Anesthetic Plans for Wide Resection of the Humerus
Primary Recommendation
For wide resection of the humerus, the optimal anesthetic plan combines general anesthesia with endotracheal intubation plus a combination interscalene-supraclavicular brachial plexus block to provide complete surgical anesthesia and extended postoperative analgesia while minimizing opioid requirements. 1, 2
Rationale for Combined Regional-General Anesthesia Approach
Why General Anesthesia is Required
- General anesthesia with a secure airway is necessary for major orthopedic oncologic procedures like humeral resection that involve prolonged surgical time, potential for significant blood loss, and need for optimal surgical positioning 1
- The procedure requires complete immobility and airway protection that cannot be reliably achieved with regional anesthesia alone 3
Why Regional Anesthesia Should Be Added
- Peripheral nerve blocks combined with general anesthesia significantly reduce total opioid consumption, decrease respiratory depression, and improve recovery quality compared to general anesthesia alone 1
- Regional anesthesia provides extended postoperative analgesia (12-24 hours for single-shot blocks) that addresses the most intense period of post-surgical pain 4
- Peripheral nerve blocks are safer than neuraxial techniques when combined with general anesthesia because they do not cause sympathectomy or widespread hemodynamic effects 3
Specific Peripheral Nerve Block Combinations
Option 1: Combined Interscalene-Supraclavicular Block (Preferred)
This combination provides complete coverage of the entire upper extremity without requiring excessive local anesthetic volumes when performed under ultrasound guidance. 2
Technical Details:
- Interscalene block covers the superior and middle trunks (C5-C7 distribution), providing anesthesia to the shoulder and proximal humerus 2
- Supraclavicular block covers the inferior trunk and provides complete distal coverage 2
- Ultrasound guidance permits performance of both blocks without the increased volume of local anesthetic that would normally be required 2
Local Anesthetic Dosing:
- Use ropivacaine 0.5% (5 mg/mL) at 20-30 mL per block site 5
- Alternative: bupivacaine 0.5% at 20-30 mL per site (maximum 2.5 mg/kg) 6
- Total volume should not exceed safe systemic limits; ultrasound guidance reduces risk of local anesthetic systemic toxicity 7, 1
Option 2: Interscalene Block Alone (Alternative)
If surgical resection is limited to proximal humerus, a single interscalene block may provide adequate coverage. 7
Important Caveat:
- Avoid interscalene block in patients with significant respiratory comorbidities due to risk of phrenic nerve blockade and hemidiaphragm paralysis 7
- In patients with respiratory concerns, choose axillary or infraclavicular brachial plexus block over supraclavicular or interscalene approaches 7
Option 3: Supraclavicular Block Alone (Less Preferred)
- Provides reliable anesthesia with 92% success rate compared to 56-86% for axillary blocks 5
- May not provide adequate proximal shoulder coverage for wide humeral resection 2
Critical Safety Considerations
Ultrasound Guidance is Mandatory
- Always use ultrasound guidance when performing any regional technique to reduce complications and local anesthetic systemic toxicity 3, 1
- Ultrasound guidance improves needle placement accuracy and reduces risk of vascular puncture 1, 8
Block Testing Before Surgery
- Thoroughly test for block success before proceeding with surgery to minimize risk of conversion to general anesthesia 7
- Allow extra onset time (15-30 minutes) to reduce risk of inadequate block 7
Respiratory Monitoring
- Respiratory monitoring should be performed with viral filters if applicable 7
- Monitor for signs of phrenic nerve involvement if interscalene approach is used 7
Local Anesthetic Systemic Toxicity Prevention
- Calculate and use safe doses of local anesthetics based on patient weight 7
- Have resuscitation equipment immediately available including lipid emulsion 1
- Monitor blood pressure and electrocardiogram throughout procedure 1
Multimodal Analgesia Integration
Baseline Analgesics (Essential)
- Always combine peripheral nerve blocks with baseline paracetamol and NSAIDs/COX-2 inhibitors unless contraindicated 6
- Paracetamol decreases supplementary analgesic requirements at all pain intensities 6
- NSAIDs/COX-2 inhibitors provide additional opioid-sparing effects 6
Adjuvants to Consider
- Dexamethasone or methylprednisolone to reduce postoperative swelling 7
- Perineural clonidine (1-2 mcg/kg) as adjuvant to prolong block duration 7, 6
- The benefit of perineural adjuvants must be balanced against risks of immunosuppression (dexamethasone) and hemodynamic effects (clonidine) 7
Continuous Catheter Techniques
When to Consider Perineural Catheters
- For major humeral resection with endoprosthesis placement, continuous catheter techniques provide prolonged analgesia that may be beneficial despite being resource-intensive 7, 9
- The opioid-sparing effect of continuous regional anesthesia can be particularly beneficial in patients with respiratory morbidity 7
- Decision should be made based on patient needs (extent of resection, expected pain severity) and available resources 7
Catheter Dosing
- Ropivacaine 0.2% at 8 mL/hour for continuous infusion 6
- Consider patient-controlled regional analgesia through electronic or elastomeric pumps 10
Special Considerations for Oncologic Cases
Metastatic Disease Management
- Multidisciplinary team approach involving endocrinology (if endocrine-active tumor), anesthesiology, and orthopedic oncology is essential 9
- Regional anesthesia is particularly valuable in oncologic cases to minimize opioid requirements and facilitate early mobilization 9
Positioning and Nerve Injury Prevention
- Use proper padding and positioning checks to prevent positioning-related nerve injury, especially important in prolonged oncologic procedures 1
- Risk of nerve damage from blocks can be minimized with meticulous injection technique 8
Common Pitfalls to Avoid
- Never perform blocks without ultrasound guidance in modern practice 3, 1
- Do not use excessive sedation during block placement or intraoperatively, as this may increase respiratory complications 7
- Avoid interscalene blocks in patients with contralateral phrenic nerve dysfunction or severe respiratory disease 7
- Do not proceed with surgery if block testing demonstrates inadequate coverage; allow more time or supplement with additional blocks 7
- Never use peripheral nerve blocks as monotherapy for postoperative pain; always integrate with multimodal analgesia 6