Fall_25_Upper_Part2

Question 1

Which procedures are best indicated for an axillary nerve block?

Answer 1

Elbow, forearm, and hand procedures.

The axillary approach anesthetizes terminal branches at the level of the axilla for distal upper-extremity surgery.

Question 2

What is the typical total local anesthetic volume for an axillary block?

Answer 2

15–20 mL.

Volume supports spread around the axillary artery and targeted branches for reliable block success.

Question 3

What is the primary objective of an axillary block?

Answer 3

Deposit local around the axillary artery to block median, ulnar, radial, and medial antebrachial cutaneous nerves.

Perivascular spread at the axillary artery achieves coverage of the major terminal branches and MAC nerve.

Question 4

What is a key consideration regarding the musculocutaneous nerve in axillary blocks?

Answer 4

It branches early and often requires a separate injection.

The MCN leaves the plexus within coracobrachialis; separate deposition improves lateral forearm coverage.

Question 5

What positioning is recommended for an axillary block?

Answer 5

Supine, arm abducted to 90°, elbow either flexed to 90° or straight.

This opens the axillary space and aligns the probe for transverse imaging on the medial upper arm.

Question 6

What ultrasound setup is recommended for axillary block?

Answer 6

High-frequency linear probe; depth ~3–5 cm; transverse probe on medial upper arm at pectoralis–biceps junction.

These settings visualize the axillary artery and surrounding nerves in the axilla.

Question 7

Which structure lies posterior in the axillary block field and informs needle path?

Answer 7

The conjoint tendon.

Anatomical awareness helps avoid posterior structures when approaching through the biceps anteriorly.

Question 8

Where does the axillary artery sit relative to the skin surface at the typical scan site?

Answer 8

Approximately 1 cm deep and palpable at this level (distinct from the needle insertion site).

Palpation aids orientation, but ultrasound guidance determines safe needle trajectory.

Question 9

What nerve stimulator twitch correlates with radial nerve capture at the axilla?

Answer 9

Finger or wrist extension.

Radial nerve activation produces classic extensor movements confirming proximity.

Question 10

What twitch suggests median nerve stimulation at the axilla?

Answer 10

Finger flexion.

Median nerve capture causes finger flexion, assisting nerve identification when images are ambiguous.

Question 11

What twitch suggests ulnar nerve stimulation at the axilla?

Answer 11

Ulnar deviation of the hand.

Ulnar nerve engagement produces ulnar-sided deviation of fingers/hand.

Question 12

What twitch indicates musculocutaneous stimulation at the axilla?

Answer 12

Biceps twitch.

Biceps contraction signals MCN proximity; it often requires separate injection within coracobrachialis.

Question 13

What scanning strategy helps locate the axillary artery?

Answer 13

Slide the transducer anterior–posterior and use color Doppler.

Dynamic scanning and Doppler differentiate artery from surrounding tissues and veins.

Question 14

How can the musculocutaneous nerve be found reliably during axillary scanning?

Answer 14

Follow the biceps contour to where it meets coracobrachialis; identify a small hyperechoic oval within.

The MCN commonly runs within or along coracobrachialis at this junction.

Question 15

What perivascular injection regimen can be used for axillary block?

Answer 15

Inject ~7 mL anterior and ~7 mL posterior to the artery, then 6 mL to the musculocutaneous nerve.

This balances efficiency and onset while ensuring MCN coverage.

Question 16

What perineural injection regimen can be used for axillary block?

Answer 16

Identify individual branches and inject 3–5 mL per branch (optionally using twitch monitoring).

Perineural deposition may speed onset but can take longer to perform than perivascular.

Question 17

What precautions reduce intravascular injection risk during axillary block?

Answer 17

Aspirate before each 3–5 mL injection and watch real-time spread.

Close proximity to the axillary artery and veins necessitates frequent aspiration and visualization.

Question 18

What is a common troubleshooting approach if spread is not visualized?

Answer 18

Stop, aspirate again, retract slightly, and reinject to observe circumferential spread.

Adjusting needle tip prevents intravascular or intrafascial misplacement.

Question 19

What overall risk profile is associated with axillary block at this level?

Answer 19

Generally minimal risk compared with more proximal approaches.

The axilla is distant from pleura and neuraxis, lowering severe complication rates.

Question 20

What is the typical per-nerve volume for blocks about the elbow?

Answer 20

Approximately 5 mL per nerve.

Small volumes suffice because nerves are superficial and readily visualized at this level.

