2. Definition
Pain is derived from Latin word ‘Poena’ means Penalty or Punishment.
“An unpleasant sensory and emotional experience associated with actual or potential tissue
damage ordescribed in terms of such damage”.
Pain is always subjective.
InternationalAssociationfortheStudyof Pain
“Pain is a complex phenomenon derived from sensory stimuli or
neurologic injury and modified by individual memory, expectations, and
emotions”.
Sternbach RA, ed. The Psychology of Pain. 1978. p 223-39.“
“Pain is whatever the experiencing person says it is, and exists whenever & wherever he says
it does.”
MargoMcCaffery
Pain is multidimensional: physical, social, emotional, psychological
3. Why treat pain?
• 50-75% of patients who die in the hospital die with pain1
• 25% of all cancer patients die with pain2
• It is estimated that 85-90% of pain is easily treated with medication,
usually opioids and adjuvants
• Pain impacts routine activities, mobility, nutritional intake
• It is considered the “Fifth vital sign”
1-www.painmed.org/PatientCenter/Facts_on_Pain.aspx
2-Medtronics Cancer Pain Fact Sheet
4. Neurophysiology Of Pain
Process of Pain ‘Nociception’ is the process where information about tissue
damage is conveyed to the central nervous system through sensory
receptors (nociceptors). There can be pain without nociception (such as
phantom limb pain), or nociception without pain.
Pain occurs through four activities:
Transduction: Energy is converted from a noxious stimulus (thermal,
mechanical, or chemical) into electrical energy (nerve impulses) by
nociceptors
Transmission: The transmission of the neural signals from the transduction
site to the spinal cord and brain
Perception: In higher structures, the arriving signals are appreciated as pain
Modulation: Occurs at the spinal cord level; descending input from the
brain influences (modulates) nociceptive transmission
6. Substance P acts on mast cells in the vicinity of sensory endings
and release of histamine, which
directly excites nociceptors.
Substance P and CGRP produces dilation of peripheral blood
vessels. The resultant edema causes additional liberation of bradykinin.
Thus Nociceptors activate and cause pain.
How Pain Occurs
Tissue damage releases bradykinin and prostaglandins,
which activate or sensitize nociceptors.
Activation of nociceptors leads to the release of substance P and
calcitonin gene related peptide (CGRP).
7. Types of Pain
NOCICEPTIVE PAIN
Pain stimulus transmitted by peripheral nociceptors
Serves a protective function
Typically responds well to opioids
It may be somatic or visceral.
Somatic pain receptors are located in skin, subcutaneous tissues, fascia, other connective tissues,
periosteum, endosteum, and joint capsules. Stimulation of these receptors usually produces sharp or
dull localized pain, but burning is not uncommon if the skin or subcutaneous tissues are involved.
VISCERAL PAIN receptors are located in most viscera and the surrounding connective tissue. Visceral
pain due to obstruction of a hollow organ is poorly localized, deep, and cramping and may be referred
to remote cutaneous sites. Visceral pain due to injury of organ capsules or other deep connective
tissues may be more localized and sharp.
Neuropathic Pain Neuropathic or pathologic pain is caused by abnormal signals in the central or
peripheral nervous systems, demonstrating injury or impairment. Causes of neuropathic pain may
include inflammation, trauma, infections, tumors, metabolic diseases, toxins, or neurological disease
40% of cancer pain is neuropathic
Is described as shooting, burning, tingling, lancinating, pins and needles sensation type, and can be
difficult to describe
Does not respond well to Mu agonist opioids
8. TYPES OF PAIN ……
Physicians and neuroscientists generally classify pain in the following ways:
Acute pain : caused by an injury to the body. It occurs when tissue injury or
potential injury initiates nociceptors , and it can develop slowly or quickly. It can last
for a few minutes to six months and goes away when the injury heals. Examples:
surgery, infection, trauma, inflammation
Chronic pain: persists for 6 months or longer. It does not warn the body to
respond
Cancer (or malignant) pain: associated with malignant tumors. Tumors invade
healthy tissues and exert pressure on nerves or blood vessels, producing pain.
Cancer pain can also be associated with invasive procedures or treatments. Some
physicians classify cancer pain with chronic pain.
9. Pain Assessment
Clinicians should evaluate the cause, severity, and nature of the pain and its effect on
activities and psychologic well-being.
