Does the MetaNeb®, a new airway clearance device, change lung function in adults with cystic fibrosis when they are hospitalised for a lung infection?

The MetaNeb® System (Hill-Rom, Inc. Batesville, Indiana, USA) is a relatively new device that has been developed to facilitate airway clearance in individuals with acute and chronic lung conditions, including CF. It was introduced for clinical use in Australia in 2016. The MetaNeb® incorporates two modes; (i) continuous positive expiratory pressure (CPEP) and, (ii) continuous high frequency oscillation (CHFO). The CPEP mode assists with lung expansion and recruitment by delivering PEP, whereas the CHFO mode aids secretion clearance by providing pulsatile positive airway pressure at two different frequencies (similar to intrapulmonary percussive ventilation [IPV].)These modes deliver positive airway pressure and airway oscillation throughout both inspiration and expiration. The device also allows three varying levels of PEP to be applied at the mouthpiece, and a nebulised mucolytic (e.g. saline or hypertonic saline) to be delivered while the device is in use. Multiple interfaces can be used to deliver the therapy including a face mask, mouthpiece or tracheostomy. In this study we will be using the mouthpiece only. Participants allocated to the experimental group will be asked to complete 30 minutes of supervised physiotherapy, twice daily, using the MetaNeb® system (Hill-Rom, Inc. Batesville, Indiana, USA) with their usual inhaled mucolytics (either normal or hypertonic saline) and if needed supplemental oxygen. The 30 minute MetaNeb treatment session will comprise breathing in and out of the mouthpiece for 5x 5 minute cycles of MetaNeb® therapy (2.5 mins each of CPEP and CHFO modes) interspersed with 1 minute of sputum clearance using huff and/or cough. This treatment will be used for the first 5 days of the participants inpatient admission. Each participant will have the settings of the MetaNeb® titrated to optimise comfort and these settings will be recorded and used for subsequent treatment sessions. All treatment sessions will occur in the patients room on the Respiratory Ward at Sir Charles Gairdner Hospital (SCGH) and will be conducted by either the PhD candidate or another trained member of the SCGH Cystic Fibrosis (CF) Physiotherapy team.