A 25-year-old man with known rheumatic heart disease is being evaluated in the critical care unit. Despite decreasing cardiac output, mixed venous blood from a pulmonary artery catheter shows an increase in Sv02. Which of the following is the most likely cause?
(A) Decreasing hematocrit
(B) Hypothermia to 35°C
(C) Metabolic alkalosis
(D) Mitral regurgitation
(E) Wedging of the catheter
E
Which of the following statements concerning absorption of irrigation fluid during transurethral resection of the prostate is true?
(A) Hydrostatic pressure has minimal effect on the amount of fluid absorbed
(B) Typically 10 to 30 ml of fluid per minute are absorbed
(C) Use of iso-osmotic solutions decreases the risk of hyponatremia
(D) CNS complications are independent of the type of fluid used
(E) Spinal anesthesia to T6 will mask the symptoms of overhydration
A newly developed inhalational anesthetic has a blood-gas partition coefficient of 0.2. Which of the following statements best describes this drug compared with isoflurane?
(A) MAC is lower
(B) The difference between Fa and Fl during maintenance of anesthesia is greater
(C) Time to emergence is shorter
(D) Rapid induction requires greater overpressure
(E) Equilibrium in a circle system with the same flow of fresh gas is slower
Which of the following inhalational anesthetics best relieves left ventricular outflow obstruction in a patient with hypertrophic obstructive cardiomyopathy (IHSS)?
(A) Desflurane
(B) Halothane
(C) Isoflurane
(D) Nitrous oxide
(E) Sevoflurane
B
A 72-year-old man has ST-segment depression of 2 mm in ECG lead II immediately after suprarenal aortic clamping. Which of the following is the most likely cause?
(A) Decreased left ventricular stroke volume
(B) Decreased venous return
(C) Increased left ventricular wall tension
(D) Reflex tachycardia
(E) Release of epinephrine from hypoperfused adrenal medulla
C
A 60-kg, 38-year-old woman undergoes laparoscopic tubal ligation. Paralysis is maintained for one hour with infusion of succinylcholine at a rate of 10 mg/min. At the end of the procedure, respirations are shallow and tetanic fade is noted on neuromuscular stimulation. In addition to continued mechanical ventilation, which of the following is the most appropriate next step in management?
(A) Observe until the patient recovers spontaneously
For any given FiO2 and PaCO2, the PaO2 is lower in a healthy paralyzed patient anesthetized with isoflurane than in the same patient unanesthetized and breathing spontaneously. The primary cause of this difference is
(A) controlled ventilation
(B) increased airway resistance
(C) inhibition of hypoxic pulmonary vasoconstriction