1. REGIONAL ANALGESIA AND ANAESTHESIA DEPT OF ANAESTHESIA AND ICU COLLEGE OF MEDICINE KING SAUD UNIVERSITY

2. Cousins & Bridenbaugh, 3rd Edition HISTORY 1885 Corning - First attempt with epidural cocaine 1891 Quincke - Describes the lumbar puncture technique 1921 Pagis - First lumbar anaesthesia for surgery 1947 Lidocaine commercially available 1949 Curbelo - First continuous lumbar analgesia with Touhy needle 1963 Bupivacaine commercially available 1979 Cousins - Epidural opioids provide analgesia 1983 Yaksh - Different spinal receptor systems mediating pain 1985 University of Keil, Germany, Anaesthesiology managed acute post-operative pain service

3. Regional/Neuraxial Anaesthesia A reversible loss of sensation in a specific area of the body. Bier block Axillary, Interscalene Spinal, Epidural Caudal Ankle block, metatarsal block Paracervical

4. Regional anaesthetic techniques categorized as follows Epidural and spinal anaesthesia Peripheral nerve blockades IV regional anaesthesia

5. SPINAL ANAESTHESIA INTRATHECAL=administration of medication into subarachnoid space

6. EPIDURAL ANAESTHESIA EPIDURAL=administration of medication into epidural space

7. OVERVIEW OF THE SPINAL ANATOMY

8. SPINAL CORD Located and protected within vertebral column Extends from the foramen magnum to lower border 1 st L1 (adult) S2 (kids) SC taper to a fibrous band - conus medullaris Nerve root continue beyond the conus- cauda equina Surrounded by the meninges (dura,arachnoid & pia mater.)

10. anatomy The vertebrae are 33 number, divided by structural into five region: cervical 7, thoracic 12, lumbar 5, sacral 5, coccygeal 3.

11. anatomy

12. EPIDURAL SPACE Potential space Between the dura mater,ligamentum flavum Made up of vasculature, nerves, fat and lymphatics. Extends from foramen magnum to the sacrococcygeal ligament

13. Regional anaesthesia Spinal lower extremities, lower abdomen, pelvis Epidural cervical thoracic lumbar caudal

14. INDICATIONS  The objective of epidural analgesia is to relieve pain. Major surgery Trauma (# ribs) Palliative care (intractable pain) Labour and Delivery abd surgery Pelvic surgery lower lime surgery

15. CONTRAINDICATIONS ABSOLUTE CONTRAINDICATIONS Patient refusal Known allergy to opioid or local anaesthetic Infection/abscess near the proposed injection site Hematological disorder Increase ICP

16. CONTRAINDICATIONS RELATIVE CONTRAINDICATIONS Sepsis Patient on anticoagulant Hypotension Hypovolemia Spinal deformity Neurological disorder.

17. Patient assume a sitting or side-lying position with the back arched toward the physician.Help to spread the vertebrae apart

18. Height of sensory block Lumbar-T4 Thoracic-T2

19. INSERTION OF EPIDURAL CATHETER Positioning of patient The site is dependent upon the area of pain Fixing the catheter Incision Level Thoracic T4-T6 Upper abdo T6-T8 Lower abdo T8-T10 Pelvic T8-T10 Lower extremity L1-L4

27. EPIDURAL CATHETERS Ideal Placement (adult) 10-12 cm at the skin Epidural catheters have markings that indicate their length. = there is a mark at the tip of the catheter = the 1st single mark at the catheter is 5cm = double mark at the catheter is 10 cm = triple mark at the catheter is 15 cm = four mark indicates 20cm A change in depth of the catheter indicates migration either into or out of the epidural space.

28. CATHETER MIGRATION Catheter migration into a blood vessel in the epidural space or subarachnoid space  Rapid onset LOC  Decrease loss of sensory or motor loss (marcain)  Toxicity  Profound hypotension

29. CATHETER MIGRATION Out of the epidural space ineffective analgesia no analgesia drugs deposited into soft tissue.

30. Advantages/Disadvantages of Regional and Local Anaesthesia.

31. advantages patient remains conscious maintain his own airway aspiration of gastric contents are unlikely smooth recovery requiring less skilled nursing care as compared to general anaesthesia

32. advantages postoperative analgesia reduction in surgical stress earlier discharge for outpatients less expensive

33. Disadvantages: patient may prefer to be asleep practice and skill is required for the best results. some blocks require up to 30 minutes or more to be fully effective analgesia may not always be totally effective- patient may require additional analgesics, IV sedation, or a light general anaesthetic

34. Disadvantages: toxicity may occur if the local anaesthetic is given intravenously or if an overdose is injected some operations are unsuitable for local anaesthetics, e.g., thoracotomies

35. DRUGS One of the most important factors influencing drug absorption and bioavailability is the drug SOLUBILITY The more lipid soluble rapid onset & shorter duration

36. MEDICATION COMMONLY USED OPIOIDS-Fentanyl +Morphine (affect the pain transmission at the opioid receptors) L.A.-Bupivacaine(marcaine) (inhibits the pain impulse transmission in the nerves with which it comes in contact)

37. LOCAL ANAESTHETICS AMIDES MAX / DOSE BUPIVACAINE 2 MG/KG LIDOCAINE 7 MG/KG ROPIVACAINE 4 MG/KG MEPIVACAINE 7 MG/KG PRILOCAINE 6MG/KG

