A 55-year-old man has quadriplegia after undergoing suboccipital craniotomy in the sitting position for treatment of acoustic neuroma. Which of the following is the most likely cause?
(A) Air embolism with the presence of a probe-patent foramen ovale
(B) Compression of the cervical cord related to neck flexion
(C) Jugular venous obstruction
(D) Postoperative tension pneumocephalus
(E) Sustained elevation of cerebral perfusion pressure
A 35-kg child requires mechanical ventilation with pure oxygen at a tidal volume of 350 ml and a rate of 20/min during a severe asthma attack. The most likely cause of severe hypotension after initiating mechanical ventilation is
A 55-year-old woman receiving chronic dialysis for renal failure comes to the emergency department with a perforated viscus. She has chest pain. Heart rate is 124 bpm, blood pressure is 90/60 mmHg, and respiratory rate is 18/min. Surgery is to be performed within the hour. Which of the following best describes this patient's ASA physical status classification?
(A) III
(B) III E
(C) IV
(D) IV E
(E) V E
D
A multiparous 24-year-old woman sustains an amniotic fluid embolism during general anesthesia. The LEAST likely clinical finding is
A 48-year-old woman underwent a posterior fossa craniotomy in the sitting position. Monitoring included precordial Doppler, arterial blood pressure, central venous pressure (CVP), and urine output. Furosemide was used intraopera-tively for cerebral decompression, and the operation was uneventful. In the recovery room, she was awake with stable vital signs when the CVP suddenly increased from 6 to 25 mmHg without any change in blood pressure. Shortly thereafter, premature ventricular contractions are noted. After administering lidocaine 1 mg/kg intravenously, the most appropriate action is to
(A) position the patient head down, right side up and aspirate the CVP catheter
(B) withdraw the CVP catheter 5 cm
(C) infuse potassium chloride rapidly
(D) administer furosemide
(E) ask the neurosurgeon to reevaluate the patient immediately
A 14-year-old girl with status asthmaticus is receiving oxygen 3 L/min through nasal prongs. Heart rate is 110 bpm. Arterial blood gas values are PaO2 90 mmHg, PaCO2 32 mmHg, and pH 7.46. If ventilation appears unchanged, which of the following is the most reliable sign of impending respiratory failure?
A patient undergoes thoracotomy in the lateral decubitus position. Which of the following maneuvers is most likely to increase PaO2 during one-lung ventilation?
(A) Applying continuous positive airway pressure to the nondependent lung
(B) Applying positive end-expiratory pressure to the dependent lung