A person’s self report is the most reliable measure of pain
The history should include the following information about the pain:
Original site of pain
Origin and mode of onset
Quality (e.g. burning, cramping, aching, deep, superficial, boring, shooting)
Severity
Radiation pattern
Progression of pain
Duration
Exacerbating and relieving factors
The patient's level of function should be assessed, focusing on activities of daily living (e.g.
dressing, bathing), employment, avocations, and personal relationships.
10. Common Pain Scales
There are a variety of pain scales used for pain assessment. The three most common scales
recommended for use with pain assessment are:
• The numeric scale
• The Wong-Baker scale (also known as the FACES scale)
• The FLACC scale
The Numeric Scale The numeric scale is the most commonly used pain scale with adult patients,
rating pain on a scale of 0-10.
Wong-Baker Scale The Wong-Baker FACES Scale uses drawn faces for patients to express their level of
pain. The faces are associated with numbers on a scale ranging from 0 to 10. This scale is most
commonly used with children, and is appropriate to use with patients ages three and older. Adults
who have developmental or communication challenges may benefit from using this scale. (Health Care
Association of New Jersey, 2011)
FLACC Scale FLACC is the acronym for Face, Legs, Activity, Cry, and Consolability. This scale is based on
observed behaviors, and is most commonly used with pediatric patients less than three years of age.
The behaviors that are described are associated with a number; each component is totaled for a
number ranging from 0 to 10. This scale is also appropriate with patients who have developmental
delays or are non-verbal
(Health Care Association of New Jersey, 2011).
11.
12. Numeric Pain Intensity Scale
Pain Faces Scale
PAINAD Scale
And for Palliative Care……
13. The most commonly used pain measurement tool, used in the
cognitively normal patient
The scale is from 0 (no pain) to 10 (the greatest intensity pain)
In general pain from 1-3 is mild pain, 4-7 is moderate pain and
8-10 severe pain
Numeric Pain Intensity Scale
0 1 2 3 4 5 6 7 8 9 10
(None) (Mild 1-3) (Moderate 4-7) (Severe 8 – 10)
14. The patient selects the face that best represents how they feel
in relation to their pain condition, from the “happiest feeling
face” to the “saddest feeling face”
The correlating number is actually the scoring card used to
quantify the patient’s pain intensity
Pain Faces Scale
15. Pain Faces Scale
Pain Faces Scale
0
Very happy,
no hurt
2
Hurts just a
little bit
4
Hurts a
little more
6
Hurts even
more
8
Hurts a
whole lot
10
Hurts as much as
you can imagine
(don't have to be
crying to feel this
much)
16. PAINAD Scale is to be utilized in evaluating non-verbal patients
A score of 0 denotes no pain, and a score of 10 the worst
possible pain
This scale is now used in place of the FLACC scale
PAINAD Scale
17. Items 0 1 2 Score
Breathing Normal Occasional labored Noisy labored breathing
Independent breathing. Long periods of
of Vocalization Short periods of hyperventilation
hyperventilation. Cheyne-Stokes respirations
Negative None Occasional moan or groan. Repeated trouble calling
Vocalization Low level of speech with a out.
negative or disapproving Loud moaning or groaning.
quality. Crying.
Facial Smiling Sad. Facial grimacing
Expression or Frightened.
inexpressive. Frown.
Body Relaxed Tense. Rigid.
Language Distressed pacing. Fists clenched.
Fidgeting. Knees pulled up.
Pulling or pushing away.
Striking out.
Consolability No need to Distracted or reassured by Unable to console, distract
console. voice or touch. or reassure.
PAINAD Scale
18. Pain Management
General approach to pain management
Use a multidimensional approach: physical, psychological, spiritual, social,
cultural, situational
Collect data: history, physical exam, medication review
Location/radiation, onset, quality, severity
What makes it better/worse? What is it associated with?
What treatments have been tried/have been effective?
Other symptoms associated with the pain?
