Dear Editor,

We thank the reader for their interest in our recent publication, Effect of the EzPAP system on tidal volume and airway pressures in healthy adults1 and appreciate the opportunity to respond to the points raised in the letter.2

The reader notes that our study was conducted in healthy adults and may not reflect responses in postoperative patients or those with impaired pulmonary mechanics. This limitation is an important point acknowledged in our manuscript, where we outlined that the study was designed as an early-phase physiological exploration to characterize the mechanical effects of incremental EzPAP flow settings under controlled conditions. The findings were not intended to represent clinical responses but to provide foundational data to inform subsequent research in patient populations.

Progressing this early research, we have since completed a follow-up physiological study evaluating EzPAP in adults admitted with thoracic trauma, a population characterised by reduced lung volumes and altered chest wall mechanics. Preliminary observations indicate that the magnitude and pattern of tidal volume and pressure responses differ from those seen in healthy adults, reinforcing the importance of evaluating EzPAP in clinically relevant groups. The study’s manuscript is currently being prepared for peer review.

The reader also raises questions regarding measurement standardization. Our study incorporated consistent calibration procedures for all equipment, with flow and pressure signals collected using a single calibrated pneumotachometer and pressure transducer system. These procedures align with the standardization principles described in the ATS/ERS technical statement on spirometry (Graham et al., Am J Respir Crit Care Med, 2019), particularly the sections on the equipment setup, calibration verification, and consistent measurement conditions (pp. e72-76). As detailed in the paper, participants were seated upright and instructed to maintain quiet tidal breathing, and the EzPAP interface was fitted by the same investigator for all participants to ensure consistency. Each flow setting was recorded for a fixed duration to minimize variability. Although word limits prevented detailed reporting of these procedures in the published manuscript, they were implemented in full. We agree that future studies, particularly those involving clinical populations, would benefit from expanded reporting of interface fit, breathing pattern monitoring, and repeated-measure reliability for greater appreciation of the impact these variables have on respiratory physiology when using the EzPAP.

We appreciate the reader’s engagement and concur that addressing population-specific responses and enhancing measurement standardization will strengthen the evidence base supporting EzPAP use in clinical practice. Our healthy-adult study provides foundational physiological data, and our subsequent thoracic-trauma work will extend this evidence into a clinically relevant population.

Funding

This study did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Competing interests

The author has completed the ICMJE uniform disclosure form and declares no conflict of interest.

AI Statement

The author confirms that no generative AI or AI-assisted technology was used to generate content.

Ethical Approval

Not required for this article type.