Which of the following statement(s) is/are true concerning the use of a ventilator in the treatment of respiratory failure?

c. A patient receiving excessive carbohydrate as a nutritional support may have an elevated minute ventilation and may tire with spontaneous breathing

d. In general, weaning requires an adequate inspiratory force, vital capacity, and a minute ventilation less than 10 L/min

Most intensivists favor setting the ventilator on the assist-control mode at a low sensitivity. In this fashion, the patient breathes at a rate that regulates the PaCO2 to normal, but each breath is mechanically assisted, providing maximal inflation. The volume of each breath is set by limiting the maximal pressure or maximal volume of each breath. Whichever method is used, the peak inspiratory pressure should not generally exceed 40 cm H2O. If the patient is comatose or paralyzed, the assist mode cannot be used and the rate is set in addition to the volume. Adequate weaning indices are: inspiratory force greater than 20 cm H2O, vital capacity twice the tidal volume, adequate gas exchange at assisted ventilation at FiO2 of 0.3 and 5 cm H2O of PEEP, and minute ventilation less than 10 L/min. If the patient is hypermetabolic or is receiving excessive carbohydrate as nutritional support, the minute ventilation will be elevated, even during assisted mechanical ventilation. If this is the case, the patient will tire rapidly on spontaneous breathing.