An anesthetized, paralyzed patient is placed in the lateral position and mechanically ventilated. End-tidal PCO2 is 34 mmHg and PaCO2 is 43 mmHg. This gradient
(A) increases during spontaneous breathing
(B) indicates increased dead space ventilation
(C) is caused by increased intrapulmonary shunt
(D) reflects inhibition of hypoxic pulmonary vasoconstriction
A 72-year-old woman is somnolent one day after left carotid endarterectomy. She has smoked 2 packs of cigarettes daily for 50 years. Six weeks ago, she underwent right carotid endarterectomy. At this time, arterial blood gases while breathing room air are PO2, 45 mmHg, PCO2, 60 mmHg, and pH 7.30. Which of the following is the most likely cause of the increased PCO2?
A 75-year-old man is confused, restless and disoriented two days after an aortic aneurysm repair. Serum sodium concentration is 112 mEq/L, serum osmolality is low, and urine is hypertonic. The most appropriate treatment is
(A) restriction of fluid intake
(B) administration of isotonic saline solution
(C) administration of hypertonic (3%) saline solution
A 70-kg patient is anesthetized for a craniotomy in the sitting position. Minute ventilation through a circle system is 15 L/min; PetC02 is 65 mmHg. Which of the following is the most likely cause of the increased PetC02?
(A) Inadequate flow of fresh gas
(B) Incompetent expiratory valve
(C) Intubation of the right mainstem bronchus
(D) Light anesthesia
(E) Venous air embolism
B
Of the following, the most reliable criterion for adequate clinical reversal of neuromuscular blockade is
A patient is scheduled for amputation of the third metatarsal. A tourniquet will not be used during the procedure. The most effective anesthesia will be provided by block of which of the following nerves?