Severe acute respiratory syndrome (SARS) is a newly recognized viral pneumonia caused by a novel coronavirus (SARS-CoV). It can cause diffuse alveolar damage and respiratory failure in the acute stage. It is unknown whether there is permanent impairment of pulmonary function. We aim to study whether SARS survivors have any persistent pulmonary function impairment.
This is a prospective study of the pulmonary functions in SARS survivors. Pulmonary function tests including spirometry, diffusion capacity for carbon monoxide (DLCO) and static lung volumes were performed at 6 and 9 months after discharge for SARS. Impaired pulmonary function was defined by FVC < 80% predicted, FEV1 < 80% predicted, FEV1/FVC < 70% or DLCO < 70% predicted.
Sixty-three patients (22 male, 41 female, mean age 39.0 ± 11.9 years) who survived SARS during the epidemic in March 2003 were studied. At 6 months after discharge, 19 (30.2%) had impaired pulmonary function as defined above: 14 patients (22.2%) had mild impairment, 4 patients (6.4%) had moderate impairment and 1 patient (1.6%) had severe impairment. By 9 months, there were significant improvement in FVC (p=0.002), FEV1 (p=0.009) and DLCO (p<0.001); most patients (95.2%) had no respiratory impairment. Only 3 patients (4.7%) had mild impairment, and none had more severe impairment.
A significant proportion of SARS survivors had impaired pulmonary functions 6 months after discharge. However, most of them showed further improvement in follow up. No patient had moderate or severe respiratory impairment at 9 months after SARS.
Regular follow up of lung function is important in SARS survivors. Information from this study is important for the disability assessment in health care workers who contracted SARS at work.
V.L. Chan, None.