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Updated: May 30, 2026
12:19
Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System
Published on: January 20, 2012
Specific evoked motor response for supraclavicular brachial block
Shahla Haleem1, Maulana M Ansari, Abdul Q Khan
1Department of Anesthesia, J. N. Medical College, Aligarh Muslim University, Aligarh (U.P.), India.
Neurosciences (Riyadh, Saudi Arabia)
|August 23, 2011
Summary
Specific evoked motor responses (EMRs) accurately predict surgical anesthesia success in peripheral nerve stimulator (PNS) assisted supraclavicular blocks. Flexion of the second and third fingers, or all four fingers, indicates a reliable block.
Area of Science:
- Anesthesiology
- Regional Anesthesia
- Nerve Blockade
Background:
- Peripheral nerve stimulator (PNS) use aids in guiding regional anesthesia.
- Supraclavicular blocks are common for upper limb surgery.
- Predicting block success is crucial for patient safety and surgical outcomes.
Purpose of the Study:
- To evaluate the predictive accuracy of various evoked motor responses (EMRs).
- To determine which EMRs reliably indicate successful surgical anesthesia.
- To assess EMRs following peripheral nerve stimulator-assisted supraclavicular block.
Main Methods:
- Prospective study of 60 patients undergoing upper limb surgery.
- Peripheral nerve stimulator used to identify EMRs at 0.25 mA, 2 ms.
- Supraclavicular block performed with 30 ml of 0.375% Bupivacaine upon EMR identification.
Main Results:
- 100% sensitivity for successful anesthesia observed with specific EMRs: flexion of 2nd/3rd fingers or all 4 fingers.
- Thumb opposition EMR showed 83% success rate.
- Other EMRs correlated with inadequate anesthesia or block failure.
Conclusions:
- Flexion of the second and third fingers, or all four fingers, are reliable predictors of complete surgical anesthesia.
- PNS-assisted supraclavicular block using these EMRs demonstrated no pneumothorax or nerve damage.
- Specific EMRs enhance the predictability of regional anesthesia success.
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