from NICE on drug management for neuropathic pain, excluding specialist pain services.
Turk, D. C., Swanson, K. S. & Tunks, E. R. (2008). Psychological approaches in the treatment of chronic pain patients–when pills, scalpels, and needles are not enough. Canadian Journal of Psychiatry, 53(4), 213–223.
A review of different psychological models concluded with showing that self-management is an important complement to biomedical approaches
Vowles, K. E. & McCracken, L. M. (2010). Comparing the role of psychological flexibility and traditional pain management coping strategies in chronic pain treatment outcomes. Behaviour Research and Therapy, 48(2), 141–146.
The study participants were 114 chronic pain sufferers. The authors examined how changes in methods of coping compared to changes in psychological flexibility. This related to improved function during a multidisciplinary treatment program. (continued on next page)
Assessment of chronic pain Table 1
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(continued)
Resource
Notes
Guidelines American Society of Anesthesiologists Task Force on Chronic Pain Management. (2010). Practice guidelines for chronic pain management: an updated report by the American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine. Anesthesiology, 112(4), 810.
USA – The purposes of these guidelines are to (1) optimise pain control, recognising that a pain-free state may not be attainable; (2) enhance functional abilities and physical and psychological well-being; (3) enhance the quality of life of patients; and (4) minimise adverse outcomes
Furlan, A. D., Reardon, R. & Weppler, C. (2010). Opioids for chronic noncancer pain: a new Canadian practice guideline. Canadian Medical Association Journal, 182(9), 923–930.
Canada – Their aim was to oversee the development and implementation of a guideline to assist physicians to manage patients with chronic noncancer pain by prescribing opioids in a safe and effective manner.
NICE CG 173 Neuropathic pain: the pharmacological management of neuropathic pain in adults in nonspecialist settings (Nov 2013) www.nice.org.uk/ guidance/cg173
UK – This information explains the drug treatments for neuropathic pain but excludes treatments in pain clinics or other specialist clinics.
SIGN 136: Management of Chronic Pain (Aug 2014) sign.ac.uk/guidelines/fulltext/136/index.html
UK – This guideline provides recommendations and treatment pathways based on current evidence for best practice in the assessment and management of adults with chronic non-malignant pain in non specialist settings, including self management, pharmacological, psychological, physical, complementary and dietary therapies
www.healthcareimprovementscotland.org/. . ./ chronic_pain/where_are_we_now.aspx
Scotland – This report presents detailed analysis of the current care provision for chronic pain services and makes recommendations for NHS boards, local Service Improvement Groups, the Scottish Government and for the National Chronic Pain Steering Group, to be achieved by 2016.
www.nationalpainaudit.org/media/files/ NationalPainAudit-2012.pdf (National Pain Audit England and Wales 2012)
England and Wales – The National Audit of Pain Services was initiated to collect detailed data on pain services. The three-year study aimed to improve NHS services for people affected by chronic pain.
