How to Keep The Patient in Pain Sleeping at Night (and you awake in the morning )

1. How to Keep The Patient in Pain Sleeping at Night (and you awake in the morning ) Barry Bass University Center for Pain Medicine UTHSC, Houston

2. Pain Management For

3. Objectives • To identify types of pain • To clarify principles of pain assessment • To clarify the basic principles of prescribing • To discuss the basic pharmacological principles of opioid and adjuvants used in pain management • To discuss the practical application of drugs used in analgesic therapy with emphasis on patient safety , risk benefit comparisons and cost containment

4. Acute Pain An unpleasant reaction/sensation secondary to tissue damage

5. Acute Pain • Corresponds to the degree of injury • Is self limiting • Serves a purpose • Responds to conventional therapy • Attracts sympathy and concern from family and caregivers • Minimal affective response • Treatment is cost effective • Good outcomes

6. Chronic Pain • Outlasts the initial injury • Subjective exceeds the objective findings • Poor response to conventional therapy • Serves no beneficial purpose • Poor response from family and care givers • Cost ineffective therapy • Accompanied by major psycho-social co-morbidity • High incidence of substanceabuse

7. Definitionof Persistent (Chronic) Pain • Any pain that • Persists beyond the expected time after a physical or emotional injury • Subjective complaints are magnified • Pain is out of proportion to clinical signs • Is accompanied by severe psycho-social issues • Responds poorly to conventional therapy

8. Persistent Pain PAIN SUFFERING DEPRESSION LOSS OF FUNCTION DRUG ABUSE FINANCIAL LOSS DOMESTIC DISRUPTION

9. Scope of The Problem • One in four Americans has persistent pain • Commonest reason for PCP office visits • Over 50% of Cancer patients have severe pain • 60% of the elderly have persistent pain • Commonest cause of disability • Health care costs related to persistent pain is $100 billion and rising rapidly • Lost work hours secondary to persistent pain can double the costs • Rising rate of substance abuse

11. The Good ACUTE PAIN The Bad Persistent nociceptive Pain The Ugly Neuropathic Pain

12. Who Gets Persistent Pain ? • Systemic disease • Diabetes mellitus • hypothyroidism • HIV/AIDS • Hepatitis C • Malignancy • Neurological disease….ALS, MS • Rheumatoid related syndromes • Obesity • Psychiatric co-morbidity

13. Types of Persistent Pain • Nociceptive • Musculo skeletal • Joint • Ligamentous • Visceral • Neuropathic • Central • Somatic • Sympathetic • Psychogenic • Mixed

14. Neuropathic Pain Pain secondary to biochemical and structural changes within the central and peripheral nervous system.

15. Pain Transduction Pain conduction Pain processing Pain perception Pain expression

16. Pain Assessment • The pain itself • Intensity • Radiation • Type • Relieving exacerbating factors • Functional assessment • Behavioral assessment • Medication usage

17. Pain Assessment • Characterize the pain • Characterize the disease, relationship between pain and disease and potentially treatable etiologies • Clarify syndromes and infer pathophysiology • Determine need for urgent therapy • Identify other needs • Develop a therapeutic strategy

18. Pain Intensity Rating Scales • Visual Analogue Scale (VAS) No pain -----------------------------------Worst pain • Numerical Rating Scale 0 ------------------------------------------- 10 Worst pain imaginable No pain • Categorical Scale None (0) Mild (1 – 4) Moderate (5 – 6) Severe (7 – 10) (Cleeland, 1991; Jacox et al, 1994)

19. Red Flags in Pain Assessment • Poor function • Pain always a 10 out of 10 • Behavioral co morbidity • Obsession with drugs • Altercations with staff • Focus on particular medications • Multiple admissions for pain therapy • Frequent ER visits • Illegal drug usage • Alcohol and tobacco abuse • Poor motivation

21. Guidelines in Pain Therapy • Assess the pain frequently • Pain assessment must be dynamic and not static • Be pre-emptive • Be mechanistic • Use around the clock therapy (ATC) • Treat and assess breakthrough pain aggressively • Where possible use oral route • Consider age, previous drug usage, hepato- renal function • Monitor for abuse • Monitor and treat side effects • Be cost effective

22. Neuro -Physiology of Pain TRANSDUCTION CONDUCTION PERCEPTION Descending Modulation CONDUCTION EXPRESSION

23. Mechanistic Approach To Therapy Modify expression..anxiolytics Increase inhibition.. Amitryptiline venlafaxine, clonidine Prevent centralization cox2,opioids, ketamine,alpha 2 agonists. Decrease inflammatoryresponse.NSAIDS, local anesthetics, steroids Decrease conductiongabapentin, carbamazepine,local anesthetics, opioids

24. Mechanistic Approach to Drug Therapy in Persistent Pain • Decrease peripheral sensitization • Delay or block conduction • Suppress automaticity • Inhibit central amplification • Increase descending inhibition • Modify central perception • Modify expression

25. The Opioids

26. Cancer Pain……… Palliation Non Malignant Pain………Rehabilitation

27. Efficacy of Opioids in Persistent Pain States • Nociceptive pain • Visceral pain • Neuropathic pain

28. WHO Analgesic “Ladder” for Cancer Pain Freedom from Pain Proposed 4th Step Intrathecal Opioid Delivery Pain persisting or increasing Step 3Opioid for moderate to severe pain± Nonopioid ± Adjuvant Pain persisting or increasing WHO 3-Step Analgesic Ladder Step 2Opioid for mild to moderate pain± Nonopioid ± Adjuvant Pain persisting or increasing Step 1± Nonopioid± Adjuvant Pain Deer T, Winkelmuller W, Erdine S, et al. Intrathecal therapy for cancer and nonmalignant pain: patient selection and patient management. Neuromodulation 1999;2:55-66.

