An audit of the clinical investigation of pleural effusion

Pleural aspiration with pleural biopsy is advised for the investigation of pleural effusion. The clinical investigation of pleural effusion in a group of teaching hospitals was audited with reference to adequacy and diagnostic value of sampling procedures.

A retrospective review of case records of all patients investigated for pleural effusion during an eight month period was performed. The records of 112 patients, age range 16-91 years, who underwent 150 procedures were reviewed.

Microbiology samples were obtained from 137 procedures, of which five provided a positive culture, including one for mycobacteria. Cytology samples were obtained from 145 procedures though approximately two thirds of samples were less than the recommended 30 ml. The pleural biopsy rate was 30%, varying from 0% in general or thoracic surgery to 68% in thoracic medicine (thoracic surgeons carried out thoracoscopy). Twenty nine per cent of pleural biopsy samples were of poor quality. The complication rate was 2% for aspiration alone, and 4% for aspiration plus biopsy. The sensitivity of the first diagnostic procedure for a diagnosis of malignancy or tuberculosis was 53% for cytology alone, 50% for biopsy alone and 72% for cytology plus biopsy.

The samples obtained from pleural aspiration and biopsy in the initial investigation of pleural effusion are often inadequate. Further education is necessary to improve the quantity and quality of specimens submitted for histological and cytological examination.