Pain ManagementDivya Suri

Patient Case• RS is a 62 yo male presents with worsening pain over the past

two days to midsternal chest and right ribs radiating to upper back accompanied with shortness of breath despite treatment with oxycodone. Patient usually has shortness of breath with increased pain. Baseline pain is 5/10 and has been waxing and waning today. Patient had CT pulmonary angiogram performed in ED with no PE evident. Patient received MS 6 IV with pain relief. Patient denies cough, nausea, vomiting, diarrhea, fever, chills.

• Height: 167.64cm (5’6”)• Weight:88.5kg• BMI = 31.5 kg/m2

Patient CaseVS• On Admission: • BP 145/105 RR 26 HR 113 T 97.7F• 6/27:• BP 142/96 RR 18 HR 72 T 98.4FLabs (latest results):• WBC: 8.8 K/uL (WNL) (normal = 4.5 – 10 K/uL)• RBC: 3.91 M/uL (low) (normal = 4.5 – 5.5 M/uL)• Hg: 11.1 g/dL (low) (normal = 13.5 – 16.5 g/dL)• Hct: 33.0% (low) (normal = 41 – 50%)• Serum creatinine: 0.50 mg/dL (0.5 – 1.1 mg/dL)• Creatinine Clearance: 77.13 mL/min

Patient Case• Home Medications

1. Oxycodone 10 mg PO tablet: 1 T PO Q4-6H PRN - breakthrough moderate pain

2. Fentanyl 75 mcg/hr transdermal film, ER: 1 patch transdermally Q72H

3. Tamsulosin 0.4 mg capsule: 1 C PO QD (after a meal)4. Atenolol 50 mg PO tablet: 1 T PO QD5. Senna PO tablet: 2 TS PO HS6. Docusate sodium 100 mg PO capsule: 1 C PO BID7. Polyethylene glycol 3350 oral powder for reconstitution: 17

grams PO QD8. Atorvastatin 40 mg PO tablet: 1 T PO HS

Patient Case• Hospital Medications

• Enoxaparin Injectable: 40mg SQ Q24H (DVT prophylaxis?)• Lactulose Syrup: 30 grams PO BID (constipation)• Magnesium Hydroxide Suspension (Milk of Magnesia): 30 mL PO QD PRN

for constipation• Hydromorphone PCA (1mg/mL)

• Initial bolus dose: 0 mg• Initial demand dose: 0.5 mg• Lockout: 15 minutes• Continuous rate: 0.8 mg/hour• Four hour limit: 11.2 mgs

• Naloxone Injectable: 0.1 mg IV push every 3 minutes PRN for ANY of the following change in patient status: RR of 10 breaths/minute; Oxygen saturation less than 90%; Sedation score of 6, stop after 4 doses (opioid overdose)

• Ondansetron Injectable: 4 mg IV push Q8H PRN for nausea• Dexamethasone Injectable: 4 mg IV push BID at 6AM and 2PM• Gabapentin capsule: 400 mg PO TID

Patient Case• Hospital Medications (Continued):

• Cyclobenzaprine tablet: 5 mg PO TID PRN for muscle spasm• Acetaminophen tablet: 650mg PO Q6H PRN for temperature over 37.9C• Acetaminophen tablet: 650mg PO Q6H PRN for mild pain• Atenolol tablet: 50 mg PO QD (HTN)• Atorvastatin tablet: 40 mg PO HS (hyperlipidemia)• Docusate capsule: 100 mg PO TID (constipation)• Senna tablet: 2 tablets PO HS (constipation)• Polyethylene glycol 3350: 17 grams PO QD – dissolve in 8 oz water, juice,

cola, or tea (constipation)• Tamsulosin: 0.4 mg PO QD (BPH)

Pain Assessment• ABCDE

• Ask about the pain regularly and assess the pain systemically (aching, throbbing, sharp, shooting, burning, dull, cramping, etc.)

