Module 3 - except 3.3 and 3.4

• process of detecting and signalling potential tissue damage

• protects body from harm

• includes relfexes

• sensory receptors - found in skin, viscera, muscles, joints and meninges

• stimulated by chemical, heat, pressure, touch, temperature

• emit signals to CNS

nociception

• only achieved when the superthreshold for nociceptors are reach and induce a pain pathway

• acute pain is protective

pain

• slow and dull

• autonomic relfexes

• pain memory and discomfort

• paleospinathalamic tract

• chronic pain

C fibers of pain

• rapid and sharp

• pain localisation with withdrawal reflexes

• neospinothalmatic tract

• somatic pain

A delta fibers

• can be acute or chronic

• somatic and visceral pain - skin, muscle, joins

• treated with analgesic and inflammatory medications

• all parts of body

• nociceptors - send signals to autonomic ganglion and conduction of spinal cord, transmission to brain and perception of pain

nociceptive pain

• due to injury to a nerve

• alteration in the process and modulation of pain

• persistent and chronic pain - worsens by psychological factors - stress, anxiety

• peripheral or central

• treatment - antidepressants, opiods, NSAIDs

• diabetic peripheral neuropathy

neuropathic pain

• Increased excitability and sensitivity to pain, leading to heightened responses to a stimulus that is normally painful

Hyperalgesia

• Painful responses triggered by a stimulus that is not normally painful

Allodynia

• Vivid perception that a limb that has been removed

• feel that the phantom limb is distorted or shorter than the original limb

• Tickling, irritation, Cramps, Shooting, piercing, or stabbing pain, numb

• even for people who are born without, not just limbs

Phantom limb pain

• mechanism to alert individual of potential harmful tissue damage

• Sudden onset, relief when stimulus removed

• seconds to days, up to 3 months - short duration

• causes stimulation of autonomic NS - increased heart rate and BP, anxiety - somatic, visceral pain

acute pain

• persistent - more than 3-6months

• no purpose - suffering

• ongoing

• absence of autonomic response

• persistent inflammation and pain - linked to neuropathic pain

• significant psychological responses

chronic pain

• internal organs

• pain and pressure

• dull, aching

visceral pain

• superifical pain - from skin

• deep arises - bones, joints, tissues, tendons, blood vessels

• touch, pressure, temperature, pain

• sharp, burning, sharp radiating pain

somatic pain

• perceived at a site which is different from the site of injury or origin of pain as innervated by same spinal segment - converge at same dorsal horn projection in spinal cord

referred pain

• subjective

• threshold - lowest intensity of pain recognised by individual

• tolerance - duration or intensity individual can endure - can decrease with repeated exposure

• increase with alcohol consumption and prolonged opioid medications

pain threshold

• nociceptive nerve endings

• dendron - pre-nerve ending before cell body in the autonomic ganglion

• transduction - impulse along dendron

• conduction - impulse along axon

sensory neurons

• Nociceptors carry out transduction along the dendron, followed by further conduction along the axon.

• the spinal cord, mediators are released until the signal threshold is reached. This leads to electrical impulse transmission along the spinothalamic tract to the brain, which leads to the integration and perception of pain.

• signal relay occurs in the thalamus.

• processing and conscious awareness take place in the cerebral cortex.

• descending inhibitory pathways lead to the modulation of pain.

• the dorsal horn in the spinal cord, mechanisms allow for gate control of pain.

pain pathway

• When an injury happens, pain receptors send an excitatory signal up through the spinal cord toward the brain

• The brain responds by sending a signal back down the spinal cord through a "descending inhibitory pathway"

• this descending signal triggers the release of natural pain-relieving chemicals called endorphins - thus feeling less pain

cause of pain going away

• Pathways traveling down from the brain release noradrenaline (NA) and serotonin (5-HT) to inhibit the transmission neuron going to the brain.

• Local interneurons release enkephalin to suppress the signal directly at the primary nociceptive nerve.

• GABA, Enkephalins, Noradrenaline (NA), Serotonin (5-HT), and Glycine.

pain blockers

• Tissue injury releases chemicals like Bradykinin, 5-HT, and prostaglandins, which excite the primary nociceptive neuron.