Assessment tools A definition of pain widely used in nursing, emphasising its subjective nature and the importance of believing the patient’s description, was introduced by Margo McCaffery in 1968 and later amended to “Pain is whatever the experiencing person says it is, existing whenever he says it does” (Pasero and McCaffery, 1999, p. 17). Pain assessment is considered to be the 5th vital sign and many pain assessment tools exist that aim to objectively describe a patient’s pain. Continual systematic assessment and re-assessment are the bases for effective pain management. Pain assessment tools are described as unidimensional or multi-dimensional. Prior to using these tools the clinician must be aware that different factors affect the choice of tool to be used, e.g. acute
or chronic pain, age, cognition, malignant or nonmalignant pathology, education level, communication ability, culture, ethnicity, biology, past experience of pain, willingness to report pain, reliability and validity, ease and time commitment when using the tool (RNAO (Registered Nurses’ Association of Ontario), 2013). Uni-dimensional tools are used to focus on one dimension of pain. While they are commonly used for the assessment of acute pain and may not be seen to be that useful with chronic pain, they are still worthy of explanation because they may be combined with other types of pain assessment. The examples of tools given here are all validated and easy to use. They may include visual, verbal, numerical or pictorial descriptors and ratings. They are often used in acute post-operative pain assessment. Examples of uni dimensional assessment tools include:
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• Visual analogue scales (VAS) – usually consisting of a 10cm horizontal line with markings for no pain at one end and pain as bad as it could possibly be at the other end. The patient marks a point on the line to represent the intensity of their pain and the number is obtained by measuring in millimetres from the start of the line to the area marked. • Verbal rating score (VRS) – a list of adjectives and numbers are used to describe varying pain intensity levels. Examples of common descriptions are 1–3 (mild), 4–6 (moderate) and 7–10 (severe). This is for use with adults, is validated and is quick and easy to use. • Numeric rating score (NRS) – patients rate their pain scale from 0 to 10, with 0 being no pain up to 10 being the worst pain possible. • Faces Pain Scale (FPS) (www.wongbakerfaces.org) – six gender-neutral faces with expressions ranging from no pain to the worst pain possible. Each face has a matching numerical score, along the range 0–2–4–6–8–10. It is commonly used with children. Multidimensional tools capture several different dimensions of pain; characteristics and quality of pain, satisfaction with pain control and how pain impacts
Box 1
mood, activity, sleep and diet. As pain is multidimensional, these tools are very helpful when a comprehensive assessment of pain is required. They are therefore more helpful for the patient with chronic pain. Examples of multidimensional tools include: • The Brief Pain Inventory (BPI) – a selfadministered questionnaire assessing pain and its impact. Originally used and developed for cancer patients, this has proven to be a reliable and valid tool for assessment of chronic pain. When used regularly, the tool helps to record pain interference with general activities of daily living. The questionnaire comprises 9 questions about pain severity using a numerical scale, yes and no answers and a visual diagram. • McGill Pain Questionnaire (MPQ) – consists of three main parts: o A pain rating index determined by two numerical values that can be designated to adjectives used to describe the pain. These are words used to describe the patient’s sensory, affective and evaluative pain experience. o Present pain intensity is assessed based on a numerical scale of 0–5. o An anatomical drawing for the patient to mark the location of their pain.
Reflection guide (adapted from Gibbs, 1988).
Description Explain what you are reflecting on; describe your learning expectations and prior knowledge of chronic musculoskeletal pain assessment. Feelings Discuss your personal thoughts and feelings about your experiences of performing chronic musculoskeletal pain assessment in your areas of practice. Have your opinions about how chronic musculoskeletal pain is assessed changed after reading this article? Evaluation What did you learn? What was helpful, what was missing, how did it make you feel? Analysis What did you gain from reading this article; did it meet your expectations? How does the information in this article relate to your current practice? Is there further evidence you need to gather relating to chronic musculoskeletal pain assessment? What are the potential implications for practice? Conclusion Summarise your thoughts, what are your general and personal conclusions about chronic musculoskeletal pain assessment and why? Action Plan Use your reflection to initiate a discussion/debate on chronic musculoskeletal pain assessment with your colleagues. Recommendations for good practice? What will you do differently? How will you disseminate any recommendations to the multi-disciplinary team?
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• Paediatric Pain Questionnaire (PPQ) – illustrated with happy and sad faces, has a genderneutral outline to illustrate the location of pain and uses descriptive words to assess sensory, affective and evaluative qualities of pain. Numerous tools are available to the clinician; evidence based best practice guidelines, papers and websites explain in-depth the assessment tools. Good assessment by a knowledgeable clinician is of paramount importance for the ongoing management of patients with chronic pain. The role of the healthcare professional is to perform the appropriate assessment, be skilled in interpreting the results and then take the relevant action to deliver that individual patient’s pain management regimen. This update has included information about the nature and assessment of chronic pain. Table 1 provides links to further information resources relating to chronic pain management which the reader should access to continue their learning (Box 1). A future feature in this series will continue the theme of chronic pain management and introduce some pharmacological management options as well as some alternative and complementary therapies.
References Bridgestock, C., Rae, C., 2013. Anatomy, physiology and pharmacology of pain. Anaesthesia and Intensive Care Medicine 14 (11), 480–483. British Pain Society, 2014.
