Assessment of diaphragmatic role in dyspneic patients with pleural effusion

Abstract
Background
Dyspnea that is caused by pleural effusion and affects patients’ quality of life may not be resolved after lung expansion following pleural tapping. This study aims to investigate the role that changes in the diaphragmatic shape and movement play in the development of dyspnea in those patients.

Methods
Thirty patients with pleural effusions and dyspnea were evaluated before and at 24 h after therapeutic thoracentesis. The primary outcomes are to investigate changes in diaphragmatic shape and movement before and after thoracentesis by chest ultrasound to evaluate factors causing effusion-related dyspnoea, while the secondary outcomes are firstly to investigate the effect of pleural effusion on the cardiorespiratory, functional, and diaphragmatic variables in causing dyspnea and secondly to detect the percentages and demographics of patients who experience post-drainage dyspnea improvement.

Results
Thirty patients with age >18 years old who had moderate to massive pleural effusion (either of benign or malignant etiology), with breathlessness were recruited from the Chest Department, Ultrasonography Unit, Ain-Shams University Hospitals. Almost all (96.7%) of the studied patients experienced shortness of breath with a mean modified Borg Score of 5.13 ± 1.78, tapping of varying amounts of pleural fluid ranging from 1000 to 2000 ml.
There is a highly significant improvement in the diaphragmatic excursion, with non-significant improvement in diaphragmatic shape, although nonsignificant correlation between diaphragmatic excursion and functional parameters (M. Borg score, spirometry, and 6MWD: 6-min walk distance), but a significant negative correlation between diaphragmatic excursion and amount of drained effusion (P value 0.045 and 95% CI for OR 1.041–36.779). 63.3% of patients experienced dyspnea improvement after thoracocentesis, and they showed highly significant improvements in M. Borg dyspnea score, spirometry, pulse rate, respiratory rate, 6MWD, and blood oxygen saturation.

Conclusion
In this study, we conclude that the improvement of the diaphragmatic excursion was negatively correlated with the amount of drained effusion, but no significant correlation was detected with the functional parameters and effusion-related indices that may be caused by the small sample size of the study.