Sweat testing by capillary collection and osmometry: suitability of the Wescor Macroduct System for screening suspected cystic fibrosis patients.
A new method of collecting and analysing sweat (Wescor Macroduct) has advantages of simplicity of collection and direct reading of results by osmometry. Forty-seven children with cystic fibrosis and 47 normal children had sweat tests performed simultaneously by the Gibson and Cooke method and by the Wescor Macroduct method. The new method had a higher rate of inadequate collection (19% vs 6%) which was more marked in children under 5 years of age. This was due partly to the difficulty of fitting a 2.5 cm pilocarpine gel disc to small arms. When an adequate collection was obtained, results were reliable with no false negatives occurring during this study. The Wescor Macroduct sweat test is a reliable method for use in peripheral centres to screen patients suspected of having cystic fibrosis. All children with an inadequate collection or a positive result should be referred to a reference centre for confirmation of the diagnosis. However, the majority will be saved the expense and disruption of travel.
Department of Gastroenterology, Royal Children's Hospital, Parkville, Victoria, Australia.
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Barnes
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Vaelioja
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McShane
D000293:Adolescent; D002199:Capillary Permeability; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000517:prevention & control*; D004566:Electrodes; D004867:Equipment Design; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012965:Sodium Chloride / Q000032:analysis; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods*; D013542:Sweat / Q000032:analysis*
D012965:Sodium Chloride