Ultrasound assessment of the relation between the quantity of pleural effusion and diaphragmatic functions

Background
Diaphragm is a necessary respiratory muscle. In cases with pleural effusion, abnormal diaphragmatic functions may be observed. Thoracic ultrasound is a simple, accurate, and noninvasive method to investigate the relation between the quantity of pleural effusion and diaphragmatic functions.


Aim
The work was done to clarify the relation between the quantity of pleural effusion and diaphragmatic functions using ultrasound.


Patients and methods
A prospective case–control study, where patients were divided into two groups: GI (cases), 20 patients with pleural effusion for ultrasound evaluation of the relation between the quantity of pleural effusion and diaphragmatic functions, and GII, (controls) 20 healthy volunteers without pleural effusion for ultrasound assessment of diaphragmatic functions. Between 2019 and 2020, clinical assessment, routine investigations, and demographic and radiological data were reviewed for the two groups.


Results
Thoracic ultrasound for GI at different quantities of pleural effusions revealed significant differences in diaphragmatic functions such as thickness at the end of inspiration, diaphragm thickening fraction, excursion at deep breathing, and excursion at quiet breathing. The statistical comparison of sonographic findings between GI and GII showed significant differences in the thickness at the end of expiration, thickness at the end of inspiration, diaphragmatic thickening fraction, excursion at quiet breathing, and excursion at deep breathing. These changes are proportionate to the quantity of pleural effusion.


Conclusion
There is an adverse effect of pleural effusion at different quantities on diaphragmatic functions as observed by thoracic ultrasound.