Abstract
Ventilatory responses to combined inspiratory and expiratory (I & E) loading were evaluated in 5 growing preterm neonates.Mean ± SEM values were gestational age: 29.6 ± 0.7 weeks, birthweight: 1178 ± 138 gm; study age: 54 ± 13 days; study weight: 1661 ± 440 gms. Pulmonary functions, tidal volume (VT), minute ventilation (MV), peak inspiratory flow (VI) and expiratory flow (VE), inspiratory time/total respiratory time (TI/Ttot), respiratory frequency (f) and work of breathing (WOB) were measured before and after application of the resistance (R). A variable resistor was used to administer a separate load of 50 (R1) and 100 (R2) cm H2O/L/sec during I & E flow for 60 seconds. Mean ± SEM control pulmonary function values were: pulmonary compliance 3.4 ± 0.26 ml/cmH2O; pulmonary resistance: (I) = 44 ± 14 and (E) = 69 ± 13 cmH2O/L/sec, respectively; VT = 13.7 ± 2.1 ml and MV = 894 ± 79 ml/min; VI = 2.75 ± 0.23 and VE = 2.85 ± 0.26 L/min; TI/Ttot = 0.48 ± 0.04 and f = 61 ± 4 breaths/min; Application of R1 resulted in a significant change (p<0.05) immediately and for a duration of 60 sees in the VT (16% decrease) and in both VI and VE, a 20.4 and 21.6% decrease, respectively. The MV only decreased (25%, p<0.01) at initial application, and compensation in MV and work was noted by 60 sec. A similar, but greated magnitude change was observed with R2. These observations show an initial decreased ventilatory response to the load and an ensueing adaptation by 60 seconds.
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Bhutani, V., Abbasi, S., Sivieri, E. et al. VENTILATORY RESPONSE OF GROWING PRETERM INFANTS TO COMBINED INSPIRATORY AND EXPIRATORY RESISTIVE LOAD. Pediatr Res 18 (Suppl 4), 386 (1984). https://doi.org/10.1203/00006450-198404001-01758
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DOI: https://doi.org/10.1203/00006450-198404001-01758