Gibbs, G., 1988. Learning by Doing: A Guide to Teaching and Learning Methods. Oxford Further Education Unit, Oxford. Holmes, A., Christelis, N., Arnold, C., 2012. Depression and chronic pain. Medical Journal of Australia 1 (4), 17–20. IASP (International Association for the Study of Pain), 1986. Classification of chronic pain. Pain Suppl 3, S1–S226. Johannes, C.B., Le, T.K., Zhou, X., Johnston, J.A., Dworkin, R.H., 2010. The prevalence of chronic pain in United States adults: results of an Internet-based survey. The Journal of Pain 11 (11), 1230–1239. Lynch, M.E., 2011. The need for a Canadian pain strategy. Pain research & management. The Journal of the Canadian Pain Society 16 (2), 77. Melzack, R., Wall, P.D., 1965. Pain mechanisms, a new theory. Science 150, 971–979. Merskey, H., 1979. Pain terms: a list with definitions and notes on usage recommended by the IASP subcommittee on taxonomy. Pain 6, 249–252. Pasero, C., McCaffery, M., 1999. Pain: Clinical Manual. Mosby, St. Louis. RNAO (Registered Nurses’ Association of Ontario), 2013. Clinical Best Practice Guidelines. Assessment and Management of Pain, third ed. (accessed 31.12.14). Stannard, C., Booth, S., 2004. Pain, second ed. Elsevier Churchill Livingstone, Edinburgh.
Beverley Wellington a,b, Sandra Flynn c, Wendy Duperouzel d, Sylvia Treloar e a New Victoria Hospital, Glasgow, UK b University of the West of Scotland, Paisley, UK. E-mail address: Beverley.wellington@ ggc.scot.nhs.uk c Countess of Chester N.H.S. Foundation Trust, Chester, UK. E-mail address: Sandra.fl[email protected] d Curtin University, Bentley, Western Australia, Australia. E-mail address: Wendy.J.Duperouzel@ curtin.edu.au e Covenant Health Misericordia Community Hospital, Edmonton, Alberta, Canada. E-mail address: [email protected]
Available online at www.sciencedirect.com
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International Journal of Orthopaedic and Trauma Nursing www.elsevier.com/locate/ijotn
PRACTICE DEVELOPMENT IN ORTHOPAEDICS AND TRAUMA
Assessment of chronic pain: A practice update It is essential that orthopaedic and trauma practitioners develop and maintain their own skills and knowledge in order to help improve and deliver quality care for patients. The utilisation of research in practice development is an important part of the process for nurses endeavouring to deliver evidence based practice to improve care and service user experience. This series aims to showcase initiatives and innovations in practice development that have transformed delivery of quality care around the world and to provide readers with brief summaries of current thinking in relation to clinical issues that are common features of orthopaedic and trauma nursing practice. The feature will provide readers with a summary of an evidence base with the aim of empowering them to initiate discussion with colleagues and question their own practice. There will be associated CPD activities incorporating self-directed learning that will enhance the series and provide nurses with an opportunity to extend their learning. The International Journal of Orthopaedic and Trauma Nursing invites contributions from clinical staff, educators and students of between 1000 and 2500 words. Items may focus on, but are not restricted to, best practice and practice development initiatives relating to clinical care issues, implementation of research findings and education and development of the workforce in the clinical environment.
