Respiratory response to inversion in normal subjects.
To evaluate the respiratory response to inversion, 20 young male athletes were suspended by their ankles in a vertical head-down position, while being monitored with ear oximetry and end-tidal CO2 nasal cannula. There was a decrease in O2 saturation (p less than 0.01), increase in end-tidal CO2 (p less than 0.01), and a decrease in respiratory rate (p less than 0.02). Spirometry was done in seven of these subjects, revealing decreases in forced vital capacity (5.7% +/- 2.0%), FEV1 (10.9% +/- 4.0%), FEF25-75 (13.3% +/- 7.4%), and peak expiratory flow rate (20.1% +/- 4.4%). Caution is advised in the use of inversion devices in patients with compromised cardiopulmonary service.
D000328:Adult; D002245:Carbon Dioxide / Q000032:analysis; D006801:Humans; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011187:Posture; D012129:Respiratory Function Tests; D013147:Spirometry; D013990:Tidal Volume
D002245:Carbon Dioxide; D010100:Oxygen