The mechanics of the vintilatory system were studied in 29 sleeping infants and young children by the analysis of a passive expiration following an end-inspiratory airway occlusion ('single breath' method). The ventilatory system time constant (τrs) to compliance ratio yielded the value of ventilatory system resistance (Rrs). The calculated ventilatory system compliance correlated well with the slope of the quasi static pressure-volume curve (r = 0.97). The allometric relationship between Rrs and height (Rrs = 81.9·103·Ht(cm)-1.76, r = -0.82) is in agreement with forced oscillation measurements during the first year of life (Wohl et al., 1969)j. τrs was found to increase significantly over the first months of life (P<0.01).
All Science Journal Classification (ASJC) codes
- Pulmonary and Respiratory Medicine