The third PLeuralEffusion And Symptom Evaluation (PLEASE-3) study: Bendopnoea in patients with pleural effusion

Pleural effusions often cause disabling breathlessness, however the mechanism is unknown. Patients with pleural effusions are subjected to pleural fluid drainage on a 'trial and error' basis, as symptom relief varies. This population commonly complain of bendopnoea (breathlessness on bending forward) which has not been investigated. Our pilot data found bendopnoea was significantly associated with presence of pleural effusion. The PLEASE-3 study will evaluate bendopnoea as a screening test for effusion-related breathlessness, its predictive value of symptomatic benefits from fluid drainage and explore its underlying physiological mechanism.

PLEASE-3 is a multi-centre prospective study. Eligible patients are assessed at baseline (pre-drainage) and for patients undergoing drainage, up to 72 h post-procedure. Outcome measures include the prevalence of bendopnoea, its correlation with size of effusion and its predictive value of breathlessness relief after drainage. The relationship of bendopnoea with breathlessness, physiological parameters, functional capacity and diaphragmatic characteristics will be assessed. The study will recruit 200 participants.

This is the first study to investigate bendopnoea in patients with pleural effusion. It has minimal exclusion criteria to ensure that the results are generalisable. The presence and clinical significance of bendopnoea in the context of pleural effusion requires thorough investigation. The post assessment of patients undergoing pleural fluid drainage will provide insight into whether the presence of bendopnoea is able to predict clinical outcomes.

Australia New Zealand Clinical Trial Registry ACTRN12622000465752. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=383639&isReview=true Registered on 24 March 2022. This study has received funding from the Sir Charles Gairdner Research Advisory Council research project grant. The study is sponsored by the Institute for Respiratory Health, a not-for-profit organisation. Mr Bi Lam; Finance manager. Level 2, 6 Verdun Street, Nedlands WA 6009. t‖ + 61 8 6151 0877 e‖ bi.lam@resphealth.uwa.edu.au : The funder is not involved in the planning of the study, gathering, analysing, and interpreting the data, or in preparing the manuscript.