Prova broncodilatadora na espirometria: comparação entre o efeito broncodilatador do salbutamol inalatório através de espaçadores de grande volume com tratamento antiestático e pela técnica usual

Abstract

Introduction: In most services the pulmonary function with bronchodilator test is performed without the use of spacer (the usual technique), with no current evidence that points superiority of one technique over another. The technique of using metered-dose inhaler requires coordination between the fire and inspiration, with approximately 10% of the drug deposited in the lungs and almost 80% in the oropharynx. Spacers can aid the use of aerosol to eliminate the difficulty of coordination. Previous studies have proven the effectiveness of the use of large volume spacers in the treatment of pulmonary obstruction disease, increasing the availability and lung deposition of aerosol particles, reducing oropharyngeal deposition and improves functional outcome. However, the utility of spacers in pulmonary function tests have not been proven. Objective: To evaluate whether the use of inhaled salbutamol through metered-dose inhaler coupled to large volume spacers on bronchodilator modifies the test result compared to the usual technique. Methodology: Prospective, paired and not crossed. Patients were recruited from the Outpatient pulmonary of the Pulmonary and Thoracic Surgery Service, Hospital das Clínicas, Universidade Federal de Minas Gerais and the Pulmonary Function Laboratory of the same service, aged between 18 and 45 years and the request showing clinical suspicion of asthma. Those who signed the informed consent wereselected. The patients underwent spirometry, using the two techniques proposed in the study. The sample size was estimated at 24 the sample size. Results: We evaluated 24 patients. There was no significant difference in the variation of volume in one second forced expiration pre and post bronchodilator among the usual technical and spacer (mean difference 0.01, 95%CI, - 0.05 to 0.06, p = 0.824). When analyzing the results of the bronchodilator test (positive or negative), no statistically significant difference when compared to the usual technical and spacer (p = 1.00). The agreement of the results of bronchodilator between techniques was excellent (kappa equals 0.909) and significant (p < 0.005). Conclusion: According to the results of this study, the bronchodilator spirometry can be performed without the use of large volume spacers, since the metered-dose inhaler is used correctly andconsistently