ERS Respiratory Channel

CDN Connection Issue

It appears that your current network does not allow connection to the CDN (Content Delivery Network) required for this service to function properly.

To resolve this issue, please try the following actions :

• Contact your network administrator : Inform them of this restriction so they can adjust the network settings accordingly.

• Use another network : Try connecting from a different network, such as another Wi-Fi network or a mobile connection.

We apologize for the inconvenience and thank you for your understanding.

Abstract

Background: Multiple-breath washout is a sensitive technique to assess lung volumes and ventilation inhomogeneity in infancy. Recent software updates for the WBreath (ndd Medizintechnik) and Spiroware (Eco Medics) setups addressed the signal correction and computation of results, but there is a lack of in-vitro validation and characterization of remaining differences between setups.

Aim: We aimed to perform an in-vitro validation of the two infant MBW setups using a revised lung model and compare functional residual capacity (FRC).

Methods: Flow and mainstream molar mass signals were gathered by ultrasonic flowmeters (WBreath 3.52.3 (WB; ndd Medizintechnik) and Spiroware 3.3.2 (SPW; Eco Medics)) using 4% sulfur hexafluorid. Using a temperature-controlled, double-chamber lung model ventilated at realistic tidal volumes, respiratory rates, and F_CO2, we generated FRCs (80 to 210ml). We assessed the accuracy of measured and model FRCs and the difference between setups.

Results: FRC_SPW was closer to the lung model (median(SD) 2.2(1.1)%) than FRC_WB (2.5(7.7)%) while intra-test variability was low for both (CV_SPW 0.97%, CV_WB 1.48%). Overall, there was no statistically significant difference between the setups (mean(95%CI) 1.2(-4.7; 7.1)ml; p=0.7). All measured FRC_SPW were below the 5% error limit (mean(range) 1.9(0.0; 4.0)%), whereas 16/22 (73%) FRC_WB exceeded the 5% error limit (6.9(0.8; 14.5)%). The addition of 5% CO₂ to the wash-in and wash-out gas mixtures had a substantial effect on FRC_WB (median(SD) 17.7(6.2)%; p?0.001), but not on FRC_SPW (-4.9 (3.5)%).

Conclusion: The lung volumes generated by the revised model are reliably and reproducibly measured by both setups, with FRC_SPW below and FRC_WB above the 5% error limit.

Abstract

#{title}