Understanding pain in 5 minutes

Transcription

1 Pain Management- PallCare Definition of Pain Pain is what the patient says hurts. Dr Simon Allan Director of Palliative Care Arohanui Hospice An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage. In other words, pain is a somatopsychic phenomenon. Twycross, R Understanding pain in 5 minutes Neuropathic Pain Associated with nerve compression or injury. Description: burning, tingling, numbness, shooting, stabbing, or electric-like feelings. Can be associated allodynia ( light touch exacerbates pain). Hyperaesthesia more common. Approx. half of nerve injury pains (cancer related) respond to NSAID and strong opioid, the remainder need adjuvant analgesics Neuropathic Pain 87 year old with severe burning and stabbing pain in rib cage. Known to have spinal mets. from breast cancer. Especially sore at night. Nature of pain, measure the pain Paracetamol? NSAID? Nortriptyline nocte? Both paracetamol/nortriptyline Re-assess success of intervention Pain 2/10 and manageable Nociceptive Pain- stimulation of nerve endings. Somatic Pain is the pain emanating from the muscles, skeleton and skin. Characteristics-May describe as sharp, aching, and or throbbing pain that is easily localized. Visceral Pain ie liver capsule pain, cardiac, lung, Gi and GU tracts Patients may find this pain difficult to describe or localize. Nociceptive pain generally responds well to opioids and/or co analgesics. 1

2 Pain in right upper abdomen 67 year old with liver metastases from colon cancer Pain 6/10 right upper abdomen and low appetite Paracetamol useless M-Eslon 10 mg bd (Laxsol) and dexamethasone 4 mg improved pain to 0/10 and improved appetite Breakthrough Pain Known as intermittent pain Generally associated with chronic cancer pain Important to assess the occurrence Obtain pain history Treated with PRN medications (please relieve now!) Titrate Incident Pain Results from a specific event for an individual such as movement or wound care Cause is usually obvious Managed by anticipatory prescribing and administration of analgesic prior to pain appearing Incident pain Mary is 68 and has metastatic melanoma to D9 with collapse of that vertebra, she is bed bound On turning her she has agonising pain 9/10 for 2 minutes and is very distressed by it Morphine 60 mg bd with morphine 10 mg s/c or mg oral 4 hrly prn Alfentanyl nasal spray, midazolam nasal, Entenox just prior Pain assessment History Site of pain - where is the pain? Type of pain - what does it feel like? Severity How severe is pain? Frequency of pain - how often does it occur? Duration of pain - how long has it been present? Aggravating factors - what makes it worse? Relieving factors - what makes it better? Responses to previous and current treatment? Consider medical history Physical examination Pain Assessment Pain assessment The Fifth Vital Sign Important that patient rate their own pain Consider tools that the patient understands For patients with cognitive impairment consider appropriate assessment tools Observation important Comprehensive history 2

3 Assessment of Pain Perception Numeric Rating Scale How do you rate the severity of the pain on a scale of 1-10, with 10 being the worse pain you could ever have? Verbal Descriptor Scale Please describe your pain from no pain to mild, moderate, severe or pain as bad as it could be? Patients that have difficulty communicating Observe Change in behaviour, increased agitation or aggression Change in appetite or sleeping pattern Change in activity (e.g. More or less wandering) Facial expressions (frowning) Verbalisations (moaning, crying) Is there any guarding of any body part? Obvious physical signs that could indicate pain? Consider observations of caregivers/relatives PAINAD: Pain Assessment in Advanced Dementia Scale A five-item observational scale used to screen individuals with advanced dementia for pain (score from 0 10) Breathing Negative vocalization Facial expression Body language Consolability Assess patient during periods of activity, such as turning, ambulating, transferring Warden V, Hurley AC, Volicer L. Development and psychometric evaluation of the pain assessment in advanced dementia (PAINAD) scale. Journal of the American Medical Directors Association 2003; 4:9-15. ABBEY Pain Scale Vocalisation 0-3 Facial expression 0-3 Change in body language 0-3 Behavioural change 0-3 Physiological change 0-3 Physical changes 0-3 Add scores none (0-2) to severe (14+) New simpler scale trialed After a trial comparing ABBEY with PAINAD a trial of a simpler tool has started looking at 3 most useful items identified by nurses in ARC: Facial expression Body language Vocalisation 3

