What’s the definition of pain?

Pain is a Sensory and Emotional experience associated with tissue damage or described in terms of such damage (I.A.S.P.)

The Pain Pathways and Mechanisms

Pain Pathways Frenchman Rene Descartes, De humine textbook

Aß FibersC Fibers

Axon Reflex Np : Neuro-peptides, BV : Blood Vessels

Physiology of the dorsal horn of the spinal cord

Hyperalgesia And pain Threshold in humans

Pain Management in the late 18 th century Barker M.D.

Different Pain management Modalities

Pre-emptive Analgesia Pre-emptive analgesia can be achieved by: local anesthetic infiltration of the skin Effective dose of systemic opioids Systemic nonsteroidal anti-inflammatory drugs (NSAIDs) Neuroaxial opioids or local anesthetic Peripheral nerve blocks

Patient Controlled Analgesia PCA 1. Increase patient satisfaction 2. Decrease side effects and complications 3. Decrease sedation 4. Decrease total amount of daily opioids 5. Avoid Basal rate in the Elderly 6. PCA Flowsheets

Regional analgesia

Isolated Extremity Injury

Brachial plexus Anatomy

Infraclavicular Approach

Lower Extremity Injury

Paravertebral Lumbar Somatic Nerve Block

Femoral Nerve Block

Sciatic Nerve Block

Neuroaxial Blocks

Opioid Spread after Epidural injection

CSF Circulation Each of the four ventricles of the brain has a choroid plexus and CSF normally circulates between them: 1. The foramen of Monro is an opening from the lateral ventricle into the third ventricle 2. The aqueduct of Sylvius is the pathway of CSF flow between the third and fourth ventricles 3. The foramina (plural of "foramen") of Magendie and Luschka are openings from the fourth ventricle into the subarachnoid space around the base of the brain and upper spinal cord 4. The daily production is around ml/ day 5. The reabsorption occurs over the surface of the brain and into the venous dural sinus drainage channels

Spread of Opioids in CSF

Pharmacokinatics of Epidural injection of Hydrophilic Drug

Pharmacokinatics of Epidural Lipophilic Opioid

Effects of Increased Pressure on Venous drainage “Pregnancy, Morbid obesity”

Complications of Epidural Morphine

Morphine concentration in Cervical CSF after lumbar Epidural injection

Epidural Homodynamic Facts Local anesthetics may cause vasodilatation and hypotension (Sympathectomy) Narcotics dose not cause Hypotension Not every post-op hypotension is related to Epidural analgesia. Epidural analgesia promotes early mobilization Nausea & vomiting response to small doses of Narcan or Zofran. Avoid Phenergan

Tunneling Technique

Adjuvant Therapy

Nonsteroidals

Conformational structure of COX-1 and COX-2 isozymes COX-1 (A)COX-2 (B)

NSAID's Blocks the production of Prostaglandin Very effective in pain control, Alone or in Combination with Narcotics Ketorolac is My drug of choice as an adjunct therapy in acute pain Use p.o. forms “Cox2 inhibitors” when possible in combination with Epidural, IV,or oral narcotics

Practical guide for NSAID’s Usage Pre-op administration significantly decreases post-op pain and cramps Toradol 30mg, IV or Celebrex 400mg, P.O. pre-op For sever acute pain Celebrex 400mg, P.O. bid X one week the 200 P.O., bid. Bextra 20mg, bid X one week the 20mg, QD PPI are the drugs of choice to treat gastric complications. H2 blockers only mask the disease Please check the patient renal function routinely prior to administration COX2 inhibitors doesn’t affect the platelet function

Practical guide for NSAID’s Usage (Continuum) All specific or non-specific NSAID’s may cause: water retention and edema Hypertension Renal dysfunction May delay bony fusion in chronic usage ?

