Pain Assessment &
Management
M3 Palliative Medicine Curriculum
Seema S. Limaye, MD
University of Chicago
GOALS
1.
2.
3.
4.
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.
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
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?
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
Pain: A Complex
Phenomenon

Pain
– 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
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
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
Consequences of Untreated
Pain

Chronic pain may lead to:
– fatigue,
– anxiety,
– depression,
– confusion,
– increased falls,
– impaired sleep, and
– decreased physical functioning/deconditioning
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 1995. Chinball and Tait Pain 2001.
Herr and Garand. Pain Management in the Elderly 2001
Use a standard scale to
track the course of pain
Faces Pain Scale and Pain
Thermometer
What are some common barriers
to pain treatment?
Remember the common patientrelated 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
Pain assessment in a
vulnerable group:
Cognitively Impaired Older
Adults
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 1998. Herr and Garand Clinics in Geriatric Medicine 2000
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.
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 1998. Herr and Garand Clinics in Geriatric Medicine 2000
Selection of pain meds



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Source/type of pain
Duration/timing/frequency
History of medication use
Impact on quality of life
Presence of associated factors
Types of Pain: A Brief Review

Nociceptive Pain
– Visceral
– Somatic



Neuropathic Pain
Mixed/Unspecified Pain
Psychologic cause
Quality: Visceral Pain

Descriptors: cramping, squeezing,

Distribution/Examples:
pressure
– Referred

heart attack, kidney stone
– Colicky

Bowel obstruction, gallstone
– Diffuse


Peritonitis
Analgesics: opioids; acetaminophen
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
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
WHO 3-Step ladder
Source: World Health Organization. Technical Report Series No. 804,
Figure 2. Geneva: World Health Organization; 1990. Reprinted with
permission.
WHO 3-STEP
LADDER
3 SEVERE
Morphine
Hydromorphone
Methadone
Oxycodone
Fentanyl
+/- Adjuvants
2 MODERATE
A/Codeine
A/Hydrocodone
A/Oxycodone
Tramadol
+/- Adjuvants
1 MILD
ASA/NSAIDS
Acetaminophen
Cox-2
+/- Adjuvants
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
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.
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
Adjuvants

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Non-pharmacologic
Topicals
Tylenol
NSAIDS, Celecoxib, steroids
Anticonvulsants
Antidepressants
Antiarrhythmics
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%)
Opioid pharmacology


Central and peripheral effects of
opioids
This leads to desired effects, as well as
side effects
Receptor
Clinical Effects
Mu 1
Supraspinal analgesia
Peripheral analgesia
Sedation
Euphoria
Prolactin release
Spinal analgesia
Respiratory depression
Physical dependence
GI dysmotility
Pruritis
Bradycardia
GH release
Mu 2
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
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
Opiod Pharmacology…

What is the peak effect (C
– PO?

max
) of morphine:
30-60 min
– IV?

5-15 min
– SC/IM?


Variable…usually 30-60 min
What is the duration of effect of morphine?
– PO?

3-4 hours
– IV?

Usually 1-2 hours, but we typically dose it q2-3 hours
Plasma Concentration
IV
SC / IM
Cmax
0
po / pr
Half-life (t1/2)
Time
. . . 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
Short Acting Opioids

Parenteral or
Oral
– morphine
– hydromorphone
(Dilaudid ®)
– meperidine
(Demerol ®)
– codeine

Oral only
– oxycodone (Percocet
® , Tylox ® )
– hydrocodone (Vicodin
® Lortab ®, Lorcet
®)
– propoxyphene
(Darvon ®, Wygesic
®)
– Note: hydrocodone is
only available as a
combination product.
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)
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)

DOSE FINDING
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
Breakthrough dosing

Use immediate-release opioids
– 10% of 24-h dose (or 1/3 of one ER
dose)
– offer after Cmax reached
po / pr
 SC, IM
 IV


q1h
 q 30 min
 q 10–15 min
Do NOT use extended-release opioids
for breakthrough
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)
Opioid Dose Escalation
Always increase by a percentage of the present dose based
upon patient’s pain rating and current assessment
50-100% increase
25-50% increase
25% increase
Mild pain
1-3/10
Moderate pain
4-6/10
Severe pain
7-10/10
Incomplete crosstolerance


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
from
100%
50%
of new
Opioid
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.
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 sulfateimmediate release:
60mg PO morphine in 24 h x 10% = 6mg PO
morphine q3h prn breakthrough pain
Part 2

She is admitted to the hospital and
unable to take oral medications-convert Mrs. T to: IV morphine
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

Part 3

Mrs. T has uncontrolled pain of
moderate intensity because of
progression of her disease. How would
you re-dose her IV morphine?
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

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?
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
