Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out
Multiple breath wash-out (MBW) testing requires prior wash-in of inert tracer gas. Wash-in efficiency can be enhanced by a rebreathing tracer in a closed circuit. Previous attempts to deploy this did not account for the impact of CO2 accumulation on patients and were unsuccessful. We hypothesised th...
| Main Authors: | , , , , , , |
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| Format: | Article |
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European Respiratory Society
2016
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| Online Access: | https://eprints.nottingham.ac.uk/39473/ |
| _version_ | 1848795844877221888 |
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| author | Horsley, Alex R. O'Neill, Katherine Downey, Damian G. Elborn, J. Stuart Bell, Nicholas J. Smith, Jaclyn Owers-Bradley, John |
| author_facet | Horsley, Alex R. O'Neill, Katherine Downey, Damian G. Elborn, J. Stuart Bell, Nicholas J. Smith, Jaclyn Owers-Bradley, John |
| author_sort | Horsley, Alex R. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Multiple breath wash-out (MBW) testing requires prior wash-in of inert tracer gas. Wash-in efficiency can be enhanced by a rebreathing tracer in a closed circuit. Previous attempts to deploy this did not account for the impact of CO2 accumulation on patients and were unsuccessful. We hypothesised that an effective rebreathe wash-in could be delivered and it would not alter wash-out parameters.
Computer modelling was used to assess the impact of the rebreathe method on wash-in efficiency. Clinical testing of open and closed circuit wash-in–wash-out was performed in healthy controls and adult patients with cystic fibrosis (CF) using a circuit with an effective CO2 scrubber and a refined wash-in protocol.
Wash-in efficiency was enhanced by rebreathing. There was no difference in mean lung clearance index between the two wash-in methods for controls (6.5 versus 6.4; p=0.2, n=12) or patients with CF (10.9 versus 10.8; p=0.2, n=19). Test time was reduced by rebreathe wash-in (156 versus230 s for CF patients, p<0.001) and both methods were well tolerated. End wash-in CO2 was maintained below 2% in most cases.
Rebreathe–wash-in is a promising development that, when correctly deployed, reduces wash-in time and facilitates portable MBW testing. For mild CF, wash-out outcomes are equivalent to an open circuit. |
| first_indexed | 2025-11-14T19:38:33Z |
| format | Article |
| id | nottingham-39473 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:38:33Z |
| publishDate | 2016 |
| publisher | European Respiratory Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-394732024-08-15T15:17:55Z https://eprints.nottingham.ac.uk/39473/ Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out Horsley, Alex R. O'Neill, Katherine Downey, Damian G. Elborn, J. Stuart Bell, Nicholas J. Smith, Jaclyn Owers-Bradley, John Multiple breath wash-out (MBW) testing requires prior wash-in of inert tracer gas. Wash-in efficiency can be enhanced by a rebreathing tracer in a closed circuit. Previous attempts to deploy this did not account for the impact of CO2 accumulation on patients and were unsuccessful. We hypothesised that an effective rebreathe wash-in could be delivered and it would not alter wash-out parameters. Computer modelling was used to assess the impact of the rebreathe method on wash-in efficiency. Clinical testing of open and closed circuit wash-in–wash-out was performed in healthy controls and adult patients with cystic fibrosis (CF) using a circuit with an effective CO2 scrubber and a refined wash-in protocol. Wash-in efficiency was enhanced by rebreathing. There was no difference in mean lung clearance index between the two wash-in methods for controls (6.5 versus 6.4; p=0.2, n=12) or patients with CF (10.9 versus 10.8; p=0.2, n=19). Test time was reduced by rebreathe wash-in (156 versus230 s for CF patients, p<0.001) and both methods were well tolerated. End wash-in CO2 was maintained below 2% in most cases. Rebreathe–wash-in is a promising development that, when correctly deployed, reduces wash-in time and facilitates portable MBW testing. For mild CF, wash-out outcomes are equivalent to an open circuit. European Respiratory Society 2016-01-22 Article PeerReviewed Horsley, Alex R., O'Neill, Katherine, Downey, Damian G., Elborn, J. Stuart, Bell, Nicholas J., Smith, Jaclyn and Owers-Bradley, John (2016) Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out. ERJ Open Research, 2 (1). 00042-2015. ISSN 2312-0541 http://openres.ersjournals.com/content/2/1/00042-2015 doi:10.1183/23120541.00042-2015 doi:10.1183/23120541.00042-2015 |
| spellingShingle | Horsley, Alex R. O'Neill, Katherine Downey, Damian G. Elborn, J. Stuart Bell, Nicholas J. Smith, Jaclyn Owers-Bradley, John Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title | Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title_full | Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title_fullStr | Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title_full_unstemmed | Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title_short | Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| title_sort | closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out |
| url | https://eprints.nottingham.ac.uk/39473/ https://eprints.nottingham.ac.uk/39473/ https://eprints.nottingham.ac.uk/39473/ |