Pulmonary function and exercise capacity in survivors of severe acute respiratory syndrome

Abstract

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS).At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing.No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment.In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.

Exercise testing in survivors of intensive care—is there a role for cardiopulmonary exercise testing?

“…The commonest reason for test termination in our cohort was leg fatigue. This is in keeping with previous studies of CPET after critical illness where more than 75% of patients described leg fatigue as the main symptom limiting exercise [8]. The RER at peak exercise was 0.96 ± 0.11 with both BR and HRR evident in most of the patients, indicating the presence of cardiorespiratory reserve at the peak exercise level achieved by the patient.…”

“…Cardiopulmonary exercise testing appears to be a practical method of assessing exercise capacity in ICU survivors when performed within 6 weeks of hospital discharge. To our knowledge, only 1 previously published study has used CPET to assess patients in a similar setting, testing 44 severe acute respiratory syndrome survivors 3 months after hospital discharge [8]. In comparison with this study, our patient cohort was older (57 vs 37 ± 11 years), spent longer in hospital (47 ± 30 vs 20 ± 17 days), and was more likely to have received mechanical ventilation (100% vs 16%).…”

“…Cardiopulmonary exercise testing is advocated as a tool to guide exercise prescription in chronic obstructive pulmonary disease and heart failure [6,7]. To date, its use after critical illness has been restricted to the study of specific patient populations including survivors of the severe acute respiratory syndrome and the acute respiratory distress syndrome (ARDS) [8,9]. To our knowledge, CPET has never been used in the assessment of general adult ICU survivors in the immediate post-hospital discharge period.…”

The long‐term impact of severe acute respiratory syndrome on pulmonary function, exercise capacity and health status

“…All the spirometric and lung volume parameters remained static during the study period except for a decreasing trend in the mean of the forced expiratory flow (FEF)% 25–75 . The percentages of patients with spirometry and lung volume impairment and restrictive abnormality at 24 months were similar to the previous 3–12 month follow‐up studies on SARS survivors 9,11,15 . The overall pattern of lung function impairment in our study suggests small airway disease and impairment in the diffusion pathway in the SARS survivors.…”

Exercise Capacity and Pulmonary Function in Hospital Workers Recovered from Severe Acute Respiratory Syndrome

“…Ong et al [14] found that 41% of recovered SARS patients had a maximum exercise capacity below the lower normal limit. Whether pre-existing illness or the previous health status played some role in the results remained unclear.…”