Pain Management in the hospitalized patient

1. Joshua Vanderloo PharmD, RPh Clinical Pharmacist, University of Wisconsin Hospital and Clinics Pain Management in the hospitalized patient

2. Disclosures • I have no actual or potential conflict of interest in relation to this presentation.

3. Objectives • Identify importance of high quality pain management • Describe basic approaches and techniques for improving pain management in the hospitalized patient • Describe the role of non-opioid and opioid therapies in the management of pain in the hospitalized patient consistent with the WHO Pain Ladder.

4. Background Or: Framing the Discussion

5. Why is high quality pain management important? • High cost of unmanaged pain • Time • Costs • $60 billion lost productivity1 and reduced patient QOL2 • Increased length of stay3 • HCAHPS* scores related to pain • Managing primary diagnosis as well as pain *HCAHPS: Hospital Consumer Assessment of Healthcare Providers and Systems 1National Institute of Neurological Disorders and Stroke. Peptides implicated in body’s response to pain. 2Postoperative pain management: a practical review, part 2. Am J Health-Syst Pharm. 2005; 62:2019-2025. 3Economic benefits of an acute interventional postoperative pain service. Anesth analg. 2007;104:S-75.

6. Neuroplasticity in Pain Processing Neuropathic pain Acute pain  chronic pain syndromes Cervero F. Pain. 1996

7. Managing Pain in the Hospitalized Patient

9. Descending Modulation Central Sensitization Peripheral Sensitization Gottschalk A, Smith DS. Am Fam Physician. 2001

10. Inhibiting Pain • Inhibitory neurotransmitters  Decrease pain transmission • Opioids • Norepinephrine • Serotonin • GABA • Excitatory neurotransmitters  Increase pain transmission • Glutamate • NMDA

11. Pain Assessment PQRST • Quality • Region/Radiation • Severity • Timing • Onset/Duration • Palliative factors • Previous therapies • Successful and nonsuccessful

12. Approaching Pain Treatment Non-pharmacologic approaches Pharmacologic • Ice • Heat • Repositioning • Distraction • Music • PT • OT • Continue home regimens • Opioids and non-opioids • Neuropathic pain • Adjuvants

13. Opioid and Non-opioid Therapies

14. WHO Pain Relief Ladder 1. Initial pain: Nonopioids 2. Addition: mild opioid or strong opioid with titration if pain inadequately managed treatments for fear/anxiety if needed 3. Schedule medications instead of PRN – “around the clock” Right drug, right dose, right time  80-90% effective and cost effective World Health Organization (2009). WHO’s Pain Relief Ladder. http://www.who.int/cancer/palliative/painladder/en/

15. Modified WHO Pain Relief Ladder PO preferred Regular intervals Analgesic chosen according to intensity Individualization Reassessment Vargas-Schaffer G. Can Fam Physician. 2010.

16. Acetaminophen • Mechanism: • COX enzyme inhibition in CNS • Analgesic & antipyretic • Indication: • Mild to moderate non-inflammatory pain • First line for osteoarthritis • First line for pain control in the elderly • PO, IV

17. Acetaminophen & Hepatotoxicity • Risk factors • Alcohol • Liver disease • > 4g daily • Daily dose limit

18. NSAIDs • Inhibition of COX enzymes Prostaglandin synthesis inhibition • Antipyretic • Anti-inflammatory • Uses • Acute and chronic pain • Somatic pain • Opioid sparing

19. NSAIDs - Examples • IbuprofenPO, IV • Ketorolac PO, IV • Naproxen PO • Aspirin PO, PR • Diclofenac PO, topical • Indomethacin PO, PR

20. NSAID Adverse Effects • Gastric, renal, cardiovascular, hematologic • Related to: • Dose • Length of treatment • Elderly • Role of COX-2 selective NSAIDs? • GI vs. cardiovascular risks • Decreasing GI risk • PPIs • Ibuprofen and diclofenac ACG Guidelines. Am J Gastroenterol. 2009;104:728-738. NSAID prescribing precautions. Am Fam Physician. 2009;80:1371-1378.

