Variability of resting respiratory drive and timing in healthy subjects

摘要: Studies of breathing pattern have focused primarily on changes in the mean values components, whereas there has been minimal investigation breath-to-breath variability, which should provide information constancy with respiration is controlled. In this study we examined variability both a and day-to-day basis by calculating coefficient variation (i.e., standard deviation expressed as percentage mean). By examining data, found that coefficients tidal volume (VT) fractional inspiratory time (TI/TT, an index timing) obtained inductive plethysmograph spirometer were within 1% each other. Examination over 15-min period 65 subjects revealed large variation, indicating need to base calculations relatively number breaths. Less was observed respiratory frequency [f, 20.8 +/- 11.5% (SD)] TI/TT (17.9 6.5%) than VT (33 14.9%) flow (VT/TI, drive; 31.6 12.6%; P less 0.0001). Older (60-81 yr) displayed greater young (21-50 yr). Use mouthpiece did not affect degree variability.(ABSTRACT TRUNCATED AT 250 WORDS)