Exploring The Normal Range Of Intraoperative Neuromonitring Emg During Thyroid Surgery

[Objective] To discuss the normal range of the recurrent laryngeal nerve EMG during the application of intraoperative nerve monitoring (IONM).[Methods] There were300cases in the study of intraoperative neuromonitoring system for monitoring and protection of recurrent laryngeal never from November2009to January2012in department of Thyroid Surgery, Yantai Yuhuangding Hospital. In the procedure, a needle loop electrode obliquely piercing the same side the incision outer edge of the diameter2cm range of skin, two needle recording electrode obliquely piercing the cricothyroid muscle, at the same time, hand-held to stimulate probe vertical stimulate neural issued a "toot toot" tone, the monitor display electromyographic signals and record the latency, amplitude and duration values.[Result]1.285cases(386sizes) showed Electromyogram (EMG) clearly, EMG were not draw out in15cases (18sizes),10case(13sizes) were false-negative because of system and annesthesia questions,5case(5sizes) were because of cricothyroid muscle cancer invision, needle electrodes can not put in properly. No permanent recurrent laryngeal never paralysis occoured,2transient nerve paralysis cases recovered in three-six monthes. 2.V195%confidence interval:482-574μV, R195%confidence interval:521-615μV, V295%confidence interval:440-531μV, R295%confidence interval:489-582μV.3. The left and right side of the vagus nerve and recurrent laryngeal nerve EMG waveform have reference value difference; female and male patients was significantly higher amplitude, but the latency period and the duration is not obvious.4. Found two cases of non recurrent laryngeal nerve (NRLN).[Conclusion]1. Application IONM in thyroid surgery, not only can reduce or avoid the damage of neural structures, but also identify those who rely on the local anatomy, light, like X-to-peer is not easy to identify the specific neural structures and boundaries in order to effectively assist the surgeon instant, comprehensive understanding of the functional status of the nervous system during surgery, timely revision surgery steps to reduce or prevent permanent nerve damage.2. Through quantitative analysis of EMG waveform parameter values in IONM and found that the amplitude of the right vagus nerve was significantly larger than the left vagus nerve, the latency was significantly smaller than the left side, but the duration no significant difference. Amplitude values of the left RLN is greater than the right. Both sides of the latency and the duration of RLN is basically the same.3. The EMG amplitude and latency of vagus nerve were significant difference in the gender comparison was statistically significant, the duration of the left vagus nerve in the female patients was significantly prolonged. The EMG amplitude of RLN is significant gender differences, female patients than male. No significant difference in male and female patients with RLN latency and duration.4. There was two NRLN. By comparison we found that the latency period when the patients have NRN with vagus nerve stimulation significantly shortened.5. The technology of IONM is not very well, in some individual cases, the impact of various factors (anesthesia, electrical interference, machine failure, etc.), but also do not100%accurate prediction of neurological function, may also be a false negative or false positive report. However, with the improvement.of monitoring techniques, IONM will be followed by further development and improvement. Therefore, with the IONM in thyroid surgery avoid RLN injury is significant.