Question 21

What needle type is commonly used for elbow-level nerve blocks and why is this relevant?

Answer 21

22–25 gauge cutting (long-bevel) needles to improve comfort, which increases intraneural injury risk.

Smaller, sharper needles are comfortable but demand meticulous tip visualization to avoid intraneural injection.

Question 22

What additional infiltration may be required for complete forearm anesthesia at the elbow level?

Answer 22

Subcutaneous circumferential field block to include antebrachial and musculocutaneous cutaneous branches.

Blocking only the three main nerves may leave cutaneous gaps unless supplemented.

Question 23

Why might distal (forearm/wrist) tourniquets still require adjuncts if not all nerves are blocked?

Answer 23

Tourniquet discomfort persists unless comprehensive sensory nerves are covered; sedation or extra meds may be needed.

Incomplete blockade can leave tourniquet pain pathways intact.

Question 24

What positioning is recommended for elbow-level blocks?

Answer 24

Supine, arm abducted 90° supported on a table or flat surface.

This provides easy access to lateral, medial, and posterior aspects for radial, median, and ulnar approaches.

Question 25

What general ultrasound settings are used at the elbow?

Answer 25

High-frequency linear probe; depth 1–3 cm; transverse orientation over target nerve windows. Shallow depth and high frequency optimize nerve resolution.

Question 26

Where is the probe placed to identify the radial nerve at the elbow?

Answer 26

About 3–4 cm proximal to the lateral epicondyle. This window shows hyperechoic humerus deep to hypoechoic brachioradialis and brachialis, with the radial nerve between.

Question 27

What is the sonographic appearance of the radial nerve at this level?

Answer 27

A hyperechoic structure between brachioradialis and brachialis over the hyperechoic humeral cortex. This 'honeycomb' nerve lies in the intermuscular plane lateral-distal arm.

Question 28

Where is the probe placed to identify the median nerve at the elbow?

Answer 28

Transverse, about 1 cm proximal to the antecubital crease at the fossa. The brachial artery (non-compressible) is found with Doppler; the median nerve lies medial and superficial to it.

Question 29

What needle trajectory minimizes vascular risk for the median nerve at the elbow?

Answer 29

Approach from the medial side, away from the brachial artery. This reduces risk of arterial puncture while maintaining in-plane visualization.

Question 30

Where is the probe placed to identify the ulnar nerve at the elbow?

Answer 30

About 3–4 cm proximal to the medial epicondyle on the medial arm. Here, hyperechoic humerus and superficial hypoechoic triceps frame a round, honeycomb ulnar nerve.

Question 31

What twitch patterns help confirm nerve identity around the elbow?

Answer 31

Radial: wrist/finger extension; Median: finger flexion; Ulnar: ulnar deviation. Classic motor responses correlate with specific terminal nerves to confirm targeting.

Question 32

What key safety tip applies to all elbow-level injections?

Answer 32

Continuously visualize the needle tip throughout the injection. Small-gauge needles can be difficult to see; tip visibility reduces intraneural and vascular risk.

Question 33

What is the typical per-nerve volume for wrist blocks?

Answer 33

Around 5 mL per nerve. Low volume reduces compartment pressure while providing sufficient perineural spread.

Question 34

Which nerves are typically targeted in a wrist block for palmar soft-tissue procedures?

Answer 34

Median, ulnar, and the superficial branch of the radial nerve. Blocking these three nerves provides palmar coverage, though supplemental field blocks may be needed.

Question 35

What is a major risk during wrist blocks related to needle and vessel proximity?

Answer 35

Intraneural injection and inadvertent arterial puncture due to small-gauge needles near arteries. Nerves and arteries are close; careful technique and Doppler use are essential.

Question 36

Why might a wrist block not fully anesthetize the entire hand and fingers?

Answer 36

The wrist crease, dorsum of hand, and first to third fingers may be spared without additional infiltration. Supplemental field blocks may be required for complete coverage.

Question 37

What positioning is recommended for wrist blocks?

Answer 37

Supine or seated; arm abducted with the volar surface up. This exposes median and ulnar windows and lateral approach for superficial radial.

Question 38

What ultrasound settings are typical for wrist blocks?

Answer 38

High-frequency linear probe; depth 1–3 cm; transverse orientation over target nerves. Shallow scanning highlights superficial neural and vascular structures.

Question 39

How is the median nerve identified for wrist-level block?

Answer 39

Place probe ≥10 cm proximal to wrist crease, tilting slightly toward the hand to visualize between flexor muscle layers. The median nerve appears as a hyperechoic structure between superficial and deep flexor groups and can be tracked along the forearm.

