P27 IMPACT OF PRE-MEDICAL THORACOSCOPY THORACIC ULTRASOUND ON PLEURAL ACCESS AND PREDICTION OF SEPTATION

A. R. L. Medford, S. Agrawal, J. A. Bennett, C. M. Free, J. J. Entwisle. Glenfield Hospital, Leicester, UK

Introduction Medical thoracoscopy (MT) is indicated to investigate unexplained pleural exudates. Problems can occur with pleural space access and fibrinous septation which may prevent pleurodesis. Thoracic ultrasound (TUS) improves the safety and accuracy of thoracocentesis but its potential value pre-MT is poorly understood (there has only been one published study in this particular application of TUS, in contrast to the wealth of data concerning chest drains and pleural aspiration). We hypothesised pre-MT TUS would reduce pleural space access failure and detect fibrinous septation more reliably.

Methods 30 patients underwent MT consecutively for investigation of pleural exudates without pre-MT TUS over a 6-month period. Over the following 6 months, 30 consecutive patients underwent TUS immediately prior to MT. The volume of pleural fluid was maximally one-third of the affected hemithorax. Pleural access rate and septation at MT and ancillary features noted at TUS were recorded.

Results In the non-TUS cohort, pleural space access failure occurred in 16.7% (requiring three CT-guided pleural biopsies and two surgical thoracoscopies) versus no failures in the TUS cohort (p = 0.05, table 1). There were no differences in prevalence of MT fibrinous septation between cohorts. In the TUS cohort, TUS identified all cases of septation versus only 12.5% identified (by pleural CT) in the non-TUS cohort (p = 0.001). All identified cases of septation on TUS did not receive pleurodesis at MT. TUS detected useful ancillary findings in 43% of cases including low-lying effusions or major organ proximity in 13% of cases.

Conclusion Pre-MT TUS reduces MT pleural access failure and can be cost saving by avoiding other procedures. It also reliably detects fibrinous septation which is a key determinant of whether talc poudrage is administered. It can also detect useful ancillary features. This study suggests MT should be ultrasound-guided if the volume of pleural fluid is not large.