Combined ultrasound and nerve stimulator-guided deep nerve block may decrease the rate of local anesthetics systemic...

Area of Science:

• Anesthesiology
• Regional Anesthesia
• Patient Safety

Background:

• Local anesthetic systemic toxicity (LAST) is a risk with peripheral nerve blocks.
• Ultrasound guidance may reduce LAST for some blocks, but its efficacy for deep lower extremity blocks is debated.
• Nerve stimulator guidance is a common alternative for these blocks.

Purpose of the Study:

• To compare the incidence of LAST between ultrasound guidance and nerve stimulator guidance for deep lower extremity nerve blocks.
• To identify risk factors associated with LAST in this patient population.

Main Methods:

• A randomized controlled trial involving 300 patients undergoing elective lower limb surgery.
• Patients received lumbar plexus and sciatic nerve blocks using ultrasound guidance (Group U), nerve stimulator guidance (Group N), or dual guidance (Group M).
• Primary outcome was the incidence of LAST; secondary outcomes included needle redirection and block characteristics.

Main Results:

• The incidence of LAST was significantly higher in the ultrasound group (12%) compared to the nerve stimulator group (4%) and dual guidance group (2%).
• Hepatitis B infection (OR 3.352) and female sex (OR 9.488) were identified as significant risk factors for LAST.
• Dual guidance demonstrated the lowest incidence of LAST.

Conclusions:

• Ultrasound guidance alone was associated with a higher incidence of LAST for deep lower extremity nerve blocks compared to nerve stimulator guidance.
• Hepatitis B infection and female sex are significant risk factors for LAST.
• Combined ultrasound and nerve stimulator guidance is recommended for patients with Hepatitis B infection or female patients undergoing these blocks to enhance safety.