Transcript Regional Anesthesia in the Outpatient Setting

Regional Anesthesia in
the Outpatient Setting
Ravindra V. Prasad, MD
Department of Anesthesiology
UNC School of Medicine
Review
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3/30 – Ghia, Axillary Block
4/1 – Wilkes, Axillary Block
4/8 – Levin, SAB
4/14 – Klein, Lower Extremity Blocks
4/15 – Prasad, ???
Overview
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Regional Anesthesia: general comments
Upper Extremity Blocks
Paravertebral Blocks
Neuraxial Blocks
Lower Extremity Blocks
Regional: advantages
 Avoid GA complications
 Less anesthetic required
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faster wake-up?
quicker recovery?
 Faster ambulation, faster discharge
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N/V less common
post-op pain minimized
Regional: problems
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Time
Equipment
Personnel
GA still backup plan
Skill
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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
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elbow
wrist
 Bier Blocks
Brachial Plexus
Dermatome Distribution
Brachial Plexus Blocks
 Indications: surgery of upper extremity
 Approaches
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Axillary
Infraclavicular
Supraclavicular
Interscalene (ISB)
ISB: technique
 Equipment
 Drugs
 Technique
ISB: complications
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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
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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
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tourniquet(s) with pressure gauge
rubber bandage (Martin, Esmarch)
 Drugs
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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
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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
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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
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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
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thoracotomy
mastectomy
nephrectomy
cholecystectomy
rib fractures
post-thoracotomy pain
post-mastectomy pain
 Lumbar: inguinal hernia
PVB: technique
 Equipment
 Drugs
 Technique
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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
Pleural puncture
Pneumothorax, symptomatic
Bloodstained aspirate
Hypotension (requiring fluid
or ephedrine)
Epidural involvement
Epinephrine absorption
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Adults
(319)
3
1
12
16
Children
(48)
1
0
2
0
Reported failure rate 10-15%
Greengrass
(156)
1
2
1
PVB: breast surgery
 Block T1-T6: go lateral to C7-T5.
 Greengrass:
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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
Require N/V med during
hospital stay
Narcotic analgesia required
during hospital stay
Discharged POD #0
PVB %
20
GA %
39
25
98
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
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1/3 had good block at emergence
failure rate 2-3/22 = 9-14%
 Of 20 “successful” blocks
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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
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Klein, SM Greengrass RA Weltz C Warner DS, 1998
PVB: inguinal hernia, satisfaction
Satisfaction with anesthetic
Not satisfied
Satisfied
Very satisfied
24 hr
0
3
17
48 hr
0
2
18
SAB
 Duration
 Disadvantages
 Advantages vs. epidural
Duration, SAB
Drug
Procaine
Lidocaine
Bupivacaine
Tetracaine
Duration of Sensory Block, SAB
Dose
2-Dermatome
Complete
Prolongation by
(mg)
regression (min) Resolution (min) -Agonists (%)
50-200 30-50
90-120
30-50
25-100 40-100
140-240
20-50
5-20
90-140
240-380
20-50
5-20
90-140
240-380
50-100
Epidural
 Duration
 Disadvantages
 Advantages vs. SAB
Duration, Epidural
Drug
Chloroprocaine 3%
Lidocaine 2%
Mepivacaine 2%
Ropivacaine 0.5-1.0%
Etidocaine 1-1.5%
Bupivacaine 0.5-0.75%
Duration of Sensory Block, Epidural
2-Dermatome
Complete
Prolongation by
regression (min) Resolution (min) -Agonists (%)
45-60
100-160
40-60
60-100
160-200
40-80
60-100
160-200
40-80
90-180
240-420
No
120-240
300-460
No
120-240
300-460
No
Summary
 Regional anesthesia is good
 Use it!