The following changes occur during posterior cervical fusion in the prone position under halothane and nitrous oxide anesthesia with mechanical ventilation: HR 78 --> 84 with frequent PVCs; BP 110/70 --> 90/50; EtCO2 4.5% --> 2.0%; EtN2 0.12% --> 4% The most appropriate next step is to
A 56-year-old woman with pulmonary fibrosis is scheduled for pneumonectomy. Which of the following parameters best predicts potential postoperative functional impairment?
In an infant, spinal anesthesia to a sensory level of T8 is achieved with tetracaine administered at the L2-3 interspace. Compared with spinal anesthesia to the same sensory level in an adult, this anesthetic is associated with a
A 62-year-old man is undergoing elective coronary artery bypass grafting and aortic valve replacement for three-vessel coronary artery disease and aortic stenosis. Shortly after intubation, heart rate increases from 75 to 100 bpm and blood pressure decreases from 130/70 to 70/40 mmHg with acute, severe ST-segment depression in lead V5. Which of the following is the most appropriate management?
A direct 5-joule shock is unsuccessful in converting ventricular fibrillation occurring after discontinuation of cardiopulmonary bypass. The most appropriate next step is to
(A) administer calcium chloride
(B) administer bretylium
(C) administer regular insulin
(D) administer sodium bicarbonate
(E) increase shock energy
E
Which of the following statements concerning carbon monoxide poisoning is true?
(A) Diagnosis is excluded if the PaO2 is greater than 300 mmHg while breathing 100% oxygen
(B) Increased inspired oxygen concentration accelerates displacement of carbon monoxide from hemoglobin
(C) Methylene blue decreases binding of carbon monoxide to hemoglobin
Following extubation after nasotracheal intubation for seven days, a 35-year-old man has fever, facial pain, nasal stuffiness, and purulent nasal secretions. The most likely cause is
Following blunt trauma to the chest, a patient has tachycardia, hypotension, and markedly distended neck veins. Each of the following is expected EXCEPT
(A) cardiac output of 2.1 L/min
(B) mixed venous oxygen saturation of 75%
(C) pulmonary artery occlusion pressure of 25 mmHg
(D) pulmonary artery diastolic pressure of 25 mmHg