The biopsychosocial complexities of managing wound pain



An introduction to the biopsychosocial complexities of managing wound pain

Cliff Richardson. PhD.

Lecturer, School of Nursing, Midwifery and Social Work, University of Manchester. UK.

Correspondence address

Cliff Richardson

School of Nursing Midwifery and Social Work

Jean McFarlane Building

Oxford Road

Manchester

M13 9PL

clifford.richardson@manchester.ac.uk

Tel 0161 306 7639

Fax 0161 306 7707

Declaration of interest

Cliff Richardson has received an unrestricted grant from Molnlycke Healthcare

Introduction

Wounds can be painful and managing this pain, especially at key points in time, such as dressing changes is one of the most challenging aspects of care for practitioners looking after people with wounds 1 2. Much has been written about wound classification and the specific differences between acute and chronic wounds but less has been described about the potential differences that these classifications may have on the pain experiences of individuals. Applying similar pain skills to patients with an acute wound healing through primary intention and a chronic oozing wound will not be effective and could negatively affect the healing process 3. Further complications occur when chronic wounds with associated chronic pain require dressing changes. At this time the chronic pain is compounded by the presence of acute/procedural pain caused by disruptions of the wound environment and irritations such as shearing forces and touch 4. This paper will explore the variations in pain that can be seen between acute and chronic wounds as illustrated by some of the important aspects of pain and will propose that wound care practitioners require a wide range of skills to manage these pains.

Pain

Pain has been classified in various ways. The simplest classification is into acute pain and chronic pain where acute pain is pain of recent onset and is projected to last less than 3 months 5. Chronic pain is pain that has lasted continuously or intermittently for at least three months 6. Using time as the only criterion however can be problematic as the point chosen for conversion between the pain types is arbitrary hence separate classifications have arisen. Examples of other taxonomies are that chronic pain should be defined as ‘pain that extends beyond the expected period of healing’ and where pain is defined in terms of time and pathology7. For ease of description within this paper, pain will be referred to here as acute and chronic.

It is universally agreed that pain is a biopsychosocial phenomenon which means that the experience (for the person with pain) and the assessment of pain (by an observer) are influenced by biological/physical, social, psychological, cultural, environmental, spiritual, and many other factors 8 9. As a consequence it makes all aspects of pain related care extremely complicated. Before moving onto the specifics for wound care it is important to explore some of these complexities.

Biological/physical

Nociception is the normal protective physiological detection of pain 10 and occurs following trauma or injury. Nociceptive pain may however induce considerable changes within the nervous system. These changes occur at the periphery, spinal cord and within the brain. This neuroplasticity can have repercussions in how pain is felt as it can provoke conditions where pain is physiologically modified. Perhaps the most reported and important of these conditions in terms of pain are allodynia and hyperalgesia. Allodynia is a condition where normally painless stimuli such as touch are felt as pain 11. Hyperalgesia is an exaggerated pain response to a normally painful stimulus 11 and is a normal consequence to injury but abnormal if it persists after healing has occurred.

Social/cultural

Pain has a significant social element which makes the context of the pain very important. Beecher’s work in the 1940’s identified that soldiers with injuries encountered on the battlefield tended to exhibit different behaviours than people with similar injuries but in a domestic type situation 12. The pivotal work of Zborowski (1950’s) in the USA found that pain behaviours varied considerably between ethnic groups 13. In his work the ethnic Irish group was generally stoic and did not show their pain whereas the ethnic Italian’s tended to outwardly show their pain. Although it has been shown that in modern multicultural societies cultural differences reduces over time it remains clear that reaction to pain will vary between cultures and that cultural concordance between pain sufferer (patient) and pain observer (HCP) is important14 15.

Psychological

Various psychological factors are known to influence pain reaction and sensitivity. In chronic pain conditions these contribute to the disabling effects 16. It is impossible to cover all of the psychological aspects that influence pain here, so to best illustrate these points key pain related factors of catastrophising and stoicism have been chosen. Broadly speaking catastrophizing is the tendency to magnify the threat of pain 17. High catastrophizers are known to exhibit magnified behavioural responses to pain and exaggerate pain intensity 18 19. The opposite extreme is stoicism. Stoics are likely to hide pain and underplay their pain. Other recognised psychological features that influence the perception of and reaction to pain are anxiety, depression, coping style and locus of control8 20. Simple measurement tools such as the Pain Catastrophising Scale (PCS)17 and Hospital Anxiety and Depression Scale (HADS)21 are available to capture the psychological status of the individual with the wound and are helpful to provide comprehensive pain assessment. Anticipation is another important consideration and is especially relevant at dressing changes and will be discussed in more depth later.

