A 70-kg man with ischemic heart disease is undergoing abdominal aortic aneurysm resection. At the time of infrarenal cross-clamping, 0.2-mV ST-segment depression appears on lead V5 of the ECG. Hemodynamic changes occurring at the same time are shown below. Systemic blood pressure 90/50 --> 150/90; Heart rate 80 --> 95; PAp 20/10 --> 45/24; Mean pulmonary artery occlusion pressure (mmHg) 10 --> 23; Cardiac output (L/min) 4.5 --> 3.2. Ischemia would be decreased by restoring the pre-clamp level of each of the following EXCEPT
After termination of cardiopulmonary bypass, a patient who is chronically digitalized receives digoxin 0.5 mg in error. An ECG shows sinus bradycardia with intermittent sinus arrest; blood pressure is 90/60 mmHg. Which of the following drugs is contraiindicated in this patient?
A 35-year-old woman who takes a diuretic daily for chronic hypertension has a serum potassium concentration of 3.1 mEq/L on the morning of an elective hysterectomy. An EKG shows left ventricular hypertrophy. The most appropriate management is to
(A) consult with a cardiologist before proceeding
(B) initiate oral potassium replacement and proceed with the operation when potassium concentration is normal
(C) initiate intravenous potassium replacement and proceed with the operation
(D) initiate intravenous potassium replacement and proceed with the operation when potassium concentration is 4 mEq/L
(E) proceed with the operation without intervention
E
A 43-year-old man has been hoarse for two weeks since undergoing anterior cervical fusion at C7-8 for treatment of a herniated disk. Laryngoscopy shows paralysis of the right vocal cord. Which of the following is the most likely cause?
(A) Damage to the glossopharyngeal nerve during surgery
(B) Damage to the superior laryngeal nerve during surgery
(C) Nerve root compression by the herniated disk
(D) Stretching of the recurrent laryngeal nerve during surgery
(E) Trauma to the vocal cords during intubation
D
During laser excision of vocal cord polyps in a 5-year-old boy, dark smoke suddenly appears in the surgical field. The trachea is intubated and anesthesia is being maintained with halothane, nitrous oxide, and oxygen. The most appropriate initial step is to