A 72 - year - old woman with stable angina is undergoing bowel resection. Anesthesia is induced with etomidate. Five minutes after starting isoflurane 1% in nitrous oxide 50%, her blood pressure decreases from 110/84 mmHg to 70/40 mmHg. Which of the following is the most likely cause?

A 38-year-old woman has a three-month history of intermittent, throbbing headaches in the left hemicranial area with associated nausea and photophobia. Examination shows no abnormalities except for a left lateral gaze palsy. Which of the following is the most appropriate initial diagnostic study?

Cessation of smoking 24 hours preoperatively is associated with which of the following perioperative findings?

A patient has seizure activity 15 seconds after receiving an injection of 0.25% bupivacaine 2 mL with epinephrine 1:200,000 for stellate ganglion block. Which of the following is the most likely cause of the seizure?

A 95-year-old man is brought to the emergency department after falling and striking his forehead. He is awake and alert and is able to walk into the emergency department on his own. Blood pressure is 85/40 mmHg, and heart rate is 58 bpm. Arterial blood gas analysis shows pH is 7.29, PaCO2 is 39 mmHg, and PaO2 is 100 mmHg. Physical examination shows severe weakness of both arms. Serum lactate concentration is elevated. Which of the following is the most likely cause of these findings?

A patient with chronic renal failure has a serum potassium concentration of 7.5 mEq/L. Which of the following is the most appropriate method for decreasing the serum potassium concentration in this patient?

During controlled ventilation, which of the following causes an increase in PETCO2 with a normal waveform on the capnograph?

A 30-year-old primiparous female was admitted to the labor and delivery suite with a 39-week intrauterine pregnancy. She had experienced a spontaneous rupture of membranes in early labor, with a cervical dilation of 4 cm and the attending OB/GYN physician requested that the epidural be placed. With the patient in the left lateral decubitus position a #18 Tuohy-Schliff needle was used with the "loss of resistance" technique. The epidural catheter easily threaded to 3 cm and was negative on aspiration for blood or cerebrospinal fluid. A test dose solution of 3 mL of 1.5% lidocaine with epinephrine 1:200,000 was slowly injected. After 2 minutes, the patient stated that she felt palpitations beginning. The heart rate increased from 88 to144 beats per minute. The blood pressure remained at 110/70, and the oxygen saturation was 96% on room air. The patient was experiencing only slight lightheadedness during this entire time and it was decided to administer adenosine. Adenosine is most effective for treatment of which of the following conditions?