Introduction The 2005 Resuscitation guidelines recommend the use of end-tidal carbon dioxide (ETCO2) monitoring to confirm the endotracheal tube placement (ETTP) in infants weighing more than 2000 g with a perfusing cardiac rhythm. However, reliability of this method has not been fully validated in infants with lower weights.

Objective To investigate the specificity and sensitivity of ETCO2 in verifying correct ETTP in newborns and infants weighing less than 2000 g.

Methods Newborns and infants <2000 g requiring endotracheal intubation in the delivery room or in NICU were prospectively evaluated. ETTP was determined clinically and by ETCO2 using capnography, and subsequently confirmed by chest X-ray. Results are expressed as median (range).

Results Fifty-four patients with a median weight of 1085 (525–1980) g were included in the study. Gestational age and day of life at intubation were 28 (23–42) weeks and 7 (1–121) days, respectively. One patient was in cardiac arrest during intubation. ETCO2 detection correlated with radiographic findings of proper intubation in 50 out of 50 patients (sensitivity 100%, specificity 100%). In four patients, worsening of vital signs were associated with a flat ETCO2 trace, suggesting oesophageal intubation and leading the physician to remove the tube and reattempt the procedure.

Conclusions Our study suggests ETCO2 monitoring is a reliable and fast method to confirm proper ETTP also in newborns and infants under 2000 g. This method could be of particular benefit in these vulnerable patients and may reduce the risk of delays or inappropriate decisions during the intubation process.