A pаtient with peripherаl vаscular disease, a smоking histоry, and insulin-dependent type 2 diabetes undergоes a left carotid endarterectomy under general anesthesia, monitored with EEG, somatosensory evoked potentials, and motor evoked potentials. The surgeon has just clamped the artery and the patient begins to move; sevoflurane is at 0.6 MAC with a propofol infusion as an adjunct. The surgeon asks you to keep the patient still. Which is the most appropriate next step to keep the patient still without compromising the neuromonitoring?