A 50-year-old patient is undergoing middle ear exploration with isoflurane, nitrous oxide, and oxygen anesthesia. Ventilation is controlled; PetC02 is 35 mmHg, heart rate is 90 bpm, and blood pressure is 120/70 mmHg. Assistance is needed to minimize bleeding in the surgical field. Which of the following is the most appropriate next step in management?
(A) Addition of 5 cmH20 positive end-expiratory pressure
(B) Changing the anesthetic agent to halothane
(C) Hyperventilation to a PetC02 of 20 mmHg
(D) Placing the patient in reverse Trendelenburg position
(E) Titration of nitroprusside to a mean arterial pressure of 55 mmHg
D
A woman has weakness of the right quadriceps and a decreased knee jerk reflex on the right one day after forceps delivery under epidural anesthesia. The most likely cause is
(A) epidural hematoma
(B) intrapelvic nerve trauma
(C) lithotomy positioning
(D) reaction to the preservative in the anesthetic solution
A 13-year-old African American boy has severe abdominal pain after debridement of an open fracture of the lower extremity. His hemoglobin concentration is 10 g/dl and a peripheral blood smear shows elongated crescent-shaped erythrocytes. The most appropriate initial therapy is
(A) sodium bicarbonate administration
(B) dopamine infusion
(C) blood transfusion
(D) volume loading with crystalloid
(E) high-dose corticosteroid administration
D
A 25-year-old woman is undergoing emergency appendectomy at 36 weeks' gestation. Following subarachnoid injection of hyperbaric bupivacaine and placement in the supine position, the patient has nausea; heart rate is 105 bpm and blood pressure is 90/60 mmHg. Which of the following is the most appropriate management?
(A) Displacement of the uterus to the left
(B) Immediate tracheal intubation
(C) Intramuscular administration of ephedrine
(D) Placement of the operating table in the reverse Trendelenburg position
During general anesthesia using a modern anesthesia machine, a patient's spontaneous ventilation is manually assisted with a fresh gas flow of 5 L/min. A sudden malfunction of the pressure-relief (pop-off) valve of the circle absorption system occurs, and the valve cannot be opened. The most appropriate next step is to