1. Pain Assessment & Management
M3 Palliative Medicine Curriculum
Seema S. Limaye, MD
University of Chicago

2. GOALS
Describe methods of pain assessment in cognitively impaired older adults.
Understand various types of pain.
Describe the basic pharmacology of opioids
Understand how to initiate and titrate opioids.

3. Self-Directed Learning Modules
Basics of Neuropathic pain
Side Effects of Opiods and Management Options
Treatment of Pain in Persons with h/o Substance Abuse

4. Mrs. P
70 y.o. female h/o Paget’s disease, renal insufficiency, osteoporosis presents to clinic with new back pain.
What do you want to obtain from the history?

5. Pain History
Pain Characteristics – onset, duration, location, quality, intensity, associated symptoms, exacerbating and relieving factors
Past and current management therapies
Relevant medical and family history
Psychosocial history
Impact of pain on daily life – work, daily activities, personal relationships, sleep, appetite, emotional state
Patient (and family’s) expected goals for treatment

6. Pain: A Complex Phenomenon
Sensory stimuli and/or neurologic injury modified by an individual’s memory, expectations, emotions
Biocultural Model of Pain:
Society also influences an individual’s pain experiences

7. FIGURE 1. Normal sensory tracts
FIGURE 1. Normal sensory tracts. The spinothalamic tract transmits input encoded for pain and temperature, and the dorsal column transmits input encoded for light touch. The free nerve ending of an A delta fiber or a C fiber senses pain and temperature and has its cell body in the dorsal root ganglion. This synapses in the dorsal horn with a second-order neuron that immediately crosses the midline and ascends on the contralateral side in the spinothalamic tract. The axons of the second-order neuron terminate in the hypothalamus and thalamus. In the thalamus, some projections are made directly to the primary sensory cortex, whereas others go to the limbic system, which includes the insula, amygdala, and cingulate cortex. The Pacinian corpuscle is a first-order neuron that senses pressure. This neuron’s cell body is also in the dorsal horn, and the axon ascends a few levels, crosses the midline, and ascends in the contralateral dorsal column/ medial lemniscus, through the medulla and midbrain, and terminates in the thalamus. There, the neuron synapses with a second-order neuron, which projects to the primary sensory cortex.

8. Pain Assessment is NOT….
Relying on changes in vital signs
Deciding a patient does not “look in pain”
Knowing how much a procedure or disease “should hurt”
Assuming a sleeping patient does not have pain
Assuming a patient will tell you they are in pain

9. Consequences of Untreated Pain
Acute pain:
increase metabolic rate and blood clotting,
impair immune function
induce negative emotions
Without intervention, pain receptors become sensitive and may have long lasting changes in the neurons

10. Consequences of Untreated Pain
Chronic pain may lead to:
fatigue,
anxiety,
depression,
confusion,
increased falls,
impaired sleep, and
decreased physical functioning/deconditioning

11. Bedside Assessment ASK the patient about pain
Asking about ADL’s and IADL’s
Asking about physical activity, mood, sleep, appetite, energy level
Identify preferred pain terminology
-hurting, aching, stabbing, discomfort, soreness
Use a pain scale that works for the individual
-Insure understanding of its use
-Modify sensory deficits
Ferrell et al. J Pain Symptom Manage Chinball and Tait Pain 2001.
Herr and Garand. Pain Management in the Elderly 2001
Ask the patient = even persons with moderate impairment (e.g. MMSE=12) can still reliably report pain with good test-retest reliability.
Preferred pain terminology is very important as the word for “pain” varies from person to person. Some people think of “pain” to be different from an intense ache or hurt. At bedside we should ask a variety of these qualifiers “Are you aching? Hurting? Having discomfort?” to illicit the best response.
Use a pain scale that works for that particular individual and remain consistent throughout subsequent interviews with the same patient
Use: -simplest, clear explanation, give examples
-give time to grasp task and respond
-repetition KEY
It is important to use a pain scale whenever possible as it can help guide you in terms of treatment efficacy. Studies have shown that more than 80% of cognitively impaired persons are able to reliably complete a pain scale. The importance is in finding one that works for the individual. I will give you some examples in the next few slides. When describing the tool to a cognitively impaired individual you want to be patient and give simple and clear explanations, providing examples whenever possible. You need to give the patient time to process the information and formulate a response. You may have to repeat the instructions a few times before they get it. Keep in mind that these patients are often hard of hearing and have poor vision so you need to make sure they are wearing their glasses and hearing aids.
High rate of completion of tools even with low MMSE (12)

