[Respiratory ultradian variations of mean and low frequencies (from 2-80 cycles per day) in premature human infants].

Oxygen consumption (VO2) and carbon dioxide production (VCO2) were continuously measured in premature human (mean gestation age of 31 weeks at birth), nursed in incubators within a neutral thermal environment and submitted to a continuous lighting. At a mean postnatal age of 30 days, and for a mean body weight of 1.8 kg, spectral analysis shows VO2 and VCO2 ultradian variations of mean and low frequencies (2 less than f less than 80 c.day--1; i.e. periods 12 greater than t greater than 0.3 hr). It is hypothesized that these periodic variations can be compared to those previously evidenced in small laboratory vertebrates and in macaques.