Background Pain is defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (Merskey, 1979, p. 250). The IASP (1986, Supplement 3) defines chronic pain as “pain which has persisted beyond normal tissue healing time” which is taken, in absence of other criteria, to be 3 months. The impact of chronic pain on individuals’ lives, their quality of life and their ability to function with activities of daily living can be overwhelming. People may be affected in a number of ways including functional, psychological, emotional, social and economic impacts. This can lead to loss of self esteem and confidence and cause withdrawal from social interactions. It can also affect intimate, personal and sexual relationships. Sleep pattern is frequently disturbed and can subsequently impact on emotional mood, psychological well-being and physical energy http://dx.doi.org/10.1016/j.ijotn.2015.03.004
levels. The experience of chronic pain is also associated with depression. This is recognised as resulting from a reaction to the many disabling effects of the chronic pain experience (Stannard and Booth, 2004). Chronic or persistent pain is a significant problem globally and imposes a high financial burden on healthcare services. For example, according to the British Pain Society, nearly 10 million people (nearly 16% of the population) in the UK suffer pain almost daily, resulting in a major impact on their quality of life (www.britishpainsociety.org.uk). In Australia, chronic pain is reported by 18.6% of adults (Holmes et al., 2012). In the USA, Johannes et al. (2010) estimated that chronic pain was experienced by approximately a third of the population, while in Canada Lynch (2011) reported that 1 in 5 of the population had chronic pain. Chronic musculoskeletal pain presents a management dilemma for the healthcare professional. Polypharmacological treatments are often complex and difficult for patients to manage, with many
156 experiencing adverse effects or some degree of dependence on the pharmacological therapy. Nonpharmacological interventions have varied evidence bases and include complimentary or alternative therapies such as acupuncture, massage, heat/ cryo therapy and visualisation. A biopsychosocial (BSP) model of pain management is promoted by many chronic pain services around the world. The model was first brought to attention by psychiatrist George Engel who discussed the concept of the ‘mind – body’ connection. He theorised that biological, psychological (thoughts, emotions, and behaviours) and social (socioeconomical, socio-environmental and cultural) factors are all part of the way humans function in the context of ill health or disease (Engel, 1977). As chronic pain is so complex and often complicated by other conditions, the aim of this paper is to explore its assessment. Appropriate, holistic and thorough assessment of the patient with chronic pain is central. The assessment process can often be the starting point for helping patients to identify, understand and manage their pain in a more effective manner.
Pathophysiology The pathophysiology of pain is complex as both electrical and chemical responses are involved. Although acute pain may initially arise from noxious stimuli such as trauma or infection to tissue, in chronic pain both the peripheral and central nervous systems are implicated. Nociceptors, found in most tissues of the body, are specialised peripheral sensory neurons that respond to noxious stimuli. The 4 stages of the nociceptive process are: • Transduction – myelinated A-delta and unmyelinated C-fibres respond to intense noxious stimuli. This includes mechanical, thermal and chemical noxious stimuli. A-delta fibres transmit ‘fast’ messages associated with acute sharp pain while C-fibres transmit ‘slow’ messages associated with throbbing pain and chronic pain sensations. • Transmission – information is relayed into the dorsal horn of the spinal column. Impulses cross over and are sent via the ascending sensory tracts in the spinal cord to the higher centres of the brain. • Perception – the somatosensory cortex aids the location and interpretation of pain. The conscious awareness of pain is controlled by the
B. Wellington et al. reticular activating and limbic systems and allows the person to be aware of the pain, respond emotionally and take action. Cerebral activity is triggered including discriminative, affective, autonomic and motor responses to the stimuli. • Modulation – direct physiological modulation of pain impulses occurs due to changes in chemicals in the spinal cord and brain. In the dorsal horn of the spinal cord pain sensation may be altered by stimulation of afferent A-beta fibres. From the brain, descending pathways of nerve fibres make inhibitory connections in the dorsal horn and so inhibit nociceptive transmission (Melzack and Wall, 1965). Tissue injury also elicits an inflammatory response (including the release of prostaglandins, cytokines, serotonin and adrenaline) that causes increased excitability. Pro-inflammatory substances (including mast cells, macrophages and neutrophils) increase the efficacy of transduction channels and an exaggeration of the firing threshold and response. However, if there is sustained activation, sensitisation can occur (known as peripheral sensitisation). Changes can occur in the nociceptors which result in heightened responsiveness and a reduced threshold to stimuli. The term ‘central sensitisation’ is used to describe ‘wind-up’ which is a condition of long term potentiation and secondary hyperalgesia. Wind-up is a state where the dorsal horn neuron responses are significantly increased as a result of repetitive stimulation. When the spinal neurons are in this more excitable state, the brain receives a stronger and longer input from a stimulus. Long-term potentiation at individual synapses is thought to be important in the learning and memory of pain. Secondary hyperalgesia can also occur in undamaged tissue adjacent to the area of actual tissue damage and may be due to an increased receptive field and reduced threshold in the dorsal horn (Bridgestock and Rae, 2013). Some of the spinal neurons associated with pain project into the limbic system of the brain and areas of the midbrain that are involved in fear, anxiety and mood and are responsible for the potential activation of autonomic responses (Dickenson, 2013). The key to successful management of chronic pain is accurate assessment by a clinician. This should be based on a broad understanding of the physiological processes. Many approaches have been used to evaluate chronic pain and the next section provides an overview of some of the available assessment tools.