12. Use a standard scale to track the course of pain
Pain Intensity Scales
Source: Acute Pain Management Guideline Panel. Acute Pain Management in Adults: Operative Procedures. Quick Reference Guide for Clinicians. Rockville, MD: US Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research. February AHCPR Pub. No
In general, short simple verbal rating scales (e.g. no pain, slight pain, moderate, or severe pain) which focus on intensity are probably the easiest and most appropriate for use in those with acute pain. Studies have documented over a 70% completion rate. Numeric pain intensity scales as well as VAS have been found in the literature to be the more difficult scales to use in the elderly, regardless of cognitive status. Physiologic measures such as blood pressure and pulse are not reliable markers as they can vary depending on medications, comorbidities, or the normal aging process in general.

13. Faces Pain Scale and Pain Thermometer
At University of Chicago we use Wong_Baker Faces scale which is similar to the Faces Pain Scale. It was developed and validated in children. Visual scales may be more suitable for people with communication difficulties such as aphasia, illiteracy, or language barriers. The only caution would be that occasionally older adults mistake the Faces Pain Scale for a measure of depression or sadness rather than pain intensity.

14. What are some common barriers to pain treatment?

15. Remember the common patient-related barriers to pain management
Drugs ..
are addicting
should be saved for when it is really needed
have unpleasant or dangerous side effects
pills are not as effective as a shot
narcotics are only for dying people

16. Pain assessment in a vulnerable group: Cognitively Impaired Older Adults

17. Assessing pain: Nonverbal, Moderate to Severe Impairment
Formal assessment tools available but not necessarily useful in routine clinical settings
Unique Pain Signature
Nonverbal Pain Indicators
Kaasalainen et al Perspectives Herr and Garand Clinics in Geriatric Medicine 2000

18. Unique Pain Signature How does the patient usually act?
What changes are seen when they are in pain?
family members
nursing staff
Communication across caregiver settings is key!
Kovach et al. J Pain Symptom Manage 1999.
Feldt et al. JAGS 1998.
Weiner et al. Aging 1998.

19. Nonverbal Pain Indicators
Facial expressions (grimacing)
-Less obvious: slight frown, rapid blinking, sad/frightened, any distortion
Vocalizations (crying, moaning, groaning)
-Less obvious: grunting, chanting, calling out, noisy breathing, asking for help
Body movements (guarding)
-Less obvious: rigid, tense posture, fidgeting, pacing, rocking, limping, resistance to moving
Kaasalainen et al Perspectives Herr and Garand Clinics in Geriatric Medicine 2000

20. Selection of pain meds Source/type of pain Duration/timing/frequency
History of medication use
Impact on quality of life
Presence of associated factors

21. Types of Pain: A Brief Review
Nociceptive Pain
Visceral
Somatic
Neuropathic Pain
Mixed/Unspecified Pain
Psychologic cause

22. Quality: Visceral Pain
Descriptors: cramping, squeezing, pressure
Distribution/Examples:
Referred
heart attack, kidney stone
Colicky
Bowel obstruction, gallstone
Diffuse
Peritonitis
Analgesics: opioids; acetaminophen

23. Quality: Somatic pain Descriptors: aching, deep, dull, gnawing
Distribution/Examples:
Well localized—patients can often point with one finger to the location of their pain
bone mets, strained ankle, toothache
Analgesics: NSAIDS, acetaminophen opioids

24. General Principles of Management
Set a goal of reduction of pain to tolerable levels, not a goal of complete relief
“Start low and go slow”
Make sure patient and family are aware of goals
Frequent clinic visits at first for assurance, validation, and monitoring of titration

25. WHO 3-Step ladder
Source: World Health Organization. Technical Report Series No. 804, Figure 2. Geneva: World Health Organization; Reprinted with permission.

