ACUTE PAINACUTE PAIN

Ahmed Ghaleb, MDAhmed Ghaleb, MD UAMSUAMS DirectorDirector Pain MedicinePain Medicine

PAINPAIN

“An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of suchdamage.”

Pain 6:249, 1979 IASP

What Is Pain ?What Is Pain ?

• Pain is a Pain is a SubjectiveSubjective Experience Experience

• In evaluating Pain, clinicians must In evaluating Pain, clinicians must remind themselves that their remind themselves that their eyes do eyes do not measurenot measure pain. pain.

• It is the nature and disposition of It is the nature and disposition of nearly all professionals to nearly all professionals to underestimateunderestimate the magnitude of the magnitude of Central Pain.Central Pain.

Classification of painClassification of pain

Types Of PainTypes Of Pain

AcuteAcute ChronicChronic

MalignantMalignant Non-MalignanNon-Malignantt

CLASSIFICATIONCLASSIFICATION

Types of Pain

Somatic Pain Visceral Pain Neuropathic Pain

CLASSIFICATIONCLASSIFICATION

two major types of pain

Nociceptive (Tissue) Pain

Neuropathic (Nerve) Pain

somatic visceral

ACUTE PAINACUTE PAIN

• Is Defined as a sharp or having a Is Defined as a sharp or having a short and relatively severe course.short and relatively severe course.

• All pain syndromes began as an All pain syndromes began as an ACUTE PAINACUTE PAIN, becoming chronic only , becoming chronic only after persisting beyond the course of after persisting beyond the course of expected healing of the causative expected healing of the causative stimulusstimulus

COMMON ACUTE PAIN COMMON ACUTE PAIN SYNDROMESSYNDROMES

• POST OPERATIVE PAINPOST OPERATIVE PAIN

• Traumatic injury-related painTraumatic injury-related pain

• Burn painBurn pain

• Acute Herpes ZosterAcute Herpes Zoster

• Sickle cell painSickle cell pain

• Cancer-related painCancer-related pain

• HeadacheHeadache

COMMON ACUTE PAIN COMMON ACUTE PAIN SYNDROMESSYNDROMES

• Chest PainChest Pain

- Angina- Angina

- Esophagitis- Esophagitis

- Pleuritic pain- Pleuritic pain

• Abdominal painAbdominal pain

- Acute - Acute PancreatitisPancreatitis

- Acute abdomen- Acute abdomen

- Renal colic- Renal colic

• Musculoskeletal Musculoskeletal painpain

• Neurogenic painNeurogenic pain

- Herniated disk- Herniated disk

- Nerve - Nerve compressioncompression

• Ischemic painIschemic pain

- PVD- PVD

POST OPERATIVE PAINPOST OPERATIVE PAIN

Planned and deliberately inflicted Iatrogenic tissue injury Known anticipated time of onset It can be approached using a preventive (preemptive ) treatment scheme Acute in origin, pain last less than four weeks Decrease with healing process

POST OPERATIVE PAINPOST OPERATIVE PAIN

Despite its common occurrence, Despite its common occurrence, predictability, and its known predictability, and its known cause, the management of Post cause, the management of Post operative pain remains operative pain remains inadequate treated in many inadequate treated in many cases.cases.

FACTORS INFLUENCING ACUTE FACTORS INFLUENCING ACUTE POST OPERATIVE PAIN POST OPERATIVE PAIN MANAGEMENTMANAGEMENT

Age, patient weight, culture, gender•Patient preoperative pharmacological and physiological management•Anesthetic management before, during and after surgery• Psychological factors• Anxious patient Aggressive• Angry Control of medical care

FACTORS WHICH INCREASE FACTORS WHICH INCREASE PERIPHERAL PAIN RECEPTORS PERIPHERAL PAIN RECEPTORS RESPONSIVENESSRESPONSIVENESS

• Increased efferent sympathetic activity• Changes in the microcirculatory blood supply• Physical activity• Chemical environment , e.g. H+ ions • Endogenous algesic substances Prostaglandins Prostacyclin Serotonin Thromboxanes Bradykinin

CENTRAL SENSITIZATIONCENTRAL SENSITIZATION

• Due to action of neuropeptides• Excitatory amino acids (EAA) i.e. Aspartate and Glutamate upon neurokinin (NK)• N- methyl – D aspartate (NMDA)• Alpha amino- 3 hydroxy - 5 methyl- 4 isoxazole propionic acid• Substance P↔ release EAA cause increase responsiveness of dorsal horn WDR neuron to NMDA

ROUTES USED FOR ANALGESICS ROUTES USED FOR ANALGESICS DELIVERY FOR POST OPERATIVE PAIN DELIVERY FOR POST OPERATIVE PAIN

MANAGEMENTMANAGEMENT • Intramuscular or Subcutaneous• Intravenous - Bolus injection• Patient controlled analgesia• Rectal administration• Epidural analgesia• Intrathecal • Intraosseous• Intrapleural• Transmucosal• Intravesical

