1 Pain Management Robert V. Brody, M.D.Attending Physician Medicine, Pain, and Palliative Care Services, and Chief, Pain Consultation Clinic, San Francisco General Hospital Medical Director, Health at Home, San Francisco Department of Public Health Clinical Professor of Medicine and Family & Community Medicine, UCSF

2 What is Pain? PAIN: an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. International Association for the Study of Pain Not just the unpleasant sensation, not just the perception of the sensation, but also the emotional reaction to or experience of the perceived sensation. Pain is therefore always SUBJECTIVE More than merely a disagreeable sensation resulting from a noxious event, pain is a multidimensional experience. Pain perception is complex, subjective, and influenced by physiologic, social, psychologic, and spiritual processes. The International Association for the Study of Pain (IASP) Subcommittee on Taxonomy defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage, or both.” This definition encompasses the sensory experience of pain and consideration of an individual’s affective and cognitive response and illustrates that the relationship between pain and tissue injury is neither uniform nor constant. Chronic pain has been described as persistent or recurrent pain, lasting beyond the usual course of acute illness or injury and adversely affecting the patient’s well-being. Thus, it is not merely a temporal extension of acute pain, and its management requires a shift in therapeutic strategy. Chronic pain occurs in cancer, in progressive diseases, in slowly evolving or nonprogressive conditions, and as a result of injury or neurologic damage. It also occurs in the absence of an easily identifiable underlying lesion. American Society of Anesthesiologists. Practice guidelines for pain management: a report by the American Society of Anesthesiologists Task Force on Pain Management, Chronic Pain Section. Anesthesiol. 1997;86: Loeser JDF, Butler SH, Chapman CR et al. Bonica’s Management of Pain. 3rd ed. Baltimore: Lippincott Williams Wilkins; 2001:19-21. Merskey H, Bogduk N, eds. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Chronic Pain Syndromes and Definitions of Pain Terms. 2nd ed. Seattle, WA: IASP Press; 1994:3-4. Portenoy RK, Kanner RM, eds. Pain Management: Theory and Practice. Philadelphia, PA: FA Davis Company; 1996:3.

3 Framework for Pain Management:Gate Control Theory of Pain Pain is an interaction between excitatory and inhibitory pathways: Excitatory “opens gates” = increases in pain Inhibitory “closes gates” = decreases in pain These pain pathways integrate information from: Sensory – physiological components Cognitive – evaluative components Motivational – affective components

4 Assessment History, including medical, psychsocial, and addiction issues and: Location & distribution Duration & periodicity Quality Pain scale 0-10 Associated signs & symptoms What makes it worse or better Previous treatments and outcomes Effect on function Patient goals and expectations Physical examination

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7 Take apart the pain complaint:What kind of pain? somatic? inflammation? muscle spasm? visceral? ischemic? crampy? neuropathic? Psychological issues? Substance use? sleeplessness? nightmares? pain? anxiety / depression? PTSD? history of sexual / physical / emotional abuse?

8 Non-Pharmacologic pain managementPhysical therapy / exercise / stretching / yoga Massage / heat and cold Acupuncture Biofeedback / neurofeedback Transcutaneous electrical nerve stimulation TENS Cognitive behavioral therapy Therapeutic provider-patient relationship.

9 Neuropathic Pain Peripheral neuropathy, nerve compression, phantom limb, radiculopathy, herpetic neuralgia, tic douloureaux Listen for the adjectives: sharp, shooting, buzzing, electric, radiating. Not aching.

