multiple-breath washout
Also written as: MBW — Multiple-Breath Washout
A lung function technique in which a tracer gas is inhaled and then washed out over multiple tidal breaths, used to assess ventilation distribution in the lungs.
Full Definition
Multiple-breath washout is an effort-independent test particularly suited to infants and preschool-aged children who cannot perform forced spirometry. The subject breathes tidally while the concentration of an inert tracer gas (such as sulfur hexafluoride or 100% oxygen for nitrogen washout) is monitored breath by breath until the gas is cleared to a defined endpoint. The resulting data yield indices of ventilation inhomogeneity, most notably the Lung Clearance Index. In editorial copy, the term should be hyphenated as a compound modifier before a noun ('multiple-breath washout testing') but left open when used predicatively.
Usage
Usage note: Hyphenate as a compound modifier before a noun. The abbreviation MBW is acceptable on second reference in technical documents.
In Context
- "Multiple-breath washout (MBW) testing was performed using sulfur hexafluoride as the tracer gas." — Methods section, clinical research paper
- "Unlike spirometry, MBW can be performed in sedated infants, broadening its applicability in the neonatal population." — Review article introduction