What are the benefits of an infraclavicular (below the collarbone) block for upper limb surgery?

Benefits of Infraclavicular Block for Upper Limb Surgery

Infraclavicular brachial plexus block provides excellent anesthesia and prolonged postoperative analgesia for upper limb surgery at or below the elbow, with superior respiratory safety compared to supraclavicular or interscalene approaches, making it the preferred choice when avoiding phrenic nerve involvement is critical. 1

Primary Advantages Over Alternative Approaches

Respiratory Safety Profile

• Infraclavicular block avoids respiratory compromise by sparing the phrenic nerve, unlike supraclavicular and interscalene blocks which carry significant risk of hemidiaphragmatic paralysis 1
• This respiratory-sparing characteristic is particularly crucial for patients with pre-existing pulmonary disease or those requiring supplemental oxygen 1
• The 2020 Anaesthesia guidelines explicitly recommend choosing infraclavicular or axillary blocks over supraclavicular blocks when minimizing respiratory interference is a priority 1

Complete Upper Limb Anesthesia

• Infraclavicular block anesthetizes all four distal upper extremity nerve territories without requiring separate musculocutaneous nerve blockade, unlike axillary approaches 2
• The block provides reliable surgical anesthesia for procedures at or distal to the elbow with success rates of 92% when performed via supraclavicular approach and 56-86% via axillary approach 3
• Median duration of sensory blockade ranges from 3.7 to 8.7 hours with 0.5% ropivacaine, with some techniques providing anesthesia lasting 11.4 to 14.4 hours when using 0.75% ropivacaine 3

Analgesic Benefits

Postoperative Pain Control

• Infraclavicular blocks provide superior postoperative analgesia compared to systemic opioids, reducing the need for rescue analgesics and minimizing opioid-related side effects such as nausea, vomiting, and respiratory depression 1
• Continuous infraclavicular catheter techniques offer extended analgesia beyond single-shot blocks, with multi-orifice catheters demonstrating lower pain scores and reduced rescue analgesic consumption during the first 24 postoperative hours compared to end-hole catheters 4
• The opioid-sparing effect is particularly beneficial for patients with respiratory morbidity, as it avoids the respiratory depressant effects of systemic opioids 1

Enhanced Recovery Profile

• Patients can be safely discharged with residual sensory or motor blockade provided the limb is protected and appropriate home support exists 1
• The technique facilitates early mobilization and faster per oral consumption post-surgery compared to general anesthesia 2
• Regional anesthesia with infraclavicular block minimizes postoperative nausea and vomiting, enhancing patient comfort and reducing recovery time 1

Technical and Safety Considerations

Ultrasound Guidance Benefits

• Ultrasound guidance should be used routinely to reduce the risk of local anesthetic systemic toxicity (LAST) and improve block success rates 1, 5
• The costoclavicular and paracoracoid approaches to infraclavicular block demonstrate equivalent onset times (approximately 16-17 minutes) and success rates when performed under ultrasound guidance 6
• Ultrasound visualization allows precise needle placement and real-time monitoring of local anesthetic spread 1

Hemodynamic Stability

• Infraclavicular blocks produce fewer hemodynamic side effects compared to neuraxial techniques because they do not cause sympathectomy-induced hypotension 1
• Studies demonstrate stable hemodynamic parameters throughout the perioperative period with no significant cardiovascular complications 2

Specific Clinical Scenarios

Day Surgery Applications

• Infraclavicular blocks are well-suited for ambulatory surgery, providing excellent anesthesia and prolonged analgesia that extends into the home recovery period 1
• Patients require clear written instructions regarding limb protection during the blockade period and guidance on when to initiate oral analgesics before block resolution 1

Deep Block Classification

• Infraclavicular block is classified as a "deep" peripheral nerve block with high hemorrhagic risk because the injection site cannot be compressed and bleeding consequences are potentially severe 1
• In patients on anticoagulants (such as dabigatran), infraclavicular blocks are contraindicated unless dabigatran concentration is ≤30 ng/mL or the anticoagulant is reversed with idarucizumab 1
• This contrasts with "superficial" blocks like femoral or popliteal sciatic blocks where hemorrhage can be controlled with compression 1

Dosing and Local Anesthetic Selection

Effective Concentrations

• Ropivacaine 0.5% (5 mg/mL) provides effective anesthesia with doses up to 275 mg for brachial plexus block 3
• Both 0.75% and 0.5% ropivacaine demonstrate similar clinical effects for vertical infraclavicular blocks, with no significant differences in sensory/motor block quality or duration 7
• For continuous infusions, bupivacaine 0.125% delivered via patient-controlled analgesia (2 mL/h infusion rate with 5 mL/h automated bolus) provides effective postoperative analgesia 4

Volume Requirements

• Standard volumes of 30-40 mL are typically used, with 30 mL (225 mg) of ropivacaine 0.75% via subclavian perivascular approach or 40 mL (300 mg) via axillary approach both providing reliable anesthesia 3
• A 35-mL mixture of 1% lidocaine-0.25% bupivacaine with epinephrine 5 µg/mL demonstrates equivalent efficacy between costoclavicular and paracoracoid approaches 6

Common Pitfalls and How to Avoid Them

• Avoid excessive sedation during block performance as this may compromise respiratory function, particularly in patients with COVID-19 or respiratory comorbidities 1
• Calculate safe local anesthetic doses carefully to prevent systemic toxicity, especially when combining multiple blocks or using higher concentrations 1, 5
• Do not perform infraclavicular blocks in anticoagulated patients without appropriate reversal or adequate time since last anticoagulant dose, given the deep location and inability to compress bleeding 1
• Ensure adequate block assessment before surgical incision to minimize conversion to general anesthesia, which increases resource utilization and patient risk 1
• Provide clear discharge instructions regarding limb protection, expected duration of blockade, and timing of oral analgesic initiation to prevent rebound pain 1