Related Experiment Video
Updated: Apr 18, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Exhaled carbon dioxide in healthy term infants immediately after birth
Georg M Schmölzer1, Stuart B Hooper2, Connie Wong3
1Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Neonatal Services, The Royal Women's Hospital, Melbourne, Australia; The Ritchie Center, Monash University, Melbourne, Australia; Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada; Critical Care Stream, Murdoch Children Research Institute, Melbourne, Australia.
Objective:
To measure exhaled carbon dioxide (ECO2) in term infants immediately after birth.
Study Design:
Infants >37 weeks gestation born at The Royal Women's Hospital, Melbourne, Australia were eligible. A combined flow sensor and mainstream carbon dioxide (CO2) analyzer was placed in series proximal to a facemask to measure ECO2 and tidal volumes in the first 120 seconds after birth.
Results:
Term infants (n = 20) with a mean (SD) birth weight of 2976 (697) g and gestational age of 38 (2) weeks were included. Infants took a median (range) 3 (1-8) breaths before ECO2 was detected. The median (range) of maximum ECO2 was 51 (40-73) mm Hg at 70 (21-106) seconds after birth. Within the first 10 breaths, CO2 increased from 0-27 (22-34) mm Hg. The median (IQR) tidal volume during the breaths without CO2 was 1.2 (0.8-3.1) mL/kg compared with 7.3 (3.2-10.9) mL/kg during the first 10 breaths where CO2 was exhaled.
Conclusions:
The first breaths for an infant after birth did not contain ECO2. With aeration of the distal gas exchange regions, tidal volume and ECO2 significantly increased. ECO2 can be used to monitor lung aeration immediately after birth.
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this...
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Pulmonary Cycle: Exhalation
Breathing
Acute Respiratory Failure-III
Respiratory Volumes and Capacities

