Regional anesthesia Cowell

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January 13, 2020

Regional anesthesia Cowell

Regional anesthesia Cowell

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us414

January 13, 2020
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  1. Regional Anesthesia Jennifer L Cowell, MD Assistant Professor Rutgers -

    RWJMS
  2. None
  3. ABA Objectives • General Topics ◦ Premedication, Patient Position, Equipment,

    Monitoring and Sedation • Spinal, Epidural, Caudal, Combined Spinal/Epidural ◦ Indications, Contraindications; Sites of Actions; Factors Influencing Onset, Duration, and Termination of Action; Systemic Toxicity, Test Dose; Complications (Precipitating Factors, Prevention, Therapy); Implications of Anticoagulants and Platelet Inhibitors: American Society of Regional Anesthesia and Pain Medicine (ASRA) Guidelines; Physiologic Effects (GI, Pulmonary, Cardiac, Renal) • IV Regional ◦ Mechanism, Agents, Indications, Contraindications, Techniques, Complications • Transversus Abdominis Plane Blocks ◦ Indications, Risks, Side Effects
  4. History of Regional Anesthesia • Local infiltration - 1880s ◦

    Cocaine!! • Spinal anesthesia - 1884 • IV regional anesthesia “Bier Block” - 1908 • Paresthesia Technique ◦ Insert needle using the described landmarks until the patient feels and electric shock ◦ Inject • Nerve Stimulation - 1900s, 1950s, 1990s • Ultrasound guided - 2000s
  5. Regional Anesthesia • Head and Neck ◦ Superficial and deep

    cervical plexus ◦ Retrobulbar and peribulbar ◦ Sphenopalatine ganglion block (not really…) • Upper extremity ◦ Interscalene ◦ Supraclavicular ◦ Infraclavicular ◦ Axillary ◦ Distal rescue ◦ Digital • Lower extremity ◦ Sciatic ◦ Popliteal ◦ Femoral ◦ Saphenous (adductor canal) ◦ Saphenous (distal) ◦ Ankle • Truncal ◦ Paravertebral ◦ Transverse Abdominis Plane ◦ Other
  6. General notes on regional anesthesia... • Outcomes are not significantly

    different for most surgeries ◦ Exceptions are AV fistulas and phantom limb pain • Advantages ◦ Attenuation of surgical stress ◦ Increased tissue perfusion ◦ DVT prophylaxis ◦ Less PONV ◦ Decreased PACU time ◦ Decreased narcotic use ◦ Earlier feeding, earlier bowel function ◦ Earlier mobilization
  7. General notes on regional anesthesia… • Contraindications to doing a

    block ◦ Patient refusal ◦ Skin infection at the site of injection (sepsis?) ◦ Coagulopathy ◦ Surgery specific contraindications • Failed block? ◦ Probably not ◦ Does the patient have to pee? ◦ Is the intern leaning on their head? ◦ Low back pain on a flat table? ◦ Many hours of the same position? ◦ Generally disinhibited?
  8. IV Regional Anesthesia - Bier Block • In an exsanguinated

    limb, the vein is filled with local anesthetic ◦ Has direct contact with nerve endings near blood vessels and additional spread is via the vasa nervorum • Good for short, distal extremity surgery • CRPS • Chemical sympathectomy • Complications: ◦ Large bolus of local anesthetic ◦ Nerve damage ◦ Thrombophlebitis ◦ Compartment syndrome • Contraindications ◦ Crush injuries ◦ “Hard stick” ◦ Overlying skin infections ◦ Compound fractures ◦ Allergy to local anesthetic ◦ Severe or unknown vascular injuries to extremity ◦ AVF or AVM precluding tourniquet use ◦ Sickle cell disease ◦ Surgery planned for longer than one hour
  9. IV Regional Anesthesia - Bier Block • IV catheter placed

    ◦ At level or distal to the site of surgery • Double pneumatic Tourniquet placed as close to site of surgery as possible • Arm is elevated and wrapped in Esmarch • Proximal cuff is inflated to suprasystolic pressures • Inject 30-50 mL of 0.5% lidocaine into IV catheter • IV catheter is removed • Surgeon may proceed • When tourniquet pain begins, the distal cuff can be inflated and the proximal cuff is deflated
  10. IV Regional Anesthesia - Bier Block • A patient is

    scheduled for transposition of the ulnar nerve. A Bier block is successfully performed for surgical anesthesia. Which of the following most accurately corresponds to the maximum duration of the surgical anesthesia? A. Concentration of local anesthetic B. Volume of local anesthetic C. Duration of tourniquet inflation D. Duration of binding of sodium channels by local anesthetic • What happens when the surgery is over?
  11. Nerve Stimulation • Electrical current is applied to the nerve

    to cause it to fire in order to locate the nerve itself. • Can be used as primary means of localization or with ultrasound • Two primary uses for nerve stimulation: ◦ Can be used to locate the nerve by starting high and decreasing ▪ Starting at 1.5 mA, current is turned down until twitch disappears ▪ If there is a twitch <0.3 mA (approx), needle should be withdrawn ◦ Can be used to demonstrate safety by starting low and increasing ▪ After positioning using ultrasound, current is turned up to approx 0.3 mA ▪ If no twitch, likely not intraneural
  12. Cervical Plexus Blocks - Deep and Superficial • C2-C4 block

