Noninvasive monitoring of carbon dioxide during mechanical ventilation in older children: End-tidal versus transcutaneous techniques
Anesthesia and Analgesia
We prospectively compared the accuracy of end-tidal CO2 (ETco2) and transcutaneous CO2 (TCco2) monitoring in older pediatric patients (4 yr or older) receiving mechanical ventilation for respiratory failure. ETco2 and TCco2 were simultaneously monitored and compared with arterial CO2 (Paco2) values when arterial blood gas analysis was performed. Eighty-two sample sets were compared. The ETco2 to Paco2 difference was 6.4 ± 6.3 mm Hg, whereas the TCco2 to Paco2 difference was 2.6 ± 2.0 mm Hg (P < 0.0001). The absolute difference of ETco2 and Paco2 was 5 or less in 47 of 82 measurements, whereas the absolute TCco2 to Paco2 difference was 5 or less in 76 of 82 measurements (P < 0.00001). Regression analysis of ETco2 and Paco2 values revealed a correlation coefficient of 0.5418 and an r value of 0.8745. Regression analysis of TCco2 and Paco2 values revealed a correlation coefficient of 1.0160 and an r value of 0.9693. Bland-Altman analysis revealed a bias of -5.68 with a precision of ±6.93 when comparing ETco2 with Paco2 and a bias of 0.02 with a precision of ±3.27 when comparing TCco2 and Paco2 (P < 0.00001). TCco2 monitoring provided an accurate estimation of Paco2 over a wide range of CO2 values and was superior to ETco2 monitoring in older pediatric patients with respiratory failure. TCco2 monitoring may be considered as a useful adjunct to monitoring of ventilation in this patient population.
Berkenbosch, J., Lam, J., Burd, R., & Tobias, J. (2001). Noninvasive monitoring of carbon dioxide during mechanical ventilation in older children: End-tidal versus transcutaneous techniques. Anesthesia and Analgesia, 92 (6). http://dx.doi.org/10.1097/00000539-200106000-00015