A healthy 18-year-old youth is scheduled for an emergency operation for removal of a steel splinter from his right iris. Anesthesia is induced with thiopental and pancuronium and, following tracheal intubation, is maintained with nitrous oxide 2 liters, oxygen 2 liters, and halothane 1.5%. Conjunctival instillation of phenylephrine solution 10% increases blood pressure from 110/70 to 230/110 mmHg and decreases pulse from 70 to 46 bpm. The ECG shows a bigeminal pattern. The most appropriate treatment is to
(A) administer lidocaine
(B) administer atropine
(C) administer propranolol
(D) decrease halothane
(E) administer nitroprusside
E
A man with alcoholic cirrhosis and a hemoglobin concentration of 10 g/dl has an intraoperative PaO2 of 75 mmHg at an FiO2 of 0.5. Which of the following is the most likely cause of the low PaO2?
Which of the following statements concerning use of temperature-corrected blood gas measurement (pH-stat) during hypothermic cardiopulmonary bypass is true?
(A) Blood gas analysis is performed at the patient's temperature
(B) Carbon dioxide should not be added to the bypass circuit
(C) The carbon dioxide content of the patient's blood is greater than it would be without temperature correction
(D) The incidence of postoperative neurologic deficits is increased compared with the alpha-stat method
(E) The patient's temperature should be maintained above 25°C
A 5-year-old child undergoes strabismus correction during spontaneous ventilation with halothane 1.5%, nitrous oxide and oxygen 50%. Intravenous atropine 0.2 mg is administered after inhalation induction. Ten minutes after incision, heart rate decreases from 110 bpm to 40 bpm. Which of the following is the most likely cause?
(A) Administration of phenylephrine eyedrops
(B) Inadvertent external pressure on the carotid sinus
(C) Paradoxical response to a small dose of atropine