The Pneumothorax And Symptom Evaluation (PASE) study: Bendopnoea in patients with pneumothorax.

Background: Pneumothorax can cause distressing breathlessness, however the effect of the accumulated air in the pleural space and its association with diaphragmatic function and symptoms of breathlessness is not well understood. Bendopnoea is an evolving clinical symptom that has been demonstrated as clinically useful in some heart and lung conditions. Whether bendopnoea is present in patients with pneumothorax, and its potential clinical usefulness has not yet been investigated. The PASE study is a pilot study to explore the incidence and clinical relevance of bendopnoea in patients with pneumothorax and may provide better understanding of pneumothorax related dyspnoea.

Methods: PASE is a prospective study. Eligible patients are assessed at baseline (pre air drainage/lung reinflation) and in patients whose pneumothorax resolves once the lung has re-expanded (post conservative management or air drainage procedure). Outcome measures include the incidence of bendopnoea, correlation of the associated symptoms (pain and breathlessness) to the severity of bendopnoea and the size of pneumothorax; and correlation with clinical outcome (i.e., response to air drainage/lung reinflation). The study will recruit 50 participants.

Discussion: This is the first study to explore bendopnoea in patients with pneumothorax. The presence and significance of bendopnoea in relation to clinical and physiological parameters in patients with pneumothorax requires investigation. The findings of this study may further current understanding of dyspnoea related pneumothorax.

Trial registration: Name of the registry: Australia New Zealand Clinical Trial Registry Trial registration number : ACTRN12623001109695p. URL of the trial registry record for this trial : https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=386631&isReview=true Date of registration : Registered on 24 October 2023. Funding of the trial : This study has not received grant support. The study is sponsored by the Institute for Respiratory Health, a not-for-profit organisation. Name and contact information for the trial sponsor : Mr Bi Lam; Finance manager. Level 2, 6 Verdun Street, Nedlands, WA 6009. Role of sponsor : The funder is not involved in the planning of the study, gathering, analysing, and interpreting the data, or in preparing the manuscript. Protocol version : 1.