Responding to symptoms of Minor ailments - Pain

RESPONDING TO SYMPTOMS OF MINOR AILMENTS

1) PAIN

INTRODUCTION

Pain is an unpleasant, subjective sensory and emotional experience associated with actual or potential tissue damage.

According to the American Academy of Pain Medicine:

Pain is “an unpleasant sensation and emotional response to that sensation.”

Dr. Don Ranney defines pain as:

A perception rather than a pure sensation, involving both detection of harmful stimuli and interpretation by the brain.

✔ Pain perception is real even if no actual tissue damage occurs
✔ It involves both physiological and psychological components

TYPES OF PAIN

Pain is broadly classified into:

1) Nociceptive Pain

• Caused by stimulation of nociceptors (pain receptors) in tissues
• Usually acute and well localized

Examples:

• Burns
• Fractures
• Appendicitis
• Surgical pain
• Myocardial ischemia

2) Neuropathic Pain

• Caused by damage or dysfunction of the nervous system
• Can occur anywhere from peripheral nerves to CNS
• Usually chronic and poorly localized

Examples:

• Diabetic neuropathy
• Nerve injury or compression
• Plexus avulsion

PATHOPHYSIOLOGY OF PAIN

1.     Tissue Injury

• Caused by mechanical, thermal, or chemical stimuli

2.     Release of Chemical Mediators

• Potassium ions (K⁺)
• Hydrogen ions (H⁺)
• Serotonin
• Bradykinin
• Substance P
• Histamine
• Prostaglandins (via arachidonic acid pathway)

3.     Peripheral Sensitization

• Inflammatory mediators increase sensitivity of nociceptors

4.     Neurotransmitter Release in Spinal Cord

• Glutamate
• Aspartate

5.     Central Sensitization

• Activation of NMDA receptors
• Increased nitric oxide production
• Enhanced pain transmission

CENTRAL PATHWAYS OF PAIN

Pain signals are transmitted via:

• Spinothalamic tract
• Spinoreticular tract
• Spinomesencephalic tract

➡ From spinal cord → brainstem → thalamus → cerebral cortex

CLINICAL PRESENTATION

Pain Characteristics

• Sharp
• Dull
• Burning
• Shooting
• Tingling
• Radiating
• Variable intensity and location

Associated Symptoms

• Anxiety
• Depression
• Fatigue
• Insomnia
• Fear

Signs (especially in acute pain)

• Hypertension
• Tachycardia
• Sweating (diaphoresis)
• Dilated pupils (mydriasis)
• Pallor

⚠ Pain is subjective → best assessed by patient history

DIFFERENCE BETWEEN PAIN TYPES

Feature	Nociceptive Pain	Neuropathic Pain
Nature	Acute	Chronic
Location	Well localized	Poorly localized
Description	Clear	Vague
Treatment response	Good with analgesics	Poor response

MANAGEMENT OF PAIN

A) ACUTE PAIN MANAGEMENT

1) Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

• Inhibit prostaglandin synthesis

Examples:

• Aspirin: 325–650 mg every 4–6 hrs
• Paracetamol: 500–650 mg every 6 hrs
• Ibuprofen: 400 mg every 8 hrs

2) Opioid Analgesics

a) Strong Opioids

• Morphine
• Hydromorphone
• Oxymorphone

✔ Used for moderate–severe pain
⚠ Side effects: respiratory depression, nausea

b) Other Opioids

• Meperidine
• Fentanyl

⚠ Meperidine metabolite (normeperidine) → seizures (especially in renal failure)

c) Methadone Group

• Methadone
  ✔ Long duration, used in chronic pain and opioid dependence

d) Mixed Agonist-Antagonists

• Pentazocine
• Butorphanol
• Nalbuphine

✔ Lower risk of respiratory depression

e) Opioid Antagonist

• Naloxone
  ✔ Reverses opioid overdose
  ✔ Dose: 0.4–2 mg IV/IM/SC

3) Central Analgesic

• Tramadol
  ✔ Mechanism:
• Weak opioid receptor agonist
• Inhibits serotonin & norepinephrine reuptake

✔ Dose: 50–100 mg
⚠ Side effect: risk of seizures

B) CHRONIC PAIN MANAGEMENT

• NSAIDs (for musculoskeletal pain)
• Methadone (long-acting)
• Epidural clonidine (refractory pain)
• Tricyclic antidepressants
• Anticonvulsants (for neuropathic pain)

NON-PHARMACOLOGICAL MANAGEMENT

1) Physical Methods

• Physiotherapy
• Massage
• Nerve blocks
• Surgery
• Muscle relaxation

2) Psychological Methods

• Counseling
• Cognitive behavioral therapy
• Hypnosis
• Stress management
• Music therapy

3) Social Support

• Support groups
• Occupational therapy
• Self-help groups

KEY POINTS FOR EXAMS

• Pain = subjective + emotional experience
• Two main types: nociceptive & neuropathic
• NSAIDs → prostaglandin inhibition
• Opioids → severe pain, risk of respiratory depression
• Naloxone → antidote for opioid overdose
• Chronic pain → requires multimodal approach