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passages: document
passages: Measurement of transfer factor during constant exhalation . BACKGROUND Transfer factor of the lung for carbon monoxide ( TLCO ) was measured by a new method based on analysis of the ratio of the concentrations of carbon monoxide to an inert gas ( methane ) relative to lung volume during a constant exhalation . Since this new technique is based solely upon exhalation , anomalies associated with inspiration and breath holding do not affect results . Additionally , because prolonged breath holding is not required , measurements can readily be made in dyspnoeic patients . METHODS Exhalation TLCO ( TLCO , ex ) was compared with the standard ( Jones and Meade ) 10 second breath holding TLCO ( TLCO , bh ) in 100 consecutive patients . Patients did not practise the exhalation manoeuvre prior to testing . RESULTS The comparative results were very close ; mean difference ( bias ) +/- standard deviation ( precision ) was 0.05 ( 0.84 ) mmol/min/kPa . The relation was equally strong in patients with severe pulmonary disease ; for patients with FEV1 < 1.51 the mean difference was 0.21 ( 0.80 ) mmol/min/kPa . CONCLUSIONS Since the results were essentially identical between the techniques , it seems that comparable pathophysiological factors affect TLCO during breath holding and constant exhalation . Constant exhalation may therefore be a useful alternative to the breath holding technique for clinical measurement of TLCO .
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entities: Intervention_Other
entities: TLCO ( TLCO
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entities: Intervention_Other
entities: standard ( Jones and Meade )
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entities: Intervention_Other
entities: TLCO ( TLCO
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entities: Outcome_Physical
entities: Transfer factor of the lung for carbon monoxide ( TLCO )
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entities: Outcome_Physical
entities: Exhalation TLCO ( TLCO , ex )
entities: 3760
entities: Outcome_Physical
entities: standard ( Jones and Meade ) 10 second breath holding TLCO ( TLCO , bh )
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entities: Outcome_Physical
entities: relation