• Believe the patient and family in their reports of pain (along with reports of what works and what doesn’t)

• Choose pain control options appropriate for the patient, family, and setting

• Deliver interventions in a timely and coordinated fashion• Empower patients and their families and enable patient and their

family to control their treatment to the greatest extent possible

http://learn.chm.msu.edu/painmanagement/assessment.asp#a

Pain Assessment• PQRSTU

• Provoke/Palliate - what makes the pain better or worse?• Quality: What does the pain feel like? (stabbing, dull, etc.)• Radiation• Severity• Time (when did it start?)• U (what impact has the pain had on you?)

Pain Assessment• OLDCARTS

• Onset (acute vs. chronic)• Location (+radiation) – does it stay in one place? (Somatic vs.

visceral)• Duration – does it come and go or stay throughout the day?

(Constant vs. intermittent)• Characteristics – how does it feel? (Ex. if it’s tingling, burning,

radiating, it’s neuropathic. If it’s short, dull, and achy, it’s nociceptive)

• Aggravating factors (moving vs. sitting)• Relieving factors – what have you done to try to relieve the pain?• Treatment – what have you tried? Including OTC

(pharmacological vs. nonpharmacological)• Severity: Pain scales

Pain Rating Scales• Numerical Scale (1 – 10)• Wong – Baker FACES Pain Rating Scale

http://onlinelibrary.wiley.com/store/10.1111/j.1553-2712.2009.00620.x/asset/j.1553-2712.2009.00620.x.pdf;jsessionid=5BCBD1A94E21389494C504C5437B11A9.f01t01?v=1&t=hx1nwoqy&s=e3afe8cf9aa4fac7e07cfbb1147235ab7b69f191

Pain Rating Scales • Behavioral Pain Scale

• None (0) – relaxed, calm expression, moves easily• Mild (1-3) – stressed, tense expression, occasional grimace, frown, able to comfort• Moderate (4-6) – guarded movement, grimacing, squirming, more reassurance to

comfort• Severe (7-9) – moaning, restless, rigid movement, difficult to comfort• Worst pain (10) – crying out, unable to comfort

• FLACC

Pain Rating Scales• PAIN AD (Pain Assessment IN Advanced Dementia)

WHO Pain Relief Ladder

http://www.who.int/cancer/palliative/painladder/en/

Natural Opioids: Phenanthrene Rings• Morphine• Codeine

Semi-Synthetic Opioids: Phenanthrene Rings• Hydrocodone

• Hydromorphone

O

OH

O

N+ CH3

H

H Cl

O

CH3O

O

N+ CH3

H

HCOO-

OH

OH

COOH

Semi-Synthetic Opioids (Phenanthrene)• Oxymorphone

O

OH

O

N+ CH3

OH

H Cl

Synthetic Opioids: Phenylpiperidines• Fentanyl

• Meperidine

O

N+

H

N

n

O

OO

O OH

O

OH

2

N+

CH3

H

O O

Cl

Synthetic Opioids: Phenylheptane• Methadone

O

CH3

N+

CH3

HCH3 Cl

Opioids: Allergy vs. Pseudoallergy

Short Acting vs. Long ActingCategory Benefits Drugs

Short-acting:

for intermittent and breakthrough pain1

Easier to titrate More rapidly

attained steady-state plasma concentrations2

Morphine sulfate Hydromorphone

Codeine Fentanyl Hydrocodone Oxymorphone Oxycodone Levorphanol

Long-acting:

For treating chronic pain in patients with consistent pain levels3,4

Makes around-the-clock therapy possible

Dosing convenience and flexibility

Relative steady-state concentrations of opioid concentrations in the blood3,4

Morphine (sustained-release)

Oxycodone (sustained-release)

Transdermal fentanyl Hydromorphone

(sustained-release)

How to Calculate a Long Acting Opioid Dose

• Calculate total daily dose (TDD) of opiates used• Use ~ 80% of dose and divide into appropriate dosing intervals• However if patient not currently controlled, can use 100%• Reassess as needed

