Peripheral airways resistance in smokers.
To determine peripheral airways resistance (Rp) in asymptomatic smokers, we used a wedged bronchoscope technique to study 19 volunteers (18 to 44 yr of age) who actively smoked for 2 to 28 pack-years. A fiberoptic bronchoscope was wedged in a subsegmental bronchus of the right upper lobe. Using a double lumen catheter inserted through the working channel of the bronchoscope, we infused 5% CO2 in air through one lumen and measured pressure through the second lumen. Rp was determined as the average of the peripheral resistance measured at three or more flow rates. This resistance ranged from 0.003 to 0.075 cm H2O/ml/min in the 19 subjects. We have previously shown normal subjects to have an average Rp of 0.009 +/- 0.002 cm H2O/ml/min (mean +/- SE) and asthmatic subjects an average of 0.069 +/- 0.017 cm H2O/ml/min. Thus, despite normal pulmonary function as assessed by spirometry, these asymptomatic smokers demonstrated a wide range of Rp values from normal to that observed in asthmatic subjects. These findings are consistent with a mechanism that considers the high resistance to result from inflammatory changes in the small airways.
Wagner
E M
EM
Department of Medicine, Johns Hopkins University, Baltimore, Maryland.
Bleecker
E R
ER
Permutt
S
S
Liu
M C
MC
D000293:Adolescent; D000328:Adult; D000403:Airway Resistance; D001980:Bronchi / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D001999:Bronchoscopy; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D012907:Smoking / Q000503:physiopathology*; D014797:Vital Capacity
D016210:Methacholine Chloride