21. Opioids

23. Delivery and formulations of Opioids Routes Formulations • Oral • Intravenous • Intramuscular • Subcutaneous • Intrathecal • Transdermal • Immediate release • Extended release • PCA • Pumps • Patches

24. More advanced techniques • PCA • Dosing • Patient-initiated boluses • Clinician-initiated boluses • Basal rates • Adjusting • Attempts vs. deliveries • Sedation, end-tidal CO2 • Epidurals • Intrathecal opioid ± clonidine ± local anesthetic

25. Opioid Side Effects Constipation Nausea and vomiting CNS effects Itching Respiratory Depression Less frequent: Opioid-induced Hyperalgesia, urinary retention, delirium, myoclonus

26. Trescot AM. Pain Physician. 2006.

27. Opioid Constipation • All segments of GI • Colon most pronounced • Increased transit time • Non-propulsive, spastic contractions • Electrolyte absorption? • Differing degrees among agents • PO formulations • Assume it will develop and will not tolerate

28. Exacerbating Opioid Constipation • Advanced age • Immobility • Other concurrent constipating medications • Intraabdominal pathologies • Neuropathy • Hypercalciemia

29. Preventing Opioid Constipation • Regular assessments of stooling • Dietary changes • Add preventative agents • Stool softener (e.g. docusate) and peristaltic stimulant/“contact cathartic”(e.g. sennosides) • Or osmotic laxative (e.g. lactulose or polyethylene glycol) • Especially for patients with consistent opioid use • Prophylactic management is ideal

30. Treating Opioid Constipation • No BM in 48 hours • Addition of agents • Lactulose, sennosides, MoM • No BM in 72 hours • Fecal impaction assessment • If impacted: • Mineral oil enema ± irritant enema ± manual disimpaction • Following disimpaction: • Prevent constipation recurrence • Methylnaltrexone? Oral naltrexone?

31. Opioid-induced Hyperalgesia (OIH) • Paradoxical response • Increased opioid exposure  pain sensitization • i.e. Loss of opioid efficacy • Suspect if • Opioid efficacy decreases with dose escalation • Especially if pain worsens or becomes more generalized

32. OIH Management • Detoxification • Dose reduction • Opioid rotation • Addition of NMDA-R antagonist

33. Adjustments for Organ Dysfunction Renal Insufficiency Hepatic Insufficiency

34. Pain Management Pearls • Multimodal approach • Prefer PO • Avoid IM • Schedule meds for persistent pain • Anticipate side effects and manage proactively • Avoid multiple opioids simultaneously • No maximum dose or analgesic ceiling • Continue to reassess pain and side effects

35. References • Cervero F, Laird JM. Mechanisms of touch-evoked pain (allodynia): a new model. Pain. 1996;68(1):13-23. • Gottschalk A, Smith DS. New concepts in acute pain therapy: preemptive analgesia. Am Fam Physician. 2001;63:1979-84. • Vargas-Schaffer G. Is the WHO analgesic ladder still valid? Twenty-four years of experience. Can Fam Physician. 2010;56:514-517. • Holmquist GL, Leon-Casasola OA, McPherson ML, Herndon CM. Patient-centered approach to pain management. ASHP Midyear Meeting. New Orleans Convention Center. New Orleans, LA. 5 Decemeber 2011. Educational programming. • Trescot AM, Boswell MV, Atluri SL, et al. Opioid guidelines in the management of chronic non-cancer pain. Pain Physician. 2006;9:1-39. • Pain: Current understanding of assessment, management, and treatments. National Pharmaceutical Council website. http://www.npcnow.org/App_Themes/Public/pdf/Issues/pub_related_research/pub_quality_care/Pain-Current-Understanding-of-Assessment-Management-and-Treatments.pdf. Accessed May 27, 2012. • Rhodes L, Groninger H, Malchow, R. Key concepts in pain management for the federal healthcare professional. MedIQ website. http://www.med-iq.com/index.cfm?fuseaction=courses.overview&cID=540. Accessed May 27, 2012. • Fine PG, Bekanich SJ. Improving acute pain management in hospitalized patients with chronic pain disorders. MedIQ website. http://www.med-iq.com/files/cme/presentation/pdfs/id_567_983.pdf. Accessed May 27, 2012. • Johnson SJ. Opioid safety in patients with renal or hepatic dysfunction. Pain Treatment Topics website. http://pain-topics.org/pdf/Opioids-Renal-Hepatic-Dysfunction.pdf. Accessed May 29, 2012.

36. Joshua Vanderloo PharmD, RPh Clinical Pharmacist, University of Wisconsin Hospital and Clinics Pain Management in the hospitalized patient