    • Two techniques for one block ◦ Deep or superficial to the SCM • Indications: Carotid endarterectomy, Thyroid surgery, Cutaneous surgeries, Proximal ⅓ of the clavicle • Complications: Arterial/intrathecal injection • Deep vs superficial describe the technique used ◦ Landmarks for deep: Mastoid process, Chassaignac Tubercle, posterior border of SCM ◦ Landmarks for superficial: SCM • Volume: 10-15 mL (total) Dee
  13. Retrobulbar and Peribulbar blocks Retrobulbar: Peribulbar:

  14. Retrobulbar and Peribulbar blocks - complications • Retrobulbar ◦ Retrobulbar

    hemorrhage ◦ Central retinal artery occlusion ◦ Globe perforation ◦ Central spread of local anesthetic ◦ Triggering of oculocardiac reflex ◦ Optic nerve atrophy ◦ Post-op Strabismus (temporary) • Peribulbar ◦ Ecchymosis ◦ Spread to contralateral eye ◦ Transient blindness
  15. Ultrasounds and needles • The ultrasound generator will produce sound

    waves at a frequencies 2-15 MHz. ◦ Higher frequencies are better for resolution, but do not penetrate tissue. ◦ Lower frequencies give a grainier picture, but can penetrate more tissue. • Nerve blocks are usually 6-13 MHz. ◦ We have 9, 12, and 13 MHz probes • Acoustic impedance is the property of a material to reflect or absorb sound waves. • Software reconstructs the absorption and reflection into a black and white image. • Short vs long bevel needle. ◦ Short bevel - higher degree, blunter ◦ Long bevel - lower degree, sharper
  16. Ultrasounds and needles

  17. Upper Extremity Blocks • All some variation of brachial plexus!

    ◦ Roots/Trunks ◦ Divisions ◦ Cords ◦ Terminal nerves • Same as the blocks ◦ Interscalene ◦ Supraclavicular ◦ Infraclavicular ◦ Axillary • Anything in between
  18. Interscalene • Most proximal of the upper extremity blocks at

    C5, C6, and usually C7 • Misses the middle and lower trunks • Ulnar sparing • Indications: Shoulder surgery, clavicle repair (distal ⅔) • Immediate onset due to lack of connective tissue • Side effects ◦ Horner’s syndrome ◦ Phrenic nerve palsy • Volume: 10 - 15 mL
  19. Interscalene

  20. Supraclavicular • Parallel to the clavicle, just lateral to the

    subclavian artery is a “bundle of grapes” • Covers almost all of the arm • Indications: any arm or hand surgery, some shoulder surgery • Complications: pneumothorax, IV injection, phrenic nerve involvement • “Patchy” • Volume: 20-30 mL
  21. Supraclavicular

  22. Infraclavicular • Below the clavicle, rotated 90 degrees, abutting the

    acromion at the level of the cords • Covers relatively the same distribution as supraclavicular • All cords may not be visualized • Indications: Arm, elbow, forearm, hand • Complications: PNEUMOTHORAX • Volume: 20-30 mL
  23. Infraclavicular

  24. Axillary • Either in the axilla or the medial upper

    arm • The further down, the more likely to miss the musculocutaneous • Covers all of the arm below the injection • Indications: Forearm, hand, elbow • Complications: Intravascular injection, missing the musculocutaneous • Volume: 20-30 mL
  25. Axillary

  26. Distal Upper Extremity • Radial, medial, and ulnar rescue blocks

  27. Distal Upper Extremity • Digital blocks

  28. Lower Extremity Blocks • Post or pre-operative pain control ◦

    Orthopedic population • Surgical anesthesia ◦ Orthopedics ◦ Vascular ◦ Podiatry • Increased hemodynamic stability compared to neuraxial • Unilateral • Lumbosacral plexus ◦ Sciatic and femoral nerves ◦ All joints innervated by both • May alter patient’s dispo plan ◦ Motor weakness ◦ Rehab vs home ◦ Overnight admission
  29. Lower Extremity Blocks • More complex with more branch points

    • More anatomical variation and opportunity to miss branches
  30. Sciatic • Transgluteal vs Subgluteal vs anterior ◦ Three approaches,

    same results ◦ Nerve stimulator vs ultrasound • Very dependent on position and habitus • Indications: Foot, ankle, BKA, AKA, Tib/fib, +/- elective knee surgery • Complications: Minimal, non-vascular ◦ Hematoma formation anteriorly • Volume: 20 mL *
  31. Sciatic Greater Trochanter & PSIS Greater Troch & Ischial Tuberosity

  32. Sciatic

  33. Popliteal • “Low sciatic” ◦ Same distribution at the level

    of injection • Patient positioning ◦ Provider dependent ◦ Patient cooperation • Indications: Foot, ankle, BKA, achilles • Complications: IV injection, easy to miss one of the two branches • Volume: 15-20 mL
  34. Popliteal Disregard!

