A patient is undergoing thoracotomy in the lateral position. Five minutes after initiation of one-lung ventilation using a double-lumen tube and 100% oxygen, SpO2 decreases from 100% to 65%. Which of the following is the most appropriate initial step in management?
(A) Adding continuous positive airway pressure to the nondependent lung
(B) Adding positive end-expiratory pressure to the dependent lung
(C) Increasing the tidal volume to the dependent lung
(D) Resuming two-lung ventilation
(E) Verifying the position of the double-lumen tube
An 8-kg, 1-year-old boy is scheduled for a bilateral inguinal hernia repair. If regional anesthesia is to be used for post-operative analgesia, which of the following statements is true?
(A) Caudal administration of 0.25% bupivacaine will provide analgesia without evidence of motor block
(B) Caudal administration of 0.125% bupivacaine is as effective as caudal administration of 0.25% bupivacaine
(C) Caudal analgesia is more difficult to achieve in young children than in adults
(D) The recommended volume of local anesthetic used for caudal analgesia in children is 3 ml per year of age
(E) The volume of 0.25% bupivacaine required for bilateral ilioinguinal and iliohypogastric nerve blocks would be too large
In a patient receiving an epidural analgesic infusion postoperatively, clear fluid is noted to drip back freely from the epidural catheter. Each of the following findings correctly identifies the associated fluid EXCEPT
(A) precipitation when mixed with an equal volume of thiopental — local anesthetic
During cardiopulmonary bypass, the perfusionist notes that the mixed venous oxygen saturation has decreased from to 55%. Which of the following is the most likely cause?
(A) Administration of a nitroprusside bolus
(B) Administration of a thiopental bolus
(C) Decrease in rectal temperature from 34°C to 28°C
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 patient with lumbar disk disease requires lumbar epidural injection of a corticosteroid for control of low back pain. Which of the following statements concerning this treatment is true?
(A) Maximum effect occurs one hour after injection
(B) Maximum effect occurs when drug concentration peaks in cerebrospinal fluid
(C) Maximum effect occurs during the acute phase of the disease
(D) The beneficial effect results primarily from sympathetic neurolysis
(E) It is contraindicated if the patient has had prior surgical procedures on the lumbar disks
A 24-year-old woman with abruptio placentae at 38 weeks' gestation has bleeding at the site of the intravenous catheter. Which of the following is the most likely cause?