Pain timeline
Treat, reassess, adjust
19. Importance of
Pain Management
• Adequate Pain Control
• Reduce the Risk of Adverse Outcomes
• Maintain the Patient’s Functional Ability, as well as
Psychological Well-being
• Enhance the Quality of Life
• Shortened Hospital Stay and Reduced Cost
20. Adverse effects of unrelieved Pain
Cardiovascular Heart Rate
Blood Pressure
Increased myocardial o2
demand
Hypercoagulation
Unstable angina
Myocardial infarction
DVT
PE
Respiratory LungVolumes
Decreased cough
Retension of secretion
Atelectasis
Pneumonia
Hypoxemia
GI Gastric Emptying
Bowel Motility
Constipation
Anorexia
Ileus
National Pharmaceutical Council (2001). Macintyre & Schug (2007).Cohen et al (2004)
21. Adverse effects of unrelieved Pain
Neuroendocrine Altered release of
multiple hormones
Hyperglycemia
Wt loss/ muscle wasting
Impaired wound healing
Impaired immune function
MSK Muscle spasm
Impaired muscle
mobility & function
Immobility
Weakness
Fatigue
Psychological Anxiety
Fear
Sleep deprivation
Post traumatic stress
disorder
22. Non-Pharmacological Management
There are a variety of approaches for decreasing pain that are non-pharmacological
Non-pharmacological interventions may include:
• Heat or cold (as appropriate) • Massage
• Therapeutic touch • Decreasing environmental stimuli (e.g. sound,
lighting, temperature)
• Range of motion or physical therapy • Repositioning
• Immobilization • Relaxation techniques and imagery
• Distraction • Psychotherapy or cognitive behavioral therapy
• Biofeedback • Music therapy
• Aromatherapy • Acupressure or acupuncture
• Transcutaneous electrical Nerve stimulus (TENS)
• Cryoanalgesia of intercostal nerves (no longer used because of the high incidence of
dysaesthesia)
23. WHO Step Ladder of Pain Management:
One tool that was developed by the World Health Organization (WHO) in
1986 is the WHO analgesic ladder. This framework was originally developed
to assist physicians in treatment choices for cancer pain. This tool continues
to be validated, and used for not just cancer pain, but other forms of acute
and chronic pain.
The analgesic ladder is used as a guideline, and is described as follows:
Step 1: Mild pain (e.g. rating of 0-3 on a scale of 0-10): Uses non-opioid
and/or a nonsteroidal anti-inflammatory drug (NSAID), and other non-
pharmacological strategies to improve quality of relief.
Step 2: Moderate pain (e.g. rating of 4-6): Continue with medications and
methods described in step 1, plus add a mild opioid.
Step 3: Severe pain (e.g. rating of 7-10): Along with medications and
strategies described in steps 1 and 2, add a more potent opioid (e.g.,
morphine, hydromorphone, fentanyl).
(CPM Resource Center, 2010a; CPM Resource Center, 2010c; Schaffer, 2010).
27. Class Drug Usual Dosage Range*
Indoles Diclofenac 50–100 mg, followed by 50 mg q 8 h
Indomethacin Sulindac 150–200 mg q 12 h
Tolmetin 200–400 mg q 6–8 h
Propionic acids Fenoprofen 200–600 mg q 6 h
Ibuprofen 400 mg q 4 h to 800 mg q 6 h
Ketoprofen 25–50 mg q 6–8 h
Naproxen 250–500 mg q 12 h
Naproxen Na 75–550 mg q 12 h
Oxaprozin 600–1200 mg q 24 h
Salicylates Aspirin 650–1000 mg q 4–6 h
Diflunisal 250–500 mg q 8–12 h
Salsalate 750–2000 mg q 12 h
Oxicam Piroxicam 20–40 mg q 24 h
Non Opioidal Drugs
28. Fenamates Meclofenamate 50–100 mg q 6–8 h
Mefenamic acid 250 mg q 6 h
Pyrazole Phenylbutazone 100 mg q 6–8 h up to 7 days
Pyrrolo-pyrrolo derivative Ketorolac 15–30 mg IV or IM q 6 h or
20, followed by
10 mg q 4–6 h for maximum 5 days
Selective COX-2 inhibitor Celecoxib 100–200 mg q 12 h
29. DRUGS FOR NEUROPATHIC PAIN
Class/Drug Dose* Comments
ANTICONVULSANTS†
Carbamazepine 200–400 mg bid Monitor WBCs when starting treatment
GabapentinS 300 mg bid Preferred drug in this class; starting dose usually
300 mg once/day
Phenytoin 300 mg once/day Limited data; 2nd-line drug
Pregabalin 75–300 mg bid Mechanism similar to gabapentinS
but more stable pharmacokinetics
Valproate 250–500 mg bid Limited data, but strong support for treatment of
headache
30. DRUGS FOR NEUROPATHIC PAIN CONT……
ANTIDEPRESSANTS
Amitriptyline 10–25 mg at bedtime May increase dose to 75–150 mg over 1–2 wk,
particularly if significant depression is present;
may not need high doses; not recommended for
the elderly or patients with a heart disorder
because it has strong anticholinergic effects
Desipramine 10–25 mg at bedtime Better tolerated than amitriptyline
