The Need to Understand Pain and its Management

Prepared and presented by:Soha AdloniMSc Clinical Pharmacy

Objectives:

1. Pain definitions & overview

2. Pain pathway & classification

3. Pharmacological Treatment of Acute Pain

4. Choice of Drugs in Treatment of Acute / Chronic Pain

5. Conclusion

1. Pain Definitions "Pain" is defined by IASP*: "an unpleasant sensory and

emotional experience arising from actual or potential tissue damage or described in terms of such damage“

Pain: the least stimulus intensity at which a subject perceives pain.

Margo McCaffery (1968)first defined pain: "whatever the person experiencing says it is, existing whenever he says it does.”

Favorite definitions: - whatever the patient thinks it is at the present

time. - something caused by OTHER surgeons * IASP: International association for the study of pain

1. Pain Definitions

Analgesia: Absence of pain in response to stimulation which

would normally be painful (e.g. using drugs) Nociceptor: A sensory receptor of the peripheral (somatosensory nervous system) that transmits noxious stimuli to CNS. Noxious stimulus: A stimulus that is damaging or threatens damage to normal tissues (chemical,

mechanical, thermal) Pain threshold: The minimum intensity of a stimulus that

is perceived as painful. Neuropathic pain: Pain caused by a lesion or disease of the nervous system.

1. Pain Overview

Factors affecting pain perception

PAIN EXPERIE

NCE

AGE

MEANING OF PAIN

ATTENTION

Sex

Anxiety

Pain Control

CULTURE

2. Pain Pathway

2. Pain classificationDiagnostic classification

A. Nociceptive pain I. Somatic: well localized; e.g. skin, bones II. Visceral: poorly localized; e.g. organs

B. Neuropathic pain I. Central: Localized and diffused; burning,

stabbing pain e.g. CNS II. Peripheral: localized neuropathiesC. Idiopathic pain usually in head, shoulders, or pelvic areas

2. Pain classifi cationCl in ica l types

Acute pain Chronic pain

Results from noxious stimuli that activates nociceptors neuron

It accompanies surgery, traumatic injury, tissue damage, and inflammatory processes.

Self-limited, resolves over days to weeks, but can persist for 3 months

Treatment is short term and curative

Results from: nociceptors, visceral, or somatic

It accompanies chronic disease, untreated condition.

Unresolved as long as underlying cause is present.

Treatment goal oriented, multidisciplinary approaches.

Acute Pain Goals:

1. provide analgesia

2. lessen side effects of analgesics

3. Minimize the dose of medication

Effective Pain control1. Early mobilization2. Shorter hospitalization3. Reduce costs4. Increase patient satisfaction

Analgesics: 1. Multimodal analgesics, preemptive analgesia2. Parenteral, PCA, Epidural3. ATC first 24 hrs post surgery, then prn

If pain is inadequately controlled, what are the

consequences?

Anxiety

Family worries

Depression

Sleep disturbances

Impaired ambulation

Medication worries

Increase hospitalization and costs

Pain

What is the pain score for this player?

Pain is whatever the patient thinks it is at the present time.

Pain is always subjective to the patient’s report

3. Pharmacological Treatment of Pain

A Non-

Opioids

BOpioids

CAdjuvants

3. Pharmacological Treatment of PainA- Non-Opioids

Paracetamol (Panadol): PO, IV. Act centrally & peripherally

max. daily dose: 3gm of OTC meds, 4 gm IV.

Non-steroidal Anti-inflammatory Drugs (NSAIDs) Ketorolac (Toradol)- inj Ibuprofen (Advil, Neurofen, Brufen) Diclofenac Na/K (Voltaren, Olfen, Cataflam) Mefanemic acid (Ponstan)

Naproxen (Naprosyn)

Celebrex (Celecoxib) Etoricoxib (Arocoxia) Meloxicam (Mobic)

Cox-1, Cox-2 inhibitors

Cox-2 inhibitors

3. Pharmacological Treatment of PainA- NSAIDs mechanism of action

3. Pharmacological Treatment of PainA- NSAIDs

Ketorolac (Toradol): Postoperatively for max 5 daysReduce amount of opioid requirement,

reduce S.E’sDose= 15 – 30 mg IV / IM Q6hrs

Cox-2 inhibitors: Effective anti-inflammatory in arthritisCarry cardiovascular risk warningLess GI S.E’s

3. Pharmacological Treatment of PainA- NSAIDs

Side effects: Prolong bleeding time

Gastric erosions/ ulceration/ perfusion

Affect kidney function: _ Water / electrolyte balance _ Interfere with diuretics/

antihypertensive _ Renal injury / nephrotic syndrome

3. Pharmacological Treatment of PainB- Opioids

MorphineOral, Rectal, IV, IM, SC, pca, Epi,

Equianalgesic potency10 mg IM

Meperidine(Pethidine)

IV, IM, pca, Epi 75 mg

FentanylIV, Epi, pca, Transdermal patches, sublingual lollipops

100 mcg

Codeine(Solpadeine: codeine 8mg/Aceta./caffeine)

Oral, Rectal, IV, IM. 130 mg

Hydromorphone

Oral, IV, SC, IM, Rectal, pca

1.5 mg

Tramadol(Tramal)

Oral, IV, IM, SC 100 mg

B- Opioids / Narcotic analgesics

Morphine: Gold standard opiate

Bolus: 2-5 mg slowly over 5min (Q 1-3 hrs).

