Longer term follow up of aerobic capacity in children affected by severe acute respiratory syndrome (SARS)
- C C W Yu1,
- A M Li1,
- R C H So2,
- A McManus3,
- P C Ng1,
- W Chu4,
- D Chan1,
- F Cheng1,
- W K Chiu5,
- C W Leung6,
- Y S Yau7,
- K W Mo8,
- E M C Wong9,
- A Y K Cheung9,
- T F Leung1,
- R Y T Sung1,
- T F Fok1
- 1Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong
- 2Sports Institute, Hong Kong Sports Development Board, Hong Kong
- 3Institute of Human Performance, The University of Hong Kong, Hong Kong
- 4Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Shatin, Hong Kong
- 5Department of Paediatrics and Adolescent Medicine, United Christian Hospital, Hong Kong
- 6Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
- 7Department of Paediatrics and Adolescent Medicine, Queen Elizabeth Hospital, Hong Kong
- 8Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
- 9Centre for Epidemiology and Biostatistics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
- Correspondence to:
Dr A M Li
Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong; albertmli{at}cuhk.edu.hk
- Received 17 May 2005
- Accepted 3 January 2006
- Published Online First 31 January 2006
Abstract
Background: A study was undertaken to investigate the aerobic capacity and pulmonary function of children 6 and 15 months after the diagnosis of severe acute respiratory syndrome (SARS).
Methods: Thirty four patients of mean age 14.7 years completed both pulmonary function and maximal aerobic capacity tests at 6 months. All had normal clinical examination and were asymptomatic. Their exercise responses were compared with a group of healthy controls. Complete data were collected on 27 of the original 34 cases at 15 months.
Results: Compared with normal controls, the patient group had significantly lower absolute and mass related peak oxygen consumption (peak V˙o2 (p<0.01)), higher ventilatory equivalent for oxygen (p<0.01), lower oxygen pulse (p<0.01), and a lower oxygen uptake efficiency slope (p<0.01) at 6 months. This impairment was unexpected and out of proportion with the degree of lung function abnormality. Residual high resolution computed tomography of thorax (HRCT) abnormalities were present in 14 patients. Those with abnormal HRCT findings had significantly lower mass related peak V˙o2 than subjects with normal radiology (p<0.01). Absolute and mass related peak V˙o2 in the patient group remained impaired at 15 months despite normalisation of lung function in all patients.
Conclusions: The mechanism for the reduced aerobic capacity in children following SARS is not fully understood, but it is probably a consequence of impaired perfusion to the lungs at peak exercise and deconditioning.
- FEV1, forced expiratory volume in 1 second
- FEF25–75, mid forced expiratory flow
- FRC, functional residual capacity
- FVC, forced vital capacity
- HR, heart rate
- OUES, oxygen uptake efficiency slope
- Peto2, end tidal oxygen partial pressure
- Petco2, end tidal carbon dioxide partial pressure
- PFT, pulmonary function test
- RER, respiratory exchange ratio
- RR, respiratory rate
- TLC, total lung capacity
- Tlco, carbon monoxide transfer factor
- VAT, ventilatory anaerobic threshold
- V˙e, minute ventilation
- V˙o2, oxygen consumption
- V˙e/V˙o2, ventilatory equivalent for oxygen
- V˙e/V˙co2, ventilatory equivalent for carbon dioxide
Footnotes
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Published Online First 31 January 2006
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CCWY and AML are joint first authors.
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No special funding.
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Competing interests: none declared.
