What are the suitable peripheral nerve block (PNB) and general anesthesia (GA) combinations for a 56-year-old female undergoing wide resection of the humerus due to high-grade spindle cell sarcoma?

PNB and GA Combinations for Upper Extremity Sarcoma Resection

Recommended Approach

For wide resection of the humerus, combine brachial plexus block with general endotracheal anesthesia to provide superior postoperative analgesia while maintaining a secure airway during this complex oncologic procedure. 1

Specific Block Techniques for Humeral Surgery

Brachial Plexus Block Options

Supraclavicular approach is preferred over axillary approach for humeral surgery, achieving 92% success rates compared to 56-86% with axillary technique. 2

• Supraclavicular block provides the most reliable coverage for humeral procedures with faster onset and more consistent anesthesia 2
• Subclavian perivascular approach using 30 mL of ropivacaine 0.75% (225 mg) provides median anesthesia duration of 11.4-14.4 hours 2
• Axillary approach using 40 mL of ropivacaine 0.75% (300 mg) offers alternative access but with lower success rates 2

Technical Execution

• Use ultrasound guidance to reduce local anesthetic systemic toxicity, improve needle placement accuracy, and allow for reduced volumes of local anesthetic 1
• Employ in-plane needling along the visual axis for improved speed and accuracy 3
• Calculate safe local anesthetic dose based on patient weight to prevent systemic toxicity 3

Advantages of Combined PNB + GA Technique

Superior Analgesia Profile

• Reduces total opioid consumption and decreases respiratory depression compared to GA alone 1
• Provides extended postoperative analgesia lasting 11.4-14.4 hours with single-shot technique 2
• Improves hemodynamic stability during surgery 1

Airway Security

• General anesthesia with secure airway is essential for procedures that may mechanically compromise the airway, such as thoracic or upper extremity surgeries requiring specific positioning 1
• Reduces risk of respiratory complications compared to deep sedation alone 1

Functional Benefits

• Decreases baseline and dynamic pain scores 4
• Reduces postoperative joint inflammation and inflammatory markers 4
• Increases patient satisfaction 4
• May reduce incidence of postsurgical chronic pain 4

Disadvantages and Risk Mitigation

Block-Specific Complications

• Vascular puncture and bleeding - minimize with ultrasound guidance and meticulous technique 5
• Nerve damage - occurs in approximately 0.21% of cases, typically resolves within 36 hours to 10 weeks 6
• Local anesthetic systemic toxicity - prevent by calculating weight-based dosing and having resuscitation equipment immediately available 3, 1

Site-Specific Risks for Brachial Plexus Block

• Pleural puncture - particularly with supraclavicular approach, requires careful ultrasound visualization 5
• Neuraxial blockade - rare complication requiring vigilant technique 5
• Phrenic nerve palsy - more common with interscalene approach, less so with supraclavicular 5

Performing Blocks Under GA

• There is no scientific evidence that performing peripheral nerve blocks under general anesthesia increases risk of nerve injury compared to awake patients 7
• The positive correlation between paresthesia and nerve injury in case reports does not establish causation 7
• Risk of systemic toxicity is not higher when blocks are performed under GA 7

Continuous vs Single-Shot Technique

Single-Shot Advantages

• Simpler technique with no catheter-related complications 5
• No risk of catheter obstruction, migration, or leakage 5
• Avoids infectious complications associated with catheters 5
• Appropriate for procedures where pain intensity decreases significantly after 12-24 hours 5

Continuous Catheter Advantages

• Provides extended analgesia beyond single-shot duration 4
• Reduces time to discharge readiness compared to single-shot 5
• Allows titration of analgesia to patient needs 4

Continuous Catheter Disadvantages

• Bacterial colonization occurs in 28.7% of catheters, though clinically significant infection is rare (0.07%) 6
• Local inflammation occurs in 3% of patients 6
• Risk factors for infection include catheter duration >48 hours, male sex, and absence of antibiotic prophylaxis 6
• Requires appropriate patient selection, education, and 24/7 availability of healthcare provider 5
• Catheter obstruction, migration, and accidental removal complicate management 5

Alternative Regional Techniques (Not Recommended for This Case)

Neuraxial Anesthesia

• Not applicable for upper extremity surgery - neuraxial techniques are recommended for lower extremity procedures like hip and knee arthroplasty 8
• Carries risk of urinary retention and hemodynamic instability 1
• Requires specific contraindication screening for coagulopathy 1

Isolated GA Without Regional Block

• Results in higher opioid consumption and increased respiratory depression 1
• Provides no extended postoperative analgesia 4
• Associated with higher pain scores in immediate postoperative period 4

Critical Safety Measures

Immediate Availability Requirements

• Have resuscitation equipment immediately available at bedside 3, 1
• Monitor blood pressure and electrocardiogram continuously, especially in patients with cardiovascular risk 3, 1
• Ensure external defibrillation equipment is readily available 8

Block Assessment

• Thoroughly test for block success before proceeding with surgery to avoid inadequate anesthesia 3, 1
• Use proper padding and positioning checks to prevent positioning-related nerve injury 1

Multimodal Analgesia Integration

Never use peripheral nerve blocks as monotherapy; always combine with baseline acetaminophen and NSAIDs unless contraindicated. 9

• Scheduled paracetamol decreases supplementary analgesic requirements at all pain intensities 9
• NSAIDs/COX-2 inhibitors provide additional opioid-sparing effects 9
• IV PCA with strong opioids for breakthrough pain is recommended over intramuscular administration 9

Common Pitfalls to Avoid

• Performing blocks without ultrasound guidance - significantly increases risk of complications 3, 1
• Inadequate block assessment before surgical incision - leads to inadequate anesthesia and patient distress 3, 1
• Failing to calculate weight-based local anesthetic dosing - increases risk of systemic toxicity 3
• Omitting multimodal analgesia - results in suboptimal pain control and higher opioid requirements 9
• Choosing axillary over supraclavicular approach for humeral surgery - results in lower success rates and longer onset times 2