Automatic measurement and analysis of neonatal O₂ consumption and CO₂ production

It is difficult to estimate daily energy expenditure unless continuous O₂ consumption (V_O2) and CO₂ production (V_CO2) can be measured. This study describes a simple method for calculating daily and interim changes in O₂ consumption and CO₂ production for neonates, especially for premature infants. Oxygen consumption and CO₂ production are measured using a flow-through technique in which the total V_O2 and V_CO2 over a given period of time are determined through a computerized system. This system can automatically calculate V_O2 and V_CO2 not only minute to minute but also over a period of time, e.g., 24 h. As a result, it provides a better indirect reflection of the accurate energy expenditure in an infant's daily life and can be used at the bedside of infants during their ongoing nursery care.