Assessment of chronic pain Table 1
157
Resources for further learning: chronic pain.
Resource
Notes
General resources Engel, G. L. (1977). The need for a new medical model: a challenge for biomedicine. Science, 196, 129–136.
Engel describes the need to move from a biomedical model of care to the framework of care encompassing social, psychological and behavioural aspects of illness.
Holmes, A., Christelis, N. & Arnold, C. (2012). Depression and chronic pain. Medical Journal of Australia Open, 1(4), 17–20.
The authors describe the current approach to the assessment and management of major depression in patients with chronic pain.
International Association for the Study of Pain. Classification of chronic pain. Pain (1986); Suppl 3: S1–S226
Descriptions of chronic pain syndromes and definitions of pain terms. Prepared by the International Association for the Study of Pain
Johannes, C. B., Le, T. K., Zhou, X., Johnston, J. A. & Dworkin, R. H. (2010). The prevalence of chronic pain in United States adults: results of an Internet-based survey. The Journal of Pain, 11(11), 1230–1239.
A cross-sectional, Internet-based survey was conducted in a nationally representative sample of United States (US) adults to estimate the point prevalence of chronic pain and to describe sociodemographic correlates and characteristics of chronic pain
Lynch, M. E. (2011). The need for a Canadian pain strategy. Pain Research & Management: The Journal of the Canadian Pain Society, 16(2), 77.
Pain is undertreated in Canada and there are major problems with access to appropriate care for all types of pain. A national pain strategy addressing educational, clinical and research needs is required.
Merskey, H. (1979) Pain terms: a list with definitions and notes on usage recommended by the IASP subcommittee on taxonomy. Pain, 6, 249–252
• See www.iasp-pain.org
RNAO (Registered Nurses’ Association of Ontario (2013) Clinical Best Practice Guidelines. Assessment and Management of Pain. 3rd Ed. www.rnao.ca/bpg/ guidelines/assessment-and-management-pain
The guideline contains recommendations for best nursing practices in the assessment and management of pain for Registered Nurses in Canada. This guideline is endorsed by the International Association for the Study of Pain.
Stannard, C. & Booth, S. (2004). Pain 2nd Ed. Elsevier Churchill Livingstone: Edinburgh.
This book is generally about the management of chronic pain associated with cancer and non malignant disease. It contains chapters on functional imaging, opioid medication and neurostimulation.
Wood, S. (2008) Assessment of pain http://www.nursingtimes.net/nursing-practice/ specialisms/pain-management/assessment-of-pain/ 1861174.article
A useful introduction to pain assessment tools that provides basic information for nurses in everyday clinical activity
http://www.britishpainsociety.org.uk/
The British Pain Society has a membership of over 1,400 and is involved in all aspects of pain and its management through the work of the Council.
http://www.iasp-pain.org/Education/Content.aspx ?ItemNumber=1698
The following pain terminology is updated from “Part III: Pain Terms, A Current List with Definitions and Notes on Usage” (pp. 209–214) Classification of Chronic Pain, Second Edition, IASP Task Force on Taxonomy, edited by H. Merskey and N. Bogduk, IASP Press, Seattle, ©1994.
www.wongbakerfaces.org
Wong Baker Faces scale is a self-assessment scale, so the patients need to be able to understand the instructions and select a face that illustrates the pain they are experiencing. It should never be used with unresponsive patients or to compare the patient’s face to the scale to determine the level of pain. (continued on next page)
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Reviews of the evidence and literature Carnes, D., Homer, K. E., Miles, C. L., Pincus, T., Underwood, M., Rahman, A. & Taylor, S. J. (2012). Effective delivery styles and content for selfmanagement interventions for chronic musculoskeletal pain: a systematic literature review. The Clinical Journal of Pain, 28(4), 344–354.