10 Anti-neuropathic Agentstricyclic agents - desipramine, nortriptyline, imipramine, amitrityline other antidepressants - duloxetine, venlafaxine, milnacipran, SSRI’s, bupropion, mirtazapine anti-epileptics - carbamazepine, gabapentin, topiramate, lamotrigine pregabalin, tiagabine, zonisamide lidocaine, mexilitene, (flecainide) baclofen capsaicin conventional analgesics

11 Anti-spasmodics baclofen carisoprodol tizanidine dantrolenecyclobenzaprine methocarbamol

12 Analgesic Ladder Step 2 Step 3 Codeine MorphineHydrocodone (Diacetylmorphine) Step 1 Meperidine Hydromorphone Butorphanol Oxycodone Aspirin Pentazocine Oxymorphone Acetaminophen Tramadol Fentanyl NSAID’s Tapentadol Methadone Buprenorphine Levorphanol

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15 Some principles of opiate useIncrease opioid dosage by percentages – 10%, 15%, 20% - not milligrams. USE THE GI TRACT Methadone is great, but… One long acting, one short acting, plus methadone for withdrawal Patient controlled analgesia - basal rate

16 Adverse Effects of OpiatesConstipation Almost universal in patients taking opiates and should be anticipated The one effect to which patients do not become tolerant Prophylactic treatment better than prn. Stool softeners and propulsants may be useful, as is sorbitol or polyethylene glycol. Avoid bulk agents Nausea Common with opiates, and often caused by constipation. Useful agents: antihistamines butyrophenones (haloperidol, droperidol) phenothiazines (prochlorperazine, promethazine) scopalamine rarely, benzodiazepines

17 Adverse Effects of OpiatesItching May respond to antihistamines, and is self-limited when due to mast cell degranulation. True allergic reactions do occur (hives). Sedation May be temporary with initiation of therapy. If persistent: Try reducing the dose of medication Increase the interval between doses Switch agents Add caffeine, or rarely dextroamphetamine or methylphenidate Respiratory depression Rare in chronic opioid therapy Observe patient closely Physical stimulation may be sufficient If naloxone required, dilute 0.4mg ampule in 10cc NS and administer 0.5ml IV push q 2 minutes. Titrate dose to avoid withdrawal, seizures, severe pain. Decreased libido, fertility with long term use.

18 Mental Health Issues and PainAnxiety / depression Post traumatic stress Substance abuse Sexual / physical / emotional abuse

19 Tolerance APS: State of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug’s effects over time Refers to the need for increasing amounts of the substance to achieve the desired effect, or markedly diminished effects with continued use of the same (usual) amount of the substance. American Pain Society, 2001

20 Physical Dependence APS: State of adaptation that is manifested by a drug class specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist. Occurs when, after a period of continuous use, abrupt discontinuation of an agent causes physical systems (withdrawal or abstinence syndrome) Is a common feature of opioids, corticosteroids, barbiturates, benzodiazepines, antihypertensive and other agents Is easily managed by gradually tapering the drug if it is no longer needed American Pain Society, 2001

21 Drug Abuse The inappropriate use of a medication for a non-medical purpose.

22 Addiction APS: Addiction is a primary, chronic, neurobiological disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include: impaired control over drug use, compulsive use, continued use despite harm, and craving There is no concensus about the percentage of patients prescirbed opioids for pain who later develop a substance use disorder or addiction. Patients with a history of SUD are at risk of relapse. American Pain Society, 2001

23 Pseudoaddiction Pseudoaddict:Patient with a chronic painful condition who requires opiates to function. May exhibit behaviors which providers label as manipulative, obsessive or drug seeking in order to find sufficient relief from pain to fully participate in life These behaviors stop promptly after adequate analgesia is provided

24 Sceening for Substance Use DisorderHave you ever tried to stop using or cut down? Has your family or anyone else complained about or discouraged your use? Have you ever had trouble with driving while under the influence? Did you ever get into trouble or have difficulty at work or school due to your use? Have you ever been injured while under the influence?

