Presented at the Neonatal Society 2013 Spring Meeting.
Schmölzer GM1,2,3, Kamlin COF1, Davis PG1, Hooper SB3
1 Neonatal Services, The Royal Women’s Hospital, Melbourne, Australia
2 Dept. of Neonatology, Royal Alexandra Hospital, Edmonton, Canada
3 The Ritchie Centre, Monash Institute for Medical Research, Melbourne, Australia
Background: Positive pressure ventilation (PPV) remains the cornerstone of respiratory support for infants after birth. Although gas flow in and out of the lung can be measured with a respiratory function monitor, gas exchange may only be confirmed by presence of exhaled CO2 (ECO2).
Methods: Deliveries of preterm infants <32 weeks gestation were attended. During PPV we measured airway pressures, gas flow and tidal volume (VT) and mainstream ECO2 using the NICO cardiopulmonary management system (Novametrix Medical System, Connecticut). Heart rate and oxygen saturations were measured using a Masimo oximeter. We compared delivered VT and heart rate before and after ECO2 was detected.
Results: ECO2 and respiratory function were recorded in 10 preterm infants; mean (SD) birth weight 902 (287) g and gestational age 27 (2) weeks. The median (IQR) VT when no CO2 was detected was 1.9 (1.0-3.8) mL/kg compared to 8.3 (2.1-10.3) mL/kg when exhaled CO2 was detected (p<0.0025). The mean (SD) heart rate while no CO2 was exhaled was 61 (6) beats per minute compared to 104 (41) beats per minute 60 seconds after CO2 was detected.
Conclusion: Delivered VT and heart rate were significantly lower when no CO2 was exhaled. The presence of exhaled CO2 was accompanied by increases in HR. Our study provides proof of principle that detection of exhaled CO2 may provide useful information on lung aeration of infants after birth.
Corresponding author: omar.kamlin@thewomens.org.au