27. Non-opioid medications
Acetominophen 650mg tid-qid : concern for hepatic toxicity >3-4grams
NSAIDs including Ibuprofen, Naproxen, COX-2 inhibitors: concern for gastric / renal toxicity, platelet dysfunction, may inhibit anti-hypertensive meds

28. Opioid combination products
The following opioids are available as combination products with acetaminophen, aspirin, or ibuprofen
Codeine; hydrocodone; oxycodone; propoxyphene
Typically used for
Moderate episodic (PRN) pain
Breakthrough pain in addition to a long-acting opioid.
Never prescribe more than one combination drug at any one time.

29. Which combination product?
Analgesic potency:
hydrocodone and oxycodone are more potent than codeine, which is more potent than propoxyphene, which some studies suggest is equipotent to aspirin.
there is little difference between hydrocodone products and oxycodone products in terms of potency.
Note: propoxyphene products are not recommended for pain in most national pain guidelines, due to side effects and unclear efficacy compared to other products

30. Adjuvants Non-pharmacologic Topicals Tylenol
NSAIDS, Celecoxib, steroids
Anticonvulsants
Antidepressants
Antiarrhythmics

31. Opioid Pharmacology
Block the release of neurotransmitters in the spinal cord
Agonist of Mu, delta, kappa receptors
Conjugated in liver
Excreted via kidney (90%–95%)

32. Opioid pharmacology Central and peripheral effects of opioids
This leads to desired effects, as well as side effects

33. Supraspinal analgesia Peripheral analgesia Sedation Euphoria
Receptor
Clinical Effects
Mu 1
Supraspinal analgesia
Peripheral analgesia
Sedation
Euphoria
Prolactin release
Mu 2
Spinal analgesia
Respiratory depression
Physical dependence
GI dysmotility
Pruritis
Bradycardia
GH release

34. Receptor
Clinical Effects
Kappa 1
Spinal analgesia
Miosis
Diresis
Kappa 2
Psychotomimesis
Dysphoria
Kappa 3
Supraspinal analgesia
Delta
Spinal and supraspinal analgesia
Nociceptin/orphanin
Anxiolysis
Analgesia

35. Clearance concerns Conjugated by liver 90%–95% excreted in urine
Dehydration, renal failure, severe hepatic failure
 dosing interval (extend time) or
 dosage size
if oliguria or anuria
STOP routine dosing of morphine
use ONLY prn

36. Opiod Pharmacology… What is the peak effect (C max ) of morphine:
PO?
30-60 min
IV?
5-15 min
SC/IM?
Variable…usually min
What is the duration of effect of morphine?
3-4 hours
Usually 1-2 hours, but we typically dose it q2-3 hours

37. Cmax Half-life (t1/2) IV SC / IM Plasma Concentration po / pr Time
This picture demontrates that for most opiates that are considered short-acting (MSIR, Oxycodone, Hydrocodone, dilaudid) the half-life is about the same no matter the route of administration. What does differ is the Cmax or the time it takes to reach maximal concentration. Once the drug has reached Cmax there will not be any additional analgesia. This becomes important when we discuss the appropriate time to give a “breakthrough dose”.
EPEC, reprinted with permission
Half-life (t1/2)
Time

38. . . . More Opioid Pharmacology
Steady state after 4–5 half-lives
steady state after 1 day (24 hours)
Side Effects:
sedation, confusion, respiratory depression, constipation, urinary retention, nausea and vomiting

39. Short Acting Opioids Oral only Parenteral or Oral
oxycodone (Percocet ® , Tylox ® )
hydrocodone (Vicodin ® Lortab ®, Lorcet ®)
propoxyphene (Darvon ®, Wygesic ®)
Note: hydrocodone is only available as a combination product.
Parenteral or Oral
morphine
hydromorphone (Dilaudid ®)
meperidine (Demerol ®)
codeine

