Tidal volume threshold for colorimetric carbon dioxide detectors available for use in neonates.

OBJECTIVE: Colorimetric carbon dioxide detectors are used for confirmation of endotracheal intubation. The colorimetric carbon dioxide detectors that are used for neonates are labeled for use with infants and small children >1 and <15 kg. The objective of this study was to determine the minimal tidal volume that causes a breath-to-breath color change on 2 colorimetric carbon dioxide detectors.

METHODS: Using an artificial-lung model, we determined the tidal volume threshold of 2 colorimetric carbon dioxide detectors (Pedi-Cap [Nellcor, Pleasanton, CA] or Mini StatCO(2) [Mercury Medical, Clearwater, FL]) during ventilation with a T-piece resuscitator or neonatal ventilator. Digital video recordings of the colorimetric carbon dioxide detectors were made during 20 seconds of ventilation at each tidal volume. Seven clinicians who were blinded to the tidal volume reviewed the videos in random order and graded the color change to determine adequacy for clinical application.

RESULTS: The Mini StatCO(2) tidal volume threshold was 0.83 mL, and the Pedi-Cap tidal volume threshold was 1.08 mL.

CONCLUSIONS: The lung model revealed that the tidal volume threshold for the tested colorimetric carbon dioxide detectors is less than the expected tidal volume of a 400-g infant and suggests that these devices are appropriate for use with any neonate to confirm intubation.