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Updated: Oct 1, 2026
Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Measurement of oxygen uptake in newborn infants during assisted and spontaneous ventilation
J C Rozé1, B Chambille, M Dehan
1Neonatal Department, Hôpital Universitaire, Nantes, France.
Abstract:
Measurements of oxygen uptake (VO2) and CO2 output (VCO2) are useful in critically ill patients. However, VO2 is not routinely measured in intensive care during mechanical ventilation (MV) especially in premature newborns. The present study describes a new method of measuring VO2 and VCO2 using a double open circuit which accounts for gas leaks around the uncuffed tracheal tube. The accuracy of the method was assessed with N2 and CO2 infusion. In case of leaks, VO2 and VCO2 measurement was significantly underestimated by the simple circuit method. This underestimation was not present with double circuit method. Five preterm newborns were studied. VO2 and VCO2 using the double open circuit were compared with the classic simple circuit. During MV, the mean underestimation assessed by the difference between simple and double circuit measurement was -12% (range from 0 to -29%) for VO2 and -14% (range 0 to -26%) for VCO2.
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