Extract
A recent study by Lenherr et al. [1] helps quantify impacts of leaks on multiple-breath washout (MBW) systems for functional residual capacity (FRC) and lung clearance index (LCI) measurements. In my view, technical leaks (post-capillary and intra-capillary leaks) are avoidable by careful testing of the equipment before connecting to the patient. However, pre-capillary leaks (interface between the device and patient) will occur, even in carefully controlled tests. The study [1], based primarily on computer modelling, provides detailed data showing that LCI measurements are relatively insensitive to expiratory leaks, but quantitative data on errors due to inspiratory leaks are not reported. It is, however, important to note that inspiratory leaks have a much higher impact on nitrogen (N2) MBW LCI and FRC measurements than expiratory leaks.
Abstract
Sulfur hexafluoride multiple-breath washout is insensitive to inspiratory leaks http://ow.ly/Y3o830lKOpY
Footnotes
Conflict of interest: J.G. Nielsen is a Chief Medical Officer and indirect owner of the company PulmoTrace ApS that develops, produces and sells devices for measurement of lung clearance index by multiple-breath washout using sulfur hexafluoride.
- Received July 23, 2018.
- Accepted August 30, 2018.
- Copyright ©ERS 2018
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