Measurement of the Skin Sympathetic Nerve Activity

Recording Sympathetic Nerve Activity From the Skin During Surgery Under General Anesthesia : a Pilot Study

Sympathetic nerve activity can be measured transcutaneously in awake patients by computer-based filtering of raw signal obtained via skin leads attached on the chest. Electrocardiogram can be removed by applying a high-pass filter setting of 150 Hz. Electromyogram can be filtered by applying a high-pass filter setting of 500 Hz or a band-pass filter setting of 500-1000 Hz.

However, it is not known whether the skin sympathetic nerve activity (SKNA) can be measured in anesthetized and/or paralyzed patients. Therefore, we planned this pilot study to observe whether the SKNA can be obtained in these patients. If the SKNA ca be observed, it will be presented in milivolt (uV).

Inclusion Criteria:

• patients scheduled to undergo resection of breast cancer under general anesthesia after insertion of laryngeal mask airway

Exclusion Criteria:

• Autonomic nervous system disease
• Medication acting on the autonomic nervous system
• Refuse to participate