Lecture_W8_Assessment and management of chronic pain.pdf

Assessment & management of pain Brooke Coombes [email protected] Learning outcomes At the end of this lecture, you should be able to: • Describe the biopsychosocial approach to assessment & management pain • Identify treatments that target pain mechanisms • Explain pain neurophysiology and...

Assessment & management of pain Brooke Coombes [email protected] Learning outcomes At the end of this lecture, you should be able to: • Describe the biopsychosocial approach to assessment & management pain • Identify treatments that target pain mechanisms • Explain pain neurophysiology and pain management concepts to patients Biomedical model of pain • Traditional biomedical models focus on pathophysiology and other biological approaches to disease • Pain is more than just a medical problem – it is shaped by the person who is experiencing it and his/her sociocultural context Patient A vs B • Both have symptoms of osteoarthritis in the knees • Both show moderate changes on x-ray • Kellgren & Lawrence Scale – grade 3 • Moderate joint space reduction & osteophytes Biopsychosocial model of pain • Describes pain and disability as a multidimensional, dynamic integration among biological, psychological and social factors that reciprocally influence one another Falla and Hodges (2017) Exerc. Sport Sci. Rev Biopsychosocial assessment of chronic pain • When assessing our patient with pain, we are trying to understand the reasons for development or persistence of their pain • This may enable more targeted interventions Falla and Hodges (2017) Exerc. Sport Sci. Rev Patient A vs B • Patient A is a 60 year old married woman who is retired and enjoys looking after her grandchildren. • Patient B is a 55 year old laborer. His work is contract based and often at short notice. He assists with caring for his grandson who has ADHD. He is divorced and has little retirement savings. Assessment toolkit • Patient interview • Patient reported outcome measures (PROs or PROMs) • +/- Quantitative sensory testing • +/- Diagnostic imaging • +/- Other investigations e.g. Nerve conduction studies Patient interview • History of pain, medical history • Location of pain • Characteristics of the pain & associated features • Behaviour of pain • Effect of pain medication How has their pain changed over time? Kongsted (2017) BMC Musc Patient interview • Impact of pain on work, sleep, leisure • Beliefs about their pain • Emotions • Cultural circumstance Falla and Hodges (2017) Exerc. Sport Sci. Rev Look for maladaptive beliefs – “Danger in me” • “I’m in pain so there must be something harmful happening • “Even the MRI can’t find it” • “The doctor misdiagnosed me” • “The physio made me worse” • “Physical activity might harm my back” • “I should not do physical activities which (might) make my pain worse” Try to understand the patient’s pain experience • Pain assessment requires empathy • Actively listen to the patient’s story in order to be in a position to provide information and advice that is valued by the patient Your pain is real Patient reported outcomes (PROs) • Pain scales Understanding pathophysiology (3rd Ed, Chap 7) Patient reported outcomes (PROs) • PainDetect • Scores >12 associated with greater likelihood of having QST signs of central sensitization in people with knee OA (Hochman 2013) • Tampa scale of kinesiophobia • Total score >37 suggests high fear of movement or (re) injury (Vlayen 1995) • Pain Catastrophisation Scale (PCS) • Catastrophisation has been shown to be an important predictor of negative pain treatment outcomes • Pain Anxiety Symptoms Scale (PASS) PASS Quantitative sensory tests (QST) • QST are used to test pain thresholds to different sensory modalities • Pain threshold is the lowest intensity at which a stimulus is perceived as pain • Pain-free grip test ("grip-pain threshold") • Can also provide information about loss and gain of sensory function to assist in diagnosis of neuropathies Other investigations • Nerve conduction studies • May be used to investigate neuropathic pain • Blood tests • To investigate inflammation or autoimmune diseases • CRP (C-Reactive Protein) – CRP is often the first evidence of inflammation or infection as its concentration increases in the blood within a few hours of an infection or inflammatory injury • HLA-B27 – associated with seronegative spondyloarthropathies Other investigations • Diagnostic maging (e.g. x-rays, MRI, CT) may be used as one part of the assessment of a patient with pain • We