10 Random Questions
A 2600-g neonate is to undergo surgical repair of a small gastroschisis. The infant is preoxygenated with 100% oxygen. Arterial hemoglobin desaturation is noted during laryngoscopy after a rapid-sequence induction. Which of the following is the most likely cause?
- (A) High fetal hemoglobin concentration
- (B) High ratio of oxygen consumption to functional residual capacity
- (C) Low functional residual capacity in milliliters per kilogram
- (D) Poor thoracic compliance
- (E) Patent ductus arteriosus
A 26-year-old woman has weakness on extension of the right knee one day after uneventful vaginal delivery under spinal anesthesia with lidocaine. The most likely cause is
- (A) femoral nerve injury from thigh abduction
- (B) obturator nerve injury from obstetric forceps
- (C) peroneal nerve compression from the leg support
- (D) saphenous nerve injury from the stirrups
- (E) chemical arachnoiditis following the spinal anesthetic
Which of the following statements concerning cerebral blood flow (CBF) during anesthesia is true?
- (A) CBF changes minimally when PaC02 increases from 30 to 40 mmHg
- (B) CBF changes minimally when P02 decreases from 160 to 100 mmHg
- (C) CBF is autoregulated when mean arterial pressure is 40 mmHg
- (D) CBF is coupled to cerebral metabolism during isoflurane anesthesia
- (E) CBF is unaffected by 1.2% isoflurane at a PaC02 of 40 mmHg
The flow-volume loop indicated by the "X" is characteristic of
- (A) asthma
- (B) bronchiectasis
- (C) emphysema
- (D) pulmonary fibrosis
- (E) tracheal stenosis
You are asked to evaluate a 2000-g male infant three hours after vaginal delivery because of a respiratory rate of 50/min, pulse rate of 115 bpm, and the following arterial blood gas values while breathing room air: PaO2 64 mmHg, PaCO2 43 mmHg, and pH 7.33. His mother received meperidine 75 mg two hours before delivery. Appropriate management includes
- (A) administration of naloxone 50 mcg intramuscularly
- (B) increasing the FiO2 to 0.4
- (C) intubation and mechanical ventilation at an FiO2 of 0.5
- (D) administration of oxygen 50% with 5 cm H2O continuous positive airway pressure
- (E) observation, with no action at present
In a patient with surgically significant aortic insufficiency, cardiac output measured by thermodilution will
- (A) be greater than right ventricular output
- (B) be less than left ventricular output
- (C) be less than cardiac output measured by the Fick method
- (D) be inaccurate because of decreased signal-to-noise ratio
- (E) underestimate net systemic arterial blood flow
Compared with an induction dose of thiopental (4 mg/kg), an induction dose of propofol (2.5 mg/kg) produces
- (A) better maintenance of cerebral perfusion pressure
- (B) greater inhibition of glucocorticoid production
- (C) higher incidence of myoclonus
- (D) less severe hypotension
- (E) less severe respiratory depression
In an anesthetized patient being mechanically ventilated, end-expired carbon dioxide is 58 mmHg and peak inspiratory airway pressure is 15 cmH20. Ventilator settings indicate a delivered tidal volume of 800 ml, but the expiratory flowmeter shows a tidal volume of 360 ml. Which of the following is the most likely cause of this discrepancy?
- (A) Fresh gas flow of 0.5 L/min
- (B) Incompetence of the pressure-relief valve
- (C) Low ventilatory rate
- (D) Presence of a hole in the ventilator bellows
- (E) Prolongation of the inspiratory phase
A patient has tonic movements of the head and neck, nystagmus, and slurred speech after receiving metoclopramide for nausea after nitrous oxide-opioid anesthesia. The most appropriate pharmacologic treatment is
- (A) diphenhydramine
- (B) midazolam
- (C) naloxone
- (D) phenytoin
- (E) physostigmine
The most likely explanation for the intraoperative capnographic tracing shown is
- (A) cardiac oscillation
- (B) exhaustion of soda lime
- (C) kinking of the endotracheal tube
- (D) partial recovery from vecuronium
- (E) presence of water droplets in the analyzer