Document Detail

The impact of sickle cell disease on exercise capacity in children.
MedLine Citation:
PMID:  22922408     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Little is known about pulmonary vascular complications in children with sickle cell disease (SCD). We hypothesized that transfer factor (diffusing capacity of the lung for carbon monoxide [D(LCO)] ) may be used as a surrogate for the size of the pulmonary vascular bed and that pulmonary vascular abnormalities in children with SCD may limit exercise capacity.
METHODS: Fifty stable patients with SCD aged 10 to 18 years and 50 healthy control subjects matched for race and age were recruited. Incremental ergometer cardiopulmonary exercise testing was performed using respiratory mass spectrometry for exhaled gas analysis. A rebreathing maneuver was used to measure functional residual capacity, effective pulmonary blood fl ow (Qpeff), and D(LCO), and helium dilution was used to calculate minute ventilation, oxygen consumption, and CO 2 production.
RESULTS: In the 89 evaluable subjects, there were no ventilatory differences between SCD and control subjects. Qpeff was consistently 15% to 20% greater in subjects with SCD than control subjects at all stages, but D(LCO) corrected for both surface area and hemoglobin was only about 7% to 10% greater in subjects with SCD at all stages. As a result, the D(LCO)/Qpeff ratio was considerably lower in SCD at all stages. Arteriovenous oxygen content difference was about one-third less in SCD at all stages.
CONCLUSIONS: Contrary to our hypothesis, failure to maintain a sufficient Qpeff to compensate for anemia led to exercise limitation. The ratio of pulmonary capillary blood volume to fl ow is reduced throughout, implying subtle pulmonary vascular disease; however, this was not a factor limiting exercise.
Rifat A Chaudry; Andrew Bush; Mark Rosenthal; Suzanne Crowley
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Chest     Volume:  143     ISSN:  1931-3543     ISO Abbreviation:  Chest     Publication Date:  2013 Feb 
Date Detail:
Created Date:  2013-03-15     Completed Date:  2013-06-20     Revised Date:  2013-11-12    
Medline Journal Info:
Nlm Unique ID:  0231335     Medline TA:  Chest     Country:  United States    
Other Details:
Languages:  eng     Pagination:  478-84     Citation Subset:  AIM; IM    
Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, England.
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MeSH Terms
Anemia, Sickle Cell / physiopathology*
Carbon Dioxide / metabolism
Case-Control Studies
Exercise Test
Exercise Tolerance / physiology*
Lung / blood supply*,  physiopathology
Oxygen Consumption / physiology
Pulmonary Diffusing Capacity / physiology*
Regional Blood Flow / physiology
Rest / physiology
Reg. No./Substance:
124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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