Accuracy of a battery-powered portable capnometer in neonates

Abstract

AbstractEnd-tidal CO2 measurement (EtCO2) is useful for confirmation of successful tracheal intubation and ensuring adequate ventilation. There are two types of EtCO2 detector, i.e., single-use-only devices and capnometers. Although portable capnometers are widely used for resuscitation, there have been no reports regarding their clinical utility in neonates. Here, the correspondence between EtCO2 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. EtCO2 level and PaCO2 showed a strong correlation (r = 0.839, P < 0.001), and the correlation equation was: EtCO2 = 0.8 × PaCO2 + 1.1. Therefore, EtCO2 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 EtCO2 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.