Noninvasive Ventilatory Support: The Detail Lies in the Interface

Clinical impact of customised positive airway pressure (PAP) therapy interfaces versus usual care in the treatment of patients with sleep-disordered breathing (3DPiPPIn): a randomised controlled trial protocol

INTRODUCTION

Sleep-disordered breathing affects 1.6 million people in the UK. The recognised treatment is positive airway pressure (PAP) therapy, delivered via a generic conventional interface (mask). PAP therapy improves morbidity, mortality and quality of life, but treatment effectiveness depends on interface fit and tolerance. Interface side effects include pressure ulcers, skin reactions and interface leak. Three-dimensional (3D) printing is an innovative technology that can produce customised interfaces.

AIMS

The primary aim is to assess the impact of customised versus conventional interfaces on residual Apnoea Hypopnea Index at 6 months.

METHODS AND ANALYSIS

This is a randomised control trial via block randomisation, minimised by age >65 and ethnicity, using a computerised random number generator. Patients with sleep-disordered breathing under the care of the Royal Free London NHS Foundation Trust will be recruited. Patients new to therapy will be randomised to customised interface or conventional interface for 6 months. A sample size of 160 is required for 80% power with a significance of 5%, accounting for a 20% dropout rate. Descriptive statistics will report demographics. The primary and secondary outcomes will be compared using linear regression adjusted for baseline score.

ETHICS AND DISSEMINATION

This protocol has been approved by the Hampshire B Research Ethics Committee (REC reference: 22/SC/0405). Results will be disseminated to healthcare professionals and patients through conferences, open-access journals, newsletters, a study webpage, infographics, animations, social media and healthcare awards.

ISRCTN REGISTRATION NUMBER

74082423.

In Vitro Evaluation of Facial Pressure and Air Leak with a Newly Designed Cushion for Non-Invasive Ventilation Masks

Background: The aim of this study was to evaluate the effect of a newly designed foam cushion on the air leakage and pressure when applied to the face. Methods: A teaching manikin connected to a bilevel positive airway pressure ventilator attached to four different brands of oronasal masks (Amara, Mirage, Forma, and Wizard) was used. The foam cushions of 5-mm and 10-mm-thickness were attached to the masks, and each mask was tested without a cushion. Six pressure sensors were placed on the manikin’s face, and data were recorded. Inspiratory volume and air leak flow from the ventilator were observed. Results: Air leakage was influenced by both the mask brand and the presence of a cushion. The presence of a cushion did not affect the Wizard mask in terms of leakage (p = 0.317) or inspiratory volume (p = 0.726). The Wizard and Amara masks generated the lowest contact pressure on the frontal forehead (p < 0.001) compared to the other five points. Conclusions: Utilisation of a cushion reduces air leakage and maintains greater inspiratory volume regardless of its thickness. The contact pressure varies depending on the brand of the mask, which would require a difference in the thickness of the cushion for pressure reduction.