A 20-kg, 5-year-old boy under treatment for five days for a cerebral contusion not requiring an operation is still unconscious. After three days of mechanical ventilation, humidified oxygen 40% via T-tube is started. Arterial blood gas analysis shows PaO2 120 mmHg, PaCO2 44 mmHg, pH 7.48, and base excess +6. A nasogastric tube is in place and draining to gravity. Daily fluid therapy has been 5% dextrose in 0.5 normal saline solution 500 ml and 5% dextrose in lactated Ringer's solution 500 ml. Serum electrolyte concentrations are sodium 140, potassium 3.2, and chloride 91 mEq/L. Serum osmolality is 300 mOsm/L. Urine output averages 15 ml/hour. Dexamethasone 8 mg/day has been the only drug therapy. This patient most likely requires
Which of the following is the most frequent cause of hemorrhagic diathesis after administration of 20 units of CPD-stored blood over six hours?
Three hours after undergoing coronary artery bypass grafting, an elderly man develops severe hypotension after intravenous administration of morphine 4 mg. Pulmonary artery occlusion pressure is 27 mmHg and central venous pressure is 30 mmHg. Transesophageal echocardiography shows decreased end-diastolic ventricular volumes. Which of the following is the most likely diagnosis?
Which of the following is the most common infection transmitted through transfusion of blood products?
A 65-year-old patient receiving long-term clonidine therapy fails to take it one day before surgery. This would most likely
Pulmonary artery diastolic pressure increases acutely from 10 to 20 mmHg in a 28-year-old man undergoing cervical laminectomy in the sitting position. The most appropriate first step in the management of this patient is to
Which of the following best explains the decreased effect of hyperventilation on cerebral blood flow when PaCO2 decreases below 20 mmHg?
A 72-year-old man has ST-segment depression of 2 mm in ECG lead II immediately after suprarenal aortic clamping. Which of the following is the most likely cause?
A patient is undergoing cholecystectomy with enflurane, nitrous oxide, fentanyl, and oxygen. He takes theophylline and cromolyn sodium for bronchial asthma. During skin incision he has bilateral wheezing; peak inspiratory pressure is 50 cmHzO, and the ECG shows occasional premature ventricular contractions. The most appropriate management is to
Which of the following is the most likely cause of a decrease in end-tidal carbon dioxide tension during general anesthesia with a constant minute ventilation?