10 Random Questions
Two days after coronary artery bypass grafting, a 62-year-old man remains sedated, tracheally intubated, and mechanically ventilated with full neuromuscular block. Over the next three hours, Pa02 decreases from 90 to 70 mmHg at an Fl02 of 0.7, peak inspiratory pressure measured proximally in the ventilatory circuit increases from 40 to 66 cmH20, and plateau pressure remains unchanged at 30 cmH20. Which of the following is the most likely cause of these changes?
- (A) Adult respiratory distress syndrome
- (B) Bronchial mucus plugging
- (C) Left ventricular failure
- (D) Lobar pneumonia
- (E) Tension pneumothorax
During controlled ventilation, which of the following will cause an increase in end-tidal carbon dioxide tension with a normal waveform on the capnograph?
- (A) Bronchospasm
- (B) Rapid blood loss
- (C) Ventricular fibrillation
- (D) Endobronchial migration of the endotracheal tube
- (E) Release of a thigh tourniquet
Which of the following findings would be considered normal in the EEG of an adult?
- (A) Decreased frequency during induction with halogenated anesthetics
- (B) Decreased frequency in frontal areas with administration of nitrous oxide 50%
- (C) Dominance of beta rhythm at 20 to 30 Hz during the awake relaxed state
- (D) Electrical silence with administration of isoflurane 2.5 MAC
- (E) The presence of burst-suppression during natural sleep
During active labor, 10 ml of bupivacaine 0.5% with epinephrine 1:200,000 is administered epidurally. Fifteen minutes later, maternal blood pressure is 70/50 mmHg and heart rate is 70 bpm; fetal heart rate is 90 bpm for 45 seconds, with loss of beat-to-beat variability. The most likely explanation for the fetal vital signs is
- (A) fetal bupivacaine cardiotoxicity
- (B) maternal bupivacaine cardiotoxicity
- (C) maternal hypotension
- (D) uterine artery vasoconstriction
- (E) umbilical cord compression
During pulmonary artery catheterization, a 65-year-old man receives morphine 6 mg and scopolamine 0.4 mg intravenously. The pulse oximeter indicates desaturation, which quickly resolves with stimulation. When the drapes are removed, he has unilateral eye pain, decreased visual acuity, and dilated and irregular pupils. These eye symptoms are most likely caused by
- (A) retinal hemorrhage
- (B) morphine-induced oculogyric crisis
- (C) corneal abrasion
- (D) carotid artery embolization
- (E) angle-closure glaucoma
Pulmonary artery occlusion pressure
- (A) does not reliably reflect left ventricular end-diastolic volume when left ventricular compliance is reduced
- (B) inaccurately reflects left atrial pressure when left atrial pressure exceeds 15 mmHg
- (C) is measured at end-inspiration in mechanically ventilated patients
- (D) overestimates left atrial pressure in patients with poor lung compliance
- (E) reflects left atrial pressure only if the catheter tip is located in zone II of the lung
Which of the following statements concerning functional residual capacity is true?
- (A) It decreases linearly during a three-hour anesthetic
- (B) It decreases in pregnancy primarily because of a decrease in the expiratory reserve volume
- (C) It increases in patients with a history of heavy smoking
- (D) It increases with pulmonary contusions
- (E) It is smaller (ml/kg) in children than in adults
A 57-year-old man who weighs 150 kg and is 170 cm (67 in) tall is scheduled for cholecystectomy. He has a 100 pack-year smoking history. Which of the following findings on pulmonary function testing are most likely?
The carbon dioxide/ventilation response curve
- (A) is primarily a measure of the integrity of the peripheral chemoreceptors
- (B) shows parallel displacement to the left in the presence of opioids
- (C) is linear between a PaCO2 of 20 and 120 mmHg
- (D) shows progressive changes in slope with increased doses of halogenated anesthetics
- (E) is unaffected by a decrease in PaO2 to 60 mmHg
Upon removal of the epidural catheter after uneventful labor and delivery in a 25-year-old primiparous woman, approximately 1.2 cm of the Teflon catheter is left behind in the epidural space. The patient is informed of the complication. The most appropriate management is
- (A) immediate surgical removal
- (B) prophylactic antibiotics
- (C) lumbar myelogram
- (D) monthly neurologic examinations
- (E) no intervention