Recognition that the differences in the response to pain is expected and that different people will experience pain differently is essential to the management of pain. The challenge for the wound care health care practitioner is to understand these multifarious issues and integrate all of them into a coherent pain and wound care strategy. This is especially true when recent evidence suggests that there is a relationship between pain and stress and that these influence wound healing22-24. One way to ensure that all aspects of pain management are covered is to utilise the Manchester P.A.I.N. model 25.

P.A.I.N model applied to wound pain

The Manchester model guides the practitioner through four key stages (Preparation, Assessment, Intervention and Normalisation) required for good pain management. Each stage includes different care needs dependent upon the type of wound being treated. For recurrent pain events using the model should be seen as a cyclic process with each stage being revisited to ensure that all aspects are covered. In more problematical wound pain each stage may need to be visited several times to ensure comprehensive coverage and successful management. It is understood that there are multiple different combinations of pain type and wound type so for clarity and brevity the model will be only be applied to three common wound care situations here. These are acute pain from acute wounds, chronic pain from chronic wounds and procedural pain of chronic wounds caused by dressing changes as it is considered that these three examples illustrate the major issues that practitioners will encounter on a day to day basis.

Acute pain of acute wounds

Preparation

Pain associated with acute wounds is generally the easiest to manage but still requires attention to detail to be successful. Preparation involves readying the patient for the pain experience. There is significant evidence that information prior to a procedure can reduce pain associated with that event 26. For post surgical wound pain this could be performed at pre-assessment clinics and be incorporated into the general post-operative information delivered at these important consultations 27. However as it is known that some patients react negatively to some forms of information hence the amount and detail of the information should be negotiated with the patient 28. Preparation of the practitioner treating the wound requires knowledge of the potential causes of pain in an acute wound. Overwhelmingly this will be due to nociception. Reaction to nociception however can be affected by social, psychological and spiritual characteristics so practitioners need to be vigilant to the potential suppression or magnification of pain resulting from traits inherent within the person with the wound during the assessment process 29.

Assessment

Assessment of pain in acute wounds requires thought and planning but due to the nature of the wound being a nociceptive event a uni-dimensional pain assessment tool is usually adequate. Visual analogue scales (VAS), numerical rating scores (NRS) and verbal rating scales (VRS) which all measure pain intensity are commonly used and are effective in this group 29 30. Pain assessment and reassessment strategies should continue until the wound is fully healed and should be measured during movement rather than at rest.

Intervention

Nociceptive pain from acute wounds can usually be treated with medication. In hospitals local anaesthetic blocks and wound infiltration are often used at the time of surgery and for patients who are likely to remain in hospital local anaesthetic infusions are now becoming common place 28. Following on from using local anaesthetics traditional analgesics such as acetaminophen (paracetamol), non-steroidal anti-inflammatories (NSAID’s) and opioids (morphine and its derivatives) are usually effective but must be utilised within their dose limits and taking account of contraindications. If the pain is sufficient for the use of an opioid then dose titration is necessary. Using paracetamol and an NSAID additional to an opioid will mean that lower doses of the opioid will be required 31. Controlling acute wound pain may mean that additional analgesia is not necessary when dressing changes are required however complex acute wounds such as those following the surgical treatment of an abscess which need regular packing will need similar strategies to those described below for procedural pain in chronic wounds. The aim of pain intervention is to enable full function or the earliest possible return back to normal (normalisation).

Normalisation

Normalisation needs to be at the forefront of all thinking during pain management of wounds. It recognises the need to ensure that the person with the wound should be able to function normally or optimally, depending upon the circumstances, despite the presence of the wound.

Chronic pain of chronic wounds

Preparation

When pain has been present for an extended period of time there are inevitable psychosocial consequences which means that the weighting of these factors in treatment strategies needs to be higher7. For instance it is documented that chronic pain is associated with significant levels of depression and anxiety 16. Practitioners treating chronic pain from chronic wounds need to be ready to utilise holistic strategies, hence the preparation phase for chronic wounds with chronic pain will involve the practitioner as much as the patient as they need to be extra vigilant of the biopsychosocial attributes of each individual. This involves being prepared for amongst other things, catastrophising/stoicism, depression/anxiety and the presence of allodynia/hyperalgesia from neuroplasticity as these will affect all stages of the PAIN model. Neuroplasticity can create clinical situations that appear irrational or counter-intuitive. An example could be that the skin for several centimetres around a chronic wound is painful to touch, indeed it is possible that the wound itself is insensate but the skin surrounding the wound is exquisitely painful.