The objective of the study was to report the evidence for effectiveness of different self-management course characteristics and components for chronic musculoskeletal pain
Eldridge, S., Spenser, A., Pincus, T., Rahman, A., Bremner, S. A., Underwood, M. R. & Diaz-Ordaz, K. (2014). OP21 Effectiveness and cost-utility of a group self-management support intervention (COPERS) for people with chronic musculoskeletal pain: a randomised controlled trial. Journal of Epidemiology and Community Health, 68(Suppl 1), A13–A14.
The authors evaluated a new and innovative, theoretically grounded self-management support intervention for chronic musculoskeletal pain.
Hogg, M. N., Gibson, S., Helou, A., DeGabriele, J. & Farrell, M. J. (2012). Waiting in pain: a systematic investigation into the provision of persistent pain services in Australia. Med J Aust, 196(6), 386–90.
The aim of this systematic investigation was to document and describe persistent pain management in outpatient services in Australia
Nicholas, M., Molloy, A., Tonkin, L. & Beeston, L. (2011). Manage Your Pain. Souvenir Press: London.
This book explains practical and positive ways in which your patients can manage and adapt to a life with chronic pain. It includes chapters for older people, pacing, exercises and treatments.
Reid, K. J., Harker, J., Bala, M. M., Truyers, C., Kellen, E., Bekkering, G. E. & Kleijnen, J. (2011). Epidemiology of chronic non-cancer pain in Europe: narrative review of prevalence, pain treatments and pain impact. Current Medical Research & Opinion, 27(2), 449–462.
Pan-Europe epidemiological data about chronic noncancer pain were obtained using systematic review principles in searching and summarising results.
Smith, B. H., Hardman, J. D., Stein, A., & Colvin, L. (2014). Managing chronic pain in the non-specialist setting: a new SIGN guideline. British Journal of General Practice, 64(624), e462-e464.
This guides you through the rationale and process of developing the SIGN guideline.
Tan, T., Barry, P., Reken, S. & Baker, M. (2010). Pharmacological management of neuropathic pain in non-specialist settings: summary of NICE guidance. BMJ: British Medical Journal, 707–709.
This summarises the most recent recommendations from NICE on drug management for neuropathic pain, excluding specialist pain services.
Turk, D. C., Swanson, K. S. & Tunks, E. R. (2008). Psychological approaches in the treatment of chronic pain patients–when pills, scalpels, and needles are not enough. Canadian Journal of Psychiatry, 53(4), 213–223.
A review of different psychological models concluded with showing that self-management is an important complement to biomedical approaches
Vowles, K. E. & McCracken, L. M. (2010). Comparing the role of psychological flexibility and traditional pain management coping strategies in chronic pain treatment outcomes. Behaviour Research and Therapy, 48(2), 141–146.
The study participants were 114 chronic pain sufferers. The authors examined how changes in methods of coping compared to changes in psychological flexibility. This related to improved function during a multidisciplinary treatment program. (continued on next page)
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(continued)
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Guidelines American Society of Anesthesiologists Task Force on Chronic Pain Management. (2010). Practice guidelines for chronic pain management: an updated report by the American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine. Anesthesiology, 112(4), 810.
USA – The purposes of these guidelines are to (1) optimise pain control, recognising that a pain-free state may not be attainable; (2) enhance functional abilities and physical and psychological well-being; (3) enhance the quality of life of patients; and (4) minimise adverse outcomes
Furlan, A. D., Reardon, R. & Weppler, C. (2010). Opioids for chronic noncancer pain: a new Canadian practice guideline. Canadian Medical Association Journal, 182(9), 923–930.
Canada – Their aim was to oversee the development and implementation of a guideline to assist physicians to manage patients with chronic noncancer pain by prescribing opioids in a safe and effective manner.
NICE CG 173 Neuropathic pain: the pharmacological management of neuropathic pain in adults in nonspecialist settings (Nov 2013) www.nice.org.uk/ guidance/cg173
UK – This information explains the drug treatments for neuropathic pain but excludes treatments in pain clinics or other specialist clinics.
