Can short Percutaneous Fixation of Nail (PFN) insertion be done under peripheral nerve block only?

Peripheral Nerve Blocks for Short PFN Insertion

Short Percutaneous Fixation of Nail (PFN) insertion can be performed under peripheral nerve blocks alone, provided appropriate block selection and technique are used, with consideration of patient-specific factors and coagulation status.

Block Selection and Risk Assessment

• Peripheral nerve blocks can be divided into two risk categories based on hemorrhage risk and compressibility of the area 1:

  • Low-risk blocks: Areas where bleeding is easily controllable or compressible (e.g., femoral block, sciatic block in popliteal fossa) 1
  • High-risk blocks: Areas where bleeding cannot be compressed or consequences are potentially severe (e.g., infraclavicular block, parasacral sciatic block, posterior lumbar plexus block) 1

• For short PFN insertion, a combination of blocks may be required depending on the surgical site:

  • Femoral nerve block for anterior thigh coverage 2
  • Sciatic nerve block for posterior thigh and lower leg coverage 2
  • Obturator nerve block may be needed for complete analgesia 2

Technical Considerations

• Ultrasound guidance is strongly recommended to:

  • Reduce risk of local anesthetic systemic toxicity 1, 2
  • Improve accuracy of needle placement 2
  • Allow for reduced volumes of local anesthetic 3

• Use in-plane needling along the visual axis for improved speed and accuracy 2

• Calculate safe dose of local anesthetic based on patient weight to prevent systemic toxicity 2

Special Considerations for Anticoagulated Patients

• For patients on anticoagulants (e.g., dabigatran), assess the risk-benefit ratio carefully 1:

  • Low-risk peripheral blocks may be performed if the benefit/risk ratio is favorable 1
  • High-risk blocks are contraindicated unless dabigatran concentration is ≤30 ng/mL 1
  • If general anesthesia is contraindicated and high-risk blocks are needed, consider administering idarucizumab to neutralize dabigatran 1

• All blocks in anticoagulated patients should be performed under ultrasound guidance by an experienced operator 1

Advantages of Peripheral Nerve Blocks for PFN Insertion

• Peripheral nerve blocks have fewer physiological and hemodynamic side effects compared to neuraxial techniques 1
• Most peripheral blocks do not cause sympathectomy leading to hypotension 1
• PNBs provide superior pain control and reduce opioid consumption compared to IV opioids 4
• Reduced risk of complications associated with neuraxial anesthesia 1

Potential Complications and Precautions

• Monitor for vascular puncture, bleeding, nerve damage, and local anesthetic systemic toxicity 4
• Specific complications to watch for:
  • Quadriceps weakness with femoral nerve block 4
  • Risk of falling if weight-bearing is attempted before block resolution 4
• Have resuscitation equipment immediately available 3
• Monitor blood pressure and electrocardiogram, especially in patients with high cardiovascular risk 2

Block Duration and Continuous Techniques

• Single-injection blocks typically last 12-24 hours 4
• For prolonged analgesia, consider continuous peripheral nerve block catheters 5
• Continuous techniques have been shown to provide effective postoperative analgesia for orthopedic procedures 5, 6
• Elastomeric pumps can be used for continuous infusion of local anesthetic (e.g., 0.1% bupivacaine) 5

Practical Approach

• Thoroughly test for block success before proceeding with surgery 2
• Position the patient appropriately with the leg slightly abducted for proximal approach techniques 2
• Use standard aseptic technique similar to neuraxial procedures 2
• Position the ultrasound machine in front of the operator rather than perpendicular for improved accuracy 2