ALTERNATIVE METHODS OF ALTERNATIVE METHODS OF ANALGESIAANALGESIA

• Neural blockade Local blockade Peripheral nerve block Plexus analgesia• Selective nerve block Intercostal Iliohypogastric Ilioinguinal Femoral nerve Sciatic nerve block

ALTERNATIVE METHODS OF ALTERNATIVE METHODS OF ANALGESIAANALGESIA

• Transcutaneous nerve stimulation• Cryoanalgesia• Intrapleural• Inhalation Analgesics Nitrous oxide Penthrane Trichloroethylene • Psychological methods Self Hypnosis Imaging Audio control- music Biofeedback Distraction

INTRAMUSCULAR INJECTIONINTRAMUSCULAR INJECTION

• Inadequate pain relief• Unpredictable drug absorption• Analgesic onset delayed• Effectiveness is unpredictable• Individual variation in achieving MEAC (Minimal effective analgesic concentrate)• Effect of body temperature and perfusion has direct correlation, i.e. hypovolemia local temperature

PATIENT CONTROL ANALGESIA PATIENT CONTROL ANALGESIA (PCA)(PCA)

• Access to small, IV doses of opioid Access to small, IV doses of opioid analgesics on as required basis. analgesics on as required basis.

• Provide the ability to select the level Provide the ability to select the level of acceptable analgesia versus side of acceptable analgesia versus side effects.effects.

• Psychological benefit of patient Psychological benefit of patient feeling in control of their pain.feeling in control of their pain.

PATIENT CONTROL ANALGESIA PATIENT CONTROL ANALGESIA (PCA)(PCA)

• Make it work:Make it work: - Opioid - Opioid - Dose- Dose - Continuous or - Continuous or

demand or bothdemand or both - Bolus- Bolus - Lockout interval- Lockout interval - Total dose limit - Total dose limit

( 1 or 4 hour limit)( 1 or 4 hour limit)

PATIENT CONTROL ANALGESIA PATIENT CONTROL ANALGESIA (PCA)(PCA)

DRUGDRUG DOSEDOSE LOCKOUT LOCKOUT 1-4 HOUR 1-4 HOUR LIMITLIMIT

MorphineMorphine

(1mg/cc)(1mg/cc)1-2 mg 1-2 mg 10-15 10-15

minutesminutes6 mg 6 mg (20mg)(20mg)

HydromorHydromor-phone-phone

0.2-0.4 0.2-0.4 mgmg

10-15 10-15 minutesminutes

1.8mg 1.8mg (6 mg)(6 mg)

FentanylFentanyl 0.01-0.02 0.01-0.02 mgmg

10-15 10-15 minutesminutes

0.06mg 0.06mg (0.2 mg)(0.2 mg)

NEUROAXIAL BLOCKNEUROAXIAL BLOCK

Spinal AnalgesiaSpinal Analgesia - Continuous spinal - Continuous spinal - Single injection of opioid.- Single injection of opioid.

Epidural AnalgesiaEpidural Analgesia - Continuous epidural- Continuous epidural - Single injection- Single injection

SPINAL ANALGESIASPINAL ANALGESIA

• Is produced by Is produced by modulation of modulation of nociceptive nociceptive transmission at the transmission at the spinal dorsal hornspinal dorsal horn

• Single opioid Single opioid injection is the injection is the most popular route most popular route for analgesiafor analgesia

EPIDURALEPIDURAL

BENEFITS OF EPIDURAL BENEFITS OF EPIDURAL ANALGESIAANALGESIA

• Improved pulmonary function• Decreased perioperative cardiac complications• Earlier mobilization• Earlier return of bowel function• Shorter hospital stay• Low incidence of side effects• Opiates, local anesthetics & other drugs can be used• Prevent thromboembolism

NERVE BLOCK NERVE BLOCK

• Brachial Plexus Block ( Upper extremities)Brachial Plexus Block ( Upper extremities)

- Interscalene block- Interscalene block

- Supra and infra-clavicular block- Supra and infra-clavicular block

- Axillary's block- Axillary's block

• Lower extremities:Lower extremities:

- Lumbar plexus block.- Lumbar plexus block.

- Sciatic block, Popliteal block- Sciatic block, Popliteal block

- Femoral block- Femoral block

BRACHIAL PLEXUS BLOCKBRACHIAL PLEXUS BLOCK

LOWER EXTREMITIES BLOCKLOWER EXTREMITIES BLOCK

pseudoaddictionpseudoaddiction

• unlike true addiction, is a syndrome resulting unlike true addiction, is a syndrome resulting from chronic undertreatment of pain . from chronic undertreatment of pain .

• It is important to differentiate between It is important to differentiate between addiction and addiction and pseudoaddictionpseudoaddiction. In . In pseudoaddictionpseudoaddiction, the individual may exhibit , the individual may exhibit drug-seeking behavior, but such behavior is drug-seeking behavior, but such behavior is due to inadequately controlled pain . If that due to inadequately controlled pain . If that patient's pain were appropriately managed, patient's pain were appropriately managed, such behavior would dissipate such behavior would dissipate