Clonidine Alpha2 agonist with outstanding properties when administered intrathecally: Pain control properties by itself Decrease the requirement of narcotics Decrease tolerance Great for neuropathic pain control Adding 1mcg/kg for children caudal block will extend pain relief up to 24h

Clonidine Oral or transdermal Clonidine:  Enhance the effect of narcotics  Decreases the daily narcotic requirement  Excellent Adjuvant therapy for narcotic dependent patients  Effective for neuropathic pain

Coanalgesic Agents Anxiolytic drugs Anticonvulsants Antidepressants Ketamine

NMDA receptors antagonist  Neuropathic pain Potent analgesic effect Small doses in combination of opioids substantially improve pain control Bolus dose of 100 mcg/kg followed by a continuous drip of 1-3 mcg/kg/min is ideal for chronic opioid users postoperatively

Mechanisms of Anti-Epileptic Drugs in Pain

Usage of Anti-Epileptic Drugs in Acute Pain Every surgical incisional pain has Neuropathic component Studies showed giving 1200 mg of Gabapentin 1 h prior to surgery decreases the opioids requirement post-op and results in better pain control without increased sedation Combining Gabapentin with opioids is ideal for re-do back surgery cases with chronic opioids usage These class of drugs are also mode stabilizers

Non Chemical Techniques Psychological treatments: Relaxation, hypnosis Cognitive therapy etc.. TENS Units Physiotherapy

Pain Management Algorithm

Trauma pain management Algorithm

Trauma Pain Management Algorithm

Trauma pain management Algorithm

Pharmacokinatic model of Spinal injection of Hydrophilic Opioid

Referred Pain

Bardram et al: [8] eight elderly high- risk patients, stress-free (i.e., laparoscopic) colonic resection8 Combination of laparoscopic surgery, epidural analgesia, early oral nutrition, and early mobilization Pain relief → early mobilization in elderly patients → accelerated recovery; hospital stay: 2 d Moiniche et al: [111] uncontrolled pilot investigation, 17 patients, open colonic resection111 Combined epidural–general anesthesia, epidural analgesia, no nasogastric tube, oral feeding in 24 h, early mobilization VAS 0 at rest, minimal with mobilization; normal defecation in 12 patients within 48 h; median hospital stay: 5 d Liu et al: [95] 54 patients, four groups, partial colectomy95 Multimodal recovery programEpidural analgesia: superior; earlier recovery of gastrointestinal function but more orthostatic hypotension; epidural bupivacaine combined with morphine: best balance of analgesia and side effects Collier: [29] 186 patients, care pathway for elective carotid endarterectomy29 Preoperative education, same-day admission, regional anesthesia, selective use of ICU 10% ICU admission; 157 patients discharged on first postoperative day; average stay: 1.27 d; cost- savings $3000 per patient ReferenceInterventionFindings PUBLICATIONS ON ACCELERATED OR MULTIMODAL POSTOPERATIVE REHABILITATION PROGRAMS

ReferencesInterventionFindings Moiniche et al: [112] 13 patients, hip replacement pilot investigation112 Epidural analgesia (bupivacaine-morphine), ibuprofen, intensive mobilization regime 11 patients ready for discharge on day 6, 2 patients discharged on day 9 (usual hospitalization was 13 d) Pedersen et al: [126] prospective study, breast surgery, questionnaires from 373 patients126 Standardized clinical protocols, support from senior management, expanded educational resources for patients Length of stay: 39% decrease; patient volume: up 22%; low incidence of surgical complications, high patient acceptance Weingarten et al: [173] retrospective study, 230 patients, total hip replacement173 Practice guideline: 5-d postoperative stay in low-risk patients Practice guideline can reduce hospital length of stay from 8.4 to 5.9 d Bardram et al: [8] eight elderly high-risk patients, stress-free (i.e., laparoscopic) colonic resection8 Combination of laparoscopic surgery, epidural analgesia, early oral nutrition, and early mobilization Pain relief → early mobilization in elderly patients → accelerated recovery; hospital stay: 2 d Moiniche et al: [111] uncontrolled pilot investigation, 17 patients, open colonic resection111 Combined epidural–general anesthesia, epidural analgesia, no nasogastric tube, oral feeding in 24 h, early mobilization VAS 0 at rest, minimal with mobilization; normal defecation in 12 patients within 48 h; median hospital stay: 5 d Liu et al: [95] 54 patients, four groups, partial colectomy95 Multimodal recovery programEpidural analgesia: superior; earlier recovery of gastrointestinal function but more orthostatic hypotension; epidural bupivacaine combined with morphine: best balance of analgesia and side effects PUBLICATIONS ON ACCELERATED OR MULTIMODAL POSTOPERATIVE REHABILITATION PROGRAMS