P125 Diaphragm dynamics in pleural effusion

Abstract

<h3>Introduction and Objectives</h3> The relationship between symptoms, pleural effusion size and the diaphragm is unclear. We conducted a pilot study to understand the role of diaphragm shape and movement in patients with unilateral pleural effusions. <h3>Method</h3> We prospectively recruited patients with unilateral pleural effusions. Routine investigations were collected. Study-specific thoracic ultrasounds (TUS) were performed at baseline, post intervention, and at day 7. A seven-day visual analogue score (VAS) diary was completed for breathlessness, starting at baseline, immediately post aspiration and then daily thereafter. <h3>Results</h3> Of the 45 patients recruited, 17/45(38%) were female. The median [interquartile] age was 71[66–77] years. The most common reported symptom was breathlessness in 43/45(96%). At baseline, the medial effusion depth was 100[80–126]mm over 4[3–5] rib spaces. Procedures were performed in 40/45(89%), including 32 therapeutic-interventions and 8 diagnostic aspirations. A median of 1,000 [481–1,500]mls of pleural fluid was aspirated. Malignancy was diagnosed in 20/45(44%) patients. A diaphragm abnormality (abnormal shape, movement or both) was seen in 22/45(49%) with a flattened diaphragm in 7/45(16%), an inverted diaphragm in 2/45(4%), paradoxical movement in 13/45(29%) and no movement in 8/45(36%). A malignant diagnosis was found in 14/22(64%) of those with a diaphragm abnormality at baseline, compared to 6/23(35%) with normal diaphragm (p&lt;0.05). Of those undergoing a therapeutic intervention diaphragm abnormalities persisted in 4/21(19%) with improvement in 15/21(71%) (two were unreported). Diaphragm shape improved in all patients, however two patients had a persistent paradoxically moving diaphragm and two had no movement. In 27 patients undergoing therapeutic intervention and completing follow up, 19/27(70%) had a diaphragm abnormality at baseline, 4/27(15%) post intervention and 11/27(41%) at day 7. VAS scores at baseline, post aspiration and day 7 were 44[27–53.5]mm, 25[13–44]mm and 36[13.5–58.5]mm in those with a diaphragm abnormality compared with 46.5[34.25–72.5]mm, 34.5[18.5–54.75]mm and 22.5[14.25–32.25]mm in those with an normal diaphragm. In those with an abnormal diaphragm at day 7, the change in VAS was -4[-11.5–1] in the abnormal diaphragm group and -23[-31- -10.25] in the normal diaphragm group (p&lt;0.05). <h3>Conclusion</h3> A diaphragm abnormality was common, demonstrated reversibility, but recurrence by day 7 was associated with loss of therapeutic benefit.