Arterial oxyhemoglobin desaturation develops more rapidly following apnea in a pregnant patient at term than in a nonpregnant patient with a large intra-abdominal tumor. Which of the following findings in pregnancy is the most likely cause?
A 5-month-old infant with tetralogy of Fallot is scheduled for elective inguinal herniorrhaphy. Which of the following would require the operation to be postponed?
A 68-year-old woman is scheduled for a mastectomy. She has not taken prescription medications for 24 hours. Preoperative examination shows a heart rate of 104 bpm and blood pressure of 200/105 mmHg. The most likely cause of these findings is omission of which of the following drugs?
(A) Amiodarone
(B) Clonidine
(C) Enalapril
(D) Hydralazine
(E) Nifedipine
B
A patient receiving mechanical ventilation with oxygen 60% postoperatively has a PaO2 of 160 mmHg and a PaCO2 of 38 mmHg. One hour later, with mechanical ventilation unchanged, the PaO2 is 150 mmHg and PaCO2 is 48 mmHg. The most likely cause of these changes is
Which of the following time concentration curves would be expected in arterial blood following intravenous injection of indocyanine green dye in a 3-year-old child with a small ventricular septal defect?
An EKG shows ventricular tachycardia in a patient with a heart rate of 160 bpm and a blood pressure of 90/60 mmHg. The best initial therapeutic maneuver prior to cardioversion is
A pulmonary artery catheter is placed in an awake patient breathing room air. Typical right ventricular and pulmonary artery pressure tracings are obtained. With the catheter balloon inflated, blood drawn from the distal port has a PaO2 of 100 mmHg, while a simultaneous radial artery sample has a PaO2 of 90 mmHg. These data indicate that the