Comparison of the Arterial PaCO 2 Values and ETCO 2 Values Measured with Sidestream Capnography in Patients with a Prediagnosis of COPD Exacerbation

Background Aim of this study is to investigate whether end-tidal carbon dioxide (ETCO 2 ) values can be used instead of partial pressure of carbon dioxide (PaCO 2 ) values in guiding treatment, and determining treatment benefits in patients that received a pre-diagnosis of chronic obstructive pulmonary disease (COPD) exacerbation at the emergency department. Methods This observational prospective study was conducted with patients who presented to the emergency department with the complaint of shortness of breath and were diagnosed with COPD exacerbation. ETCO 2 was measured with the sidestream method during blood gas analysis in patients with indications for this analysis. Measurements were repeated at hour 1 after treatment. Results The study included a total of 121 cases. There was a positive correlation between the PaCO 2 and ETCO 2 values measured before and after treatment ( r = 0.736, p