Decreasing Pain and Improving Quality of Life: Clinical Strategies for Chronic Wound Patients
May 2012
Pain is a common experience among those living with chronic wounds. Pain impacts all aspects of everyday life, including physical activity, sleep, and social functioning. In the process, pain can erode one’s quality of life.2-4 Some patients continue to provide vivid descriptions of their painful experiences long after their ulcers are healed.5 While wound-associated pain often is caused by intrinsic wound pathology and exacerbated by local manipulation that is part of routine wound management, the intensity of pain is subjected to influences of many personal and social factors.
The complexity of pain necessitates a systematized approach to obtain a thorough pain history, evaluate aggravating and alleviating factors, assess the wound and surrounding tissue, and monitor outcomes. Optimal pain management must be incorporated as an integral part of comprehensive wound care in order to improve quality of life. It is imperative to approach wound-associated pain by first identifying the triggers (related to wound pathologies or procedures) and by evaluating the number of neurobiopsychosocial factors that may affect the pain experience. A variety of approaches drawing on expertise from interprofessional teams is crucial to optimize pain management. Studies of patients living with various chronic wound types validate the pervasiveness of pain. Szor and Bourguignon6 reported in a study that as many as 88% of people with pressure ulcers express pressure ulcer pain at dressing change and that 84% experienced pain even while at rest. Of those with venous leg ulcers, the majority experienced moderate to severe levels of pain described as aching, stabbing, sharp, tender, and tiring.7 Pain has been documented to persist up to at least 3 months after wound closure.7,8 Contrary to the commonly held belief that most patients with diabetic foot ulcers do not experience pain due to loss of protective sensation, up to 50% of patients experience varying degrees of predominantly neuropathic painful symptoms, according to researchers.9
For controlling more severe (7-10 out of 10) and refractory pain, opioid analgesics should be considered. Management of neuropathic pain or associated symptoms (eg, anxiety and depression) may include the possibility of adding adjuvant treatments. Three classes of medications are recommended as first-line treatments for neuropathic pain: antidepressants with both norepinephrine and serotonin reuptake inhibition (tricyclic antidepressants and selective serotonin and norepinephrine reuptake inhibitors), calcium channel a2d ligands (gabapentin and pregabalin), and topical lidocaine (lidocaine patch 5%).20 In addition to the severity and pain types, selection of appropriate pharmaceuticals should always take into account the characteristics of the drug (onset, duration, available routes of administration, dosing intervals, side effects; see Table 2) and individual factors (age, coexisting diseases, and other over-the-counter or herbal medications).20
Consequences of Wound Pain
To avoid pain, many patients feel forced to limit their activities of daily living (eg, bathing), social interaction, time with family, and work. Patients often describe wound-associated pain as all-encompassing and one of the most devastating aspects of living with chronic wounds.4 Upton et al1 have documented that pain is a significant predictor of acute and chronic stress in chronic wound patients. As part of the cascade of stress response, the overproduction of cortisol and catecholamines can have a significant impact, delaying wound healing due to alteration in the immune system.10 Woo and Sibbald11 followed 111 home care clients with either leg or foot ulcers prospectively for 4 weeks to determine the effectiveness of comprehensive wound assessment and management. Wound-related pain was addressed by education, careful selection of wound dressings, application of topical analgesics during dressing changes, and use of systemic analgesics. The average pain-intensity score was reduced from 6.3 at baseline to 2.8 at week 4 (P P Wound-Related Mechanisms Pain can be present due to a number of factors. Wound-related triggers. Underlying wound-related pathologies resulting in ischemic damages, prolonged inflammation, and nerve injuries are often the reason for background persistent pain. The presence of unexpected pain/tenderness along with other criteria is also indicative of infection in chronic wounds.17,18 Following repeated insult, excessive and prolonged inflammation can lead to spontaneous “wind-up” pain or exaggerated or prolonged painful responses to normally painful stimuli (hyperalgesia) and even non-painful stimuli (allodynia).20 Procedure-related triggers. Despite obvious therapeutic values and primary intentions to optimize wound healing, many wound-management procedures are painful. Most obvious, debridement using a sharp surgical instrument can cause a considerable amount of pain.23 Trauma at dressing removal has been documented to cause pain in several observational studies.4 Dressing materials often adhere to the fragile wound surface due to the glue-like nature of dehydrated or crusted exudate. Potential local trauma may evoke pain each time the dressing is removed. In addition, the granulation tissue and capillary loops may grow into the product matrix — especially gauze dressings and with the use of negative pressure wound therapies — potentiating the likelihood of trauma and bleeding with dressing removal. According to a review of dressings and topical agents for secondary intention healing of post-surgical wounds, patients experienced significantly more pain with gauze than with other types of dressings.24 Wound care providers practicing evidence-based care should avoid the use of gauze products in painful wounds. To ensure dressing securement, strong dressing adhesives or tapes are often used. However, repeated application and removal of adhesive tapes and dressings strip the stratum corneum from the skin epithelial cell surface, damaging the skin. In severe cases, contact irritant dermatitis results in local erythema, edema, and blistering of the wound margins.25 Wound cleansing is part of routine wound care that is likely to cause pain during dressing changes.26 The routine practice of using abrasive materials and gauze to scrub the wound surface should be discouraged. Clinicians must understand that pain can be caused by pressure-relieving equipment and treatment-related activities, such as repositioning, especially among patients who have significant contractures, increased muscle spasticity, and spasms. Some patients consider compression therapy treatment of venous stasis to be uncomfortable. Briggs and Closs27 indicate that only 56% of patients in their study were able to tolerate full compression bandaging, with pain being the most common reason for non-adherence.Wound-Associated Pain
Pain is a complex biopsychosocial phenomenon. Melzack28 introduced the term “neuromatrix” to connote the intricate interactions among a number of modulating factors. Despite seemingly comparable levels of pain intensity, persons with pain experience varying degrees of physical limitations, emotional distress, and suffering. The integrated wound-associated pain model in Figure 1 posits the multi-dimensionality of pain in response to wound- and procedure-related triggers. Understanding that emotions, cognitive process, social environment, and attitudes can influence how people feel, the various separate dimensions are created merely for heuristic purpose. For instance, nocebo effect or negative placebo effect delineates pain amplification by expectation of pain and heightened anxiety.29, 30 The result is a vicious cycle of pain, stress/anxiety, and worsening of pain. In a study of 96 patients with chronic wounds, Woo26 reported those who experienced high levels of anxiety also reported high levels of anticipatory pain, leading to high levels of pain at dressing change. Certain personalities may be more vulnerable to noxious stimuli in light of their propensity to experience anxiety and catastrophize their experience. Comprehensive wound pain management should incorporate an assessment of the person’s anxiety level, stress, expectation, and social environment.
