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

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

doi:10.3389/fphar.2022.840320

Abstract

Background: 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. Methods: 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−1 h−1) (D1 group), and one group received TIVA combined with dexmedetomidine delivered in a loading dose (1 μg kg−1 in 10 min) followed by a constant infusion rate (0.5 μg kg−1 h−1) (D2 group). The IONM data recorded before test drug administration was defined as the baseline value. We aimed at comparing the parameters of IONM. Results: In the D2 group, within-group analysis showed suppressive effects on IONM parameters compared with baseline value after a bolus dose of dexmedetomidine. Furthermore, the D2 group also showed inhibitory effects on IONM recordings compared with both the D1 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 D1 group. Conclusion: 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.

Highlights

Thoracic spinal decompression surgery (TSDS) is not as prevalent as cervical or lumbar spinal decompression surgery (Eggspuehler et al, 2007)
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−1 h−1) (D1 group), and one group received TIVA combined with dexmedetomidine delivered in a loading dose (1 μg kg−1 in 10 min) followed by a constant infusion rate (0.5 μg kg−1 h−1) (D2 group)
Special attention should be paid to the timing of a bolus dose of Loading Doses of Dexmedetomidine Inhibits intraoperative neuromonitoring (IONM)

Summary

Introduction

Thoracic spinal decompression surgery (TSDS) is not as prevalent as cervical or lumbar spinal decompression surgery (Eggspuehler et al, 2007). Propofol has become one of the primary medications used for total intravenous anesthesia (TIVA) during spinal surgery with IONM (Macdonald et al, 2013; CoreyWalker and Park, 2020). It was demonstrated that propofol–remifentanil-based TIVA has an advantage over inhalation–intravenous combined anesthesia, because TIVA exerts less influence on synaptic transmission and has minimal effects on the amplitude and latency of IONM (Hermanns et al, 2007; CoreyWalker and Park, 2020). Those effects lead to a lower rate of false-positive waveform changes compared with inhaled anesthetics (Macdonald et al, 2013; CoreyWalker and Park, 2020). 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

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Discussion

Conclusion