Tentiran Koass Nyeri

General View of Pain Management

Emergency Department PGH

“International Association for The Study of Pain

Definition of pain:

“An unpleasant sensory and emotional experience associated with actual or potential tissue damage and expressed in terms of such damage”

What is pain?

Nociception

Spinothalamictract

Peripheralnerve

Dorsal Horn

Dorsal root ganglion

Pain

Modulation

Transduction

Ascendinginput

Descendingmodulation

Peripheralnociceptors

Trauma

Adapted from Gottschalk A et al. Am Fam Physician. 2001;63:1981, and Kehlet H et al. Anesth Analg. 1993;77:1049.

Perception

Transmission

Nociceptive afferent fiber

Normal Nerve Impulses Leading to Pain

Noxiousstimuli

Descendingmodulation

Ascendinginput

Spinal cord

Perceived pain

Activation of the Central Nervous System

at the Spinal Cord Level

Tissue DamageActivation of the

Peripheral Nervous System

Transmission of the Pain Signal to the Brain

Pain

.The Pain Response

Samad TA et al. Nature. 2001;410:471-5.

Dorsal Horn

Dorsal rootganglion

Peripheral sensoryNerve fibers

A

A

C

Largefibers

Smallfibers

There are Two Sensory Afferent Neurons

1. Large myelinated A fibers• Very fast conduction velocity • Respond to innocuous stimuli

2. Small myelinated A & C unmyelinated fibers• Slow conduction velocity • Respond to noxious stimuli

Activation

External

Stimuli

Heat

Mechanical

Chemical

VR1

Ca2+

mDEG

P2X3

Generator potentials

action potentials

Voltage gated sodium channels

Pain and auto-sensitization

Woolf & Mitchel, 2001

Transduction

ATP

Na+

Modifikasi Meliala, 2003

ACTION POTENTIALACTION POTENTIAL

KERUSAKAN JARINGAN

INFLAMASI

SSA MI NOS

SENSITISASI

AKTIFASIECT. DISC.

Si-Na+

KORNU DORSALIS

PgB5HTAdenosin

PengalamanKognitifBehaviourPsikologik

Inhibisi desenden

OTAK

PAIN – NO PAIN

R-NE

Pharmacologic Methods*Non-opioids (e.g paracetamol, aspirin,

NSAID) for mild pain *Non-opioids with weak opioid (e.g codeine) for mild – to moderate pain *Opioid / morphin for moderate to severe pain *Alternative strong opioids *Adjuvant drugs (e.g corticosteroids,

antidepressants, anticonvulsant, neuroleptics)

Current Pain Management

Route Time to Half-life Analgesic Analgesic Maximum

peak (hr) (hr) onset (hr) duration (hr) recommended

daily dose (mg)

-----------------------------------------------------------------------------------------------------------------------

Salicylates

Aspirin Oral 0.5-2 2-3 0.5-1 2-4 3,600

Propionic acids

Ibuprofen Oral 1-2 1.8-2.5 0.5 4-6 3,200

Ketoprofen Oral 0.5-2 2-4 4-6 300

Naproxen Oral 2-4 12-15 1 4-7 1,500

Acetic Acids

Indomethacin Oral 1-2 4.5 0.5 4-6 200

Ketorolac Oral/im 1 2.4-6 0.5-1 4-6 120

Nonopioid analgesics

Route Time to Half-life Analgesic Analgesic Maximum peak (hr) (hr) onset (hr) duration (hr)

recommended daily dose

(mg) -----------------------------------------------------------------------------------------------------------------------

Fenamates

(anthranilic acids)

Meclofenamate Oral 0.5-1 2 0.5-1 4-6 400

Mefenamic acid Oral 2-4 2-4 1 4-6 1,000

Oxicams

Piroxicam Oral 3-5 30-86 1 48-72 20

Phenylacetic acids

Diclofenac Oral 2-3 2 1 1.6 200

P-Aminophenols

Acetaminophen Oral 0.5-1 1.4 0.5 2-4 1,200

Phenacetin Oral 1 2,400

Selective COX-2 Inhibitors

Celecoxib Oral 2-3 1 8-12 400

Rofecoxib Oral 2-3 0.4 12-24 50

Nonopioid analgesics

Dosage (mg) Onset (hr) Peak (hr) Duration (hr) Comment

------------------------------------------------------------------------------------------------------------

Morphine 2.5-15 iv 0.125 Rapid onset, peak

Respir depr 10 min

Meperidin 50-100 im 0.12-0.5 1 2-4

Codeine 15-60 oral 0.25-1 0.5-2 3-4

Methadone 2.5-10 oral 0.5-1 1.5-5 4-8

Pentazocine 50 oral 4-7

30-60 im 0.12-0.5 1-3 3-6

Opioid Analgesics

Arachidonic Acid Cascade& COX Hypothesis

Arachidonic Acid

COX-1 COX-2

Body Homeostasis• Gastric integrity• Renal function• Platelet function

InflammationPain

Needleman P. et al. J Rheumatol 1997;24(suppl 49):6-8Fitzgerald GA et al. N Engl J Med 2001;345:433-42

Cyclooxygenase (COX)

Nonselective NSAID

COX-2 selective InhibitorX XX

COX-1 & COX-2

.