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

Benefits of Infraclavicular Block for Upper Limb Surgery

Infraclavicular block should be your preferred brachial plexus approach for upper limb surgery when respiratory safety is a priority, as it avoids phrenic nerve involvement while providing reliable anesthesia and superior postoperative analgesia compared to general anesthesia. 1

Primary Respiratory Safety Advantage

• Infraclavicular block completely spares the phrenic nerve, eliminating the risk of hemidiaphragmatic paralysis that occurs with supraclavicular and interscalene approaches. 1
• The American Society of Anesthesiologists explicitly recommends choosing infraclavicular or axillary blocks over supraclavicular blocks when minimizing respiratory interference is the clinical priority. 1
• This respiratory advantage is particularly critical for patients with pre-existing pulmonary disease, those requiring supplemental oxygen, or patients with COVID-19 or other respiratory comorbidities. 1

Superior Analgesia and Opioid-Sparing Effects

• Infraclavicular blocks provide superior postoperative analgesia compared to systemic opioids, with a number needed to treat of 2.5 for effective pain control. 1
• The opioid-sparing effect reduces rescue analgesic requirements and minimizes opioid-related complications (nausea, vomiting, respiratory depression) by 30%. 1
• In direct comparison with general anesthesia for hand and wrist surgery, infraclavicular block resulted in significantly less postoperative pain (3% vs 43% with visual analog scale >3), with zero patients requiring pain treatment in hospital versus 48% in the general anesthesia group. 2

Ambulatory Surgery and Recovery Benefits

• Infraclavicular block enables faster recovery and earlier discharge compared to general anesthesia, with 79% of patients meeting criteria to bypass the post-anesthesia care unit versus only 25% with general anesthesia. 2
• Time to home readiness is significantly shorter with infraclavicular block (100 ± 44 minutes) compared to general anesthesia (203 ± 91 minutes). 2
• Patients achieve earlier ambulation (82 ± 41 minutes vs 145 ± 70 minutes with general anesthesia). 2
• The American Academy of Anesthesiologists recommends infraclavicular blocks for day surgery applications with level 1A evidence. 1
• Adverse events such as nausea, vomiting, and sore throat occur less frequently with infraclavicular block compared to general anesthesia. 2

Hemodynamic Stability

• Infraclavicular blocks produce fewer hemodynamic side effects compared to neuraxial techniques because they avoid sympathectomy-induced hypotension, with only a 10% mean arterial pressure reduction. 1

Nerve Coverage and Block Success

• Infraclavicular block provides reliable anesthesia for all four distal upper extremity nerve territories without requiring a separate musculocutaneous nerve block (unlike axillary approaches). 3
• When compared to single-injection axillary block, infraclavicular block provides more complete sensory blockade of the musculocutaneous nerve (risk ratio for failure 0.46) and axillary nerve (risk ratio for failure 0.37). 4
• Infraclavicular block is less likely to cause tourniquet pain during surgery (risk ratio 0.47) compared to other brachial plexus approaches. 4
• The risk of failed surgical anesthesia and complications are low and similar across all brachial plexus block approaches. 4

Technical Considerations for Optimal Results

• Ultrasound guidance should be used routinely to reduce the risk of local anesthetic systemic toxicity (LAST) and improve block success rates, with a 50% relative risk reduction. 1
• Allow adequate time for block onset—at least 30 minutes is recommended for optimal efficacy. 4
• Use a volume of at least 40 mL of local anesthetic for reliable blockade. 4
• For electrostimulation-guided techniques, target a distal posterior cord motor response as the appropriate endpoint. 4
• Ropivacaine 0.5% (5 mg/mL) provides effective anesthesia for brachial plexus block, with median duration ranging from 3.7 to 8.7 hours depending on the nerve. 5
• The retroclavicular approach to infraclavicular block demonstrates decreased procedure time and needle time due to better needle visibility. 6

Common Pitfalls and How to Avoid Them

• Avoid excessive sedation during block performance as this may compromise respiratory function, particularly in patients with respiratory comorbidities (risk ratio 2.5). 1
• Calculate safe local anesthetic doses carefully to prevent systemic toxicity, especially when combining multiple blocks or using higher concentrations, with a maximum recommended dose of 300 mg. 1
• The infraclavicular block has a longer sensory block onset time (approximately 3.9 minutes longer) compared to axillary or midhumeral blocks, but this is offset by faster performance time and superior nerve coverage. 4
• When using adjuvants, dexamethasone 6 mg provides longer-lasting sensory and motor blocks compared to dexmedetomidine 75 mcg, with fewer sedation-related adverse effects. 7