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The following is a summary of “Ultrasound analysis of hemidiaphragm function in case of pleural effusion,” published in the January 2025 issue of Pulmonology by Boussuges et al. 

Researchers conducted a retrospective study to establish criteria for evaluating the effects of pleural fluid on diaphragm function and identifying diaphragmatic muscle impairment.  

They performed the study at a university hospital, recruiting patients with free pleural effusion from the lung function test laboratory’s ultrasound consultations. Chest ultrasound was used to quantify pleural effusion and analyze diaphragmatic function while seated. If abnormal diaphragmatic motion was observed, the examination was repeated in the supine position.  

The results showed 109 pleural effusions (57 left, 52 right) were analyzed. Pleural effusions were identified in 89% of cases post-thoracic surgery, with the remaining cases related to medical conditions. Deep inspiration excursion decreased with fluid volume: 4.3 ± 2.1 cm for small effusions, 3.2 ± 1.7 cm for moderate effusions, and 1.1 ± 1.8 cm for large effusions. In 23 large pleural effusions, excursions were always below the normal range. Paradoxical motion, indicating possible hemidiaphragm paralysis, was observed in some cases. When inspiratory thickening was normal, paradoxical motion was absent in the supine position. Among 53 moderate effusions, 68% showed hemidiaphragm excursion above the lower normal limit. Repeated ultrasounds confirmed hemidiaphragm paralysis in cases with paradoxical motion. In 32 small pleural effusions, excursions were typically normal.  

Investigators concluded the ultrasound analysis of diaphragm excursion and thickening in both sitting and supine positions effectively assessed the impact of pleural effusion and identified impairments in diaphragm muscle function. 

Source: frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1532214/full