Diagnosis and etiologies of unilateral pleural effusion in a District General Hospital in the United Kingdom

Abstract

Background: The lungs are enveloped by a serous membrane called visceral pleura, while the chest wall and pericardium are covered by parietal pleura. Lung hila connect these layers, and a small amount of fluid in the pleural space lubricates movement. Pleural effusion, excess fluid in the pleural cavity, indicates underlying pulmonary, pleural, or extra-pulmonary diseases. Objective: To study the various causes of unilateral pleural effusion in patients presenting to a District General Hospital in the United Kingdom.Methodology: This was a prospective study conducted at Worsecter Royal Infirmary, UK, from July 2021 to June 2022. All (58) adult patients (age above 18 years) admitted to the chest ward from various sources with unilateral pleural effusion were included. Case notes were reviewed and data was collected. Diagnostic pleural tap was performed in every case and aspirate was sent for biochemical, microbiological and cytological analysis. Pleural biopsies were taken where diagnosis could not be established with the help of other investigations. Results: Among 58 patients with unilateral pleural effusion (34 men, 24 women), most were aged 50-89 (mean age 69). Among study cases, 16% were referred for surgery (VATS or thoracotomies), with an average 11-day waiting period. Effusions were transudate (15) or exudate (43), and malignancy was confirmed in 31 cases. Complications included intercostal drain dislodgement (19%) and subcutaneous emphysema (12%). Malignancy was the most common cause of unilateral pleural effusion, followed by parapneumonic effusion, left ventricular failure, TB, and asbestos-related benign effusion.Conclusion: In conclusion, this study highlights malignancy as the primary cause of unilateral pleural effusion confirmed through cytology and biopsies. Managing these patients is complex, involving prolonged hospitalization, multiple thoracocentesis attempts, and often prompt surgical intervention. Imaging, especially contrast CT chest, is crucial for lesion identification. Complications like drain dislodgement and subcutaneous emphysema underscore the challenges in pleural effusion management.