AUTHOR=Liu Tun , Qin Yue , Qi Huaguang , Luo Zhenguo , Yan Liang , Yu Pengfei , Dong Buhuai , Zhao Songchuan , Wu Xucai , Chang Zhen , Liu Zhian , Liu Xuemei , Yuan Tao , Li Houkun , Xiao Li , Wang Gang 

TITLE=A Loading Dose of Dexmedetomidine With Constant Infusion Inhibits Intraoperative Neuromonitoring During Thoracic Spinal Decompression Surgery: A Randomized Prospective Study

JOURNAL=Frontiers in Pharmacology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.840320

DOI=10.3389/fphar.2022.840320

ISSN=1663-9812

ABSTRACT=<p><bold>Background:</bold> The effect of a bolus dose of dexmedetomidine on intraoperative neuromonitoring (IONM) parameters during spinal surgeries has been variably reported and remains a debated topic.</p><p><bold>Methods:</bold> A randomized, double-blinded, placebo-controlled study was performed to assess the effect of dexmedetomidine (1 μg/kg in 10 min) followed by a constant infusion rate on IONM during thoracic spinal decompression surgery (TSDS). A total of 165 patients were enrolled and randomized into three groups. One group received propofol- and remifentanil-based total intravenous anesthesia (TIVA) (T group), one group received TIVA combined with dexmedetomidine at a constant infusion rate (0.5 μg kg<sup>−1</sup> h<sup>−1</sup>) (D<sub>1</sub> group), and one group received TIVA combined with dexmedetomidine delivered in a loading dose (1 μg kg<sup>−1</sup> in 10 min) followed by a constant infusion rate (0.5 μg kg<sup>−1</sup> h<sup>−1</sup>) (D<sub>2</sub> group). The IONM data recorded before test drug administration was defined as the baseline value. We aimed at comparing the parameters of IONM.</p><p><bold>Results:</bold> In the D<sub>2</sub> group, within-group analysis showed suppressive effects on IONM parameters compared with baseline value after a bolus dose of dexmedetomidine. Furthermore, the D<sub>2</sub> group also showed inhibitory effects on IONM recordings compared with both the D<sub>1</sub> group and the T group, including a statistically significant decrease in SSEP amplitude and MEP amplitude, and an increase in SSEP latency. No significance was found in IONM parameters between the T group and the D<sub>1</sub> group.</p><p><bold>Conclusion:</bold> Dexmedetomidine delivered in a loading dose can significantly inhibit IONM parameters in TSDS. Special attention should be paid to the timing of a bolus dose of dexmedetomidine under IONM. However, dexmedetomidine delivered at a constant speed does not exert inhibitory effects on IONM data.</p>