  35. Popliteal

  36. Femoral • Sensory and motor block ◦ Cannot walk after

    ◦ Includes part of the hip • To be done above branchpoint of profunda • Lateral femoral cutaneous may be missed • Indications: Femur, patella, quadriceps tendon, and knee surgery; analgesia for hip fracture • Complications: IV injection ◦ Quad weakness? • Volume: 15 mL
  37. Femoral

  38. Saphenous (Adductor Canal) • “Low femoral” ◦ Femoral nerve after

    branching of anterior femoral cutaneous ◦ Minimal to no motor at this point • Adductor canal ◦ Potential space between the sartorius, adductor longus and vastus medialis • Very variable coverage • Indications: Saphenous vein stripping, supplemental to surgery at or below the knee • Complications: IV injection • Volume: 10 mL
  39. Saphenous (Adductor Canal)

  40. Saphenous (distal)

  41. Ankle

  42. Ankle

  43. Paravertebral • Tend to do thoracic • Unilateral pain control

    without side effects of neuraxial • Erector Spinae is a variation • Probe held vertical • May need curvilinear • Indications: Thoracotomy, Sternotomy, Breast, Rib fractures, Chest tubes, Herpetic Neuralgia, CPRS ◦ Also: most abdominal surgery • Complications: Pneumothorax, LAST • Volume: 10 mL per level
  44. Paravertebral

  45. Paravertebral

  46. Paravertebral

  47. Transverse Abdominis Plane Block • Field block providing unilateral analgesia

    from approximately T6-L1 * ◦ The subcostal nerve (T12) ◦ The iliohypogastric and ilioinguinal nerves (L1) ◦ *The intercostal nerves (T6/7-T10/11) are not typically involved, but the TAP can be modified to include these nerves • Analgesia provided to the parietal peritoneum, muscle, and skin ◦ Does not provide analgesia to the viscera ◦ Variable efficacy • Indications ◦ Abdominal surgery, primarily below the umbilicus ◦ More effective in surgeries with a lesser degree of organ manipulation • Risks ◦ Infection, bleeding, bowel perforation
  48. Transverse Abdominis Plane Block • Surface landmarks ◦ Iliac crest

    ◦ 11th or 12 rib • Ultrasound anatomy ◦ Ext. oblique, int. oblique, transverse abdominis
  49. Transverse Abdominis Plane Block

  50. Local Anesthetic Systemic Toxicity (LAST) • Due to inadvertent IV

    injection of local anesthetics or from absorption of deposited local anesthetic • Local anesthetics bind to and inhibit sodium and calcium channels ◦ Local anesthetics can accumulate in cardiac tissue ◦ Lethal due to cardiac dysrhythmias • Symptoms: ◦ Altered mental status, perioral numbness, tinnitus, agitation, dysarthria, and confusion. ◦ Seizures, coma. ◦ Hypertension and tachycardia, followed by hypotension and bradycardia followed by ventricular arrhythmias and asystole. • Onset: usually within the first minute after injecting.
  51. Local Anesthetic Toxicity (LAST)

  52. Local Anesthetic Systemic Toxicity (LAST) • Variables that increase toxicity

    ◦ Type of local anesthetic - lipophilic have increased risk of toxicity ◦ Location of injection - intercostals, epidural, brachial plexus, lower extremity ◦ Larger doses ◦ Patient risk factors - renal or hepatic dysfunction, underlying disease process, protein binding ◦ Extremes of age - possibly from decreased muscle mass ▪ Mild symptoms in young children will be missed • Occurrence ◦ Peripheral blocks - 1.6-2/1000 in 1990, now 0.08-0.98/1000 ◦ Epidural - 9.75/1000 in 1980s, 0.1-1.2/1000 in 1990s, now 0.1/1000
  53. Local Anesthetic Systemic Toxicity (LAST)

  54. Local Anesthetic Toxicity (LAST) • ABCs • Seizures • ACLS*

    • Interlipid • ICU
  55. Lipid Resuscitation Therapy • Propofol is not a suitable substitute

    • Adverse effects of lipid emulsion ◦ Acute kidney injury ◦ Cardiac arrest ◦ Ventilation–perfusion mismatch ◦ Acute lung injury ◦ Venous thromboembolism ◦ Hypersensitivity ◦ Fat embolism ◦ Fat overload syndrome ◦ Pancreatitis ◦ Extracorporeal circulation machine circuit obstruction ◦ Allergic reaction ◦ Increased susceptibility to infection
  56. Sources www.nysora.com www.usra.ca www.neuraxiom.com Hadzic’s Textbook of Regional Anesthesia and

    Acute Pain Management Second Edition Sekimoto K, Tobe M, Saito S. Local anesthetic toxicity: acute and chronic management. Acute Med Surg. 2017;4(2):152–160. Published 2017 Mar 6. doi:10.1002/ams2.265