Diffusion coefficient of carbon dioxide in relation to partial pressure of carbon dioxide as a marker for weaning from high-frequency oscillatory ventilation

Abstract

Background Respiratory distress syndrome and transient tachypnea of newborn are common causes for admission to neonatal ICU. Measurement of diffusion coefficient of carbon dioxide (DCO2) and partial pressure of carbon dioxide in arterial blood (PaCO2) are useful to detect changes in alveolar ventilation, pulmonary perfusion, and CO2 production and help adjust ventilation settings. Aim Our study evaluated DCO2 in relation to PaCO2 as a maker for weaning from high-frequency oscillatory ventilation (HFOV). Patients and methods A total of 40 neonates were included in the study and were divided into two equal groups based on their gestational age (preterm vs. full term), and we measured DCO2 and PaCO2 in both groups at the time of shifting to HFOV and every 4 h till weaning from HFOV. Results The mean value of DCO2 was significantly higher in the full-term group, and there was no statistically significant difference between both studied groups regarding the mean value of PaCO2, except on the third day and at the time of weaning to conventional mechanical ventilation, where it was significantly higher in the preterm group. There was a significant negative correlation between mean value of DCO2 and mean value of PaCO2 on the first, second, and third day of HFOV and at the time of weaning to conventional mechanical ventilation. Conclusion DCO2 can be used roughly as a reflection for CO2 status but cannot be used alone as an indicator for weaning from HFOV but could be used in combination with other markers.