25 Urine Toxicology Know your laboratoryApproximate duration of detectability of drugs in urine by commonly used screening tests: Amphetamines 2-4 days Barbiturates 3 days Phenobarbital 2 weeks or longer Cannabinoids Infrequent user: up to 10 days Chronic user: 30 days or longer Cocaine metabolite 2-3 days Methadone 2-4 days Other opiates 2-3 days Phencyclidine (PCP) 3-8 days Confirmatory tests: Gas liquid chromatography with or without mass spectrometry High performance liquid chromatography Beating the test: Substitution Adulteration with chemicals Dilution – Substance Abuse and Mental Health Services Administration uses a cut off of specific gravity of and urine creatinine concentration of 40 mg/dl

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29 Opportunities for Improvement in Your Pain PracticeBelieve patient’s report of pain. Ascertain and treat the cause of pain. Prevention of pain is better than treatment Take the pain apart. Diagnose and treat psychiatric disorders in your pain patients. Pay attention to sleep disturbance. Abolish PTSD nightmares with alpha blocking agents like prazosin. Cognitive behavioral therapy changes lives.

30 Opportunities for Improvement in Your Pain PracticeSubstance use is common – order a Utox. Cocaine is a marker for diversion. Include non-pharmacologic management approaches. Recognize neuropathic pain and spasm and treat specifically Individualize the dosing regimen - the right dose of medication is the dose that works, i.e. improves function. Titrate the dose of your medication to effect or undesirable side effects Use the GI tract.

31 Opportunities for Improvement in Your Pain PracticeUnderstand how to use an equianalgesic table. Use methadone cautiously. Limit number of opiates – one long acting, one short acting for breakthrough, plus methadone for opioid use disorder Pain is a quality of care issue. Seek help from others with more experience.

32 Take apart the pain complaint:What kind of pain? somatic? inflammation? muscle spasm? visceral? ischemic? crampy? neuropathic? Psychological issues? Substance use? sleeplessness? nightmares? pain? anxiety / depression? PTSD? history of sexual / physical / emotional abuse?

33 55 y/o man remote h/o IVDU p/w back pain, LE weakness, found to have osteomyelitis, diskitis, epidural abscess T12-L3, s/p laminectomy, corpectomy, spinal fusion, complicated by E. coli bacteremia Labs: WBC 18.4, H/H 7.8/25, plts 424, Na 123, K 3.9, Cl 91, CO2 29, BUN 18, Cr 0.71, glu 100 Current meds: APAP prn, ascorbic acid 500mg BID, CaCo4 prn, ceftriaxone 2gm q12h, docusate 250mg bid, enoxaparin 40mg, ferrous sulfate 325mg, hydromorphone 1mg IV q2h prn, oxycodone 10mg q4h prn, lansoprazole 30mg, rifampin 300mg bid, senna nightly, silvadene, thaiamine 100mg, vancomycin 750mg q12h, Vit A, zinc S: “the pain starts in my back and travels to my feel, its very intense, sharp at time, dull at time, its tight in my lower back, my shoulders are achy and sore, I’ve had a bad rotator cuff for years. I smoke weed every day to relax and for my arthiritis pain, I don’t sleep very well, I have nightmares now and then, about my dad and family and how I was treated. I want off the shots – I saw my dad die with my stepmom giving him shots of morphhine and a drip, that scares me.”

34 O: appears in acute discomfort, distress, anxious, tearfulpatient has received 9 doses IV hydromorphone + 1 dose oxycodone per 24hrs A/P c/o acute somatic and neuropathic pain, chronic somatic pain, spasms, endorses anxiety, mentions use of cannabis for pain and to relax, insomnia due to pain and anxiety, nightmares of childhood abuse, requesting off IV opioids, willing to try anti-neuropathic and anti-spasm agents, trial of SNRI warranted once hyponatremia corrected. Therefore would recommend: MSContin 30mg po q8hr Gabapentin 300mg q8h for neuropathic pain Baclofen 5mg po q12hr for spasms Change oxycodone to 10mg po q2hr prn breakthrough pain Change hydromorphone to 0.6mg IV q6hr prn severe pain if oral pain meds ineffective

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