A 75-year-old, 5-foot, 7-inch female patient with an exacerbation of COPD is placed on the fol-lowing NIV settings: IPAP = 8 cm H2O, EPAP = 4 cm H2O, rate = 12 breaths/min, FIO2 = 0.3

The resulting VT is 255 mL. An arterial blood gas sample is drawn 1 hour later, and the results are: pH = 7.33, PaCO2 = 70 mm Hg, PaO2 = 58 mm Hg, HCO3? = 35 mEq/L. What action should the respiratory therapist take at this time?
a. Increase the rate to 14 breaths/min.
b. Increase the IPAP to 10 cm H2O.
c. Intubate and mechanically ventilate the patient.
d. Increase the IPAP to 10 cm H2O and the EPAP to 6 cm H2O.

ANS: B
NIV was initiated at the appropriate settings for this patient; however, the arterial blood gas val-ues show that the patient still has hypercapnia in addition to her chronic ventilatory failure. The current settings are yielding a VT of 4 mL/kg. The IPAP needs to be increased to maintain the exhaled VT at 5-7 mL/kg. This will decrease the PaCO2 to an acceptable DIF for this patient.