A 55-year-old male with hypertension, chronic obstructive pulmonary disease, and benign prostatic hypertrophy (BPH) presents for a transurethral resection of the prostate (TURP). Pre-operative vital signs include a blood pressure of 145/70 mm Hg, a pulse of 90 beats/min, respiration rate of 20, and a temperature of 36.4 °C. The procedure is performed under spinal anesthesia. After placement of the spinal and proper positioning of the patient, the procedure is begun without incident. About 1 hour into the procedure, the patient complains of a headache and difficulty breathing. The blood pressure is noted to be 90/50 mm Hg. Other vital signs include respirations of 25, heart rate of 65 beats/min, and an oxygen saturation of 97% on 3 L nasal cannula. What are your major concerns? Are there any laboratory tests to order? Should the procedure have been done under general anesthesia instead? How should the patient’s headache and breathing difficulties be treated?