Upper Extremity Blocks Flashcards Preview

AS - N931 Advanced Principles of Anesthesia > Upper Extremity Blocks > Flashcards

Flashcards in Upper Extremity Blocks Deck (65)
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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
  1. Visualization anatomic structures
  2. Real-time needle movements
  3. 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
Q

C7

A

Elbow extension

26
Q

C8

A

Finger flexion

27
Q

T1

A

Finger abduction/adduction

28
Q

Block Evaluation

A

Baseline push, pull, pinch (medial), pinch (lateral)

29
Q

Brachial Plexus Blocks

A

Supraclavicular SCB
Interscalene ISB
Infraclavicular
Axillary

30
Q

Supraclavicular

A

TRUNK & DIVISION LEVEL
Reliable upper extremity block
Procedures involving upper arm & hand
Brachial plexus most compact at this level

31
Q

SCB Technique

A
  • 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
Q

SCB Complications

A

↑risk phrenic nerve paralysis & stellate ganglion block
Pneumothorax most important complication
Possible inadvertent subclavian artery puncture

33
Q

Interscalene Block

A

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
Q

ISB Technique

A
  • 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
Q

ISB Pearls

A

Nerve stimulation not required
Pre-procedure scan w/ color doppler performed prior to injection to limit inadvertent injections & identify anatomic variations

36
Q

ISB Complications

A
Phrenic blockade occurs nearly 100% time
Stellate ganglion block
LAST
High spinal
Injury to dorsal scapular & long thoracic nerves
37
Q

Stellate Ganglion Block

A

Horner’s syndrome

  • Ptosis
  • Miosis
  • Anhidrosis
38
Q

Infraclavicular Block

A

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
Q

Infraclavicular Technique

A
  • 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
Q

Infraclavicular Pearls

A

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
Q

Infraclavicular Complications

A
Poor needle visualization → inadvertent
- Pneumothorax/hemothorax
- Vascular puncture
- LAST event
Uncomfortable pressure d/t separating tissue vs. nerve pain
42
Q

Axillary Block

A
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
Q

Axillary Technique

A
  • 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
Q

Axillary Pearls

A

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
Q

Axillary Complications

A

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
Q

Elbow Nerve Blocks

A

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
Q

Median Nerve

A

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
Q

Radial Nerve

A

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
Q

Ulnar Nerve

A

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
Q

IV Regional Anesthesia

A

Bier block
Upper or lower extremity procedures
Local anesthetic injected into the venous system
Extremity exsanguinated via compression & isolated by tourniquet

51
Q

IVRA Mechanisms

A

Direct - local bathing nerve endings in tissue

Indirect - local anesthetic transported to the nerves substance via the vasa nervorum

52
Q

IVRA Indications

A
Superficial procedures
- Ganglion cyst excision
- Carpal tunnel release
- Dupuytren's contractures
- Fraction reduction (pediatrics)
Regional pain syndromes treatment
- Analgesia
- Reduce neurogenic inflammation
53
Q

IVRA Contraindications

A
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
Q

IVRA Procedure

A

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
Q

IVRA Pearls

A

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
Q

IVRA Complications

A
LAST
Damage to radial, median, & ulnar nerves
Compartment syndrome
Arterial thrombosis
Death or permanent brain damage
57
Q

LAST

A

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
Q

LAST Clinical Presentation

A

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
Q

LAST Incidence

A

0.4 per 10,000

60
Q

LAST most commonly associated w/

A

Epidural
Axillary
Interscalene

61
Q

LAST Prevention

A

Test dosing
Incremental injection 5mL w/ aspiration
Use pharmacologic markers
Ultrasound

62
Q

LAST Treatment

A
Prompt recognition & diagnosis
Airway management
Suppress seizure 
- Benzodiazepines 
- Succinylcholine
Prevent hypoxia & acidosis
Lipid emulsion therapy
Vasopressors
- Epi <1mg/kg
63
Q

Nerve Injury

A

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
Q

Nerve Injury

↑Risk

A
Diabetes - diabetic neuropathy ↓sensation baseline
Pre-existing neurologic disease
Smoking
↑BMI
Male
65
Q

Lipid Emulsion Therapy MOA

A
Capture LA in blood (lipid sink)
↑fatty acid uptake by mitochondria
Na+ channel binding interference
Ca2+ entry promotion
Accelerated shunting