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Regional Anesthesia in the Outpatient Setting
Ravindra V. Prasad, MD
Department of Anesthesiology
UNC School of Medicine
Review3/30 – Ghia, Axillary Block4/1 – Wilkes, Axillary Block4/8 – Levin, SAB4/14 – Klein, Lower Extremity Blocks4/15 – Prasad, ???
OverviewRegional Anesthesia: general commentsUpper Extremity BlocksParavertebral BlocksNeuraxial BlocksLower Extremity Blocks
Regional: advantagesAvoid GA complicationsLess anesthetic required
faster wake-up? quicker recovery?
Faster ambulation, faster discharge N/V less common post-op pain minimized
Regional: problemsTimeEquipmentPersonnelGA still backup planSkill
regional techniques management of awake or LIGHTLY sedated
patients
Block PlacementMonitoringEmergency equipment and drugs should be
readily availableBlock equipment readied before startingPOSITIONINGSEDATION (preoperative, intraoperative)Patient selection
Upper Extremity Blocks
Brachial Plexus BlocksPeripheral Nerve Blocks
elbow wrist
Bier Blocks
Brachial Plexus
Dermatome Distribution
Brachial Plexus Blocks
Indications: surgery of upper extremityApproaches
Axillary Infraclavicular Supraclavicular Interscalene (ISB)
ISB: technique
EquipmentDrugsTechnique
ISB: complications
PneumothoraxPhrenic nerve paralysisHorner’s syndromeC6 root neuropathy (intraneural injection;
root pinned against C6 tubercle)
Bier Block
Intravenous Regional Anesthesia (IVRA)Described by Bier in 1908Intravenous injection of local anesthetics in an
extremity isolated from the systemic circulation
A simple technique which is easy to performWidespread 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 usedPatients with a painful extremityCertain 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 endingsDiffusion 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 painTourniquet deflationProlonged surgeryLower extremity surgery
Paravertebral Blocks (PVB)
Paravertebral spaceSpinal 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
EquipmentDrugsTechnique
2.5-3 cm lateral to spinous process, caudal and 1-2 cm deep to transverse process
4-5 ml local anestheticVariations
PVB: risks
Complication Adults(319)
Children(48)
Greengrass(156)
Pleural puncture 3 1Pneumothorax, symptomatic 1 0 1Bloodstained aspirate 12 2Hypotension (requiring fluidor ephedrine)
16 0
Epidural involvement 2Epinephrine 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 duringhospital stay
20 39
Narcotic analgesia requiredduring hospital stay
25 98
Discharged POD #0 96 76
PVB: inguinal hernia repair
Block T10-L2: go lateral to T10-L2Onset of surgical anesthesia 15-30 min
PVB: IH Repair, outcome22 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 hrNot satisfied 0 0Satisfied 3 2Very satisfied 17 18
SAB DurationDisadvantagesAdvantages vs. epidural
Duration, SAB
Duration of Sensory Block, SABDrug Dose
(mg)2-Dermatomeregression (min)
CompleteResolution (min)
Prolongation by-Agonists (%)
Procaine 50-200 30-50 90-120 30-50Lidocaine 25-100 40-100 140-240 20-50Bupivacaine 5-20 90-140 240-380 20-50Tetracaine 5-20 90-140 240-380 50-100
Epidural
DurationDisadvantagesAdvantages vs. SAB
Duration, Epidural
Duration of Sensory Block, EpiduralDrug 2-Dermatome
regression (min)CompleteResolution (min)
Prolongation by-Agonists (%)
Chloroprocaine 3% 45-60 100-160 40-60Lidocaine 2% 60-100 160-200 40-80Mepivacaine 2% 60-100 160-200 40-80Ropivacaine 0.5-1.0% 90-180 240-420 NoEtidocaine 1-1.5% 120-240 300-460 NoBupivacaine 0.5-0.75% 120-240 300-460 No
Summary
Regional anesthesia is goodUse it!