Upper Extremity Blocks Flashcards
1
Q
Indications
A
Primary anesthetic Postop pain management History PONV Malignant hyperthermia risk Patient severity unable to tolerate general anesthesia Surgeon preference
2
Q
Absolute Contraindications
A
Patient refusal Severe aortic stenosis Active bleeding in anticoagulated patient Local anesthetic allergy Infection at proposed block site
3
Q
Relative Contraindications
A
Respiratory compromise Inability to cooperate/understand the procedure Anesthetized patient Bloodstream infection Pre-existing peripheral neuropathy
4
Q
Ultrasound advantages over traditional landmark technique
A
- Visualization anatomic structures
- Real-time needle movements
- Local anesthetic spread
SAFER
Nerve stimulation?
- Not always necessary in experienced providers
Long thoracic nerve stimulation helpful to AVOID
5
Q
How much volume?
A
20-40mL per block
US guided vs. landmark technique
Complete block success demonstrated w/ 5mL
20mL relatively safe vs. 40mL local anesthetic (LAST risk)
Only inject 5mL after negative aspiration
6
Q
Pre-Procedure
A
Verify correct patient Obtain informed consent Ensure patient understands procedure & risks Correct procedure & extremity Gather all necessary equipment Sedation pre-medication Place oxygen on patient w/ ETCO2 Obtain baseline vital signs & monitor during procedure Administer proper/adequate sedation
7
Q
Cervical Plexus Block
Indications
A
Carotid endarterectomy
Superficial neck surgery
Clavicle fractures
8
Q
Cervical Plexus
Branches & Nerves
A
Cervical nerve root C2-C4 Major nerves include - Transverse cervical - Great auricular - Lessor occipital - Supraclavicular
9
Q
Cervical Plexus Block
A
Provides anesthesia to anterolateral neck, anterior & retro-auricular areas, & anterior chest inferior to the clavicle
10
Q
Cervical Plexus Technique
A
- Position patient w/ head turned to non-operative side
- Place transducer at sternocleidomastoid muscle midpoint & move laterally until posterior edge identified
- Identify brachial plexus b/w anterior & middle scalene muscle
- Cervical plexus located in plane above prevertebral fascia
- Needle passed lateral to medial in-plane to area b/w sternocleidomastoid muscle & prevertebral fascia
11
Q
Cervical Plexus Pearls
A
Visualization plexus nerves not necessary
Purely sensory nerves
Low local anesthetic concentration used
12
Q
Cervical Plexus Complications
A
Poor needle visualization → intrathecal injection d/t close proximity to vertebral nerve roots
Potential intravascular injection in vertebral artery
13
Q
Brachial Plexus
A
Ventral rami C5-T1 nerve roots
Converge & diverse into trunks, divisions, cords, branches, & terminal nerves
Supplies sensory & motor innervation to the upper extremity
14
Q
Roots
A
5
C5 → T1
15
Q
Trunks
A
3
Superior/upper
Middle
Inferior/lower
16
Q
Divisions
A
6
Anterior (3)
Posterior (3)
17
Q
Cords
A
3
Lateral
Posterior
Medial
18
Q
Branches
A
5 Musculocutaneous Axillary Median Radial Ulnar
19
Q
Proximal Branches
A
Dorsal scapular
Phrenic
Long thoracic
20
Q
Medial Branches
A
Medial pectoral
Medial cutaneous to arm & forearm
21
Q
Lateral Branches
A
Suprascapular
Subclavius
Lateral pectoral
22
Q
Posterior Cord
A
Upper & lower subscapular
Thoracodorsal
EXTENSION
23
Q
C5
A
Should abduction
24
Q
C6
A
Elbow flexion
25
C7
Elbow extension
26
C8
Finger flexion
27
T1
Finger abduction/adduction
28
Block Evaluation
Baseline push, pull, pinch (medial), pinch (lateral)
29
Brachial Plexus Blocks
Supraclavicular SCB
Interscalene ISB
Infraclavicular
Axillary
30
Supraclavicular
TRUNK & DIVISION LEVEL
Reliable upper extremity block
Procedures involving upper arm & hand
Brachial plexus most compact at this level
31
SCB Technique
