What is the key question?

• What is the effect of pleural effusion and pleural fluid drainage on cardiorespiratory, functional and diaphragmatic parameters and what is the proportion as well as the characteristics of patients who develop dyspnea relief after drainage?

What is the bottom line?

• Dyspnea is the most common presenting symptom of pleural effusions and its pathophysiologic mechanism is complex, multifactorial and poorly understood. In this single-center study, the investigators prospectively enrolled 145 patients with symptomatic pleural effusions and assessed them at both pre-therapeutic drainage and at 24–36 hours post-therapeutic drainage.
• While improvements in vital signs and spirometry were modest, breathlessness scores (mean VAS, Dyspnea-12, and resting Borg score) improved post-drainage and the 6-min walk distance significantly increased.
• The ipsilateral hemi-diaphragm was flattened or everted in 50% of participants pre-drainage and 48% of participants exhibited paradoxical or no diaphragmatic movement. Post-drainage, hemi-diaphragm shape and movement were normal in 94% and 73% of participants, respectively.
• Drainage provided meaningful breathlessness relief in 73% of participants irrespective of whether the lung expanded. Based on multivariate analyses, predictors of breathlessness relief included significant breathlessness pre-drainage, baseline abnormal/paralyzed/paradoxical diaphragm movement, a benign etiology for the pleural effusion, a higher pleural pH and a higher serum albumin level.

Why read on?

• The PLEASE study is one of the largest and most comprehensive prospective datasets on symptoms, cardiorespiratory status, exercise capacity, radiographic and diaphragm features in patients with moderate-to-large pleural effusions necessitating fluid evacuation.