A 45-year-old, 73-inch-tall, 200 lb male patient is admitted to the emergency department with an exacerbation of myasthenia gravis.
The respiratory therapist assesses the patient and finds the patient's maximum inspiratory pres-sure is 15 cm H2O and his vital capacity is 1200 mL. It is decided that the patient requires venti-latory support. The most appropriate ventilator settings for this patient are which of the follow-ing?
a. Pressure support ventilation (PSV) 5 cm H2O, continuous positive airway pressure (CPAP) 10 cm H2O, FIO2 0.50
b. Pressure-controlled continuous mandatory ventilation (PC-CMV), f = 16 breaths/min, peak inspiratory pressure (PIP) = 35 cm H2O, positive end-expiratory pressure (PEEP) 3 cm H2O, fractional inspired ox-ygen (FIO2) 0.45
c. Noninvasive positive pressure ventila-tionbilevel positive airway pressure (NPPVBiPAP), f = 14 breaths/min, in-spiratory positive airway pressure (IPAP) = 28 cm H2O, expiratory positive airway pressure (EPAP) = 5 cm H2O, FIO2 0.30
d. Volume-controlled intermittent mandatory ventilation (VC-IMV), f = 12 breaths/min, tidal volume (VT) = 725 mL, PSV 5 cm H2O, PEEP 5 cm H2O, FIO2 0.24
Question 2
Patients with acute severe asthma requiring mechanical ventilation are difficult to manage be-cause of which of the following?
a. Diaphragmatic paralysis
b. Increased lung compliance
c. Decreased airway resistance
d. Uneven alveolar hyperexpansion