- Transverse image using in-plane needle insertion
- Trunks/divisions found lateral to pulsating subclavian artery & superior to 1st rib
- Needle inserted lateral to medial toward inferior plexus aspect where the rib & artery meet (the corner pocket)
32
SCB Complications
↑risk phrenic nerve paralysis & stellate ganglion block
Pneumothorax most important complication
Possible inadvertent subclavian artery puncture
33
Interscalene Block
ROOT LEVEL
Primary brachial plexus block for procedures involving the shoulder & proximal upper arm (suprascapular nerve)
Nerve roots C5-C7 found in interscalene groove b/w anterior & middle scalene muscles
Stoplight or snowman
34
ISB Technique
- Supine position w/ head turned to non-operative side
- Place transducer in mid-clavicular fossa & move cephalad
- Inject up to 20-30mL
Lateral → medial OR posterior → anterior
5cm
B level needle
35
ISB Pearls
Nerve stimulation not required
Pre-procedure scan w/ color doppler performed prior to injection to limit inadvertent injections & identify anatomic variations
36
ISB Complications
```
Phrenic blockade occurs nearly 100% time
Stellate ganglion block
LAST
High spinal
Injury to dorsal scapular & long thoracic nerves
```
37
Stellate Ganglion Block
Horner's syndrome
- Ptosis
- Miosis
- Anhidrosis
38
Infraclavicular Block
CORD LEVEL
Alternative to supraclavicular block especially in patients w/ severe COPD or respiratory insufficiency
Cords labeled by relation to the axillary artery - lateral, posterior, & medial
39
Infraclavicular Technique
- Patient supine w/ head turned to non-operative side
- Abduct arm → shallow image
- Transducer placed perpendicular to clavicle medial to coracoid plexus
- Short-axis image (sagittal plane)
- Cords are arranged around the axillary artery
22G 8cm needle
Insert in-place cephalad → caudal
20-30mL incremental local anesthetic injection
40
Infraclavicular Pearls
Low frequency transducer depending on patient body habitus
Additional subcutaneous injection local anesthetic
Needle sliding medially ↑pneumothorax/hemothorax risk
Thoraco-acromial artery & pectoral veins pass b/w the pectoral muscles
Doppler useful to help identify structures & prevent inadvertent puncture
41
Infraclavicular Complications
```
Poor needle visualization → inadvertent
- Pneumothorax/hemothorax
- Vascular puncture
- LAST event
Uncomfortable pressure d/t separating tissue vs. nerve pain
```
42
Axillary Block
```
TERMINAL BRANCHES LEVEL
- Musculocutaneous
- Radial
- Ulnar
- Median
Procedures below the elbow
Less attractive block b/c other blocks able to be done w/ ultrasound efficiently w/ minimal complications
```
43
Axillary Technique
- Supine position w/ head turned to non-operative side
- Arm abducted & rotated externally
- Place transducer in the crease formed by biceps muscle & pectoris major
22G 5cm
B level needle
Insert in-plane
20-40mL incremental local anesthetic injection
44
Axillary Pearls
Compressing the veins ↓risk vascular puncture
Block the radial nerve 1st (deep)
Pre-procedure scan
Slide transducer distally to appreciate each nerve then follow proximally
45
Axillary Complications
Not common
↑risk vascular puncture b/c needle re-directed several times to achieve adequate local anesthetic distribution
Paresthesia d/t multiple needle punctures may result in neuropathy
CAUTION multiple veins located around the artery
46
Elbow Nerve Blocks
Incomplete block rescue
Localized procedure
- Radial
- Median & ulnar (blocked w/ arm abducted)
Find the contrast
All 3 nerves are close to vascular structures or bone
47
Median Nerve
Median nerve alongside brachial artery in upper arm to the elbow
Insert needle lateral → medial in-plane
