An EKG shows ventricular tachycardia in a patient with a heart rate of 160 bpm and a blood pressure of 90/60 mmHg. The best initial therapeutic maneuver prior to cardioversion is
A patient spontaneously breathes nitrous oxide 60%, oxygen 40%, and enflurane for one hour. The nitrous oxide is then replaced with oxygen, and the inspired enflurane concentration is increased from 1% to 2%. Over 10 minutes, the end-tidal carbon dioxide tension increases from 30 to 40 mmHg. The most likely cause is
(E) decreased central ventilatory response to carbon dioxide
E
During right upper lobectomy and one-lung ventilation with a double-lumen endotracheal tube, the PaO2 decreases to 40 mmHg. The PaCO2 is 39 mmHg. Which of the following is most appropriate?
(A) Confirm position of the tube with bronchoscopy
(B) Apply 5 cmH20 continuous positive airway pressure to the nondependent lung
(C) Apply 5 cmH20 positive end-expiratory pressure to the dependent lung
(D) Resume two-lung ventilation
(E) Clamp the pulmonary artery of the nondependent lung
A 45-year-old woman undergoes aortic valve replacement for aortic stenosis. Two minutes after removal of the venous cannulae, air is noted in the arterial inflow cannula. Heart rate is 80 bpm, blood pressure is 95/60 mmHg, and cardiac index is 1.5 L/min/m2. ST-segment elevation is noted in EKG leads II, III, and aVF. The most appropriate next step is to
(A) administer thiopental
(B) decrease left ventricular afterload
(C) increase arterial blood pressure
(D) replace the left ventricular vent
(E) resume cardiopulmonary bypass
C
Which of the following findings best indicates complete resolution of spinal anesthesia?