Tomografia computadorizada e testes de função pulmonar na análise da fisiopatologia respiratória de pacientes adultos com fibrose cística

Abstract

Cystic fibrosis (CF) is an autosomal recessive hereditary disease that affects multiple organs, with progressive course characterized by a triad of pancreatic insufficiency, pulmonary chronic suppurative disease and loss of salt in sweat. The lung disease is what has more impact on morbidity and mortality and is secondary to recurrent infections of the airways. There was an increase in patient survival reflecting a better multidisciplinary management of CF and the identification of a wide range of phenotypes and genes. Because of the recent emergence of this type of population, further studies are needed. Although computed tomography (CT) allows detailed evaluation of pulmonary changes, these analyzes are generally limited by the use of subjective quantification methods. The CT pulmonary densitovolumetry allows quantitative assessment of some of the changes seen in patients with CF, contributing to a better understanding of the pathophysiology of the disease and improving diagnosis and staging. There are no studies in the literature that relate this method of quantification multidetector computed tomography CT (Q-MDCT) used in this study with pulmonary function parameters in adult CF patients. In this context, this study has the following objectives: enhance the use of chest CT in patients with CF through the use of methods of quantification of lung volumes; quantitatively determine the type and extent of tomographic findings in these patients; investigate the association between specific structural changes in lower airways, evaluated by Q-MDCT, and pulmonary function parameters. This is a cross-sectional controlled study involving two groups: a control and the other with CF diagnosis. The patients underwent CT scans, by forced oscillation technique (FOT), spirometry, body plethysmography, measurement of carbon monoxide diffusion capacity (DLCO) and respiratory muscle strength, and later held the Q-MDCT. In the control group (CG), 22 healthy subjects were included, and the CF group, 21 patients completed all examinations. Q-MDCT demonstrated that the CF group had a higher amount of non-aerated compartments and poorly aerated, and a minor amount of normal aerated compartments, compared to the CG. Q-MDCT showed significant correlations with the measurements obtained by spirometry, body plethysmography, DLCO, muscle strength and FOT. It was observed a strong direct correlation of total lung volume (TLV) parameters and total lung air (TLA) measured by Q-MDCT and plestimografic parameter total lung capacity (TLC). The Q-MDCT was able to estimate the volumes of compartments with different densities and including determining the air and not air content of the lungs, providing information on the weight of the body and its compartments.