Mrs. Williams is an 82-year-old woman with severe chronic obstructive pulmonary disease (COPD), hypertension, and diastolic heart failure who is admitted to the medical intensive care unit (ICU) with acute hypercapnic/hypoxemic respiratory failure necessitating rescue noninvasive bilevel positive airway pressure. She seems to be fatigued and volume overloaded on physical examination, with coarse breath sounds bilaterally. You have started diuretics and empiric treatment for a COPD exacerbation, but you worry that she may not be responding adequately to noninvasive ventilation. This is her third admission in the last 6 months. She has never required intubation, and from a brief chart review, it does not seem that intubation has been previously discussed in detail.