Which of the following statements concerning anesthetic management for MRIs is true?
(A) ECG wires are associated with patient burns
(B) Mechanical ventilation of the lungs is not feasible
(C) Monitors with ferromagnetic components may be used
(D) Oxygen analysis of inspired gas is inaccurate
(E) Pulse oximetry is not reliable near the MR scanner
A
A 45-year-old woman with mitral stenosis is scheduled for elective mitral valve replacement. Two minutes after tracheal intubation, she develops atrial fibrillation with a ventricular response rate of 150 bpm and a decrease in blood pressure to 75/45 mmHg. Which of the following is the most appropriate first step in management?
(A) Increasing the concentration of enflurane
(B) Increasing the infusion rate of lactated Ringer's solution
(C) Intravenous administration of digoxin
(D) Intravenous administration of propranolol
(E) Electrical cardioversion
E
Each of the following decreases hepatic blood flow EXCEPT
Ninety minutes after administration of succinylcholine 1 mg/kg to a 28-year-old woman, the train-of-four shows a T4:T1 ratio of 25%. This is most consistent with
Which of the following is characteristic of the pharmacokinetics of alfentanil?
(A) Clearance is greater than that of fentanyl
(B) Elimination half-life is normal in patients with hepatic insufficiency
(C) Protein binding is minimal
(D) The majority of alfentanil in plasma is ionized
(E) Volume of distribution is smaller than that of fentanyl
E
A 3-day-old infant is comatose 18 hours after surgical correction of transposition of the great vessels. Tracheal suctioning produces only a tachycardic response. Anesthesia included midazolam 0.5 mg/kg, fentanyl 60 mcg/kg, and pancuronium 0.3 mg/kg. Which of the following is the most appropriate first step in evaluation of this infant?
A 72-year-old man has massive venous hemorrhage during a radical prostatectomy. Blood pressure decreases from 110/60 to 75/30 mmHg and central venous pressure decreases from 12 to 4 mmHg. PetC02 decreases from 34 to 24 mmHg during constant minute ventilation. The most appropriate next step should be to
(A) apply positive end-expiratory pressure to the breathing circuit
(B) attempt to aspirate air from the central venous catheter
(C) expand intravascular volume
(D) place the patient in the Trendelenburg position
(E) turn the patient to the left lateral decubitus position