SIGN 136: Management of Chronic Pain (Aug 2014) sign.ac.uk/guidelines/fulltext/136/index.html
UK – This guideline provides recommendations and treatment pathways based on current evidence for best practice in the assessment and management of adults with chronic non-malignant pain in non specialist settings, including self management, pharmacological, psychological, physical, complementary and dietary therapies
www.healthcareimprovementscotland.org/. . ./ chronic_pain/where_are_we_now.aspx
Scotland – This report presents detailed analysis of the current care provision for chronic pain services and makes recommendations for NHS boards, local Service Improvement Groups, the Scottish Government and for the National Chronic Pain Steering Group, to be achieved by 2016.
www.nationalpainaudit.org/media/files/ NationalPainAudit-2012.pdf (National Pain Audit England and Wales 2012)
England and Wales – The National Audit of Pain Services was initiated to collect detailed data on pain services. The three-year study aimed to improve NHS services for people affected by chronic pain.
Assessment tools A definition of pain widely used in nursing, emphasising its subjective nature and the importance of believing the patient’s description, was introduced by Margo McCaffery in 1968 and later amended to “Pain is whatever the experiencing person says it is, existing whenever he says it does” (Pasero and McCaffery, 1999, p. 17). Pain assessment is considered to be the 5th vital sign and many pain assessment tools exist that aim to objectively describe a patient’s pain. Continual systematic assessment and re-assessment are the bases for effective pain management. Pain assessment tools are described as unidimensional or multi-dimensional. Prior to using these tools the clinician must be aware that different factors affect the choice of tool to be used, e.g. acute
or chronic pain, age, cognition, malignant or nonmalignant pathology, education level, communication ability, culture, ethnicity, biology, past experience of pain, willingness to report pain, reliability and validity, ease and time commitment when using the tool (RNAO (Registered Nurses’ Association of Ontario), 2013). Uni-dimensional tools are used to focus on one dimension of pain. While they are commonly used for the assessment of acute pain and may not be seen to be that useful with chronic pain, they are still worthy of explanation because they may be combined with other types of pain assessment. The examples of tools given here are all validated and easy to use. They may include visual, verbal, numerical or pictorial descriptors and ratings. They are often used in acute post-operative pain assessment. Examples of uni dimensional assessment tools include:
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• Visual analogue scales (VAS) – usually consisting of a 10cm horizontal line with markings for no pain at one end and pain as bad as it could possibly be at the other end. The patient marks a point on the line to represent the intensity of their pain and the number is obtained by measuring in millimetres from the start of the line to the area marked. • Verbal rating score (VRS) – a list of adjectives and numbers are used to describe varying pain intensity levels. Examples of common descriptions are 1–3 (mild), 4–6 (moderate) and 7–10 (severe). This is for use with adults, is validated and is quick and easy to use. • Numeric rating score (NRS) – patients rate their pain scale from 0 to 10, with 0 being no pain up to 10 being the worst pain possible. • Faces Pain Scale (FPS) (www.wongbakerfaces.org) – six gender-neutral faces with expressions ranging from no pain to the worst pain possible. Each face has a matching numerical score, along the range 0–2–4–6–8–10. It is commonly used with children. Multidimensional tools capture several different dimensions of pain; characteristics and quality of pain, satisfaction with pain control and how pain impacts
Box 1
mood, activity, sleep and diet. As pain is multidimensional, these tools are very helpful when a comprehensive assessment of pain is required. They are therefore more helpful for the patient with chronic pain. Examples of multidimensional tools include: • The Brief Pain Inventory (BPI) – a selfadministered questionnaire assessing pain and its impact. Originally used and developed for cancer patients, this has proven to be a reliable and valid tool for assessment of chronic pain. When used regularly, the tool helps to record pain interference with general activities of daily living. The questionnaire comprises 9 questions about pain severity using a numerical scale, yes and no answers and a visual diagram. • McGill Pain Questionnaire (MPQ) – consists of three main parts: o A pain rating index determined by two numerical values that can be designated to adjectives used to describe the pain. These are words used to describe the patient’s sensory, affective and evaluative pain experience. o Present pain intensity is assessed based on a numerical scale of 0–5. o An anatomical drawing for the patient to mark the location of their pain.
