Statistical analysis of 20 patients shows a mean cardiac output (CO) of 5 L/min with a standard deviation of 1 L/min. The distribution pattern in the sample population is normal. Which of the following is the most appropriate conclusion?
(A) Approximately 33% of the sample population would be expected to have a CO between 4 and 6 L/min
(B) Approximately 95% of the sample population would be expected to have a CO between 3 and 7 L/min
(C) Ten of the sample patients have a cardiac output greater than 5 L/min
(D) The mean and the median are both at the 50th percentile
(E) The median and the mode are the same in the sample population
Two days after total abdominal hysterectomy, a 54-year-old woman develops lethargy followed by seizures and coma. Laboratory studies show a serum sodium concentration of 108 mEq/L and serum osmolality of 225 mOsm/kg. The most appropriate next step in management is administration of which of the following?
A 40-year-old patient has pain following injection of 8 ml of thiopental 2.5% through a right radial artery catheter. His hand remains pink. Which of the following is the most appropriate next step?
(A) Injection of lidocaine through the catheter
(B) Injection of nitroglycerin through the catheter
The five curves shown represent the uptake of enflurane, desflurane, halothane, isoflurane, and nitrous oxide. Which uptake curve best depicts desflurane?
A 70-kg, 46-year-old man is undergoing clipping of a cerebral aneurysm with nitrous oxide, opioid, relaxant anesthesia. He is otherwise healthy. As the surgeons are about to enter the dura, the brain is noted to be tense and bulging. Heart rate is 100 bpm and mean arterial pressure is 90 mmHg. PaO2 is 120 mmHg, PaCO2 is 23 mmHg, and pH is 7.50. Which of the following should be done immediately?
(A) Hyperventilation to a PaCO2 of 15 to 20 mmHg
(B) Administration of furosemide 20 mg intravenously
(C) Administration of mannitol 0.5 g/kg
(D) Administration of thiopental 250 mg in increments
A 75-year-old man with a left bundle branch block is undergoing placement of a pulmonary artery catheter through the right internal jugular vein. He becomes pale and his heart rate decreases to 40 bpm when the catheter tip enters the right ventricle. The most likely cause is