• spinal cord synapse, Substance P (SP), Glutamate, and Nitric Oxide (NO) are released to transmit the excitatory signal onward to the brain

pain promotors

• Block peripheral generation of the nociceptive impulses

• inhibit prostaglandin synthesis

• reduce sensitivity of sensory nociceptive nerve ending to spinal cord

NSAIDs

• Act on spinal cord & limbic system

• Stimulate descending inhibitory pathways

• inhibit transmission to dorsal horn

• minimal peripheral action

opioids

• Semi rigid and slightly flexible structure which acts as a surface for articulating ends of skeletal joints

cartilage

• attach bone to muscle

tendons

• attach bone to bone

ligament

• pain

• limitation on mobility

• decrease Qol

• pyschological effect

disadvantages of muscoskeletal pain

• Muscle strain or overuse

• Stress fractures

• Degenerative disc disease

• Arthritis

• Spondylitis

• Lower back injury - due to hyperextension of lumbar spine

lower back pain causes

• Worsening pain over several days

• Pain radiating down into the leg(s)

• Severe shooting pains into the leg(s) accompanied by loss of function or weakness in the leg(s)

• Urinary or bowel incontinence

referral for lower back pain

• local muscle damage due to mechanical overloading

• sports related or trauma related

• sudden, forced motion - stretch beyond normal capacity

strain

• no muscle deformities

minimal strain

• pain and brusing - for some muscle tearing

partial tearing strain

• minimal pain, complete tear

• muscle deformity

complete tear

• Injury to ligaments surrounding the joint

• pain, rapid swelling, heat, loss of function

• pain and swelling subside more slowly

• abnormal or excessive joint movement

sprain

• ankle

• knee

• elbow

• wrist

site of sprain injury

• Severe pain, immediate swelling, loss of function, marked deformity and abnormal mobility

fracture

• Very obvious, joint appears deformed. Displaced bone end often causes an abnormal lump or ridge or depression

dislocation

• Suspected fracture

• Bone abnormalities

• Accompanying head injury

• Severe pain at rest

• Pain & wt bearing not better within 5-7 days.

• Associated injury to skin (may require tetanus prophylaxis)

• Suspected arthritis or other diseases

referral for pains

• painful menstruation

Dysmenorrhoea

• pain on sexual intercourse

Dyspareunia

• 1st period

• 12 years

• day 1

menarche

• FSH stimulates follicle development, leading to increased oestrogen and endometrial proliferation

• Occurs at around Day 14 when a mature egg is released from the ovary - ovulation

• period - 4 to 7 days - 30-40ml

• 21-35 days

• optimal fertility - 18-31

menstrual cycle

• FSH causes around 20 tiny sacs (follicles), each containing an egg (ovum), to start growing.

• One follicle grows faster than the rest and becomes the dominant follicle.

• The dominant follicle produces and releases oestrogen.

• High oestrogen levels signal the body to lower FSH levels (negative feedback). Without enough FSH, the other competing follicles stop growing and break down.

• The main winning follicle matures into a fully developed structure called the Graafian follicle (GF), which is ready to release the egg.

follicle growth

• main hormone that stimulates oestrogen release

• controls the proliferative phase of endometrium, which causes the endometrium to regenerate (thickens and increases vascularity, occurs days 5 to mid cycle)

• High oestrogen level in mid cycle leads to surge of LH secretion

Follicle stimulating hormone

• main hormone controlling subsequent progesterone secretion from the corpus luteum

• Surge of LH stimulates ovulation mid cycle

• Graafian follicle swells and ruptures releasing the ovum

Luteinising hormone

• pain associated with menstruation in the absence of pathology

• significant pain associated with menstruation

• Recurrent, significant pain associated with menstruation

• just before and during menstruation

primary dysmenorrhea

• endometrial cells release prostaglandins - causing uterine contractions causing high pressure vasoconstriction, ischameia causes accumulation of anaerobic metabolites and nerve sensitsation

• activation of stretch receptors

• prostaglandins relaxes the bowel muscles - period poo

• increase in progesterone - constipation

pathophysiology of mensturation

• Early menarche

• Younger age

• Stress

• Heavy/long duration of menstrual flow

• Family history

• Nulliparity

• smoking

• obesity

risk of primary dsymenorrhea

• cramping

• suprapubic pain

• lower back and thigh pain

• several hours before menstruation

• diarrhoea, nausea, vomiting

• altered pain sensitivity

• hours before period

• peak pain - max blood flow

symptoms of primary dysmenorrhea

• constant pain

• comes in goes within the cycle

• pain during sex or passing motion

• progression of symptom severity

• bladder pain

• symptoms after 25

• how disabled they feel

• maybe screen for STIs and rule out secondary dsymenorrhea

referral for period pain

• reduce prostaglandin synthesis

• decrease pain, nausea, diarrhoea

• may require loading dose

• can be trialled for 3 months

NSAIDS for period pain

• reduced endometrium - reduced PG - reduced pain

• less evidence

• need continous use

• trial for 3 months

• pill, vaginal ring, IUD

Contraceptive pill

• Low fat vegetarian diet

• Increased dairy intake

• Vitamin E for 5 days starting 2 days before menses - 500units daily OR 200units BD

