A patient in the ICU is severely tachypneic and hypoxemic.
The respiratory rate is 30 breaths/min. On approximately 50% O2 by
mask at sea level, PaO2 is 50 mm Hg, PaCO2 is 30 mm Hg,
pH is 7.51, and HCO3 − is 23 mEq/L. The patient is in distress
but alert and able to cooperate and follow instructions.
1. What is this patient’s P(A − a)O2?
2. What type of respiratory failure is this?
3. What is the appropriate initial therapy?