Influence of F(IO2) on Pa(CO2) in COPD patients with chronic CO2 retention

Abstract

We have read with interest the original article entitled “Influence of FIO2 on PaCO2 During Noninvasive Ventilation in Patients with COPD.”1 In this article, the authors prospectively evaluated 17 CO2-retaining COPD subjects recovering from acute respiratory crisis on noninvasive ventilation (NIV) with FIO2 of ≤ 0.5, and they studied the response of PaCO2 to an FIO2 of 1.0. The authors found that during NIV with an “FIO2 sufficient to maintain a normal PaO2,” a further increase in FIO2 did not result in an increased PaCO2.