Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.
Pleural Medicine Unit, Institute for Respiratory Health, Perth, Western Australia, Australia.
Respirology. 2022 Oct;27(10):882-889. doi: 10.1111/resp.14307. Epub 2022 Jun 7.
The pathophysiology of breathlessness in pleural effusion is unclear. In the PLEASE-1 study, abnormal ipsilateral hemidiaphragm shape and movement, assessed qualitatively, were independently associated with breathlessness relief after pleural drainage. Effects of pleural effusion on contralateral hemidiaphragm function are unknown. PLEASE-2, a prospective exploratory pilot study, assessed the effects of unilateral effusion and drainage on both hemidiaphragms using advanced quantitative bedside ultrasonography.
Individuals with symptomatic unilateral pleural effusion undergoing therapeutic drainage were included. Measurements pre- and post-drainage included severity of breathlessness (visual analogue scale) and ultrasound measurements of diaphragm excursion and thickness, in addition to shape and movement. Diaphragm measurements were compared to published reference values.
Twenty participants were recruited (mean age 68.9 [SD 12.8] years, 12 females). During tidal breathing, contralateral hemidiaphragm excursion exceeded ipsilateral excursion and reference values (all p ≤ 0.001). Contralateral excursion was greatest in participants with abnormal ipsilateral hemidiaphragm movement and was inversely correlated with ipsilateral tidal excursion (r = -0.676, p = 0.001). Following drainage (mean volume 2121 [SD = 1206] ml), abnormal shape (n = 12) and paradoxical movement (n = 9) of the ipsilateral hemidiaphragm resolved in all participants, and tidal excursion of the contralateral hemidiaphragm normalized. Relief of breathlessness post-drainage correlated with improvement in ipsilateral hemidiaphragm excursion (r = 0.556, p = 0.031).
This pilot study suggests, for the first time, that unilateral pleural effusion not only impairs ipsilateral hemidiaphragm function but also causes compensatory hyperactivity of the contralateral hemidiaphragm, which resolves post-drainage. These findings provide a basis for detailed studies of diaphragmatic function and ventilatory drive in patients with symptomatic pleural effusion.
胸腔积液所致呼吸困难的病理生理学机制尚不清楚。在 PLEASE-1 研究中，定性评估发现异常同侧膈肌形态和运动与胸腔引流后呼吸困难缓解独立相关。胸腔积液对侧膈肌功能的影响尚不清楚。PLEASE-2 是一项前瞻性探索性试点研究，使用先进的定量床旁超声评估单侧胸腔积液和引流对双侧膈肌的影响。
纳入因症状性单侧胸腔积液而行治疗性引流的患者。引流前后的测量包括呼吸困难严重程度（视觉模拟量表）和超声测量的膈肌移动度和厚度，以及形态和运动。将膈肌测量值与已发表的参考值进行比较。
共纳入 20 名参与者（平均年龄 68.9 [12.8] 岁，12 名女性）。在潮气量呼吸过程中，对侧膈肌移动度超过同侧和参考值（均 p ≤ 0.001）。异常同侧膈肌运动患者的对侧膈肌移动度最大，且与同侧潮气量移动度呈负相关（r= -0.676，p= 0.001）。引流后（平均容量 2121 [1206] ml），所有患者的同侧膈肌异常形态（n=12）和反常运动（n=9）均得到解决，对侧膈肌的潮气量移动度恢复正常。引流后呼吸困难缓解与同侧膈肌移动度改善相关（r=0.556，p=0.031）。
本试点研究首次表明，单侧胸腔积液不仅会损害同侧膈肌功能，还会导致对侧膈肌代偿性过度活动，引流后可恢复正常。这些发现为进一步研究有症状胸腔积液患者的膈肌功能和通气驱动提供了基础。
