ACUTE PAIN Ahmed Ghaleb, MD Ahmed Ghaleb, MD UAMS UAMS Director Director Pain Medicine Pain Medicine PAIN An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Pain 6:249, 1979 IASP What Is Pain ? Pain is a Subjective Experience Pain is a Subjective Experience In evaluating Pain, clinicians must remind themselves that their eyes do not measure pain. In evaluating Pain, clinicians must remind themselves that their eyes do not measure pain. It is the nature and disposition of nearly all professionals to underestimate the magnitude of Central Pain. It is the nature and disposition of nearly all professionals to underestimate the magnitude of Central Pain. Classification of pain Types Of Pain AcuteChronic Malignant Non- Malignant CLASSIFICATION Types of Pain Somatic Pain Visceral Pain Neuropathic Pain CLASSIFICATION two major types of pain Nociceptive (Tissue) Pain Neuropathic (Nerve) Pain somaticvisceral ACUTE PAIN Is Defined as a sharp or having a short and relatively severe course. Is Defined as a sharp or having a short and relatively severe course. All pain syndromes began as an ACUTE PAIN, becoming chronic only after persisting beyond the course of expected healing of the causative stimulus All pain syndromes began as an ACUTE PAIN, becoming chronic only after persisting beyond the course of expected healing of the causative stimulus COMMON ACUTE PAIN SYNDROMES POST OPERATIVE PAIN POST OPERATIVE PAIN Traumatic injury-related pain Traumatic injury-related pain Burn pain Burn pain Acute Herpes Zoster Acute Herpes Zoster Sickle cell pain Sickle cell pain Cancer-related pain Cancer-related pain Headache Headache COMMON ACUTE PAIN SYNDROMES Chest Pain Chest Pain - Angina - Angina - Esophagitis - Esophagitis - Pleuritic pain - Pleuritic pain Abdominal pain Abdominal pain - Acute Pancreatitis - Acute Pancreatitis - Acute abdomen - Acute abdomen - Renal colic - Renal colic Musculoskeletal pain Musculoskeletal pain Neurogenic pain Neurogenic pain - Herniated disk - Herniated disk - Nerve compression - Nerve compression Ischemic pain Ischemic pain - PVD - PVD POST 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 PAIN Despite its common occurrence, predictability, and its known cause, the management of Post operative pain remains inadequate treated in many cases. Despite its common occurrence, predictability, and its known cause, the management of Post operative pain remains inadequate treated in many cases. FACTORS INFLUENCING ACUTE POST OPERATIVE PAIN MANAGEMENT Age, patient weight, culture, gender Patient preoperative pharmacological and physiological management Anesthetic management before, during and after surgery Psychological factors Anxious patientAggressive AngryControl of medical care FACTORS WHICH INCREASE PERIPHERAL PAIN RECEPTORS RESPONSIVENESS 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 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 DELIVERY FOR POST OPERATIVE PAIN MANAGEMENT Intramuscular or Subcutaneous Intravenous - Bolus injection Patient controlled analgesia Rectal administration Epidural analgesia Intrathecal Intraosseous Intrapleural Transmucosal Intravesical ALTERNATIVE METHODS OF ANALGESIA Neural blockade Local blockade Peripheral nerve block Plexus analgesia Selective nerve block Intercostal Iliohypogastric Ilioinguinal Femoral nerve Sciatic nerve block ALTERNATIVE METHODS OF ANALGESIA Transcutaneous nerve stimulation Cryoanalgesia Intrapleural Inhalation Analgesics Nitrous oxide Penthrane Trichloroethylene Psychological methods Self HypnosisImaging Audio control- musicBiofeedback Distraction INTRAMUSCULAR 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 (PCA) Access to small, IV doses of opioid analgesics on as required basis. Access to small, IV doses of opioid analgesics on as required basis. Provide the ability to select the level of acceptable analgesia versus side effects. Provide the ability to select the level of acceptable analgesia versus side effects. Psychological benefit of patient feeling in control of their pain. Psychological benefit of patient feeling in control of their pain. PATIENT CONTROL ANALGESIA (PCA) Make it work: Make it work: - Opioid - Opioid - Dose - Dose - Continuous or demand or both - Continuous or demand or both - Bolus - Bolus - Lockout interval - Lockout interval - Total dose limit ( 1 or 4 hour limit) - Total dose limit ( 1 or 4 hour limit) PATIENT CONTROL ANALGESIA (PCA) DRUGDOSELOCKOUT 1-4 HOUR LIMIT Morphine(1mg/cc) 1-2 mg minutes 6 mg (20mg) Hydromor- phone mg minutes 1.8mg (6 mg) Fentanyl mg minutes 0.06mg (0.2 mg) NEUROAXIAL BLOCK Spinal Analgesia - Continuous spinal - Continuous spinal - Single injection of opioid. - Single injection of opioid. Epidural Analgesia - Continuous epidural - Continuous epidural - Single injection - Single injection SPINAL ANALGESIA Is produced by modulation of nociceptive transmission at the spinal dorsal horn Is produced by modulation of nociceptive transmission at the spinal dorsal horn Single opioid injection is the most popular route for analgesia Single opioid injection is the most popular route for analgesia EPIDURAL BENEFITS OF EPIDURAL ANALGESIA 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 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 BLOCK LOWER EXTREMITIES BLOCK pseudoaddiction unlike true addiction, is a syndrome resulting from chronic undertreatment of pain. unlike true addiction, is a syndrome resulting from chronic undertreatment of pain. It is important to differentiate between addiction and pseudoaddiction. In pseudoaddiction, the individual may exhibit drug-seeking behavior, but such behavior is due to inadequately controlled pain. If that patient's pain were appropriately managed, such behavior would dissipate It is important to differentiate between addiction and pseudoaddiction. In pseudoaddiction, the individual may exhibit drug-seeking behavior, but such behavior is due to inadequately controlled pain. If that patient's pain were appropriately managed, such behavior would dissipate