GASEOUS METABOLISM IN THE INFANT: THE EFFECT OF SEDATION AND OF WAKEFULNESS.

Accurate oxygen consumption figures are desirable in quantitation of blood flow and shunts in infants with heart disease. Figures derived from normal infants fail to take into account effects of sedation or wakefulness.Oxygen consumption and ventilatory data were obtained in nine infants in natural sleep, in sedated sleep and in wakefulness. In sedated sleep oxygen consumption fell by a mean of 22% below the figure for natural sleep, and arterial carbondioxide tension rose by a mean of 7.04 mm. Hg. Infants who were awake but quiet (less than five limb movements per minute) showed an average increase in oxygen consumption of 28% as compared with data obtained during natural sleep.Direct measurement of oxygen consumption of infants is desirable in every instance where flow calculations are to be derived from the Fick equation. When the demands of urgency make this impractical, assumed oxygen consumptions should take into account the factor of sleep or wakefulness.