An infant with congenital lobar emphysema is scheduled for thoracotomy. Which of the following should be included in the anesthetic management of this infant?
(A) Helium-oxygen inspired gas mixture
(B) Nitrous oxide administration
(C) Positive pressure ventilation
(D) Prophylactic placement of a chest tube
(E) Spontaneous ventilation until the chest is opened
A 60-kg, 17-year-old girl with severe idiopathic scoliosis is scheduled for Harrington rod fixation. Which of the following respiratory parameters is compatible with this disorder?
(A) Alveolar-to-arterial oxygen tension difference (A-aDO2) less than 100 mmHg while breathing pure oxygen
A 70-year-old patient has absence of the left radial pulse one month after repair of an aortic aneurysm. Arterial pressure was monitored perioperatively with a 20-gauge left radial artery catheter. Which of the following statements concerning this complication is true?
(A) A preoperative Allen's test would have predicted this complication
(B) Stellate ganglion block should be performed
(C) This complication would have been less likely with an 18-gauge catheter
(D) This patient has poor collateral circulation in the hand
(E) The pulse will likely return
E
Which of the following is the most likely effect of long-term exposure to nitrous oxide at a concentration of 50 ppm?
(A) Impaired cognitive function
(B) Inhibition of vitamin B-12 absorption
(C) Megaloblastic changes in bone marrow
(D) Teratogenesis
(E) Thrombocytopenia
C
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 25-year-old woman is undergoing emergency appendectomy at 36 weeks' gestation. Following subarachnoid injection of hyperbaric bupivacaine and placement in the supine position, the patient has nausea; heart rate is 105 bpm and blood pressure is 90/60 mmHg. Which of the following is the most appropriate management?
(A) Displacement of the uterus to the left
(B) Immediate tracheal intubation
(C) Intramuscular administration of ephedrine
(D) Placement of the operating table in the reverse Trendelenburg position
Which of the following is the most appropriate initial therapy for acute pulmonary hypertension with right ventricular dysfunction and severe systemic hypotension that occurs during anesthesia?