Exploring intermittent transcutaneous CO₂ monitoring

Objective: To explore the accuracy of a continuous transcutaneous CO₂ (TCCO₂) monitor, used in an intermittent rather than a continuous fashion, to obtain quick (<5 mins) CO₂ readings. Design: Prospective study. Setting: An urban pediatric intensive care unit in a university teaching hospital. Patients: A convenience sample of pediatric patients with indwelling arterial catheters. Intervention: Transcutaneous monitoring was done simultaneous with arterial blood gas monitoring. Measurements and Main Results: There were 49 simultaneous-readings on 19 patients, age 5 days to 16 years, with 13 different diagnoses. The TCCO₂ was related to the PCO₂ by a Pearson product coefficient of 0.79 (p < .0005), with a mean difference of 1.94 (TCCO₂ > PCO₂) and 95% confidence interval of -0.12 to 4.07. The scatterplot produces a regression line characterized by the following equation: PCO₂ = (TCCO₂ x 1.05) - 4.08. Conclusions: Further study to evaluate intermittent TCCO₂ as a practical clinical variable is warranted. This study should encourage refinement of the technology to be more accurate for this use.