Which of the following is the most likely cause of a decrease in end-tidal carbon dioxide tension during general anesthesia with a constant minute ventilation?
(A) Administration of sodium bicarbonate
(B) Intravenous administration of hypertonic glucose solution
(C) Decrease in cardiac output
(D) Decrease in fresh gas flow in a Bain circuit
(E) Malfunction of the inspiratory valve in a circle system
A 70-kg 22-year-old patient with head trauma and multiple fractures of the long bones is scheduled for fixation of bilateral femoral fractures. Preoperative laboratory studies show a serum sodium concentration of 150 mEq/L, a serum potassium concentration of 3.1 mEq/L, and a urine output greater than 500 ml/hr. Which of the following agents will decrease urine output?
Three hours after total thyroidectomy, a 33-year-old man develops inspiratory stridor. The most likely cause is
(A) hematoma formation
(B) tracheomalacia
(C) tetany
(D) recurrent laryngeal nerve injury
(E) superior laryngeal nerve injury
A
A 40-year-old woman has continuous nondermatomal burning pain of the distal foot four weeks after sustaining a metatarsal fracture. On examination, the foot is mildly swollen, tender, and cool. Which of the following statements concerning this condition is true?
(A) A radiograph of the distal bones of the painful foot will show severe osteoporosis
(B) A technetium scan of the distal joints of the painful foot will show decreased uptake
(C) Early use of opioid analgesia will prevent progression of the symptoms
(D) Intravenous phentolamine will relieve the pain
(E) The chance of spontaneous recovery within eight weeks is greater than 80%
A 66-year-old woman with essential hypertension has a preoperative blood pressure of 160/95 mmHg despite receiving the usual dose of labetalol on the morning of surgery. Following endotracheal intubation, blood pressure increases to 220/120 mmHg. Which of the following is the most likely explanation?
(A) Decreased arteriolar compliance
(B) Increased circulating blood volume
(C) Increased receptor sensitivity to norepinephrine