This study was designed to use volumetric capnography to evaluate the breathing pattern and ventilation inhomogeneities in patients with chronic sputum production and bronchiectasis and to correlate the phase 3 slope of the capnographic curve to spirometric measurements. Twenty-four patients with cystic fibrosis (CF) and 21 patients with noncystic fibrosis idiopathic bronchiectasis (BC) were serially enrolled. The diagnosis of cystic fibrosis was based on the finding of at least two abnormal sweat chloride concentrations (iontophoresis sweat test). The diagnosis of bronchiectasis was made when the patient had a complaint of chronic sputum production and compatible findings at high-resolution computed tomography (HRCT) scan of the thorax. Spirometric tests and volumetric capnography were performed. The 114 subjects of the control group for capnographic variables were nonsmoker volunteers, who had no respiratory symptoms whatsoever and no past or present history of lung disease. Compared with controls, patients in CF group had lower SpO(2) (P < 0.0001), higher respiratory rates (RR) (P < 0.0001), smaller expiratory volumes normalized for weight (V(E)/kg) (P < 0.028), smaller expiratory times (Te) (P < 0.0001), and greater phase 3 Slopes normalized for tidal volume (P3Slp/V(E)) (P < 0.0001). Compared with controls, patients in the BC group had lower SpO(2) (P < 0.0001), higher RR (P < 0.004), smaller V(E)/kg (P < 0.04), smaller Te (P < 0.007), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0002). The pooled data from the two patient groups compared with controls showed that the patients had lower SpO(2) (P < 0.0001), higher RR (P < 0.0001), smaller V(E)/kg (P < 0.05), smaller Te (P < 0.0001), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0003). All of the capnographic and spirometric variables evaluated showed no significant differences between CF and BC patients. Spirometric data in this study reveals that the patients had obstructive defects with concomitant low vital capacities and both groups had very similar abnormalities. The capnographic variables in the patient group suggest a restrictive respiratory pattern (greater respiratory rates, smaller expiratory times and expiratory volumes, normal peak expiratory flows). Both groups of patients showed increased phase III slopes compared with controls, which probably indicates the presence of diffuse disease of small airways in both conditions leading to inhomogeneities of ventilation.

BackgroundObstructive lung diseases of different etiologies present with progressive peripheral airway involvement. The peripheral airways, known as the silent lung zone, are not adequately evaluated with conventional function tests. The principle of gas washout has been used to detect pulmonary ventilation inhomogeneity and to estimate the location of the underlying disease process. Volumetric capnography (VC) analyzes the pattern of CO2 elimination as a function of expired volume.ObjectiveTo measure normalized phase 3 slopes with VC in patients with non-cystic fibrosis bronchiectasis (NCB) and in bronchitic patients with chronic obstructive pulmonary disease (COPD) in order to compare the slopes obtained for the groups.MethodsNCB and severe COPD were enrolled sequentially from an outpatient clinic (Hospital of the State University of Campinas). A control group was established for the NCB group, paired by sex and age. All subjects performed spirometry, VC, and the 6-Minute Walk Test (6MWT). Two comparisons were made: NCB group versus its control group, and NCB group versus COPD group. The project was approved by the ethical committee of the institution. Statistical tests used were Wilcoxon or Student’s t-test; P<0.05 was considered to be a statistically significant difference.ResultsConcerning the NCB group (N=20) versus the control group (N=20), significant differences were found in body mass index and in several functional variables (spirometric, VC, 6MWT) with worse results observed in the NCB group. In the comparison between the COPD group (N=20) versus the NCB group, although patients with COPD had worse spirometric and 6MWT values, the capnographic variables mean phase 2 slope (Slp2), mean phase 3 slope normalized by the mean expiratory volume, or mean phase 3 slope normalized by the end-tidal CO2 concentration were similar.ConclusionThese findings may indicate that the gas elimination curves are not sensitive enough to monitor the severity of structural abnormalities. The role of normalized phase 3 slope may be worth exploring as a more sensitive index of small airway disease, even though it may not be equally sensitive in discriminating the severity of the alterations.

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Dedico este trabalho aos meus pais João eNercy que, mesmo longe, estiveram sempre perto e, a uma pessoa muito especial, que esteve sempre ao meu lado, não me deixando desistir, esse trabalho é nosso. v AGRADECIMENTOSAgradeço a minha orientadora Dra. Ilma Paschoal, pela paciência e dedicação comigo, sem ela seria impossível a concretização de mais esta etapa na minha vida. Não tenho palavras para demonstrar minha gratidão. Muito obrigada! A Dra Mônica Corso, pelos direcionamentos, acompanhamento e sem dúvida, pela paciência, o meu muito obrigada. Vera (Verinha) da secretaria de Pneumologia, nossa o que seria de mim sem você, obrigada por me socorrer nos meus momentos de desespero, pelas palavras de carinho e persistência. Que Deus te ilumine e acompanhe sempre.Ao Marcos, Fisioterapeuta, pela realização dos exames de capnografia volumétrica, muito obrigada por sua ajuda e atenção, que o Senhor esteja sempre com você.Ao Prof. Dr. Eduardo Capitani e a Dra Ana pelas tardes em que fiquei no ambulatório de Pneumologia, acompanhando a rotina e os pacientes com fibrose cística e bronquectasia, muito obrigada. Ao SAM, pelos prontuários solicitados, muito obrigada.Ao meu grande amigo Roulien, por todas as noites que incomodei o seu sono, pelo socorro no momento em que precisei, muito obrigada pelo computador. E, em especial, aos pacientes que tornaram possível a realização deste trabalho, concordando com a realização exames e autorizando a utilização de seus resultados, muito obrigada e acreditem, este ato colaborou para a evolução no acompanhamento destas doenças. vi