Carbon dioxide measurement is useful for confirmation of successful tracheal intubation and ensuring adequate ventilation. There are two types of CO2 detectors, i.e., single-use-only colorimetric devices and capnometers. Although portable capnometers are widely used for resuscitation, there have been no reports regarding their clinical utility in neonates. The correspondence between end-tidal CO2 (PetCO2) level determined using a battery-powered portable capnometer and arterial CO2 (PaCO2) was investigated using paired data obtained simultaneously from 26 neonates weighing 1262 ± 589 g at examination on mechanical ventilation. PetCO2 level and PaCO2 showed a strong correlation (r = 0.839, P < 0.001), and the correlation equation was: PetCO2 = 0.8 × PaCO2 + 1.1. Therefore, PetCO2 readings obtained with a battery-powered portable capnometer were likely to be underestimated. This became more pronounced with decreasing infant body weight at examination as the net difference in measurements of PaCO2 and PetCO2 was significantly positively correlated with infant body weight at examination (r = 0.451, P < 0.001). The observations presented here may be helpful in the use of battery-powered portable capnometers in neonates requiring controlled ventilation with tracheal intubation.
Keywords: Capnometer; End-tidal CO2; Premature infants.
© 2021. The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.