A 62-year-old man, who had a myocardial infarction three years ago, complicated by congestive heart failure and renal failure, is undergoing a colectomy. A pulmonary artery catheter demonstrates a cardiac output higher than measurements recorded during a cardiac catheterization two months after the infarction. Which of the following most likely contributes to the increased cardiac output?
(A) Creation of an arteriovenous fistula
(B) Increased hemoglobin concentration from 10 to 12 g/dl
(C) Stimulation of carotid body receptors
(D) Transcutaneous nitroglycerin
(E) Use of a beta-adrenergic blocker to prevent myocardial reinfarction
Oxygen 100 ml/min is bubbled through a vaporizer containing an anesthetic with a vapor pressure of 150 mmHg, and this mixture is added to a fresh gas flow of 5 L/min. The delivered anesthetic concentration is
A 1150-g, 10-day-old infant is undergoing a bowel resection for necrotizing enterocolitis. Heart rate is 200 bpm and blood pressure measured through a femoral artery catheter is 45/24 mmHg. The most appropriate next step is administration of
Following cardiopulmonary bypass, right ventricular distention is noted after infusion of protamine 40 mg. Pulmonary artery pressure has increased from 25/18 to 50/30 mmHg and systemic arterial pressure has decreased from 110/65 to 0 mmHg. Which of the following is the most appropriate treatment?
(A) Administration of amrinone
(B) Administration of nitroglycerin
(C) Administration of phenylephrine
(D) Initiation of intra-aortic balloon pump assist
(E) Reheparinization and resumption of cardiopulmonary bypass