Assessment of the microbial load of airway clearance devices used by a cohort of children with cystic fibrosis

Design and initial testing of a novel disposable oscillating positive expiratory pressure device

BACKGROUND

Oscillating positive expiratory pressure (OPEP) devices play a key role in airway clearance, particularly in patients with cystic fibrosis. These devices, however, have the potential to become reservoirs for pathogenic organisms and require daily, or even more frequent, cleaning. This places a large burden on patients and their carers.

AIMS

The objective of this work was to develop a disposable OPEP device, with comparable mechanical performance to commercial devices, that negates the need for cleaning after use thus reducing microbiological risks.

METHODS

3D printing was used to iterate and develop a prototype disposable device (The University of Limerick OPEP, abbreviated to the UL-OPEP) that was compared with a selection of commercially available devices for mean pressure and oscillation amplitude (cmH2O), as well as oscillation frequency (Hz). All devices were tested using a healthy volunteer at a target expiratory flow of ~ 20 L/min. The target therapeutic range was 10-20 cmH2O at a flow rate of 10-20 L/min as is reported widely in the literature.

RESULTS

The prototype disposable device achieved a mean pressure of 14.82 cmH2O at a mean flow rate of 18.82 L/min, and generated an oscillation frequency of 26 Hz with an amplitude of 1.28 cmH2O. These characteristics compare favourably with existing, more complex, reusable OPEP devices.

CONCLUSIONS

The UL-OPEP device is a small, disposable OPEP device, that generates pressure and oscillation amplitudes for clinically effective airway clearance. The device negates the need for cleaning and disinfecting, removing the risk of devices acting as a potential reservoir for pathogenic organisms while maintaining mucus-clearing benefits.

An initial evaluation of the safety of a disposable oscillating positive expiratory pressure device in patients with chronic obstructive pulmonary disease: a sort-term pilot study

Background

Handheld oscillating positive expiratory pressure (OPEP) devices have been a mainstay of treatment for patients with hypersecretory conditions such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) since the 1970s. Current devices are reusable and require regular cleaning and disinfection to prevent harbouring potentially pathogenic organisms. Adherence to cleaning regimens for respiratory devices is often poor and in response to this, a prototype disposable OPEP device—the ‘UL-OPEP’ (University of Limerick—Oscillating Positive Expiratory Pressure device)—was developed to mitigate the risk of contamination by pathogens. The device was previously evaluated successfully in a group of paediatric CF patients. The aim of the current study was to initially evaluate the safety of the prototype in patients with COPD over a period of 1 month to ensure no adverse events, negative impacts on lung function, exercise tolerance, or quality of life. Data on user experience of the device were also collected during post-study follow-up.

Methods

A sample of 50 volunteer participants were recruited from pulmonary rehabilitation clinics within the local hospital network. The patients were clinically stable, productive, and not current or previous users of OPEP devices. Participants were invited to use a prototype disposable OPEP device daily for a period of 1 month. Pre- and post-study lung function was assessed with standard spirometry, and exercise tolerance with the 6-min-walk-test (6MWT). Quality of life was assessed using the St. George’s Respiratory Questionnaire (SGRQ), and user experience of the prototype device evaluated using a post-study questionnaire.

Results

24 Participants completed the study: 9 were female. Overall median age was 67.5 years, range 53–85 years. Lung function, 6-min walk test, and SGRQ scores showed no significant change post-study. User feedback was positive overall.

Conclusions

The results indicate that the UL-OPEP is safe to use in patients with COPD. No adverse events were recorded during the study or in the follow-up period of 2 weeks. The device did not negatively impact patients’ lung function, exercise tolerance, or quality of life during short term use (1 month), and usability feedback received was generally positive. Larger, longer duration studies will be required to evaluate efficacy.

Registration The study was approved as a Clinical Investigation by the Irish Health Products Regulatory Authority (CRN-2209025-CI0085).