Low-dose sevoflurane co-administered with propofol-based general anaesthesia obliterates intra-operative neurophysiological monitoring in an infant

Abstract

The influence of general anaesthetic agents on intra-operative neurophysiological monitoring in neonates and infants has rarely been reported. Propofol-based anaesthesia is recommended to avoid suppression of neurophysiological monitoring. However, the administration of propofol in children undergoing prolonged procedures, especially those younger than six months, should be carefully controlled due to the potential risk of propofol infusion syndrome. Adding a small dose of inhalational anaesthetic can be an option to reduce propofol requirements. Recent guidelines in Japan suggest limiting inhalational anaesthetics to less than 0.5 minimum alveolar concentrations when co-administered with low-dose propofol during intra-operative neuromonitoring. However, there is still insufficient evidence regarding the impact of sevoflurane on neurophysiological monitoring when co-administered with propofol in infants. This report describes a case of a three-month-old infant undergoing spinal lipoma resection in which there was a dramatic suppression of neurophysiological monitoring with the addition of 0.35-0.45% sevoflurane to propofol-based anaesthesia.

Keywords: infants; intraoperative neurophysiological monitoring; motor evoked potentials; sevoflurane; total intravenous anaesthesia.

Figure 1

(a) Motor evoked potentials were suppressed with sevoflurane of 0.45% end‐tidal concentration (0.14 age‐adjusted MAC) with propofol‐based total intravenous anaesthesia (propofol 66 μg.kg⁻¹.min⁻¹ with remifentanil 0.5 μg.kg⁻¹.min⁻¹). (b) Motor evoked potentials emerged (black arrows) after discontinuing sevoflurane (propofol 66 μg.kg⁻¹.min⁻¹ and with remifentanil 0.5 μg.kg⁻¹.min⁻¹ maintained). (c) Motor evoked potentials were suppressed again with sevoflurane of 0.35% end‐tidal concentration (0.1 age‐adjusted MAC) with propofol‐based total intravenous anaesthesia (propofol 66 μg.kg⁻¹.min⁻¹ with remifentanil 1.0 μg.kg⁻¹.min⁻¹). (d) Motor evoked potentials emerged (black arrows) after discontinuing sevoflurane (propofol 66 mcg.kg⁻¹.min⁻¹ with remifentanil 1.0 mcg.kg⁻¹.min⁻¹ maintained). Lt: left, Rt: right.