• Vitamin B1 100mg daily

• Vitamin B6 100mg daily

• Fish Oil Supplement

• Ginger powder - days 1-3 of cycle

complementary medications for dysmenorrhea

• Aerobic exercise

• High frequency transcutaneous electrical nerve stimulation (TENS)

• Acupuncture

• Heat packs (may be as effective as ibuprofen)

• Behavioural interventions

non-pharmacological for dysmenorrhea

Prolonged direct heat exposure, at a threshold below causing a thermal burn

• heat packs, hot bottles

• painless

• rash will fade

• temporary in early stages - fixed and darker of exposure continues

• retinoids - reduce discolouration

Erythema Ig Abne

• involves cyclically recurring mood, physical, and cognitive symptoms during the luteal phase, starting 4–10 days before a period and resolving a few days after menses begin.

• can worsen other chronic conditions such as epilepsy, migraine, asthma, and Premenstrual Exacerbation (PME).

• potential factors include progesterone or prostaglandin (PG) fluctuations, hormonal interactions (such as allopregnanolone) with central neurotransmitters (especially serotonin), and genetic or family history.

pre-menustral syndrome

• irritability

• anxiety/ nervous tension

• lower coping ability

• difficulty concentrating

• wanting to be alone

• lower libido

emotional PMS symptoms

• fluid retention (swollen fingers or ankles)

• bloating around the abdomen

• breast swelling and tenderness

• skin problems such as acne

• headaches and/or migraines

• poor coordination or clumsiness

physical PMS symptoms

• limited to luteal phase

• impact daily life

• present for 2 consecutive cycles

• not explained by other diagnosis

diagnosis of PMS

• daily symptoms for 2-3months

• if symptoms are not cyclial or not in luteal phase - alternate diagnosis

• symptoms dont interfere with daily living

• tried anything, other medical conditions, changes in period

assessment for PMS

• Stress reduction strategies

• patient education and symptom diary

• better sleep practises

• avoid minimise alcohol

• exercise

• diet - reduce caffeine and sodium if needed

non pharm management PMS

• Chasteberry - 20-40mg

• Vitamin B6 - 50mg

• Magnesium 900mg daily

• Calcium 600mg bd

complementary medicines for PMS

• Recommended first-line treatment when mood is the primary symptom.

• Any SSRI can be used, with fluoxetine studied most in clinical trials.

• Intermittent dosing (taken 2 weeks before menses through day 1–3 of the period) is just as effective as continuous daily dosing.

• Switch to continuous dosing if intermittent treatment is ineffective or causes withdrawal symptoms.

• Remains the drug of choice for PMDD.

SSRIs for PMS

• Suppress the hypothalamic-pituitary-ovarian axis and prevent ovulation.

• Address both mood and physical symptoms, though trial results are mixed: 50% report no change, 25% improve, and 25% worsen.

• Recommended for continuous use (no pill-free interval to prevent bleeding), supported by evidence for a 168-day cycle.

• Formulations with an anti-androgen progestogen can be considered if fluid retention is a prominent symptom.

Contraceptive oral pill for PMS

• 25-100mg/day during luteal phase

• Most helpful for fluid retention, bloating, breast tenderness (not emotional symptoms)

Diuretics – spironolactone - PMS

• Naproxen, mefenamic acid - for physical symptoms

NSAIDs for PMS

• Symptoms – mood and physical

• Comparison to start of therapy

• Side effects

• Additional therapies

• Non-pharmacological

• Support from friends/family

• Try one agent for 2-4 cycles before switching to alternate therapy

monitoring PMS

• Repetitive stress on lower back including frequent bending, lifting heavy object

• Long period of sitting down e.g. truck driver

• Acute injury from excessive twisting

• Long period of sitting down e.g. truck driver  Acute injury from excessive twisting

• localised or diffuse

• stiff, aching

• quick onset of pain

• movement - restricted

• low long symptoms have been present

acute low back pain

• Worsening pain over several days

• Pain that radiates to the leg(s)

