A patient with COPD, who has been receiving mechanical venti…

A patient with COPD, who has been receiving mechanical ventilation for 3 weeks, has been weaned down to the following settings:  FIO2   0.30     Mandatory rate 8/min   Mode SIMV   VT(set)  400 mL   VT(spont)  320 mL   PEEP  3 cm H2O   PS  4 cm H2O  On these settings the following laboratory data is observed:  pH   7.36   PaO2  65 mm Hg   PaCO2 70 mm Hg   HCO3-  30 mEq/L   BE   -1 mEq/L  The respiratory therapist should recommend

A patient is undergoing a transport of 100 miles in a non-pr…

A patient is undergoing a transport of 100 miles in a non-pressurized helicopter. The patient is breathing spontaneously and is receiving oxygen by non-rebreather mask. As the helicopter ascends above 5,000 ft, the patient begins to exhibit cyanosis and shortness of breath. The most likely reason for this is