How to Calculate an Immediate Release Dose• After calculating LA dose/day, take 50-70% and divide into

appropriate dosing intervals

Immediate Release Opioid

Onset of Analgesia (minutes)

Duration of Effect (hours)

Morphine PO 30 – 40 4

Oxycodone PO 30 4

Oxymorphone PO 30 4 – 6

Hydromorphone PO 30 4

Methadone PO 10 – 15 4 – 8

Fentanyl Transmucosal 5 – 10 1 - 2

Patient Controlled Analgesia• Precise and convenient method of providing opioid therapy to

patients with moderate to severe acute or chronic pain.• Uses a computerized pump that has a syringe, cartridge, or infusion

bag that contains the opioid locked inside the pump.• Onset of IV opioids range from 1 – 4 minutes with a peak effect of

15 – 20 minutes.

Patient Controlled Analgesia• Converting to PCA Infusions to opioid intolerant patients

• Step 1: determine the patient’s current opioid regimen and calculate a conversion to the parenteral opioid you will be using

• Step 2: if the patient’s current opioid regimen is effective, go with the dose calculated in step 1 If not, increase the dose by 25 – 100%

• Step 3: If the continuous infusion you will be starting represents a dosage increase from the patient’s previous opioid regimen, provide a loading dose (not necessary in this case) so it will boost their blood level of the opioid so they won’t have to wait several hours to receive pain relief

• Step 4: Bolus calculation: 50 – 150% of the hourly infusion rate.• Step 5: Select a dosing interval for the PCA bolus dose• Step 6: Assess the patient! Assess for therapeutic effectiveness and potential

adverse effects every 10 – 15 minutes until the patient is stable.• Step 7: Assess the patient! Reassess the need to alter continuous infusion

rate every 6 – 8 hours. If the patient isn’t getting adequate relief, don’t increase the continuous infusion rate more than 100% at any one time. When increasing continuous infusion, give a loading dose to more rapidly achieve steady state blood levels of the opioid.

Potential Adverse EffectsSystem/Type Adverse Effect

Gastrointestinal Constipation

Nausea and vomiting

Central nervous system Sedation

Cognitive impairment: “mental clouding”/confusion

Respiratory Respiratory depression

Dermal Pruritus

Endocrine Decrease in libido

Hypogonadism

Treatment Options for Potential Adverse EffectsAdverse Effect Treatment

Nausea and vomiting Use antiemetic; switch opioids

Constipation Treat preemptively with diet and regular use of stool softeners and laxatives

Sedation Reduce dose; add nonopioid or adjuvant analgesic; add mild stimulants

Mental clouding Eliminate nonessential medications with central nervous system effects; consider neuroleptics for persistent delirium

Respiratory depression Stop opioid and administer naloxone, only if strongly indicated

Pruritus Switch opioids; use antihistamines

Endocrine dysfunction/ decreased libido

Monitor endocrine function; use replacement therapy, endocrine consultation

Naloxone

• FDA approved indications• Opioid antagonist indicated for emergency treatment of

known or suspected opioid overdose, as manifested by respiratory and/or central nervous system depression

• Immediate administration as emergency therapy in settings where opioids may be present

• Warnings/Precautions• Acute opioid withdrawal

• Symptoms: pain, HTN, sweating, agitation, irritability• CV: Pulmonary edema and cardiovascular instability,

including ventricullar fibrillation, associated with abrupt reversal when using opioid antagonists in those with CV disease or patients receiving medications with potential CV effects (ex. hypotension, arrhythmias)

Naloxone• Adverse Reactions: related to reversing dependency and

precipitating withdrawal• CV: cardiac arrest, fever, flushing, hypertension,

hypotension, tachycardia, ventricular fibrillation, ventricular tachycardia

• CNS: agitation, coma, encephalopathy, hallucination, irritability, nervoussness, restlessness

• GI: abdominal cramps, NVD• Neuromuscular and skeletal: paresthesia, piloerection,

tremor, weakness• Respiratory: dyspnea, hypoxia, pulmonary edema,

respiratory depression, rhinorrhea, sneezing