Capnography as an aid in localizing the phrenic nerve in brachial plexus surgery. Technical note

Area of Science:

• Neurosurgery
• Anesthesiology
• Neurology

Background:

• Brachial plexus injuries often require surgical intervention.
• Accurate identification of the phrenic nerve is crucial during supraclavicular exploration.

Purpose of the Study:

• To evaluate the reliability of end-tidal Carbon Dioxide monitoring (capnography) for identifying the phrenic nerve.

Main Methods:

• Three patients with brachial plexus injuries underwent neurotization under anesthesia avoiding muscle relaxants.
• Capnography and diaphragmatic contraction were observed during blind electrical stimulation of the phrenic nerve.

Main Results:

• A distinct notch in the capnographic waveform correlated with phrenic nerve stimulation.
• Progressive waveform changes and palpable diaphragmatic contraction occurred with increased stimulation.

Conclusions:

• Capnography serves as a sensitive intraoperative tool for phrenic nerve localization.
• This method aids in the supraclavicular approach for brachial plexus surgery.