Infant multiple breath washout using a new commercially available device: Ready to replace the previous setup?

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Multiple breath washout (MBW) is a sensitive method for assessing lung function in infants.
• Current infant MBW setups, often using ultrasonic flowmeters, require complex signal processing that can impact reliability.
• A novel MBW setup aims to address limitations of existing systems, but requires validation.

Purpose of the Study:

• To evaluate the feasibility of a new infant multiple breath washout (MBW) system.
• To compare functional residual capacity (FRC) measurements obtained from the new MBW setup against a conventional system.
• To assess the in vivo and in vitro performance of the new MBW setup.

Main Methods:

• MBW measurements were conducted in four healthy infants and four infants with cystic fibrosis.
• A Plexiglas lung simulator was used to mimic realistic infant lung volumes and breathing patterns.
• Both the new (Exhalyzer D, Spiroware 3.2.0) and old (Exhalyzer D, WBreath 3.18.0) setups were used in random sequence.

Main Results:

• The new MBW setup demonstrated 100% technical feasibility in infant testing.
• While intra-subject variability in FRC was low for both setups, significant differences in FRC values were observed (mean relative difference 39.7%).
• Software correction reduced FRC discrepancies (14.0%), but results remained non-interchangeable, confirmed by in vitro testing.

Conclusions:

• Infant MBW testing using the new setup is technically feasible.
• Despite software adjustments, FRC measurements from the new and old setups are not interchangeable.
• Further research is necessary before the new MBW setup can be widely adopted for clinical use.