Etiological diagnosis utilization value of bronchial provocation test in patients with chronic cough

Objective To study the bronchial provocation tests before and after the small airway function in patients with chronic cough,airway resistance,and the status of the extrathoracic airway reaction. Methods Sixty-eight patients with chronic cough were histamine bronchial provocation tests, observation FEV1,mid expiratory flow rate(MEF50) the change of the mid and suction flow rate (MIF50),and applies the patients before and after the forced oscillation technique determination inspire airway resistance. Results Bronchial provocation tests positive rate 52%,arouse positive patients before MEF50,R0 patients with negative group difference was statistically significant.MEF50 excitation after/ before ratio(MEF50%)and FEV 1,stimulate after/before ratio(FEV 1%) were positively correlated,and R0 stimulates the difference before and after the negative correlation(R0-d).Thirteen patients present external chest high reaction(accounts for 20% of total cases),among them 6 cases to exist alone external chest high response,7 cases of patients with airway hyperresponsiveness bronchial merger. Conclusions To observe change of small airway function in patients with chronic cough,is helpful to early diagnosis and treatment of asthma.Proocation tests joint observation of bronchial airway responses and extrathoracic airway reaction,can provide clues for clinical diagnosis. Key words: Chronic cough; Bronchial provocation tests; Small airway function; External chest high response