Regional Anesthesia in the Outpatient Setting Ravindra V. Prasad, MD Department of Anesthesiology UNC School of Medicine Review 3/30 – Ghia, Axillary Block 4/1 – Wilkes, Axillary Block 4/8 – Levin, SAB 4/14 – Klein, Lower Extremity Blocks 4/15 – Prasad, ??? Overview Regional Anesthesia: general comments Upper Extremity Blocks Paravertebral Blocks Neuraxial Blocks Lower Extremity Blocks Regional: advantages Avoid GA complications Less anesthetic required faster wake-up? quicker recovery? Faster ambulation, faster discharge N/V less common post-op pain minimized Regional: problems Time Equipment Personnel GA still backup plan Skill regional techniques management of awake or LIGHTLY sedated patients Block Placement Monitoring Emergency equipment and drugs should be readily available Block equipment readied before starting POSITIONING SEDATION (preoperative, intraoperative) Patient selection Upper Extremity Blocks Brachial Plexus Blocks Peripheral Nerve Blocks elbow wrist Bier Blocks Brachial Plexus Dermatome Distribution Brachial Plexus Blocks Indications: surgery of upper extremity Approaches Axillary Infraclavicular Supraclavicular Interscalene (ISB) ISB: technique Equipment Drugs Technique ISB: complications Pneumothorax Phrenic nerve paralysis Horner’s syndrome C6 root neuropathy (intraneural injection; root pinned against C6 tubercle) Bier Block Intravenous Regional Anesthesia (IVRA) Described by Bier in 1908 Intravenous injection of local anesthetics in an extremity isolated from the systemic circulation A simple technique which is easy to perform Widespread use in surgical cases of short duration Bier Block: indications Surgery of the extremities, especially hand and forearm Surgery of short duration (less than 1 hour) Soft tissue procedures (block is less dense than nerve blocks; may have pain if bony involvement) Bier Block: contraindications Disease processes or states prolonged tourniquet times contraindicated (Sickle Cell Disease or Trait) more susceptible to toxic effects of agents used (Heart Block) Hypersensitivity/allergy to agents used Patients with a painful extremity Certain patient body habitus Bier Block: technique Equipment tourniquet(s) with pressure gauge rubber bandage (Martin, Esmarch) Drugs Local Anesthetics: Lidocaine 0.5% or Prilocaine 0.5% Opioids Ketorolac Bier Block: mechanisms of action Direct action at nerve endings Diffusion into nerve trunks Nerve trunks consist of fascicles covered with epineurium Blood vessels contained within the epineurium Capillaries within endoneurium extend intraneurally as vasa nervorum Local anesthetic diffusion occurs from nerve core to the periphery Bier Block: complications Local anesthetic systemic toxicity Premature tourniquet release, malfunctioning tourniquet Leakage through intraosseous veins or ordinary veins Direct tissue local anesthetic toxicity (neuronal, muscular, vascular injury ) Ischemic injury (prolonged tourniquet time, excessive tourniquet pressure) Bier Block: pearls Tourniquet pain Tourniquet deflation Prolonged surgery Lower extremity surgery Paravertebral Blocks (PVB) Paravertebral space Spinal root emerges from intervertebral foramen, divides into dorsal and ventral rami and sympathetics Unilateral motor, sensory, and sympathetic block PVB Indications Thoracic thoracotomy mastectomy nephrectomy cholecystectomy rib fractures post-thoracotomy pain post-mastectomy pain Lumbar: inguinal hernia PVB: technique Equipment Drugs Technique 2.5-3 cm lateral to spinous process, caudal and 1-2 cm deep to transverse process 4-5 ml local anesthetic Variations PVB: risks Complication Adults Children Greengrass (319) (48) (156) Pleural puncture 3 1 Pneumothorax, symptomatic 1 0 1 Bloodstained aspirate 12 2 Hypotension (requiring fluid 16 0 or ephedrine) Epidural involvement 2 Epinephrine absorption 1 Reported failure rate 10-15% PVB: breast surgery Block T1-T6: go lateral to C7-T5. Greengrass: Retrospective review, 156 blocks in 145 patients vs. 100 GA over 2-year period 85% block alone 91% block + local 2.6% complication (4/156) PVB vs. GA: breast surgery Complication PVB % GA % Require N/V med during 20 39 hospital stay Narcotic analgesia required 25 98 during hospital stay Discharged POD #0 96 76 PVB: inguinal hernia repair Block T10-L2: go lateral to T10-L2 Onset of surgical anesthesia 15-30 min PVB: IH Repair, outcome 22 patients. 3 converted to GA 1/3 had good block at emergence failure rate 2-3/22 = 9-14% Of 20 “successful” blocks Onset of discomfort 14 11 hrs, first narcotic 22 18 hrs 13 (65%) no incisional discomfort for at least 10 hrs after block 3 (15%) epidural spread Klein, SM Greengrass RA Weltz C Warner DS, 1998 PVB: inguinal hernia, satisfaction Satisfaction with anesthetic 24 hr 48 hr Not satisfied 0 0 Satisfied 3 2 Very satisfied 17 18 SAB Duration Disadvantages Advantages vs. epidural Duration, SAB Duration of Sensory Block, SAB Drug Dose 2-Dermatome Complete Prolongation by (mg) regression (min) Resolution (min) -Agonists (%) Procaine 50-200 30-50 90-120 30-50 Lidocaine 25-100 40-100 140-240 20-50 Bupivacaine 5-20 90-140 240-380 20-50 Tetracaine 5-20 90-140 240-380 50-100 Epidural Duration Disadvantages Advantages vs. SAB Duration, Epidural Duration of Sensory Block, Epidural Drug 2-Dermatome Complete Prolongation by regression (min) Resolution (min) -Agonists (%) Chloroprocaine 3% 45-60 100-160 40-60 Lidocaine 2% 60-100 160-200 40-80 Mepivacaine 2% 60-100 160-200 40-80 Ropivacaine 0.5-1.0% 90-180 240-420 No Etidocaine 1-1.5% 120-240 300-460 No Bupivacaine 0.5-0.75% 120-240 300-460 No Summary Regional anesthesia is good Use it!
Pages to are hidden for
"Regional Anesthesia in the Outpatient Setting"Please download to view full document