Reflection guide (adapted from Gibbs, 1988).
Description Explain what you are reflecting on; describe your learning expectations and prior knowledge of chronic musculoskeletal pain assessment. Feelings Discuss your personal thoughts and feelings about your experiences of performing chronic musculoskeletal pain assessment in your areas of practice. Have your opinions about how chronic musculoskeletal pain is assessed changed after reading this article? Evaluation What did you learn? What was helpful, what was missing, how did it make you feel? Analysis What did you gain from reading this article; did it meet your expectations? How does the information in this article relate to your current practice? Is there further evidence you need to gather relating to chronic musculoskeletal pain assessment? What are the potential implications for practice? Conclusion Summarise your thoughts, what are your general and personal conclusions about chronic musculoskeletal pain assessment and why? Action Plan Use your reflection to initiate a discussion/debate on chronic musculoskeletal pain assessment with your colleagues. Recommendations for good practice? What will you do differently? How will you disseminate any recommendations to the multi-disciplinary team?
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• Paediatric Pain Questionnaire (PPQ) – illustrated with happy and sad faces, has a genderneutral outline to illustrate the location of pain and uses descriptive words to assess sensory, affective and evaluative qualities of pain. Numerous tools are available to the clinician; evidence based best practice guidelines, papers and websites explain in-depth the assessment tools. Good assessment by a knowledgeable clinician is of paramount importance for the ongoing management of patients with chronic pain. The role of the healthcare professional is to perform the appropriate assessment, be skilled in interpreting the results and then take the relevant action to deliver that individual patient’s pain management regimen. This update has included information about the nature and assessment of chronic pain. Table 1 provides links to further information resources relating to chronic pain management which the reader should access to continue their learning (Box 1). A future feature in this series will continue the theme of chronic pain management and introduce some pharmacological management options as well as some alternative and complementary therapies.
References Bridgestock, C., Rae, C., 2013. Anatomy, physiology and pharmacology of pain. Anaesthesia and Intensive Care Medicine 14 (11), 480–483. British Pain Society, 2014.
Gibbs, G., 1988. Learning by Doing: A Guide to Teaching and Learning Methods. Oxford Further Education Unit, Oxford. Holmes, A., Christelis, N., Arnold, C., 2012. Depression and chronic pain. Medical Journal of Australia 1 (4), 17–20. IASP (International Association for the Study of Pain), 1986. Classification of chronic pain. Pain Suppl 3, S1–S226. Johannes, C.B., Le, T.K., Zhou, X., Johnston, J.A., Dworkin, R.H., 2010. The prevalence of chronic pain in United States adults: results of an Internet-based survey. The Journal of Pain 11 (11), 1230–1239. Lynch, M.E., 2011. The need for a Canadian pain strategy. Pain research & management. The Journal of the Canadian Pain Society 16 (2), 77. Melzack, R., Wall, P.D., 1965. Pain mechanisms, a new theory. Science 150, 971–979. Merskey, H., 1979. Pain terms: a list with definitions and notes on usage recommended by the IASP subcommittee on taxonomy. Pain 6, 249–252. Pasero, C., McCaffery, M., 1999. Pain: Clinical Manual. Mosby, St. Louis. RNAO (Registered Nurses’ Association of Ontario), 2013. Clinical Best Practice Guidelines. Assessment and Management of Pain, third ed.
Beverley Wellington a,b, Sandra Flynn c, Wendy Duperouzel d, Sylvia Treloar e a New Victoria Hospital, Glasgow, UK b University of the West of Scotland, Paisley, UK. E-mail address: Beverley.wellington@ ggc.scot.nhs.uk c Countess of Chester N.H.S. Foundation Trust, Chester, UK. E-mail address: Sandra.fl[email protected] d Curtin University, Bentley, Western Australia, Australia. E-mail address: Wendy.J.Duperouzel@ curtin.edu.au e Covenant Health Misericordia Community Hospital, Edmonton, Alberta, Canada. E-mail address: [email protected]
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