Exercise capacity and pulmonary function in hospital workers recovered from severe acute respiratory syndrome

Abstract

Background: Persistent impaired pulmonary function and functional capacity are common among survivors of severe acute respiratory syndrome (SARS). Whether the impairment was caused by SARS or pre-existing physical condition remains unclear.

Objective: This study investigated the influence of SARS on exercise capacity and pulmonary function of previously healthy medical staff.

Methods: Pulmonary function tests, including spirometry and carbon monoxide diffusing capacity (DLCO), as well as symptom-limited cardiopulmonary exercise testing (CPET) with an incremental protocol using an electronically braked cycle ergometer, were performed by 13 previously healthy hospital workers 14 months after SARS recovery. Other 14 age- and sex-matched healthy medical workers completed CPET simultaneously, and exercise capacities of these two groups were compared.

Results: Most values of spirometry performed were within normal range. Only one showed mildly restrictive abnormality with decreased forced expiratory volume in 1 s (72.2% predicted) and forced vital capacity (68.1% predicted). Eight subjects had decreased DLCO levels (mean 79.37 +/- 7.73%), and low exercise capacity was noted in 9 subjects. Discordance in impairment of the measured DLCO and exercise capacity was revealed by comparison. Besides, there was no significant difference in results of CPET between subjects recovered from SARS and those never infected.

Conclusions: Minor pulmonary function defects as well as decreased exercise capacity were detected in previously healthy medical staff after recovering from SARS. No significant correlation between exercise capacity and pulmonary function was found.