P.R., a 66-year-old woman who has no history of respiratory
disease, is being admitted to your intensive
care unit (ICU) from the emergency department (ED) with a diagnosis
of pneumonia and acute respiratory
failure (ARF). The ED nurse tells you that P.R. was stuporous and
cyanotic on her arrival to the ED. Her
initial vital signs were 90/68, 134, 38, 101° F (38.3° C) with an
Spo2 of 53%. She was endotracheally intubated
orally and placed on mechanical ventilation and...