Which of the following statements concerning the choice of nitroprusside or nitroglycerin to induce deliberate hypotension is true?
(A) Nitroglycerin is more potent
(B) Nitroglycerin produces hypotension by acting on both arterial and venous capacitance vessels
(C) Nitroprusside produces less rebound hypertension on discontinuation
(D) The toxic effects of nitroprusside are independent of dose
(E) The therapeutic effects of nitroprusside may persist on discontinuation
B
Postoperatively, a patient is being mechanically ventilated by a constant-flow, pressure-cycled ventilator with the following initial settings: inspiratory/expiratory (I/E) ratio of 1:2, peak inspiratory pressure (PIP) of 25 cmH2O, and rate of 10/min. One hour later, the I/E ratio is 1:4. Which of the following would ensure that the minute ventilation is the same as that initially set?
(A) Inflate the endotracheal tube cuff to prevent leakage
(B) Double the respiratory rate
(C) Decrease the expiratory pause until the I/E ratio is 1.0
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
To eliminate all pain during the second stage of labor, a lumbar epidural block must extend from
(A) T6 to LI
(B) T10 to LI
(C) T10 to SI
(D) T10 to S4
(E) LI to S5
D
The graphs shown illustrate various respiratory patterns in a patient who is breathing spontaneously with continuous positive airway pressure. Which of the following patterns is associated with the LEAST work of breathing?
(A) 1
(B) 2
(C) 3
(D) All patterns are associated with equal work
(E) There is not enough information to answer the question
An intubated patient is breathing spontaneously through the T-piece shown in Figure 1. Addition of tubing at A and B as shown in Figure 2 without an increase in minute ventilation will result in
(A) unchanged FiO2 and increased PaCO2
(B) unchanged FiO2 and unchanged PaCO2
(C) increased FiO2 and increased PaCO2
(D) increased FiO2 and unchanged PaCO2
(E) decreased FiO2 and increased PaCO2
C
When succinylcholine is administered intravenously to infants, intragastric pressure
(A) is usually unchanged
(B) increases to a peak of 30 cmH20 within two minutes
(C) increases because of abdominal muscle fasciculations
(D) increases because of an acetylcholine-like effect on the vagus nerve