Properly Assessing Pain
Pain assessments should be well documented to facilitate the continuity of patient care and to benchmark the effectiveness of management strategies. Many methods of pain assessment have been developed, ranging from subjective self-reports to objective behavioral checklists. Remember that pain is a subjective experience. An individual’s self-report of pain is the most reliable method to evaluate pain. Other assessment methodologies include physiological indicators, behavioral manifestations, functional assessments, and diagnostic tests. Categorical scales, numerical rating scales, pain thermometers, visual analogue scales, face scales, and verbal categorical scales are one-dimensional tools commonly used to quantify pain in terms of intensity, quality (characteristics), pain unpleasantness, and pain relief.31 To obtain a comprehensive assessment of pain, multidimensional measurements are available to evaluate the many facets of pain and its impact on daily functioning, mood, social functioning, and other aspects of quality of life. The key questions to ask about pain can be remembered through the mnemonic PQRSTU.32,33 See below: • P — Provoking/Palliating Factors: What makes your pain worse? What makes your pain better (eg, warm weather, walking, certain types of cleansing solutions or dressings)? • Q — Quality of Pain: What does your pain feel like? Descriptors (eg, burning, electrical shocks, pricking, tingling pins) may help differentiate the two types of pain: nociceptive and neuropathic. • R — Regions and Radiation: Where is the pain, and does the pain move anywhere (eg, in and around the wound, the wound region, unrelated)? • S — Severity or Intensity: How much does it hurt on a scale of 0–10, with 0 representing “no pain” and 10 representing “pain as bad as it could possibly be”? • T — Timing or History: When did the pain start? Is it present all the time? (A pain diary may help to map out the temporal pattern of pain, ie, the pain worsens at night.) • U — Understanding: What is important to you for pain relief? How would you like to get better? As an alternative, studies have shown the observation of nonverbal indicators encompassing a wide range of vocalized signals and bodily movements may provide a means of assessing pain in patients (eg, neonates or cognitively impaired) who are not able to verbalize pain. Several tools are available, including: • Abbey Pain Scale Assessment of Discomfort in Dementia Protocol Checklist of Nonverbal Pain Indicators; • Discomfort Scale-Dementia of the Alzheimer’s Type; • Face, Legs, Activity, Cry, and Consolability Pain Assessment Tool; • Pain Assessment in Advanced Dementia Scale; and • Pain Assessment Scale for Seniors with Severe Dementia. Despite the robust psychometric properties of these measurement tools, it is important to remember behaviors (eg, facial expression, body movements, crying) that signal pain may vary significantly among individuals, and there is no evidence that any single behavior or number of behaviors is more reliable to measure the presence or intensity of pain.31,34 Pain measurement tools may include word descriptors to qualify pain and allow clinicians to differentiate neuropathic from nociceptive pain. Nociceptive pain incurred by tissue damage stimulates pain receptors in the muscle, bone, joints, and ligaments (somatic pain) or in the viscera and peritoneum (visceral pain). Nociceptive pain is often described as sharp, dull, aching, throbbing, or gnawing. In contrast, neuropathic pain is caused by injury and sensitization of the peripheral or central nervous system. Neuropathic pain is mostly described as burning, electrical shocks, pricking, tingling pins, and increased sensitivity to touch. Specific assessment protocols are developed to evaluate neuropathic pain.35 In all, no single tool has been deemed universal and useful for all patients. The selection of a specific pain scale must take into account the patient’s age, language, educational level, sensory impairment, developmental stage, and cognitive status. Once chosen, the same measurement scale should be used for subsequent assessments for ongoing comparison. Changes in pain levels may indicate a need to reassess the choice and timing of analgesics and/or other interventions used in pain management.
Managing Wound Pain
A patient-oriented and multifaceted approach (see Table 1) is recommended for the management of wound-associated pain with the objectives to address pain relief, increase function, and restore overall quality of life. Pharmacotherapy continues to be the mainstay for pain management. Appropriate agents are selected based on severity and specific types of pain. The World Health Organization’s analgesic ladder36 proposes that treatment of mild (1-4 out of 10) to moderate (5-6 out of 10) nociceptive pain should begin with a non-opioid medication, such as acetaminophen and nonsteroidal anti-inflammatory drugs.