2001 年 40 巻 4 号 p. 322-326
We determined whether expiratory flow influences the level of exhaled nitric oxide (NO) in a test using a bagtrap.
Subjects were 14 healthy volunteers whose exhaled NO was measured through the mouth and nose at 4 different expiratory flow rates. Oral and nasal exhaled NO were measured with subjects inhaling NO-free air using a bagtrap based on a chemiluminescence NO analyzer, ML9841, at a detection limit of 1 part per billion (ppb). The 4 expiratory flow rates were identified at 0.05, 0.1, 0.2, and 0.3L/s.
Oral exhaled NO concentrations were 36.7 (SE:±7.30) ppb at an expiratory flow of 0.05L-/s, 26.7 (±5.45) at 0.1, 20.18 (±4.25) at 0.2, and 16.4 (±3.85) at 0.3. Oral exhaled NO concentrations inversely correlated with the expiratory flow rate (R=0.941). Nasal exhaled NO concentrations were 72.6 (±8.39) at 0.05L/s, 59.9 (±8.31) at 0.1, 39.0 (±4.49) at 0.2, and 29.1 (±4.09) at 0.3. Nasal exhaled NO concentrations had also inversely correlated with the expiratory flow rate (R=0.983). Nasal exhaled NO concentrations were significantly higher than oral at all flow rates.
We concluded that oral and nasal exhaled NO concentrations using a bagtrap were flow-dependent, and thus constant expiration (0.1L/s) is recommended.