Measurement of exhaled nitric oxide by three different techniques.
The purpose of the study was to compare exhaled nitric oxide (NO) determined by three techniques. Ninety-one subjects performed a slow vital capacity maneuver: (1) through the mouth directly into a NO chemiluminescence analyzer (peak oral NO), (2) through the mouth into a collection bag (mean oral NO), and (3) through the nose into a collection bag (mean nasal NO). Peak oral NO was higher in patients with asthma (n = 18, 174.2 +/- 27.0 ppb), but lower in smokers (n = 36, 39.6 +/- 4.8 ppb) compared with nonsmoking control subjects (n = 23, 105.5 +/- 8.4 ppb, p < 0.05 both comparisons). Mean oral NO levels were significantly lower than peak oral NO levels (p < 0.05), but still higher in patients with asthma in comparison with nonsmoking healthy control subjects and asymptomatic smokers (27.2 +/- 3.5 versus 14.5 +/- 1.1 and 7.3 +/- 0.7 ppb, respectively, p < 0.05). In contrast, there was no significant difference in mean nasal NO levels between the three groups. Peak oral NO and mean oral NO levels correlated (r = 0.772, p < 0.0001). Determination of exhaled oral NO levels is qualitatively independent of the technique used, but nasal exhalation may affect NO determination in conditions associated with airway inflammation.
Robbins
R A
RA
Research Service, Omaha VA Medical Center, Nebraska.
Floreani
A A
AA
Von Essen
S G
SG
Sisson
J H
JH
Hill
G E
GE
Rubinstein
I
I
Townley
R G
RG
D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001249:Asthma / Q000378:metabolism; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007249:Inflammation; D008163:Luminescent Measurements; D008173:Lung Diseases, Obstructive / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000378:metabolism; D009297:Nasal Mucosa / Q000378:metabolism; D009569:Nitric Oxide / Q000032:analysis*; D012119:Respiration; D012907:Smoking / Q000378:metabolism; D013048:Specimen Handling; D014797:Vital Capacity
D018927:Anti-Asthmatic Agents; D009569:Nitric Oxide