• Severe shooting pains into the leg(s) with loss of function/weakness in your leg(s) - sciatica

• Urinary or bowel incontinence

• Need for analgesic for > 7 days

• Persistent pain after 4 weeks

acute lower back pain referral

• topical NSAID

• ibuprofen, ketoprofen, diclofenac, benzydamine, piroxicam, naproxen sodium

• massage gently 2-4 times a day

• caution with asthmatics

• avoid preg

• safe in breastfeeding

• anticoagulant, lithium interactions

• diarrhoea, heart burn, hypertension

• take soon or after food

treatment of acute lower back pain - NSAIDs

• Cause vasodilation, producing warmth that distracts the patient from underlying pain.

• Contain salicylates and menthol (e.g., Metsal®, Dencorub® cream).

• Apply to the affected area 2 to 3 times daily.

• Salicylate-containing products require caution in patients with an aspirin allergy.

• Common side effects include rash and skin irritation.

• Herbal remedies (devil’s claw, white willow bark, cayenne)

• Acupuncture

• Massage

topical rubefacient

• 500 mg to 1 g qid; max of 4 g daily (Immediate release tablet)

• 1.33 g tds ; max of 3.99 g daily (Controlled release tablet)

• safe in preg and breastfeeding

paracetamol - back pain

• 300 mg to 900 mg qid (max dose of 3.6 g daily)

• Commonly associated with GI bleed especially in elderly

• Avoid in patients with asthma, past history of GI bleed, children under age of 16

• Avoid concurrent administration with warfarin

• Avoid in pregnancy and breastfeeding

aspirin

• product has 8-15mg of codeine

• doses are too low to have significant effect

compounds with codeine

• good posture

• excerise at a moderate level for at least 30 minutes

• proper lifting technique

• wear low heeled shoes

• take breaks

• bed mattress

acute back pain self care

• Suspected Fracture: More common in children under 12 years old and the elderly.

• Bone Abnormalities: Deformed-looking joints.

• Head Injury: Any accompanying trauma to the head.

• Severe Pain at Rest: High pain levels even without movement.

• Lack of Improvement: Pain and ability to bear weight do not improve within 5–7 days.

• Associated Skin Injury: Open wounds or skin damage that may require tetanus prophylaxis.

• Underlying Conditions: Suspected arthritis or other underlying diseases

referral for sprains and strains

• heat, alcohol, running, massage

management for strain and sprains

• Sprain and strain related injury can take 1 up to 6 weeks to recover depending on severity of injury

• gradually increase movement after pain and swelling

• prevent injury by wearing suitable footwear and protective clothing when playing sport

• Warm up before sport

• Run on even surface

• Allow adequate recovery time in between training session

management for strain and sprains self care

• Tension-type headache (episodic or chronic)

• Migraine (with or without aura)

• Cluster headache

primary headache

• Headache that is caused by associated condition or disease (minor or serious and life threatening)

secondary headache

• systemic symptoms

• neurological symptoms

• severe

• older age

• positional headache

• sneezing, coughing

• pregnancy

• painful eye

• pain killer overuse

referral for headache

• Proton pump inhibitors (PPIs) and H2 antagonists.

• Selective serotonin reuptake inhibitors (SSRIs).

• Amphetamine and dexamphetamine.

• Glyceryl trinitrate, long-acting nitrates, dipyridamole, and dihydropyridine calcium channel blockers.

• Sildenafil, tadalafil, and vardenafil.

medications that cause headache

• more common in men than women

• acute - less than 15 days

• chronic - more than 15 days

• in the front of the head or neck

• triggered by Mental and physical stress, Poor posture, High caffeine intake or caffeine withdrawal, Getting too much or too little sleep, Menstrual cycle-related problems.

tension type headache

• Bilateral pain that is non-throbbing (dull, aching), feels like pressure or tightness around the head, and may extend into the back of the neck and shoulders.

• Lasts anywhere from 30 minutes to 7 days, often occurring in the late afternoon or evening.

• Mild to moderate in intensity and not aggravated by routine physical activity; symptoms generally do not stop a person from carrying out day-to-day activities.

• treated with aspirin, paracetamol or other NSAIDs

tension type headache symptoms

• Use heat packs or cold packs.

• Perform massage therapy on target areas.

• Stretch tight neck and scalp muscles.

• Focus on posture correction.