31. Breakthrough Pain • End of dose • Pathological • Incidental • Tolerance

33. Principles of Breakthrough Pain Therapy • Should not exceed 25% of the daily dose • Should stay within the therapeutic window • Should have minimal side effects • Should not be randomly escalated • If needed more than 4 hrly. Increase ATC. • Assess for abuse vs tolerance

35. Opioids Used for Pain Management Strong Opioids • Morphine Sulphate • Hydromorphone (Dilaudid) • Demerol • Fentanyl • Methadone • Buprenorphine • Pentazocine • Oxycodone (Roxycodone, Tylox, Percocet) • Hydrocodone (vicodin, lortab, Norco) • Propxyphene ( Darvon, Darvocet) • Codeine Partial agonists Weak opioids

36. Routes of Administration • Intravenous • PRN nurse administered • PCA • Oral • PRN • Around the clock • Transdermal • Rectal • Transmucosal……oral or nasal • Neuraxial • Intrathecal • epidural

37. The PRN Scenario 20 minutes

38. The PCA

39. PHARMACOKINETIC GOALS SIDE EFECTS NO PAIN PAIN HOURS

40. Indications for PCA • Moderate to severe pain requiring opioids • Pain anticipated to last >10-12 hours • Patients willing to control their analgesia • Patient able to understand PCA • Oral route is not appropriate • Procedural pain

41. Choice of Opioid in PCA • Depends on: • Allergies • Renal function • Liver function • History of abuse • Individual response • Previous surgical history • Cost consideration

42. Loading Dose • Morphine 50 mg/kg q 10 minutes • 80 kg = 50 X 80 = 4,000 mg = 4 mg • Fentanyl 0.5 mg/kg q 5 minutes • 80 kg = 0.5 X 80 = 40 mg • Hydromorphone 10 mg/kg q 10 minutes • 80 kg = 10 X 80 = 800 mg = 0.8 mg

43. Maintenance Dose • Morphine 25 mg/kg q 10 minutes • 80 kg = 25 X 80 = 2,000 mg = 2 mg • Fentanyl 0.25 mg/kg q 5 minutes • 80 kg = 0.25 X 80 = 20 mg • Hydromorphone 5 mg/kg q 10 minutes • 80 kg = 5 X 80 = 400 mg = 0.4 mg

44. III. PCA • Morphine 1 mg / ml (5 mg/ml) • Fentanyl 10 mg/ml (50 mg/ml) • Hydromorphone 0.2 mg/ml (1 mg/ml and 5 mg/ml) • Meperidine 10 mg/ml

45. The Demand Dose with PCA • <0.5 mg MS is associated with poor analgesia • >2 mg MS associated with over sedation • Excessive demands • Poor pain relief or change in medical status • Pump failure • Patient confusion…………..elderly • Family interference………..elderly and children • Inappropriate patient use…….abuse • Adjust bolus dose if poor pain relief with >4 demands per hour • With line occlusion alarm set for 3 failed demands

46. The Lockout Interval • Time interval to assure full effect and to minimize sedation…..a safety feature • Too long a lockout will reduce the effectiveness of the PCA • Too short a lockout will increase risk of sedation • Lockout of 7 -11 minutes for morphine • Lockout of 6-10 minutes for hydromorphone • Lockout 5-8 minutes for fentanyl Ginsberg. Pain.1995:62:95

47. The Lockout Interval • Time interval to assure full effect and to minimize sedation…..a safety feature • Too long a lockout will reduce the effectiveness of the PCA • Too short a lockout will increase risk of sedation • Lockout of 7 -11 minutes for morphine • Lockout of 6-10 minutes for hydromorphone • Lockout 5-8 minutes for fentanyl Ginsberg. Pain.1995:62:95

48. Basal Infusions with PCA • Infusion will continue regardless of sedation level • Responsible for most instances of over-sedation ..1-3% cf. <0.5% with demand • Removes the feed back loop • Does not offer improved pain relief • Does not offer improved sleep • No difference in number of demands • Does increase total opioid delivered • Increased risk of programming errors • Only to be used if patient is opioid tolerant with knowledge of daily requirements Rudolph.Anes.Analg.1999.89:1226

49. Inadequate Analgesia with PCA • Check • Demands • The machine • The IV • The lesion being treated • Abuse potential

50. Inadequate Analgesia with PCA • Increase the bolus dose • Decrease the lockout • Educate the patient • Start basal infusion • Change the route • Change the opioid • Add an adjuvant • Antidepressant • Anticonvulsant • Anti inflammatory • Treat the lesion