May increase dose to 150 mg or sometimes higher
Duloxetine 30 mg bid Better tolerated than tricyclic antidepressants
CENTRAL Α2-ADRENERGIC AGONISTS
Clonidine 0.1 mg once/day Also can be used transdermally or intrathecally
Tizanidine 2–20 mg bid Less likely to cause hypotension than clonidine
31. DRUGS FOR NEUROPATHIC PAIN -CONTD
CORTICOSTEROIDS
Dexamethasone 0.5–4 mg qid Used only for pain with an inflammatory component
Prednisone 5–60 mg once/day Used only for pain with an inflammatory component
NMDA-RECEPTOR ANTAGONISTS
Memantine 10–30 mg once/day Limited evidence of efficacy
Dextromethorphan 30–120 mg qid Usually considered 2nd-line
ORAL NA CHANNEL BLOCKERS
Mexiletine 150 mg once/day to 300 mg
q 8 h
Used only for neuropathic pain
For patients with a significant heart disorder, cardiac
evaluation considered before the drug is started
32. DRUGS FOR NEUROPATHIC PAIN -CONTD
TOPICAL
Capsaicin 0.025–0.075% tid Some evidence of efficacy in neuropathic pain and
arthritis
EMLA® tid, under occlusive dressing
if possible
Usually considered for a trial if lidocaine patch is
ineffective; expensive
Lidocaine5% Daily Available as patch
OTHER
Baclofen 20–60 mg bid May act via GABAB receptor
Helpful in trigeminal neuralgia; used in other types of
neuropathic pain
Pamidronate 60–90 mg/mo Evidence of efficacy in complex regional pain syndrome
*Route is oral unless otherwise indicated.
†Newer anticonvulsants have fewer adverse effects.
EMLA = eutectic mixture of local anesthetics; GABA = γ-aminobutyric acid; NMDA = N-methyl-d-aspartate.
33. NEURAL BLOCKADE
Interrupting nerve transmission in peripheral or central pain pathways via drugs or physical methods
provides short-term and sometimes long-term relief. Neuroablation (pathway destruction is used
rarely; it is typically reserved for patients with an advanced disorders and a short life expectancy.
Local anesthetic drugs (eg, lidocaine) can be given IV, intrathecally, intrapleurally, transdermally, sc, or
epidurally.
Epidural analgesia using local anesthetics or opioids is particularly useful for some types of
postoperative pain. Long-term epidural drug administration is occasionally used for patients with
localized pain and a short life expectancy. Generally, for long-term neuraxial infusion, an intrathecal
route via an implanted pump is preferred.
NEUROMODULATION
Stimulation of neural tissues may decrease pain, presumably by activating endogenous pain
modulatory pathways.
The most common method is transcutaneous electrical nerve stimulation (TENS), which applies a small
current to the skin.
Also, electrodes may be implanted along peripheral nerves or along the dorsal columns in the epidural
space.
Stimulation of brain structures (deep brain stimulation and motor cortex stimulation) has also been
used, but evidence of benefit is slight.
34. post operative pain
management
When to start pain management?
• Pre-operatively
• Discuss options with patients
• Teach about assessment, treatment options
• Pre medication with paracetamol
• Intra-operatively
• Wound infiltration with local anaesthetic (surgeon)
• Administer analgesics (IV or rectally)
35.
36.
37. Pharmacological Postoperative Pain Management
• Multimodal Analgesia
• The combination of drugs from different classes to achieve more effective analgesia with less side effects
Advantages:
• May be opioid sparing
• May result in decreased side effects
• More effective analgesia
• World Health Organisation (WHO) analgesic step ladder approach to pain relief
• Accurate pain assessment is key to providing adequate pain relief
38. Mild pain
1 – 3
Paracetamol
+
NSAID (if no CI)
+
infiltration with LA
Moderate pain
4 – 6
Paracetamol
+
NSAID (if no CI)
+
Codeine or Tramadol
+
infiltration with LA
Severe pain
7 – 10
Paracetamol
+
NSAID (if no CI)
+
Morphine
+
infiltration with LA
CI= contraindication; LA = local anaesthetic
How to treat post-surgical pain?
39. Non-pharmacological Postoperative Pain Management
• Psychological strategies
• Distraction ( toys, books, iPad )
• parental presence in recovery room
• Education
• Physical Strategies
• TENS
• Ice/heat
• Elevation/positioning
• Simple distraction techniques that divert attention away from the painful stimulus
• Positive incentive techniques which provide a small reward (e.g stickers, prizes)
• These strategies aim to decrease anxiety but are not adequate as a sole means of post operative pain
management