CI: 1mg/hr titrated to the desired analgesic effect.

IM; 5-10 mg (Q3-4 hrs).

SC: not recommended in repeated dose. Meperidine: used in acute pain only, alternative for

morphine intolerance.

limited use due to toxic metabolite, sedative, and emetic effect.

Fentanyl: 100 times more potent, rapid onset of action

given bolus, CI, oral, patches. Tramadol: Acts on opioid & non-opioid receptors (moderate pain)

Show poor analgesic effect as compared to morphine.

B- Opioids Side Effects

Nausea and vomiting Constipation

Pruritis Irritable movement

Psychomimetic effects Sedation

Broncho-constriction Respiratory Depression

N.B: If respiratory depression/sedation develops, the nurse must be familiar with administration of Naloxone, which will reverse the effect . Naloxone is diluted (0.4 mg in 10 mL NS) every 1-2 min until the patient's respiratory status improves and the patient starts to arouse.

3. Pharmacological Treatment of PainC- Adjuvants

Agents used to induce analgesic effect indirectly

Local anesthetics

Antidepressants

Anticonvulsants

Corticosteroids

Muscle relaxants

Anti histamines

4. Choice of Drugs in Treatment of Acute / Chronic Pain

4. Choice of Drugs in Treatment of Acute / Chronic Pain

4. Choice of Drugs in Treatment of Acute / Chronic Pain

1) Severity of pain

2) Routes of administration

3) Patient information

4) Pharmacokinetic of drug

5) Patient’s preference

5. Conclusion

If pain is not controlled effectively, it can result in negative physiologic and psychological consequences. Nurses must learn how to properly assess pain and how to optimize safe pain management for all patients in their care.

Frequency/ routes of administering analgesics are highly significant in treatment:

- Opioid ATC vs. prn in the first 24 hrs post surgery

- Analgesics could be given in incidental pain - IV vs. SC vs. IM

Opioids can be titrated upward for maximum efficacy, but are limited by their side effects.

5. Conclusion

The administration of Opioid + non-opioid promote co-analgesic effect (reduced doses, lessen S.E’s).

Acute pain can activate the sympathetic branch producing : hypertension, tachycardia, diaphoresis, shallow respiration, restlessness, facial grimacing, pallor, and pupil dilation

Addiction is so rare when Opioids are taken for medical reasons.

Case1: Post operative (sleeve) patient , ordered for morphine

3mg Q4 hrs, perfalgan 1g Q6hrs. Patient received 2 doses of morphine, and 4 doses of perfalgan during the first 24 hrs; but still in pain, what is the cause of his pain?

a. Patient is complainer & will be fine in few hours

b. Need different analgesic than morphine

c. Morphine was given prn not ATC

d. Patient is sedated and can not be assessed probably

Pain assessment for effective pain control:e. Pain score 4 – 7

f. Multimodal analgesic (opioid + non-opioid)

g. Morphine should be given ATC

h. Pain assessment should be done appropriately

Case 2: LSCS patient is receiving Epidural in the first 24hrs.

Pain is increasing with time, but nurse keeps comforting patient that “it will go away”. The correct nurse’s response should be:

a. Check the epidural catheter site

b. Check the epidural pump

c. Call the anesthesiologist for pain assessment

d. Assess the patient for pain score over time

Pain assessment for effective pain control:e. Pain catheter could be dislocated

f. Epidural pump may not be delivering medication

g. Anesthesiologist is called if needed

h. Pain is “whatever the patient thinks it is at the present time”

Case 3: Patient with moderate - sever pain was ordered for morphine 5mg

Q4hrs, perfalgan 1 g Q6hrs. Patient was requesting pain killers due to constant pain around the clock, but nurse administer morphine 1mg Q4hrs instead because of fear of addiction. What are the consequences of this action on patient’s pain control?

a. Reducing the dose will reduce addiction possibilities of morphine

b. Pain will increase with time

c. Patient’s pain is tolerable and will decrease as soon as he mobilize

d. Physician will be glad that the nurse has taken this action

Pain assessment for effective pain control:e. Addiction is so rare when Opioids are taken for medical reasons.

f. Reducing the dose of morphine results in ineffective pain control

g. Patient can’t mobilize because of increased pain with time

h. Nurse have to inform physician about changing the dose of morphine