4 What exactly to look for Vocalisation-whimpering, groaning, crying Facial expression-looking tense, frowning, grimacing, looking frightened Body language- fidgeting, rocking, guarding, withdrawn Behavioural- increased confusion, refusing to eat, alterations in usual patterns Pain Management-Holistic approach Diversional Therapy Address psycho-social and spiritual issues Relaxation Superficial heat (mild) Aromatherapy Mobilising exercise/physiotherapy Listening to the person s story Involve family and friends Pets Radiotherapy WHO management principles Titrate for individual patient (by the ladder) Adequate doses Regular doses (by the clock) Oral route where possible (by mouth) Management plan for breakthrough pain (prn) Supervision Keep reviewing and reassessing effectiveness of treatment- Document Non-Opioids Paracetamol NSAIDs Weak Opioids Codeine Tramadol Strong Opioids Morphine Methadone Oxycodone Fentanyl Adjuvants Corticosteroids Anti-epileptics Anti-depressants Anti-spasmodics Muscle relaxants Biphosphonates NMDA receptor channel blockers Analgesia Pain treatment can be started at any step of the ladder according to pain intensity Adjuvant drugs are used at any time to enhance analgesic efficacy Adequate doses of PRN as required basis Review effectiveness of any medication Ensure all patients on a step 2 or 3 analgesic are on regular laxatives and monitor bowels Drugs Step 1. Mild Pain Paracetamol, NSAIDs. (Caution with the elderly due to gastric and renal side effects) Step 2. Mild to Moderate Pain Codeine, (10% of people cannot metabolize) DHC, Tramadol Step 3. Moderate to Severe Pain Morphine, Methadone, Oxycodone, Fentanyl 4

5 Morphine Oxycodone Opiate analgesic of choice for moderate to severe pain Dose-dependent analgesic action Oral, subcut, rectal, PEG, sprinkled More effective for noci-ceptor pain than neuropathic pain because it selectively binds to opioid receptor sites in CNS and smooth muscle Useful for breathlessness, cough. Caution in renal impairment Second in line to morphine (more expensive) but not shown to be any more effective than morphine Approx 1 ½ to 2 x potency of morphine Acts on receptor sites in brain and spinal chord Analgesic, anxiolytic, antitussive, sedative Plasma concentrations greater by 15% in elderly 25% in females than males (body weight adjusted basis) Better handled in renal failure but caution still required Methadone CAUTION- Not to be initiated without consulting a palliative care specialist Affects NMDA receptors useful for neuropathic pain. Useful in renal impairment Analgesic effect within approx 1 hour of administration Has a wide variation in individual response and half-life hours (can be up to 120 hours) 4 5 days for tissue and plasma levels to stabilize & accumulation continues until steady state at about 10 days Allow time for response between dose increases Respiratory depression more of a risk due to above Opioids Start low and go slow Desirable Effects: analgesia, decreased anxiety and decreased dyspnoea Undesirable Effects: Side effects- nausea, constipation, somnolence, dry mouth, pruritis. Signs of toxicity- Myoclonus, hyperalgesia. Delirium, hallucinations, cognitive impairment. Opioids Side Effects Common SE Nausea -usually resolves within 48 hours. Some are wrongly wired for opioids! Constipation never resolves. Laxatives required and monitor bowels Sedation usually resolves within 48 hours Dry Mouth never resolves Less Common SE Urinary retention-elderly males Pruritis (itch)-often difficult to resolve Pain in last days of Life Oral medications not appropriate in last days of life When patient is diagnosed as dying medications reviewed- non essentials discontinued If resident on slow release opioids- convert to syringe driver If resident morphine naïve PRN medications prescribed- Morphine 2.5-5mg sub cut Use PRN medications in response to pain- can use a butterfly cannula and leave in situ. Anti-emetics When 3 or more doses of PRN morphine used in 24 hour period consider a syringe driver 5

6 66 year old woman Been on M-Eslon 60 mg bd for bone pain from breast cancer and is now unable to eat/drink, has been a little nauseated and anxious s/c pump considered Morphine- Dose? Anti-emetic? Anything else for pump? Any other considerations? 66 year old woman- S.C.P. Morphine 60 mg Levomepromazine (Nozinan) 6.25 mg Midazolam 10 mg Over 24 hours 66 year old woman Been on Oxycontin 10 mg bd unable to swallow much, has been restless and has accumulating chest secretions Scp- Oxycodone dose? I tend to reduce by 20% roughly, say 15 mg s/c Add drying agent Add anxiolytic 66 year old woman-s.c.p. Oxycodone 15 mg Midazolam 10 mg Hyoscine butylbromide (Buscopan) 60 mg 66 year old woman Been on methadone 10 mg bd for pain which has had a neuropathic quality. Also had nausea and on metoclopramide 10 mg 6 hrly For scp- methadone reduce by about 20 %, 15 mg s/c (assuming pain is OK) Add and antiemetic-could be metoclopramide or Nozinan Add dexamethasone 1 mg to scp for reduced tissue reaction Principles of pain management 1. Ask or read the person about the pain 2. Accept their word about their pain 3. Never underestimate the potential effects of pain on QOL 4. Effective management requires a combination or pharmacological and non-pharmacological interventions and education 5. Evaluate efficacy of interventions 6. Document results!!! 6