A 62 year-old man with an 80-year history of chronic bronchitis reports to his healthcare provider with complaints of increasing shortness of breath, ankle swelling, and a feeling of fullness in his upper abdomen. The expiratory phase of his respirations is prolonged and expiratory wheezes and crackles are heard on auscultation. His blood pressure is 160/90 mm Hg, his red blood cell count is 6.0 x 106 uL (normal 4.2 to 5.4 x 106 uL), his hematocrit is 65% (normal male value 40% to 50%), his arterial PO2 is 55 mm Hg, and his O2 saturation, which is 85% while he is resting, drops to 55% during walking exercise.
- Explain the physiologic mechanisms responsible for his edema, hypertension, and elevated red blood cell count.
- His arterial PO2 and O2 saturation indicate that he is a candidate for continuous low-flow oxygen. Explain the benefits of this treatment in terms of his activity tolerance, blood pressure, and red blood cell count.
- Explain why the oxygen flow rate for persons with COPD is normally titrated to maintain the arterial PO2 between 60 and 65 mm Hg.