Straight to Medical Thoracoscopy Approach for Exudative Pleural Effusions - Adapting to the COVID-19 Era

Background: medical thoracoscopy (MT) is the gold standard diagnostic test for undiagnosed exudative pleural. The definitive diagnosis of malignancy is possible on pleural fluid only in about 35% of times, and the microbiological yield of TB on pleural fluid is notoriously low. This study aimed to assess the effect of a 'straight to MT' approach on the time from presentation to definitive diagnostic test and the number of unnecessary thoracoscopies done using this approach. Methods: patients presenting with a new pleural effusion with low suspicion pleural infection or a non-pulmonary etiology (e.g. a disease known to cause pleural effusion) were offered a diagnostic aspiration to confirm the effusion was a lymphocytic exudate followed by an MT on the next day. For patients referred with a CT showing obvious pleural malignancy, results of fluid biochemical analysis were not awaited. In patients with gross appearance of pleural malignancy during thoracoscopy and a large pleural effusion at presentation, thoracoscopic pleurodesis was done. A control group of patients with undiagnosed pleural effusion and negative cytology referred to the unit for MT was used. In all patients, chest tube removal and discharge following MT was done on the same day if pleurodesis was not carried out and the patient was stable. Results: Between August and November 2020, 25 patients underwent MT;10 of whom through the straight to MT approach (group 1) and 15 through standard approach (group 2). In group 1, the median (range) time between presentation and procedure was 1 (0-2) days. The etiology was malignancy in 5/10, TB in 4/10 TB and non-specific pleuritis in 1/10. In 1/10 the pleural fluid results were conclusive (metastatic lung cancer), but this patient also underwent pleurodesis during MT. In group 2, the median time from presentation to MT was 12 (7-30) days (p<0.001). The etiology was malignancy in 10/15, non-specific pleuritis in 4/15 and TB in 1/15. None of the 25 patients experienced serious complications at or immediately after thoracoscopy and the median time (range) to discharge was 1 (0-4) days. Conclusion: A straight to MT approach reduces the waiting time to diagnosis, with a small risk of 'over-investigating'. This approach is particularly helpful in the time of COVID to keep the number of encounters with hospital staff a minimum especially with the capacity to combine diagnostic and therapeutic modalities (i.e. pleurodesis) in the same procedure.