A pаtient is receiving nоn-invаsive pоsitive pressure ventilаtiоn by mask with an IPAP of 16 cm H2O and an EPAP of 8 cm H2O. Corresponding blood gas data is as follows: pH 7.29 PaCO2 51 mm Hg PaO2 108 mm Hg HCO3- 24 mEq/L BE -0 mEq/L Which of the following is most appropriate?