Objective: To investigate the changes and pattern of pulmonary function in severe acute respiratory syndrome (SARS) patients during convalescent period.
Methods: Pulmonary function tests were performed in 26 SARS convalescent patients regularly every 3 months after their discharge from hospital. The significance of changes in pulmonary function indexes was analyzed.
Results: Restrictive pulmonary ventilation function and diffusing dysfunction of the lung were found in one third of the patients during third to sixth month from onset. There was a little improvement in forced vital capacity (FVC), one second forced expiratory volume (FEV(1.0)), functional residual capacity (FRC) and residual volume (RV) as convalescent period was prolonged, but no difference was found between different stages (3-6 months, 6-9 months, 9-12 months, 12-15 months and 15-17 months). Meanwhile, the FEV(1.0)/FVC showed no significant change. However, there was an obvious improvement in total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (DLCO) with the elapse of time, and also a significant difference was found between the later stage and the earlier stage.
Conclusion: Pulmonary dysfunction is found among some SARS patients after convalescence presenting mainly as restrictive ventilatory function and diffusing capacity abnormality. These dysfunctions would improve gradually with the elapse of time.