Prova broncodilatadora na espirometria: efeito do uso de espaçador de grande volume com tratamento antiestático na resposta ao broncodilatador

Abstract

Objective: To evaluate whether the use of inhaled albuterol via a metered-dose inhaler with a large-volume spacer with antistatic treatment modifies the bronchodilator test results when compared with the usual technique (no spacer). Methods: A prospective study involving 24 patients, 18-45 years of age, clinically suspected of having asthma, and under treatment at the Outpatient Pulmonary Clinic of the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. All of the patients underwent two bronchodilator tests: one with and one without the use of a large-volume spacer. Results: There was no significant difference in the variation of FEV 1 prior to and after bronchodilator use between the two techniques (mean ΔFEV 1 = 0.01 L; 95% CI: −0.05 to 0.06; p = 0.824). No statistically significant difference was found between the two techniques regarding the qualitative results on the bronchodilator test (p = 1.00). There was concordance between the techniques in terms of the bronchodilator test results (kappa coefficient = 0.909; p < 0.005). Conclusions: According to the results of this study, the use of large-volume spacers does not significantly modify bronchodilator test results.Keywords: Asthma; Spirometry; Inhalation spacers. ResumoObjetivo: Avaliar se o uso de salbutamol inalatório através de inalador dosimetrado acoplado a espaçadores de grande volume com tratamento antiestático na espirometria com prova broncodilatadora modifica os resultados do teste quando comparado à técnica usual (sem espaçador). Métodos: Estudo prospectivo envolvendo 24 pacientes, com idades entre 18 e 45 anos e suspeita clínica de asma, atendidos no Ambulatório de Pneumologia do Hospital das Clínicas da Universidade Federal de Minas Gerais, em Belo Horizonte (MG). Os pacientes foram submetidos a duas espirometrias com prova broncodilatadora realizadas com e sem o uso de espaçador de grande volume. Resultados: Não houve diferença significativa na variação do VEF 1 antes e após o uso de broncodilatador entre as duas técnicas (ΔVEF 1 média = 0,01 L; IC95%: −0,05 a 0,06; p = 0,824). Não houve diferença estatisticamente significativa entre as duas técnicas em relação ao resultado qualitativo da prova broncodilatadora (p = 1,00). Houve concordância dos resultados da prova broncodilatadora entre as técnicas (coeficiente kappa = 0,909; p < 0,005). Conclusões: De acordo com os resultados deste estudo, a utilização de espaçadores de grande volume não modificou de forma significativa os resultados da prova broncodilatadora.Descritores: Asma; Espirometria; Espaçadores de inalação. Original ArticleSpirometry with bronchodilator test: effect that the use of large-volume spacers with antistatic treatment has on test response J Bras Pneumol. 2011;37(6):752-758 753 test results in patients clinically suspected of having asthma when compared with the usual technique (no spacer).

Airway disease: similarities and differences between asthma, COPD and bronchiectasis

“…In asthma, the typical finding of airflow obstruction that is characterized by a decrease of VEF1/FVC (forced vital capacity) with a disorder reversal after the administration of a bronchodilator is the mainstay in the diagnostic confirmation of the disease (79). However, many patients may present with a reversal after the use of a bronchodilator without exhibiting normalization in pulmonary function tests, thus indicating signs of bronchial remodeling.…”