Assessment

Taking account of the biopsychosocial factors influencing pain makes assessment of chronic pain more difficult than for acute wounds with acute pain. In chronic pain from a chronic wound a simple intensity scale is insufficient on its own. Instead a full assessment of the factors contributing to the pain is required. A full sociocultural assessment is required which will vary depending on the environment in which the assessment is being made, the therapeutic relationship, and the presence or absence of significant others. There are assessment tools for anxiety and depression such as the Hospital Anxiety and Depression Scale (HADS) 21, coping style including the coping strategies questionnaire (CSQ) 32 and catastrophizing (PCS) 17, and these can be used alongside a multidimensional pain assessment tool such as the McGill Pain Questionnaire (MPQ) 33 or the Brief Pain Inventory (BPI) 34. The multidimensional pain assessment tools will enable full capture of the pain and its effects on the person. Words such as sharp, throbbing and aching tend to be associated with nociceptive pain whereas words such as burning, shooting and ‘electric shocks’ tend to be associated with neuropathic pain. Neuropathic pain occurs when nerves are damaged and may also be associated with allodynia or hyperalgesia. This means that the assessment of pain in chronic wounds may require assessment of the skin surrounding the wound in order to ensure that the correct dressing and fixatives are utilised. If it is suspected that there is a neuropathic element to the pain then a specific neuropathic pain assessment tool such as the LANSS can be used35. Comprehensive and differential assessment taking account of all the biopsychosocial attributes is essential to guide accurate treatment strategies.

Intervention

With chronic wound pain management analgesics are often inadequate on their own. Additional attention to the psychosocial consequences of the pain is required alongside analgesics for comprehensive and effective pain management. Creative thinking is required by the practitioner to manipulate the psycho-socio-cultural-environmental influences extant upon the person with the chronic wound. Powerful social forces such as health beliefs (of the patient and their relatives/friends) and psychological traits such as catastrophizing which affect the pain experience can be worked upon within the therapeutic relationship built up between the practitioner and the patient as this is the principle of most pain management programmes in the UK 36. An over-riding requirement of this is consistency hence as far as possible for optimal care the same practitioner should be involved as much as possible in the wound/pain care.

The choice of analgesics is based upon the comprehensive assessment. Nociceptive elements should be targeted with paracetamol, NSAID’s and Opioids. These should be given regularly rather than on an ad hoc basis and titrated against the effect of the pain on function.

Neuropathic pain identified in the wound area may require adjuncts such as antidepressants and anticonvulsants 37 38. Commonly utilised antidepressants are amitriptyline and nortriptyline which are given at low dose compared to that used for depression and a good strategy especially for the anti-depressants is to deliver them at night because they can cause drowsiness. This side effect can be used constructively in people with chronic pain as it can help them to sleep and reducing sleep deprivation can have a significant positive effect on the pain as well 37. It is good practice to state clearly to the patient that the antidepressants are being utilised as analgesics and that their use does not make a statement as to their mood state. Gabapentin and pregabalin are anticonvulsants that are widely used for neuropathic pain with good efficacy data 39 40.

Normalisation

The ultimate aim for all pain interventions is for the individual to be able to function normally or to an optimum level based upon the condition causing the pain. In wound care this is likely to be a return to their original function based on the baseline assessments that were performed. Full normalisation will ensure that wound healing will be maximised by achieving full vascularisation and prevent immunosuppression 41.

Procedural pain of chronic wounds (and open acute wounds)

Dressing changes are particularly painful and has been cited to be the worst time for many people with wounds 42. The principles used are the same as for managing pain during dressing of an acute wound with a few additions mainly associated with neuropathic pain and/or neuroplasticity elements. It should be noted however that acute wounds will have an area of hyperalgesia around them due to the normal physiological processes of healing and chronic wounds may have areas of allodynia/hyperalgesia surrounding them, hence regard must be taken of this especially when choosing the type of dressing to be applied and any fixatives used.

Preparation

For good pain management during dressing change it is essential that full preparation is achieved. Optimal pain relief is best achieved within a trusting therapeutic relationship. Taking the lead from evidence that suggests that information reduces pain postoperatively it is assumed that doing the same pre-dressing change will have the same result however there are no studies to confirm this in wound care. Similarly to pre-surgical information giving, there needs to be caution exercised for particular individuals who will react negatively to particular forms of information 43 such as high catastrophizers. Comprehensive assessment of the individual is essential and information given to people found to be high catastrophizers needs to be delivered sensitively.

