Pleural manometry during thoracocentesis in patients with malignant pleural effusion: A randomized controlled trial

Abstract Background Large volume therapeutic thoracentesis may be associated with re-expansion pulmonary edema RPE. Without the use of pleural manometry, this limits the amount of fluid drained. We investigated whether monitoring of pleural pressure with manometry during thoracentesis would avoid RPE or allow larger volume drainage. Research Question We wanted to see if using manometry to measure pleural pressure during thoracentesis may help minimize RPE or allow for more volume drainage. Patients and Methods We did a randomized controlled trial involving 110 patients with large malignant pleural effusions. Patients were randomly allocated to obtain thoracentesis with or without pleural manometry. The primary outcome was overall chest discomfort symptoms, the amount of fluid aspirated, and pleural pressures. This trial is listed on ClinicalTrials.gov as NCT04420663 Results The mean amount of total paracentesis fluid withdrawn from the control group was 945.4 ± 78.9(ml) and 1690.9 ± 681.0(ml) from the cases group (p < 0.001). clinical signs of RPE appeared in (n = 20) (36.3%) of patients of cases group while no signs of RPE appeared in controls (p-value < 0.001). opening pleural pressure was 13.4 ± 12.7 cm H2O in non-REP cluster vs 23.5 ± 5.7 cm H2O in REP cluster (p-value = 0.002). The difference between opening and closing pressures between the non-REP and REP cluster was (32.8 ± 15.6 vs 42.2 ± 13) respectively. (p-value = 0.02). Total fluid withdrawn from non-REP was 1828.5 ± 505ml in comparison to 1450 ± 875ml in the REP cluster (p-value = 0.04) Interpretation Pleural manometry is useful in malignant pleural effusion to increase the amount of fluid withdrawn But has no role in preventing RPE. The drop of pleural pressure of more than 17cm H2O should be avoided. Our findings do not support the routine use of this approach.