Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2014
Minimal Current Intensity to Elicit an Evoked Motor Response Cannot Discern Between Needle-Nerve Contact and Intraneural Needle Insertion.
The ability of an evoked motor response (EMR) with nerve stimulation to detect intraneural needle placement reliably at low current intensity has recently been challenged. In this study, we hypothesized that current intensity is higher in needle-nerve contact than in intraneural needle placement. ⋯ The confidence interval for differences suggests minimal current intensity to elicit a motor response that cannot reliably discern between a needle-nerve contact from intraneural needle placement. In addition, an EMR at threshold currents <0.2 mA (irrespective of the applied pulse duration) indicates intraneural needle placement or needle-nerve contact.