Question 40

What is the needle approach for the median nerve at the wrist?

Answer 40

In-plane or out-of-plane approaches are acceptable depending on visualization. Technique is chosen to maintain continuous needle tip visualization and avoid vessels.

Question 41

How is the ulnar nerve identified for wrist block?

Answer 41

Slide medially from the median window to locate the ulnar artery; the ulnar nerve lies medial to the artery. The nerve is hyperechoic; approach in-plane from the medial side to stay away from the artery.

Question 42

How is the superficial branch of the radial nerve identified at the wrist?

Answer 42

Move laterally from the median window to find the radial artery; the nerve lies lateral to the artery above the radius. An in-plane lateral approach facilitates safe deposition while avoiding the artery.

Question 43

What troubleshooting tip applies across elbow and wrist blocks?

Answer 43

Use nerve stimulation and maintain needle tip visualization when anatomy is uncertain. These adjuncts reduce the risk of intraneural injection and improve accuracy in small windows.

Question 44

What is the purpose of the diaphragm-sparing shoulder block?

Answer 44

Provide shoulder analgesia while minimizing phrenic nerve involvement. Combines suprascapular and axillary nerve blocks to reduce respiratory compromise risk compared with interscalene.

Question 45

Does the diaphragm-sparing shoulder block replace interscalene for surgical anesthesia?

Answer 45

No; it is primarily for analgesia and reduced post-op opioids. It does not reliably produce surgical anesthesia; interscalene remains the standard for surgery requiring dense block.

Question 46

What motor and sensory territories are covered by the suprascapular nerve?

Answer 46

Motor to supraspinatus and infraspinatus; sensory to posterior shoulder. Blocking SSN reduces posterior joint pain and improves shoulder analgesia.

Question 47

What motor and sensory territories are covered by the axillary nerve?

Answer 47

Motor to deltoid (abduction), teres minor, long head of triceps; sensory to anterior shoulder joint and over deltoid skin. Axillary coverage complements SSN to address anterior/anterolateral pain sources.

Question 48

What total local anesthetic volume is used for the diaphragm-sparing shoulder block?

Answer 48

Approximately 20 mL divided between SSN and axillary targets. Two injections are required—one per nerve or at lateral/posterior cord targets.

Question 49

What are practical limitations of the diaphragm-sparing shoulder block?

Answer 49

Two-injection technique, longer setup, potential difficulty visualizing SSN and axillary nerve on ultrasound. Despite time and visualization challenges, it is valuable in patients who cannot tolerate phrenic nerve paresis.

Question 50

How should the patient be positioned for the suprascapular component?

Answer 50

Position as for a supraclavicular scan; then slide laterally until the subclavian artery sits at the distal screen edge. This view reveals the omohyoid and middle scalene muscles with the SSN coursing between them.

Question 51

Which structures help identify the suprascapular nerve in the supraclavicular window?

Answer 51

Hypoechoic omohyoid and middle scalene muscles with the nerve between, aligned toward the subclavian artery. The SSN lies in a fascial plane identifiable by its trajectory toward the scapular notch region.

Question 52

What is the recommended ultrasound depth and probe for the shoulder block?

Answer 52

High-frequency linear probe; depth 1–3 cm. Superficial anatomy requires high-resolution imaging in shallow fields.

Question 53

What landmarks assist in locating the axillary nerve for the shoulder block?

Answer 53

Acromion and axillary fold; sagittal probe orientation between them. Tilting posteriorly reveals the posterior circumflex humeral artery and scapular spine near the humeral neck.

Question 54

What sonographic planes are typically visualized while seeking the axillary nerve?

Answer 54

Two hypoechoic planes: trapezius and supraspinatus, with a hyperechoic fascial layer between; the scapular spine is hyperechoic. Layer recognition and vascular cues (PCHA) assist in locating the nerve in the quadrilateral space.

Question 55

Why may Doppler be unreliable for the posterior circumflex humeral artery at this level?

Answer 55

Flow may be small or poorly oriented to the beam, limiting sensitivity. Slow, deliberate probe movements and angle adjustments improve detection when Doppler is limited.

Question 56

What general risks apply to the shoulder block?

Answer 56

General regional anesthesia risks including vascular puncture, intraneural injection, and local anesthetic systemic toxicity. While phrenic-sparing, vigilance for standard complications remains necessary.

Question 57

What counseling point should be discussed with patients regarding the shoulder block?