know: • Pain is a person’s experience that cannot be seen on images • There is often a mismatch between imaging findings and pain • Unnecessary imaging may do as much harm as good Diagnostic imaging • A patient’s knowledge of imaging abnormalities can lead to fear-avoidance and catastrophising behaviours that may predispose to chronicity What I learnt from Dr Google… Diagnostic imaging • Sometimes imaging may not be recommended • Provide clear information & recommendations • • Elicit Patient Beliefs/Questions • • “The good news is that based on your history and your normal physical examination I do not think that you need an xray.” “Is there anything you are concerned about?” Provide Empathy, Partnership • “I want to reassure you that your symptoms are very different from someone with a herniated disc” • “I'd like try this treatment and review your progress over the next 6 weeks. If you develop any new symptoms like weakness in your legs, numbness or pain down the leg you should call me. However, I expect like most people with low back pain you will start to feel better with the treatment.” • “Are you comfortable with this plan” https://www.aafp.org/patient-care/clinical-recommendations/all/cw-back-pain.html Pain is always real, no matter what the cause The key to eliminating the stigma and marginalization experienced by many chronic pain patients is acknowledgement that pain is “real.” This is still the most important aspect in the treatment of chronic pain General principles for management of pain • Address the cause if there is one • Educate the patient • Promote self-management • Optimise function and quality of life • Control pain Pain management team painhealth.csse.uwa.edu.au Role of physiotherapist • Physiotherapists can provide advice/ education on • Understanding pain • How to start moving and exercising • What exercise is best • Physiotherapists may use exercise, manual therapy, massage, electrotherapy or other evidence-based treatments • Physiotherapists can assist patients to set goals, monitor progress and communicate with other health professionals Role of psychologist • Clinical psychologists can help patients to manage their pain by • Changing maladaptive their thoughts about pain • Managing low mood, anxiety and stress • Managing sleep patterns • Relaxation and meditation techniques • Cognitive behavioural therapy (CBT) is a structured approach that explores the links between thoughts, emotions and behaviour Role of GP • Coordinating care • Prescribing pain medication • Referral to health professionals • Liase with employer or Work Cover nociplastic nociceptive neuropathic Psychosocial factors Mechanism-based approach to management of pain Pharmacological management of pain • Not all pain responds to the same pain medications • E.g. NSAIDs and steroids are used for nociceptive inflammatory pain • Tricyclic antidepressants or anti-convulsants are used for neuropathic pain • By employing different classes of analgesic, it is possible to use lower doses of each, improving the side effect profile Pharmacological management of pain Chimenti 2018 Pharmacological management of pain – WHO analgesic ladder Schedule 8 (S8) medicines can only be supplied by a pharmacist on prescription and are subject to tight restrictions because of their potential to produce addiction Understanding pathophysiology (3rd Ed, Chap 7) Pharmacological management of pain How effective are medications for musculoskeletal pain? • The Number (of patients) Needed to Treat (NNT) explains how likely a medication is to “work”. A NNT of 2 means that 1 patient in 2 treated with the pain-reliever will get a reduction in pain (by at least 50%), compared to a placebo. • The Number Needed to Harm (NNH) is what is used to explain how likely a medication is to give side-effects. An NNH of 8 means that 1 in every 8 people taking the medication will experience a side effect, compared to placebo, because of the medication. Pharmacological management of pain painHEALTH-NNT-and-NNH-for-pain-medications.pdf Activating the body’s own medicine chest • Our body and nervous system produce chemicals that act the same way opioid drugs do. These “endogenous opioids” includes endorphins, enkephalins, and other related molecules. • Endogenous analgesia systems help the body control pain • These systems are not under volitional control but can be engaged by other means Activating the body’s own medicine chest • How can endogenous analgesia systems be engaged? • Pain - Pain inhibits pain is a phenomenon • Exercise – daily walking can increase serotonin & noradrenalin • Manual therapy • Acupuncture • Smiling– helps release serotonin • Chocolate • Placebo Physiotherapy management of pain Chimenti 2018 TENS • Traditional TENS selectively activates non-nociceptive (Aβ) fibres which close the gate to noxious input (spinal gating) • Acupuncture like TENS activates descending pain inhibition What might happen if the stimulus was too strong? Manual therapy • Mechanical stimuli via manual therapy or massage can elicit a chain of neurophysiological mechanisms, at a peripheral, spinal cord and supraspinal level Bialowski 2010 Manual therapy Bialowski 2010 Exercise • Physical activity and exercise is an intervention with few adverse events that may improve physical function and QOL • More research is needed to determine optimal mode/dose/factors affecting adherence Acute exercise • Exercise induced analgesia is the phenomenon where an acute bout of exercise leads to increased pain thresholds • Not fully understood • Likely to be multiple mechanisms including • Activation of descending pain inhibitory pathways • Spinal gating (non-noxious input from mechanoreceptors causes reduced transmission of noxious input at a spinal cord level) Acute exercise • Exercise of varying modes & intensities can promote analgesia in healthy individuals • Exercise induced analgesia may be impaired in some patients e.g. fibromyalgia Exercise – A double edged sword While regular exercise can reduce pain and disability, many people with chronic pain struggle because of symptoms • Some patients are fearful of pain and avoid exercise • Others do too much exercise causing pain flares and fatigue • Sometimes patient experience a boom-bust cycle whereby they do both too little and too much exercise painhealth.csse.uwa.edu.au Principles of pacing & goal setting • Pacing and goal setting are used to provide a structured approach to increasing exercise tolerance • Pacing is based on a ‘time-contingent’ approach to activity rather than a ‘pain-contingent’ approach painhealth.csse.uwa.edu.au Principles of pacing & goal setting • A ‘pain-contingent’ approach is where activity is based on whether pain is experienced. The disadvantage of this approach is that it often leads to a boom-bust cycle • Too little (avoidance) • Too much (pain flares & fatigue) Principles of pacing & goal setting • A ‘time-contingent’ approach is where activity is based on measurement of the time, distance or number of repetitions. • A target and a limit is set e.g 15 mins walking or 20 mins light housework. • Using this approach helps to build activity tolerance How to teach pacing • Step 1: Set a baseline – measure time/distance/reps that you can do the task without pain • Step 2: Repeat the task daily • Step 3: Slowly increase the time/distance/reps each week • Step 4 : Build up your activity levels using SMART goals Helpful tips for pacing • On a good day, do not more than the pacing schedule allows • On a bad day, try to do some activities • Have a plan and aim to change only one or two things at a time • Keep a record • Build up time on task gradually • Remember that setbacks or flare-ups will happen from time to time What else? • Graded motor imagery can help patients explore movement through safe, pain-free ways e.g. by thinking about moving Pain & sleep • People with chronic pain find it difficult to fall asleep or sleep is disrupted with long awakenings (poor quality) • Reciprocal relationship – mainly poor sleep causes increased sensitivity to pain https://painhealth.csse.uwa.edu.au/pain-module/sleep-and-pain/ Pain & sleep • Education can help patients to understand that sleep comes in waves of lighter & deeper sleep • Promote good sleep hygiene – routine, only go to bed when sleepy, relaxation, avoid napping https://painhealth.csse.uwa.edu.au/pain-module/sleep-and-pain/ Evidence for Pain Neurophysiology Education (PNE) • PNE aims to reconceptualize an individuals’ understanding of their pain as less threatening to facilitate rehabilitation • Evidence suggests PNE has small clinically important effect on pain catastrophisation & kinesiophobia Watson (2014) J Pain Our research Have you done your BIT? Our research Our research Our research Our research References • Davidson’s Principles and Practice of Medicine 23rd Edition Ralston (Ed) Elsevier Edinburgh, Chapter 34 Pain • Van Griensven 2015 The patient’s pain experience. In Grieves Modern Musculoskeletal Physiotherapy Chapter 28.1 • https://painhealth.csse.uwa.edu.au/about