A 55-year-old man is undergoing craniotomy in the sitting position. Mean arterial pressure is 75 mmHg; arterial blood gas values are PaCO2 41 mmHg and pH 7.37. End-tidal CO2 is 7 mmHg. Which of the following is the most likely cause of the increased PaCO2 to PetCO2 gradient?
(A) Decreased cardiac output
(B) Endobronchial intubation
(C) Hyperinflation of the lungs
(D) Partial disconnect of the capnograph sample tubing
After the first 70 minutes of a transurethral resection of the prostate, a 70-year-old man becomes confused and has tachycardia, hypertension, and shortness of breath. Serum sodium concentration is 116 mEq/L. After informing the surgeon that the procedure should be terminated as soon as possible, the most appropriate next step would be to
(A) administer furosemide
(B) administer labetalol
(C) administer 3% sodium chloride
(D) change the irrigating solution to normal saline
A patient is undergoing exploration of a stab wound to the left side of the neck. On awake laryngoscopy, the left vocal cord is in midposition and the right vocal cord is abducted during inspiration. The most likely cause of these findings is trauma to which of the following structures on the left?