A 65-kg 70-year-old man in the PACU is breathing spontaneously at 20/min through an endotracheal tube connected to a T-piece with a fresh gas flow of 5 L/min. He has a tidal volume of 350 mL and an FiO2 of 0.5. SpO2 decreases from 98% to 84% over one hour, then improves to 92% with an FiO2 of 1.0. Which of the following is the most likely cause of the hypoxemia?
(A) Decreased functional residual capacity
(B) Increased dead space ventilation
(C) Inhibition of hypoxic pulmonary vasoconstriction
A 50-year-old woman has episodes of electric-shock-like pain of one minute in duration affecting the right side of the face. In between episodes of this pain, she is relatively pain free. Which of the following is the most appropriate management?
(A) Beta-adrenergic blockers
(B) Carbamazepine
(C) Infrared heat therapy
(D) Nonsteroidal anti-inflammatory drugs
(E) Stellate ganglion block
B
A 75-year-old, 60-kg man with moderately disabling heart failure secondary to ischemic heart disease is undergoing a transurethral prostatic resection under halothane-nitrous oxide anesthesia. Resection time is 30 minutes, and fluid replacement has been lactated Ringer's solution 500 mL. Although heart rate is unchanged, the arterial pressure monitor used because of his cardiac condition has changed from A to B over the last 15 minutes. The most appropriate management is to
(A) discontinue halothane
(B) adminster ephedrine 10 mg intravenously
(C) administer digoxin one half of his daily dose intravenously
A normotensive 66-year-old man undergoes total hip arthroplasty. Mean arterial pressure is maintained at 60 mmHg with isoflurane and labetalol; intraoperative FiO2 is 1.0. Eight units of red blood cells are administered intraoperatively because of an injury to the femoral artery. Five days later, the patient develops jaundice. Which of the following is the most likely cause of the jaundice?