Exhaled Carbon Dioxide and Neonatal Breathing Patterns in Preterm Infants after Birth.

Abstract

To examine the amount of exhaled carbon dioxide (ECO2) with different breathing patterns in spontaneously breathing preterm infants after birth. Preterm infants had a facemask attached to a combined carbon dioxide/flow sensor placed over their mouth and nose to record ECO2 and gas flow. A breath-by-breath analysis of the first 5 minutes of the recording was performed. Thirty spontaneously breathing preterm infants, gestational age (mean ± SD) 30 ± 2 weeks and birth weight 1635 ± 499 g were studied. ECO2 from normal breaths and slow expirations was significantly larger than with other breathing patterns (P < .001). ECO2 per breath also increased with gestational age P < .001. The expiratory hold pattern was the most prevalent breathing pattern both during the first minute of recording and overall. Breathing pattern proportions also varied by gestational age. Finally, ECO2 from the fifth minute of recording was significantly greater than that produced during the first 4 minutes of recording (P ≤ .029). ECO2 varies with different breathing patterns and increases with gestational age and over time. ECO2 may be an indicator of lung aeration and that postnatal ECO2 monitoring may be useful in preterm infants in the delivery room.