• Engagement in regular exercise.

• Practice relaxation exercises.

• Utilization of a supporting neck pillow.

• Reduction in caffeine intake.

tension type headache non-pharmacological treatment

• for amitriptyline or noradrenaline 10 ot 75 mg daily

• for 3-6 months and reduce dose

tension type headache - referral

• common in women

• family tendency

• peak in adolscence

• 35-39 years

• can cause aura - visual issues - can be positive or negative

• cause by accumulation of factors

• assess monthly frequency and medication tolerance after 8-12 weeks

migraine headache

• Unilateral pain that is moderate to severe in intensity and described as pulsating.

• Can be significantly disabling both physically and psychologically, and is aggravated by physical exercise.

  • Photophobia (sensitivity to light)

  • Phonophobia (sensitivity to sound)

  • Nausea (and vomiting)

  • Fatigue

  • Altered cognition

headache phase of migraine

• fatigue, mood, difficulty concentrating

postdromal phase of migraine

• fluctuating hormones

• too much or little sleep

• fasting

• stress

• change in weather

• scents

• glare

migrane triggers

• Rest or sleep in a quiet, dark room.

• Practice mental and physical inactivity, including meditation and relaxation techniques.

• Apply hot and cold therapies.

• Maintain fluid hydration if possible.

• Keep a headache/migraine diary.

non-pharmacological treatment of migraines

• Soluble aspirin: 900–1000 mg every 4 to 6 hours as needed (Maximum 4 g in 24 hours). prevent gastric statis

• Ibuprofen: 400–600 mg every 4 to 6 hours as needed (Maximum 2.4 g in 24 hours).

• Naproxen sodium: 550–825 mg every 4 to 6 hours as needed (Maximum 1.25 g in 24 hours).

• Diclofenac sodium: 50 mg every 4 to 6 hours as needed (Maximum 200 mg in 24 hours).

• Soluble paracetamol: 1000 mg every 4 to 6 hours as needed (Maximum 4 g in 24 hours).

• take early stage

1st line for headaches

• failure after 3 consecutive occasions

• Eletriptan: 40mg

• Naratriptan: 2.5mg

• Rizatriptan: 5mg

• Sumatriptan: 50mg

• Zolmitriptan: 2.5mg

• contains 2 tablets

• can affect mental coordination

• only used if migraine is diagnosed

2nd line headache

• Constrict cranial vessels by acting selectively at 5HT 1B/1D receptors.

• Thought to inhibit the abnormal activation of trigeminal nociceptors.

5HT antagonist

• Cardiovascular conditions (e.g., uncontrolled hypertension, peripheral vascular disease, history of myocardial infarction, ischaemic heart disease, stroke).

• Concomitant use with SSRIs and SNRIs.

• Oral efficacy is not established in patients aged 12–17 years; intranasal products are preferred.

• Sensations of tingling, flushing, dizziness, drowsiness, dry mouth, transient increase in blood pressure, and heaviness or tightness in any part of the body (including chest and throat).

• Dependence may occur with overuse, leading to recurrent/rebound headaches and withdrawal.

precautions and contraindications for triptans and NSAIDs

• work to block dopamine

• Metoclopramide 10-20 mg

• Prochlorperazine 5-10 mg

• Domperidone 20 mg

Anti-Emetics

• 4 days of migraine symptoms per month

• Individual attacks are difficult to manage with acute treatment

• reduce frequency and decrease disability from attack

treatment of migraine is only for

• Avoid identified trigger factors.

• Reduce caffeine intake.

• Utilize relaxation techniques.

• Employs a "problem-focused" approach.

• Employs an "action-oriented" approach.

prevention of migraine - non pharmacological

• Adverse effects

• Comorbidities and other medicines

• Patient preference and symptoms

• start slow and work up

• trial for 8-12 weeks

choice of migraine drug depends on

• Topiramate 25 –

• Sodium Valproate

• Propranolol

• Botox - chronic migraines

• CGRP peptide

• complementary - Magnesium, Riboflavin

best drugs for migraine prevention

• Migraine occurs due to the withdrawal of oestrogen between Day –2 and +3 of the menstrual cycle.

• Start 1 to 2 days prior to the onset of menses and continue for 5 to 7 days, or as needed.

• Ibuprofen: 400 mg three times daily (tds), OR

• Naproxen SR: 750–1000 mg once daily, OR

• Naratriptan: 1.25–2.5 mg twice daily

menstrual migraine