Which arterial blood gas result is most indicative that the intubated and mechanically ventilated patient is ready to have the ventilator rate weaned?

The 20-year-old patient with asthma presents to the emergency department with increased work of breathing and severe wheezing after exposure to household dust and mold. The patient used the albuterol inhaler 6 times in the previous 4 hours with minimal relief. Upon inspection, the nurse notes extensive accessory respiratory muscle use with moderate supraclavicular retractions and nasal flaring. The nurse auscultates expiratory wheezing in all lung fields. The patient is afebrile, normotensive, significantly tachypneic, and mildly tachycardic. The nurse anticipates which findings on a chest x-ray?

A patient’s cerebrospinal fluid (CSF) is noted to have a protein level of 52 mg/dL and a glucose level of 28 mg/dL (serum glucose level 82 mg/dL). Additionally, there is an abundance (>1,000 cells/mL) of polymorphonucleocytes (PMNs) present but no erythrocytes. How does the nurse interpret these results?