Teste de broncodilatação: a incorporação de novos parâmetros na sua avaliação / Bronchodilator test: the incorporation of new parameters in its evaluation

A avaliação da resposta broncodilatadora nas doenças pulmonares obstrutivas crônicas é fundamental no diagnóstico e no acompanhamento clínico, sendo importante no manejo terapêutico e na avaliação prognóstica. A espirografia é o primeiro teste funcional realizado e o mais importante na rotina da maioria desses pacientes. Outros testes, como a medida dos volumes estáticos e da resistência pulmonar, assim como o teste da caminhada de 6 minutos, podem ajudar nesta avaliação. A medida do óxido nítrico tem sido estudada na asma, mas a sua relevância clínica ainda não está estabelecida. A presente revisão descreve os testes funcionais mais usados na prática clínica e evidências científicas recentes sobre a melhor forma de interpretá-los.

The evaluation of the bronchodilator response in the chronic obstructive pulmonary disease is fundamental to the diagnosis and clinical follow up, also being important to the therapeutic management and the prognostic evaluation. The spirometry is the first and most important functional test in the routine of the majority of these patients. Other tests, as the measure of the static volumes and the pulmonary resistance, as well as the six-minutewalk test, may be help ful in this evaluation. The measure of exhaled nitric oxide levels has been studied in asthma, but its clinical relevance has not yet been established. The review describes the major functional tests used in clinical practice and the recent scientific evidences regarding the interpretation of the results of those tests.

Diagnostic value of fractional exhaled nitric oxide in non-typical bronchial asthma / 中国医师进修杂志

Objective To study the diagnostic value of fractional exhaled nitric oxide(FeNO)in non-typical bronchial asthma.Methods Ninety-five patients with unknown-cause respiratory symptoms including wheezing,cough and breathlessness were enrolled.FeNO was measured by nitric oxide analyzer.The clinical symptoms and bronchial bronchodilator test were defined as golden standard for asthma diagnosis.The diagnostic value of FeNO was assessed and the optimal operating point of FeNO test was determined by means of the receiver operating characteristic(ROC)curve.Results Among 95 patients,44 cases were diagnosed as asthma,51 cases were diagnosed as non-asthma.The level of FeNO of asthma patients were higher than that of non-asthma patients[(55.2±14.0)nmol/L vs.(18.9±5.2)nmol/L,P＜0.01].A non-linear correlation of FeNO with FEV1％ was revealed in the cases with asthma(r=-0.162,P＞0.05).Area under ROC curve was 0.858.The optimal diagnostic cut off point was 36 nmol/L which was capable of differentiating asthma and non-asthma with sensitivity of 80.2％,specificity of 79.5％,positive predictive value of 85.4％,negative predictive value of 83.3％ and accuracy of 85.9％.Conclusions FeNO test may be helpful in the diagnosis of non-typical asthma with high sensitivity and specificity,which can also improve the diagnostic effectiveness and avoid misdiagnosis,missed diagnosis when combined with lung function test.

Severity Staging of Chronic Obstructive Pulmonary Disease: Differences in Pre- and Post-Bronchodilator Spirometry

PURPOSE: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines for chronic obstructive pulmonary disease (COPD) uses the post-bronchodilator spirometry for diagnosis and severity staging. We evaluated differences in the severity classification of COPD, based on pre- and post-bronchodilator spirometry. MATERIALS AND METHODS: From 2000 to 2004, 207 COPD patients who underwent spirometry before and after inhalation of 400 microg of fenoterol were analyzed. A responder to the bronchodilator test (BDT) was defined by the American Thoracic Society (ATS) as an increase in forced expiratory volume in one second (FEV1) or forced vital capacity > or = 12% and > or = 200 mL, and by the European Respiratory Society (ERS) as an increase in FEV1 > or = 10% of the predicted value. COPD severity was classified according to the 2008 GOLD guidelines. RESULTS: For the entire study population, the FEV1 increased by 11.8 +/- 12.5% of baseline after BDT and 41.1% and 27.1% of subjects were classified as responders using the ATS and ERS criteria, respectively. Based on pre-BDT spirometry, 55, 85, 58, and 9 patients were classified as Stage I-IV COPD, respectively. Sixty-seven (32.4%) patients changed severity staging after BDT, including 20.0%, 28.2%, 44.8%, and 66.7% of pre-BDT patients Stages I through IV, respectively. More ATS or ERS BDT-responders had a change in severity staging than non-responders (52.9% vs. 18.9% and 62.5% vs. 21.2%, both p < 0.001). CONCLUSION: Our data suggest that the severity staging of COPD using pre-BDT spirometry might lead to significant differences as compared to staging, based on post-BDT spirometry, as recommended by the current GOLD guidelines.