NIM TriVantage™ electromyogram endotracheal tube kinking and the preclusion using a tube stand in patients undergoing thyroid surgery

ABSTRACT Background: The NIM TriVantage™ electromyogram endotracheal tube (NIM [Nerve Integrity Monitoring] tube) is positioned at the midline of the mouth, as the electrodes must attach to both sides of the vocal cords for neural monitoring during thyroid surgery. The tube possibly kinks below the slip joint, resulting in ventilatory disturbance. We examined whether kinking of the NIM tube altered ventilation in a simulation model and assessed whether using a tube stand during thyroid surgery prevented such kinking and associated ventilatory instability. Methods: We assessed the impact of bending warmed (32°C) NIM tubes (7.0- and 8.0-mm ID, n = 10 per group) on airway pressure and measured tidal volume within a simulator. Additionally, we investigated whether a custom-designed tube stand could mitigate ventilatory impairment when employing a midline-fixed NIM tube in patients undergoing thyroid surgery. Results: In a simulator, 75° bending of the NIM (7.0 mm) tube significantly augmented airway pressure (31 [28 to 34] cmH 2 O, median [IQR], P < 0.001), and 60° and 75° bending of it caused a slight, but significant decrease in the measured tidal volume compared with 0° bending. Using our custom tube stand prevented kinking of the 7.0-mm NIM tube, with no clinically meaningful changes in airway pressure or delivered tidal volume during surgery. Conclusions: The NIM (7.0 mm) tube is vulnerable to kinking-induced ventilatory impairment in the clinical setting, and a tube stand prevents this issue. We recommend using a tube stand during thyroid surgery to ensure safe and effective neural monitoring.