Cognisance also needs to be taken of previous experiences of dressing changes. If the individual has encountered pain during the dressing before then anticipation may become problematic. Most wound care practitioners will have encountered patients who flinch prior to any contact. It is now clear from brain imaging studies that anticipation of pain induces similar brain responses to the actual pain 44 45. Flinching and withdrawing prior to the dressing change therefore is a reasonable response and will only be reduced once good pain management is achieved during the dressing change. Good preparation is crucial to commence this process. Discussing previous experience and devising a strategy using shared decision-making skills will be an all important first stage.

Social, contextual and environmental preparation will involve the creation of an appropriate area into which to place the person prior to the dressing change. Busy, noisy and rushed environments are anxiety inducing that can provoke worse pain experiences than calm and quiet settings46. The presence of a spouse or trusted friend/family member can assist in creating a therapeutically appropriate environment however it should not be taken for granted that because someone is with the patient that they should be present. Social interaction is complicated and some relationships and situations have the potential to encourage the patient to tolerate pain rather than manage it and vice versa. An example is Bert Trautmann a goalkeeper for Manchester City Football Club during the 1950’s. Although unaware of it Bert broke his neck during the 1956 cup final, played on, made full length saves and dived at the feet of on-coming forwards after picking up the injury. Contextually Bert could not leave the field (it was the days before substitutes) and the occasion of playing in the biggest match of his life in front of 100,000 live fans and countless millions on TV enabled him to tolerate his pain. The wound care practitioner has to use all their communication skills to pick up on non-verbal cues from the patient which guide actions to be taken and should try to ensure that they do not encourage a situation where the patient has to act as a hero.

Assessment

Assessment during a dressing change can generally follow acute pain principles hence a simple intensity scale such as the 0-10 numerical rating scale can be utilised. Additionally however practitioners will need to utilise assessment strategies as mentioned in the chronic wounds section for instance allodynia and hyperalgesia have to be taken into account when choosing the dressing and fixative. Non-adherence to a particular dressing strategy can be avoided if the dressing is chosen to minimise irritation of allodynic or hyperalgesic areas. For instance compression bandaging is known to be very effective for venous leg ulcer management but if the bandaging stimulates continuous pain then it is unlikely to be tolerated beyond the end of the appointment. NRS scores can be assessed at various points through dressings that take a long time to enable the practitioner to understand the important times and learn for the future.

Intervention

Careful consideration and accommodation must be given to the psychosocial and environmental issues identified at the preparation stage before deciding on the analgesic strategy. Appropriate continuous pain relief may reduce the pain felt on dressing change but it is likely that some additional analgesia will be required to cover this key time. Practitioners have to be mindful of the doses already taken and ensure that no contraindications exist between analgesics chosen. If the patient is not already on maximal dose of acetaminophen (paracetamol) and NSAID’s then additional doses can be targeted for dressing times as long as it does not exceed the maximum therapeutic dose. Extra doses of opioid’s can be given and titrated against the pain experienced whilst remaining cognisant of the need to ensure that the medication chosen has had time to reach therapeutic effect. The target dose of all analgesics needs to be revised based on the patient experience of the previous dose during the dressing. A useful adjunct for dressing changes is the inhalation agent nitrous oxide. A 50:50 mix of nitrous oxide and oxygen such as Entonox™ can be self administered by the patient through a mask or mouthpiece with a demand valve between the mask and the cylinder which only allows delivery when the person breathes in. Nitrous oxide has strong analgesic properties 47 and is also anxiolytic 48 making it very useful for people who have had previously painful dressing change experiences. Additional issues that makes nitrous oxide useful for dressing changes is that it reaches therapeutic levels within minutes and then wears off in a similar period of time once administration ends. This means that it can be tailored to most therapeutic environments. With minimal training required, cheap equipment and with it being a low cost drug, nitrous oxide has few contraindications for use in wound care.

Focus has also turned towards the dressing itself and whether it can be analgesic49. Ten potential mechanisms have been described but these require rigorous testing to confirm the analgesic effects. It is likely however that dressings that have lower peel forces and minimal trauma on removal will induce lower pain levels.

Normalisation

As the majority of dressings of this kind occur in the patient’s home or in outpatient or GP clinics the need is for the patient to be able to get on with normal life as soon as possible after the dressing. Pain should not restrict them in continuing with their daily activities. Reassessment of pain and continued therapeutic discourse will help this to happen and assist in the evaluation of the procedure to enable feed forward to the next dressing.

Conclusion

Pain management in wounds is complex and requires many and varied nursing skills in order to be successful. Key aspects to maximise success are developing a strong therapeutic relationship, understanding how pain may be perceived, full patient preparation, comprehensive assessment and innovative intervention. Achieving this will enable the patient to return to and maintain optimal or full function despite the wound.

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