Clinical, radiographic and functional predictors of pulmonary gas exchange impairment at moderate exercise in patients with sarcoidosis

Nenhuma Miniatura disponível
Data
2004-01-01
Autores
Barros, WGP
Neder, J. A.
Pereira, CAC
Nery, L. E.
Orientadores
Tipo
Artigo
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Background: Pulmonary gas exchange impairment (GEI) is a common consequence of intrathoracic sarcoidosis presenting with important therapeutic and prognostic implications. Objective: To determine the role of clinical, radiographic and functional variables in predicting GEI during moderate exercise at the estimated lactate threshold (theta(L)) in patients with sarcoidosis. Methods: Fifty-four outpatients (29 females) with biopsy-proven sarcoidosis had clinical evaluation (baseline dyspnea index), lung function tests and an incremental cardiopulmonary exercise test with theta(L) estimation. On a separate day, patients underwent a constant work rate test at theta(L) with assessment of arterial blood gas tensions. Results: There was no evidence of GEI [DeltaP (A - a) O-2/VO2 >20 mm Hg.l.min(-1)] in patients with radiographic stages 0-1 (n = 13). in the remaining 41 patients, GEI was associated with more extensive radiographic involvement and reduced diffusing capacity of the lung for carbon monoxide (DLCO), forced expiratory volume in 1 s, total lung capacity and forced vital capacity (% predicted; p < 0.05); baseline dyspnea index and resting arterial blood gas tensions, in contrast, were not significantly related to GEI. DLCO correlated best with GEI. the negative predictive value of DLCO >70% predicted (absent-to-mild impairment) was 91.3% (sensitivity = 81.8%) and the positive predictive value of DLCO less than or equal to50% predicted (severe impairment) was 83.3% (specificity = 96.6%, likelihood ratio = 13.35). There was no improvement in diagnostic accuracy when other physiological tests were added to DLCO. These results were consistent with those found in a multiple logistic regression analysis with GEI as the dependent variable (p < 0.01). Conclusions: Conventional chest radiography and DLCO measurements suffice to estimate the individual risk of GEI at moderate exercise in patients with sarcoidosis. Copyright (C) 2004 S. Karger AG, Basel.
Descrição
Citação
Respiration. Basel: Karger, v. 71, n. 4, p. 367-373, 2004.