Avaliação dos mecanismos determinantes de limitação ao esforço e da capacidade de exercício em pacientes com histiocitose pulmonar de células de Langerhans
Year: 2019
Type: dissertation
Study design: Observational Study
Abstract: Heiden GI. Evaluation of the mechanisms determinants of exercise limitation and the exercise capacity in patients with pulmonary Langerhans cell histiocytosis[ ] " São P "; 2019 Introduction: Pulmonary Langerhans cell histiocytosis (PLCH) is a smokingrelated diffuse cystic disease, which determines reduced exercise capacity.The speculated mechanisms of exercise limitation in PLCH include ventilatory limitation, dynamic hyperinflation (DH), cardiocirculatory limitation that encompasses pulmonary hypertension (PH) and impaired gas exchange.Objectives: To evaluate the mechanisms of exercise limitation and to define the exercise capacity, the prevalence of PH and clinical, functional and hemodynamic characteristics in patients with PLCH.In addition, to evaluate the predictors of effort limitation and PH.Methods: In a cross-sectional study, 35 patients with PLCH underwent clinical evaluation, transthoracic echocardiography, six-minute walk test, pulmonary function tests, and incremental treadmill cardiopulmonary exercise test (CPET) with evaluation of DH.Those patients with carbon monoxide diffusion capacity (DLCO) less than 40% of predicted and/or transthoracic echocardiogram with tricuspid regurgitation velocity (TRV) greater than 2.5 m/s and/or with indirect PH signs underwent right heart catheterisation (RHC) to confirm the diagnosis of PH based on the mean pulmonary artery pressure (mPAP).Results: Thirtyfive patients were included (68% were women, with 47 ± 11 years old, 91% were current or ex-smokers and with baseline dyspnea index of 8 ± 3).At CPET, ventilatory limitation, cardiocirculatory limitation and impairment suggestive of PH occurred in 58%, 63%, and 29% of patients, respectively.The limitation was multifactorial in 71% of cases.The maximum oxygen consumption ( O 2 peak) was 73 ± 19% of predicted, and was reduced in 70% of patients.Dynamic hyperinflation occurred in 68% of patients.Forced expiratory volume in the first second (FEV 1 ), residual volume and total lung capacity ratio (RV/TLC) and DLCO were 64 ± 22% of predicted, 44 ± 11 and 56 ± 21% of predicted, respectively.Reduction in DLCO, an obstructive pattern, and air trapping occurred in 80%, 77% and 37% of patients, respectively.The TRV was 3.0 (2.4 -3.2) m / s.Eighteen patients underwent CCD, and the mPAP obtained was 32 ± 12 mmHg.The prevalence of PH was 41% (CI95% = 24 -59%), with pre-capillary pattern in 85% of cases.There was a correlation between mPAP and FEV 1 , DLCO, O 2 % of O 2 peak at the anaerobic threshold in the CPET and TRV in echocardiogram.FEV 1 and DLCO presented good accuracy to predict reduction of exercise capacity.Conclusion: Exercise limitation is multifactorial and frequent in patients with PLCH.The most prevalent mechanisms include ventilatory, cardiocirculatory and suggestive of PH limitations.Pulmonary hypertension is also common in PLCH, predominantly pre-capillary.
Author: Glaucia Itamaro Heiden
Language: Portuguese
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2995541967