40. Routine oral dosing extended-release preparations
Improve compliance, adherence
Dose q 8, 12, or 24 h (product specific)
don’t crush or chew tablets
may flush time-release granules down feeding tubes
Adjust dose q 2–4 days (once steady state reached)

41. Transdermal Fentanyl Duration 24-72 hours
12-24 hours to reach full analgesic effect
Not recommended as first-line in opiate naïve patients
Lipophilic
Simple Conversion rule:
-1 mg po morphine = ½ mcg fentanyl
-(60 mg morphine roughly 25 mcg patch)

42. DOSE FINDING

43. ADDING AN OPIOID To achieve quick pain relief: (LOAD)
1. Start low dose, short-acting
2. Dose q peak
3. Re-eval in 4 hrs. to figure out what dose is needed

44. Breakthrough dosing Use immediate-release opioids
10% of 24-h dose (or 1/3 of one ER dose)
offer after Cmax reached
po / pr  q 1 h
SC, IM  q 30 min
IV  q 10–15 min
Do NOT use extended-release opioids for breakthrough

45. Ongoing assessment
Increase analgesics until pain relieved or adverse effects unacceptable
Be prepared for sudden changes in pain
plan for breakthroughs (prior to dressing changes or patient care activities)

46. Opioid Dose Escalation
Always increase by a percentage of the present dose based upon patient’s pain rating and current assessment
50-100% increase
Severe pain
7-10/10
25-50% increase
Moderate pain
4-6/10
25% increase
Mild pain
1-3/10

47. Incomplete cross-tolerance
If a switch is being made from one opioid to another it is recommended to start the new opioid at ~50% of the equianalgesic dose.
This is because the tolerance a patient has towards one opioid, may not completely transfer (“incomplete cross-tolerance”) to the new opioid. to
50%
of new Opioid
from
100%

48. Pain Problem #1
You started Mrs. T on 10 mg morphine every 4hrs around the clock for her cancer pain with good effect. She says she’s tired of taking a pill every 4 hours. Convert her to long-acting morphine with appropriate prn doses.

49. Pain Problem #1: Answer 24 hour use:
10mg PO morphine x 6 = 60 mg PO morphine
Convert to long-acting twice a day dosing:
60 mg PO morphine / 2 = 30mg PO morphine SR BID
Calculate prn dosing of morphine sulfate-immediate release:
60mg PO morphine in 24 h x 10% = 6mg PO morphine q3h prn breakthrough pain

50. Part 2
She is admitted to the hospital and unable to take oral medications--convert Mrs. T to: IV morphine

51. Part 2: Answer Ratio of IV:PO morphine sulfate: 1mg:3mg
Therefore: 60/x = 3/1
X=20mg IV morphine in 24hr period
Dose q 3h = 20mg/8 = 2.5mg IV q3hr
PRN dose?
2mg IV morphine q 2hr prn breakthrough pain

52. Part 3
Mrs. T has uncontrolled pain of moderate intensity because of progression of her disease. How would you re-dose her IV morphine?

53. Part 3-Answer
Increase pain regimen by 25-50% for moderate uncontrolled pain
Let’s increase by 25%
25% of 20mg IV morphine = 25mg IV morphine in 24 hours
Dosing q3h= 25mg/8 = 3mg IV morphine q3h

54. Pain Problem #2
Mr. T is a 73 yo man with lung cancer, a malignant plueral effusion, and chronic chest pain. He has undergone therapuetic thoracentesis and pleuradesis. He is currently receiving meperidine 75 mg IM q6h, for pain. You want to switch him to oral morphine because you are aware that:
1. IM meds hurt!
2. it’s metabolite, normeperidine, can accumulate in pts (with renal failure) and cause CNS toxicity such as tremulousness, dyphoria, myoclonus and sz.
Without adjusting for incomplete cross-tolerance, what dose and schedule would you choose?

55. Pain Problem #2: Answer Ratio of IV meperidine: PO morphine 50mg:15mg
75mg x 4 = 300mg
300/x = 50/15
X=90 mg PO morphine in 24h
Adjust for incomplete cross-tolerance:
Decrease by 1/3 = 60mg
Dosing PO morphine q4h:
10mg PO morphine q4h