Clinical experiences with bronchial provocation test using oscillation technique in Chinese patients.
Bronchial provocation tests using the forced oscillation method were conducted on 115 Chinese. Each subject continuously inhaled stepwise increased concentrations of methacholine and respiratory resistance (Rrs) was measured. The test results were regarded as responsive if Rrs increased by twice the baseline values. It was found that all normal subjects and patients with restrictive lung diseases were nonresponders. One hundred percent of the asthmatic patients and 61% of the patients with chronic obstructive pulmonary disease (COPD) were responders. However, only 29% of the 28 patients with acute bronchitis showed bronchial hyperreactivity. Baseline Rrs values for the various groups are as follows: normal subjects, 3.2 +/- 0.7 cmH2O/L/sec; patients with restrictive lung diseases, 4.2 +/- 0.6 cmH2O/L/sec; asthmatic patients, 5.6 +/- 0.9 cmH2O/L/sec; COPD patients, 7.5 +/- 0.7 cmH2O/L/sec; and those with acute bronchitis, 4.3 +/- 0.8 cmH2O/L/sec. Baseline Rrs was significantly higher in patients with airway obstruction than in normal subjects. The cumulative dose (DA, the bronchial sensitivity) of methacholine to induce a positive reaction in responders was not correlated with either respiratory conductance (Grs) or the bronchial reactivity (SGrs, the slope of Grs during a positive reaction). The dose-response curves can be classified into 6 types according to their appearances: flat form (type I), isolated spike form (type II), terminal spike form (type III), triangular form (type IV), step form (type V) and mixed form (type VI). Normal subjects and patients with restrictive lung diseases usually manifested with type I or II curves. Most asthmatic patients had type IV curves, but occasionally types V and VI were also encountered.(ABSTRACT TRUNCATED AT 250 WORDS)
Yang
S C
SC
Department of Clinical Pathology, National Taiwan University Hospital, Taipei, R.O.C.
D000328:Adult; D000368:Aged; D000403:Airway Resistance; D000704:Analysis of Variance; D001980:Bronchi / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000379:methods; D005260:Female; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D013624:Taiwan