copd co2 levelscopd and elevated co2 levelsco2 levels in copd patientsnormal co2 levels for copdnormal co2 levels in copd patientselevated co2 in copdnormal co2 for copdco2 range for copdemphysema co2 levelsnormal co2 for copd patientscopd and high carbon dioxide levelscarbon dioxide levels in copd patients
