Routine monitoring with pleural manometry during therapeutic large-volume thoracentesis to prevent pleural-pressure-related complications: a multicentre, single-blind randomised controlled trial

Background In patients with non-expandable lung, removal of pleural fluid can result in excessively negative pleural pressure, which is associated with chest discomfort, pneumothorax, and re-expansion pulmonary oedema. Pleural manometry is widely used to safeguard against pressure-related complications during thoracentesis despite little evidence to support the approach. We investigated whether monitoring of pleural pressure with manometry during thoracentesis could protect against complications compared with assessment of symptoms alone. Methods We did a prospective randomised single-blind trial involving patients with large pleural effusions at two academic medical centres in, Nashville, TN, and Baltimore, MD, USA. Eligible patients were adults with free-flowing effusions estimated to be at least 0·5 L who could remain seated throughout the procedure. Patients were randomly assigned 1:1 to receive thoracentesis guided by symptoms only (control) or by symptoms plus manometry at timepoints based on volume drained. The randomisation schedule was computer generated, used permuted blocks of four and six, and was stratified by participating institution. Patients, who were masked to study-group assignment, were asked to rate chest discomfort on 100 mm visual analogue scales before, during, and after drainage. In both groups drainage was discontinued before complete evacuation of pleural fluid if patients developed persistent chest discomfort, intractable cough, or other complications. In the manometry group, an additional criterion for stopping was if end-expiratory pleural pressure was lower than −20 cm H2O or declined by more than 10 cm H2O between two measurements to a value less than or equal to −10 cm H2O. The primary outcome was overall chest discomfort from before the start to after the procedure measured by patients 5 min after the end of drainage. Analysis was by modified intention to treat (ie, included all patients with any procedure or outcome data). This trial is registered with ClinicalTrials.gov, number NCT02677883. Findings Between March 4, 2016, and Sept 8, 2017, 191 patients were screened, of whom 128 were randomly assigned treatment and 124 were included in the final analysis (62 in each group). Four patients were excluded because of manometer malfunction (n=2), inability to access effusion due to pleural tumour burden (n=1), and inability to remain seated (n=1). Groups did not differ for the primary outcome (mean difference in chest discomfort score 2·4 mm, 95% CI −5·7 to 10·5, p=0·56). Six (10%) of 62 patients in the control group had asymptomatic pneumothorax ex vacuo compared with none in the manometry group (p=0·01). No serious complications occurred in either group. Interpretation Measurement of pleural pressure by manometry during large-volume thoracentesis does not alter procedure-related chest discomfort. Our findings do not support the routine use of this approach.<br /

The impact of gravity vs suction-driven therapeutic thoracentesis on pressure-related complications: the GRAVITAS multicenter randomized controlled trial

BACKGROUND: Thoracentesis can be accomplished by active aspiration or drainage with gravity. We investigated whether gravity drainage could protect against negative-pressure related complications, such as chest discomfort, re-expansion pulmonary edema or pneumothorax, compared to active aspiration. METHODS: This prospective, multicenter single blinded randomized controlled trial allocated patients with large free-flowing effusions estimated ≥ 500 mL 1:1 to active aspiration or gravity drainage. Patients rated chest discomfort on 100 mm visual analog scales before, during, and after drainage. Thoracentesis was halted at complete evacuation or for persistent chest discomfort, intractable cough, or other complication. The primary outcome was overall procedural chest discomfort scored five minutes post-procedure. Secondary outcomes included measures of discomfort and breathlessness through 48 hours post-procedure. RESULTS: One hundred forty-two patients were randomized with 140 in the final analysis. Groups did not differ for the primary outcome (mean VAS score difference 5.3 mm, 95% CI -2.4 to 13.0, p = 0.17). Secondary outcomes of discomfort and dyspnea did not differ between groups. Comparable volumes were drained in both groups but procedure duration was significantly longer in the gravity arm (mean difference 7.4 minutes, 95% CI 10.2 to 4.6, p<0.001). There were no serious complications. CONCLUSIONS: Thoracentesis via active aspiration and gravity drainage both appear safe and result in comparable levels of procedural comfort and dyspnea improvement. Active aspiration requires less total procedural time