Inject 4-5mL local anesthetic
Additional 2-3mL inject when circumferential spread not noted
48
Radial Nerve
Scan distally along the lateral humerus
Identify the nerve - anterior course along the humerus
Lateral → medial in-plane needle insertion
Inject 4-5mL local anesthetic
Additional 2-3mL inject when circumferential spread not noted
49
Ulnar Nerve
Scan medially to identify the medial epicondyle
Identify where nerve enters proximal & distal
Medial → lateral in-plane needle insertion
Inject 4-5mL local anesthetic
Additional 2-3mL inject when circumferential spread not noted
50
IV Regional Anesthesia
Bier block
Upper or lower extremity procedures
Local anesthetic injected into the venous system
Extremity exsanguinated via compression & isolated by tourniquet
51
IVRA Mechanisms
Direct - local bathing nerve endings in tissue
| Indirect - local anesthetic transported to the nerves substance via the vasa nervorum
52
IVRA Indications
```
Superficial procedures
- Ganglion cyst excision
- Carpal tunnel release
- Dupuytren's contractures
- Fraction reduction (pediatrics)
Regional pain syndromes treatment
- Analgesia
- Reduce neurogenic inflammation
```
53
IVRA Contraindications
```
Patient refusal
Injuries to the injury (crush or open fractures)
Inability to cannulate peripheral vein
Local skin infection or cellulitis
True allergy to local anesthetics
Pre-existing AV fistula
Sickle cell disease
Surgery >1hr
```
54
IVRA Procedure
Place IV catheter 22G distal
Apply double pneumatic tourniquet
Elevate the extremity & apply esmarch bandage
Occlude the axillary
Inflate proximal cuff 50-100mmHg > patient systolic
Remove esmarch
Inject 30-50mL 0.5-1% lidocaine
Tourniquet pain → inflate distal cuff then deflate proximal cuff
55
IVRA Pearls
Tourniquet must remain inflated at least 30 minutes following local anesthetic injection regardless surgery length
Cuff tourniquet deflation cyclical
- Deflate then instantly re-inflate
- Evaluate S/S LAST or other complications
- Wait 1-2 minutes
- Repeat
56
IVRA Complications
```
LAST
Damage to radial, median, & ulnar nerves
Compartment syndrome
Arterial thrombosis
Death or permanent brain damage
```
57
LAST
Local anesthetic systemic toxicity
Serious, but rare event during regional anesthesia
Occurs from inadvertent IV injection
- Blocking inhibitory neurons causes seizures
- Cardiac ion channel blockage → bradycardia
Short-acting local anesthetics less cardiotoxic
More potent agents ↑lipid solubility & protein binding
58
LAST Clinical Presentation
Rapid onset usually w/in 1 minute
Agitation, tinnitus, circumoral numbness, blurred vision, & metallic taste
Followed by muscle twitching, unconsciousness, & seizures → cardiac & respiratory arrest
59
LAST Incidence
0.4 per 10,000
60
LAST most commonly associated w/
Epidural
Axillary
Interscalene
61
LAST Prevention
Test dosing
Incremental injection 5mL w/ aspiration
Use pharmacologic markers
Ultrasound
62
LAST Treatment
```
Prompt recognition & diagnosis
Airway management
Suppress seizure
- Benzodiazepines
- Succinylcholine
Prevent hypoxia & acidosis
Lipid emulsion therapy
Vasopressors
- Epi <1mg/kg
```
63
Nerve Injury
Direct needle trauma - peripheral nerve injury varies w/ location
Local anesthetic neurotoxicity
US allows practitioner to identify important structures - dura, pleural, vasculature, bowel
Visualize needle in real-time & observe LA spread
64
Nerve Injury
| ↑Risk
```
Diabetes - diabetic neuropathy ↓sensation baseline
Pre-existing neurologic disease
Smoking
↑BMI
Male
```
65
Lipid Emulsion Therapy MOA
```
Capture LA in blood (lipid sink)
↑fatty acid uptake by mitochondria
Na+ channel binding interference
Ca2+ entry promotion
Accelerated shunting
```
