Assessment of flow waves and colorimetric CO2 detector for endotracheal tube placement during neonatal resuscitation

Abstract

AimClinical assessment and end-tidal CO2 (ETCO2) detectors are routinely used to verify endotracheal tube (ETT) placement. However, ETCO2 detectors may mislead clinicians by failing to identify correct placement under a variety of conditions. A flow sensor measures gas flow in and out of an ETT. We reviewed video recordings of neonatal resuscitations to compare a colorimetric CO2 detector (Pedi-Cap®) with flow sensor recordings for assessing ETT placement. MethodsWe reviewed recordings of infants <32 weeks gestation born between February 2007 and January 2010. Airway pressures and gas flow were recorded with a respiratory function monitor. Video recording were used (i) to identify infants who were intubated in the delivery room and (ii) to observe colour change of the ETCO2 detector. Flow sensor recordings were used to confirm whether the tube was in the trachea or not. ResultsOf the 210 infants recorded, 44 infants were intubated in the delivery room. Data from 77 intubation attempts were analysed. In 35 intubations of 20 infants both a PediCap® and flow sensor were available for analysis. In 21 (60%) intubations, both methods correctly identified successful ETT placement and in 3 (9%) both indicated the ETT was not in the trachea. In the remaining 11 (31%) intubations the PediCap® failed to change colour despite the flow wave indicating correct ETT placement. ConclusionColorimetric CO2 detectors may mislead clinicians intubating very preterm infants in the delivery room. They may fail to change colour in spite of correct tube placement in up to one third of the cases.