A patient spontaneously breathes nitrous oxide 60%, oxygen 40%, and enflurane for one hour. The nitrous oxide is then replaced with oxygen, and the inspired enflurane concentration is increased from 1% to 2%. Over 10 minutes, the end-tidal carbon dioxide tension increases from 30 to 40 mmHg. The most likely cause is
A 66-year-old patient with aortic stenosis is scheduled for aortic valve replacement. Examination shows blood pressure of 110/60 mmHg and sinus rhythm at a rate of 75 bpm. Pulmonary artery occlusion pressure (PAOP) is 20 mmHg with a prominent a-wave on the tracing. Which of the following is the most appropriate management?
A 64-year-old patient with chronic obstructive pulmonary disease sustained fractures of ribs 4 through 8 on the left one hour ago. Examination shows agitation, heart rate of 120 bpm, respiratory rate of 30/min, and blood pressure of 180/100 mmHg. PaO2 is 70 mmHg and PaCO2 is 35 mmHg on room air. Radiographs of the chest show no abnormalities. Which of the following is the most appropriate immediate management?
Which of the following pre-existing conditions predisposes to new-onset third-degree heart block during pulmonary artery catheterization?
A patient has severe hypotension, bronchospasm, and edema of the upper airway after injection of radiocontrast medium during cerebral angiography. The most appropriate immediate treatment is administration of
Heparin-induced thrombocytopenia
Mepivacaine 40 ml of a 1% solution with epinephrine 1:200,000 is injected into the brachial plexus sheath at the axilla after eliciting a paresthesia in the ulnar nerve distribution. Which of the following is most likely to remain intact?
A 3-day-old infant is comatose 18 hours after surgical correction of transposition of the great vessels. Tracheal suctioning produces only a tachycardic response. Anesthesia included midazolam 0.5 mg/kg, fentanyl 60 mcg/kg, and pancuronium 0.3 mg/kg. Which of the following is the most appropriate first step in evaluation of this infant?
An endobronchial Robertshaw tube is inserted for resection of a midesophageal tumor under isoflurane, oxygen, pancuronium anesthesia. Forty minutes into a planned two-hour resection, arterial blood gas values are reported as PO2 45 mmHg, PCO2 45 mmHg, and pH 7.33. Ten minutes earlier, the values were PO2 210 mmHg, PCO2, 41 mmHg, and pH 7.39. The first action should be to
One full E-cylinder of oxygen at 20°C can deliver 2 L/min of oxygen for at most