38. LOCAL ANAESTHETICS ESTERS MAX /DOSE CHLOROPROCAINE 20 MG/KG COCAINE 3 MG/KG NOVOCAINE 12 MG/KG TETRACAINE 3 MG/KG

39. Metabolism Amides –Primarily hepatic –Plasma conc. may accumulate with repeated doses –Toxicity is dose related, and may be delayed by minutes or even hours from time of dose. Esters –Ester hydrolysis in the plasma by pseudocholinesterase –Almost no potential for accumulation –Toxicity is either from direct IV injection tetracaine, cocaine or persistent effects of exposure benzocaine, cocaine

40. Clinical Pharmacology Patients with genetically abnormal pseudocholinesterase are at increased risk for toxic side effects, as metabolism is slower.

41. Clinical Pharmacology CSF lacks esterase enzymes, so the termination of action of intrathecally injected ester local anesthetics, eg, tetracaine, depends on their absorption into the bloodstream.

42. METHODS OF ADMINISTRATION  BOLUS (FENTANYL, DURAMORPH)  CONTINUOUS INFUSION(MARCAINE+FENTANYL)  All drugs administered epidural should be preservative free.  All epidural opioids should be diluted with normal saline prior to intermittent bolus administration.

43. Mechanism of Action  Bupivacaine (marcaine) - local anaesthetic works as an analgesic (subanaesthetic dose) - inhibiting impulse transmission in the nerve fibers - sensory nerves are blocked first before the motor fibers - sensory fibers carrying the pain is blocked before those carrying heat, cold, touch and pressure.

44. Progression of local anaesthesia Loss of: 1. Pain 2. Cold 3. Warmth 4. Touch 5. Deep pressure 6. Motor function

45. EPIDURAL LOCAL ANAESTHETIC(MARCAINE ) Onset 10-15 minutes Duration- 4 hrs+ after a bolus or after infusion is stopped Marcaine(0.0625%-0.125%-0.25%) Extend of spread influenced by volume and position of patient

46. OPIOIDS Mechanism of action-distribution  Vascular uptake by blood vessels in the epidural space  Diffusion through dura into CSF to spinal cord to the site of action.  Uptake by the fat in the epidural space.

47. Morphine (Duramorph/Astramorph) Hydrophilic(water soluble) Slow to diffuse across the dura on to the spinal cord Can cause late respiratory depression Monitor respiratory status for 12 hrs after the last dose of duramorph Duration 6 hrs+ Broad spread

48. Fentanyl (preservativefree) Lipophilic(fat soluble) Crossess the dura rapidly Rapid onset of action(segmental) Decreased risk of late respiratory depression Onset 5-20 mins Duration 2-4hrs Excellent for breakthrough pain

49. Adverse Effects -Opioids  Sedation and resp.depression- IV narcan (Naloxone)  Nausea / Vomiting- Opioids stimulate the chemoreceptor trigger zone primperan  Pruritus- diphenhydramine or narcan (low dose)  Urinary retention- low dose narcan and /or catheterization  Slowing of GI motility  Hypotension

50. Adverse Effects L.A Hypotension- -assess intravascular volume status -no trendelenberg positioning Teach patient to move slowly from a lying position to sitting to standing position. Treatment fluids

51. Cont. Temporary lower- extremity motor or sensory deficits. Tx: lower the rate or concentration. Urine retention Tx: catheter Local anaesthetic toxicity (neurotoxicity) Tx: stop infusion. Resp. insufficiency Tx:stop infusion - ABC (100% o2 call for help) - Assess spread and height of block - Alt.analgesia

52. OTHER COMPLICATIONS Headache (dural puncture) Tx: symptomatic treatment Autologous blood patch Infection nausea and vomiting. Intravenous placement of catheter Subdural placement of catheter Haematoma

53. Signs and Symptoms of Local/Regional Anaesthesia Toxicity CNS Cardiovascular

54. S/S CNS Toxicity Unconsciousness Generalized convulsions Coma Apnea Numbness of the mouth and tongue, metal taste in the mouth

55. S/S CNS Toxicity Light-headedness Tinnitus Visual disturbance Muscle twitching

56. Cardiovascular toxicity slowing of the conduction in the myocardium myocardial depression peripheral vasodilatation

57. Prevention and Treatment of Local/Regional Anaesthesia Toxicity

58. prevention Always use the recommended dose Aspirate through the needle or catheter before injecting the local anesthetic. Intravascular injection can have catastrophic results. If a large quantity of a drug is required, use a drug of low toxicity and divide the dose into small increments, increasing the total injection time always inject slowly (<10 ml/min) and communicate with the pt

59. treatment All necessary equipment to perform resuscitation, induction, and intubation should be on hand before injection of local/regional anesthetics Manage airway and give oxygen Stop convulsions if they continue for more than 15 to 20 seconds – Thiopental 100 mg to 150 mg IV – or Diazepam 5 mg to 20 mg IV

60. OTHER BLOCKS

61. Caudal Anaesthesia

63. Anatomy of Lumbar and Sacral Plexus

69. Classes: The rule of “i” Am i des L i docaine Bup i vacaine Levobup i vacaine Rop i vacaine Mep i vacaine Et i docaine Pr i locaine –Esters Procaine Chloroprocaine Tetracaine Benzocaine Cocaine