Analysis on the correlation factor of percutaneous electrical nerve stimulation thresholds to locate the me-dian nerve / 临床麻醉学杂志

ABSTRACT

Objective Observed by ultrasound,this study investigated anatomical characters of median nerve affecting the minimal current intensity of percutaneous electrical nerve stimulation (PNS).Methods Forty healthy adult volunteers were enrolled in this prospective observational stud-y.PNS was performed with a stimulating pen in 2 Hz,0.2 ms,3 mA probe mode for cubits the me-dian nerve localization.Stimulation current was adjusted according to the motor response and the min-imal current intensity at which the motor response was obtained was recorded.There after,the medi-an nerve was observed with ultrasound imaging at the location point.Then,the depth,diameter,area and circumference of the nerve were determined.Results The minimal current intensity was (1.9 ± 0.6)mA and the depth of nerve was (6.1±1.7)mm.The linear regression equation between the mini-mal current intensity and the depth of nerve isY (nerve depth,cm)=0.359 +0.135X1 (minimum current intensity,mA),the determination coefficient R2 =0.25 1 (P <0.01).Conclusion The stimu-lation threshold of PNS localization the median nerve was correlated to the depth of nerve,which sug-gests that PNS not only can determine the position of the peripheral nerve,but also can help predict the depth of the peripheral nerve according to the minimum stimulus current.