Review Question - QID 109845

A 55-year-old man with no significant medical history presents to the hospital for an elective total right knee replacement. He works as a construction worker and said that frequent kneeling and squatting has caused his knees to wear out faster. He has not had anything to eat since last night. After consent is obtained for regional anesthesia via an adductor canal block, monitors are applied, which shows that his pulse is 100/min with a pattern shown in Figure A. Blood pressure is 120/70 mmHg, respirations are 14/min, and oxygen saturation is 100%. A 12-lead electrocardiogram is in Figure A. The surgery is canceled. Further laboratory workup and echocardiography reveals no findings. Which of the following is the most appropriate next step in management?