Figure 2.

Bland-Altman plot for the first transcutaneous carbon dioxide (Tcco₂)– partial pressure of carbon dioxide (Paco₂) pairs. The Bland-Altman plot is based on the first measurement per patient to avoid the bias introduced by repeat measurements in the Bland-Altman plot analysis. The mean bias between Paco₂ and Tcco₂ was –4.4 mm Hg with 95% limits of agreement, shown by the dashed lines, ranging from –27 to 18.3. There is no significant difference in the distribution among those on high-frequency oscillatory ventilation/high-frequency percussive ventilation (HFOV/HFPV), conventional mechanical ventilation (CMV), and noninvasive ventilation (NIV).