Answer 57

It may not block motor and is less satisfying than a dense interscalene block. Setting expectations improves patient satisfaction when using an analgesic-focused technique.

Question 58

When choosing axillary vs elbow vs wrist blocks, what principle guides block level selection?

Answer 58

Match block level to surgical site: more distal surgery favors more distal blocks; proximal coverage needs more proximal blocks. Selecting the lowest effective level reduces risk (pleura/neuraxis) and targets the necessary sensory territory.

Question 59

What is a practical strategy to ensure complete hand coverage when using elbow-level blocks?

Answer 59

Combine radial, median, and ulnar nerve blocks with supplemental subcutaneous field infiltration. Cutaneous gaps remain without field blocks, especially near the wrist crease and dorsum.

Question 60

What monitoring step should accompany all injections around major arteries (axillary, brachial, radial, ulnar)?

Answer 60

Frequent aspiration and real-time ultrasound visualization of spread. These steps reduce intra-arterial injection and local anesthetic systemic toxicity risk.

Question 61

How does perivascular axillary technique compare to perineural in onset and placement time?

Answer 61

Similar success; perineural may have faster onset but requires longer placement time than perivascular. Choice balances efficiency and desired onset characteristics for the case.

Question 62

What is the advantage of using shallow depths (1–3 cm) and high frequency at the elbow and wrist?

Answer 62

Improved nerve resolution and needle tip visualization in superficial windows. High-frequency probes enhance imaging of small superficial nerves and vessels.

Question 63

Which nerve commonly requires separate injection in both axillary and elbow-level strategies to avoid sensory gaps?

Answer 63

Musculocutaneous nerve. Early branching and lateral cutaneous territory make dedicated injection helpful for complete coverage.

Question 64

Why might an axillary block be preferred over infraclavicular in certain patients?

Answer 64

Easier visualization in obesity or when infraclavicular anatomy is deep or obscured. Axillary approach avoids deep structures and is generally lower risk with reliable outcomes.

Question 65

In tourniquet cases, which supplement improves patient comfort when not all nerves are blocked?

Answer 65

Light sedation and systemic analgesics in addition to regional blocks. Tourniquet discomfort may persist without comprehensive sensory blockade.

Question 66

What scanning tip helps distinguish artery from vein in all regions?

Answer 66

Use compression and color Doppler: arteries are non-compressible; veins are compressible. This basic vascular differentiation prevents inadvertent venipuncture or arterial puncture.

Question 67

What step should immediately prompt stopping injection during any of these blocks?

Answer 67

High resistance to injection or severe pain suggesting intrafascicular injection. Cease injection to prevent nerve injury; reposition and reassess before proceeding.

Question 68

How do you confirm correct perivascular spread in axillary block when the image is suboptimal?

Answer 68

Hydrodissect with 1–2 mL, observe circumferential spread around the artery, then continue incrementally. Test spread delineates the correct plane and reduces intravascular risk before larger volumes.

Question 69

What is a practical landmark-based cue for the axillary scanning window?

Answer 69

Medial upper arm at the intersection of pectoralis major and biceps. This surface landmark aligns with the typical transverse ultrasound window for axillary block.

Question 70

Which approach choice is important to decide early in axillary block technique?

Answer 70

Perivascular versus perineural deposition strategy. Technique selection guides needle paths, volumes, and time required for placement.

Question 71

What is a key limitation of wrist blocks for complete digital anesthesia?

Answer 71

Sparing of dorsal hand and certain digital territories without additional field infiltration. Anatomical innervation patterns require supplementation for comprehensive digit coverage.

Question 72

Why is the SSN often difficult to visualize in the supraclavicular window for shoulder block?

Answer 72

It is small and runs between muscle planes with variable echogenicity. Patience with slow probe movements and plane optimization improves identification.

Question 73

What feature helps recognize the axillary nerve near the quadrilateral space?

Answer 73

Its proximity to the posterior circumflex humeral artery near the humeral neck. Vascular accompaniment aids nerve localization when the nerve itself is subtle.

Question 74

How should you counsel a patient regarding expectations for diaphragm-sparing shoulder block?

Answer 74

Explain it prioritizes analgesia and may leave some motor function intact compared with interscalene. Transparent expectations improve satisfaction and align goals with technique capabilities.

Question 75

Which general principle applies to needle trajectory across all these blocks?

Answer 75

Plan in-plane when possible and keep the needle parallel to critical structures. In-plane visualization and parallel trajectories help maintain continuous tip control and safety.