A 52-year-old man is undergoing emergency repair of a perforated duodenal ulcer. During induction, the anesthesiologist observes that after loss of consciousness, the patient exhibits rapid eyeball movements with nystagmus, increased salivation, lacrimation, and involuntary limb movements. The blood pressure is elevated (160/95 mmHg) and heart rate is 110 bpm. Respiration is irregular with periods of breath-holding. What is the current stage of anesthesia, and what is the primary concern at this stage?