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
During enflurane anesthesia for colectomy in a 75-year-old man with sepsis, urine output decreases to 10 ml/hr. Heart rate is 120 bpm, blood pressure is 100/50 mmHg, central venous pressure is 10 mmHg, and pulmonary artery occlusion pressure is 15 mmHg. The most appropriate management at this time is to
A 19-year-old woman receives a spinal anesthetic for a repeat cesarean delivery. Two days later she is afebrile but has severe occipital pain that is aggravated by sitting or standing and relieved by lying flat. Associated findings would likely include
After a gastric stapling procedure, a 150-kg woman is extubated and breathing spontaneously in the recovery room at a rate of 26/min and an FiO2 of 0.5. Arterial blood gas analysis shows PaO2 96 mmHg, PaCO2 44 mmHg, and pH 7.37. The parameter most closely related to her increased alveolar-arterial oxygen tension gradient is
When treating reflex sympathetic dystrophy of an arm, which of the following is the best indicator of a successful sympathetic blockade?
(A) A pinprick sensory deficit in the distribution of C6
(B) A 5°C increase in the temperature of the skin of the hand
(C) An accentuated psychogalvanometric response in the forearm
(D) An ipsilateral positive Horner's syndrome
(E) Decreased temperature sensation in the hand
B
Monitoring of a patient with a closed head injury shows the following pressures: Intracranial pressure 30 mmHg, Central venous pressure 5 mmHg, Mean arterial pressure 65 mmHg, Peak airway pressure 25 cmH,0. The cerebral perfusion pressure is
(A) 30 mmHg
(B) 35 mmHg
(C) 40 mmHg
(D) 60 mmHg
(E) 65 mmHg
B
A 70-kg, 50-year-old man is scheduled for muscle flap closure of a decubitus ulcer over the sacrum. He has been quadriplegic at the level of C6-7 for six years. Which of the following is most likely to result from subarachnoid anesthesia with tetracaine 10 mg for this procedure?