Correlation of End-Tidal Carbon Dioxide with Arterial Carbon Dioxide in Mechanically Ventilated Neonates: A Scoping Review

Abstract

Monitoring CO2 levels in intubated neonates is highly relevant in the face of complications associated with altered CO2 levels. Thus, this review aims to present the scientific evidence in the literature regarding the correlation between arterial carbon dioxide measured by non-invasive methods in newborns submitted to invasive mechanical ventilation. The search was carried out from January 2020 to January 2021, in the Scopus, Medline, The Cochrane Library, Web of Science, CINAHL and Embase databases. Also, a manual search of the references of included studies was performed. The main descriptors used were: “capnography,” “premature infant,” “blood gas analysis,” and “mechanical ventilation.” As a result, 221 articles were identified, and 18 were included in this review. A total of 789 newborns were evaluated, with gestational age between 22.8 and 42.2 weeks and birth weight between 332 and 4790 g. Capnometry was the most widely used non-invasive method. In general, the correlation and agreement between the methods evaluated in the studies were strong/high. The birth weight did not influence the results. The gestational age of fewer than 37 weeks implied, in its majority, a moderate correlation and agreement. Therefore, we can conclude that there was a predominance of a strong correlation between arterial blood gases and non-invasive methods, although there are variations found in the literature. Even so, the results were promising and may provide valuable data for future studies, which are necessary to consolidate non-invasive methods as a reliable and viable alternative to arterial blood gasometry.

Microstream end-tidal carbon dioxide and capillary carbon dioxide in mechanically ventilated extreme preterm neonates: a methods comparison study

“…A recent scoping review of 18 studies on methods of assessment of CO2 reported that all the studies reported strong correlation and agreement between the methods with moderate correlation in gestation < 37 weeks. [7] However, none have reported having used a microstream device to measure ETCO2. We included only those neonates who were mechanically ventilated in their rst week of life to compare the two methods while the cardio-pulmonary transition is still taking place.…”

“…Most studies have used arterial samples, whereas very few have used a mix of arterial and arterialized capillary (heel-prick) samples to measure PCO2 (PacCO2). [7] We report the results of a comparison of microstream ETCO2 and PacCO2 (arterial or arterialized capillary) in mechanically ventilated extreme preterm neonates in their rst week of life.…”