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

Abstract

Background: In patients with non-expandable lung, pleural fluid removal can result in excessively negative pleural pressure, associated with chest discomfort, pneumothorax, and reexpansion pulmonary edema. Monitoring pleural pressure during thoracentesis may reduce discomfort and protect against complications. Methods: In this prospective randomized single-blind trial, subjects with large pleural effusions at two academic medical centers were randomly assigned (1:1 ratio) to symptom-guided ("control") versus symptom-plus-manometry-guided ("manometry") thoracentesis. All had free-flowing effusions meeting pre-specified criteria suggesting volume of at least 500 milliliters. Subjects, who were blinded to assignment, rated chest discomfort on visual analog scales before, during, and after drainage. Pleural pressure was measured at regular intervals in the manometry group. Drainage was discontinued before complete evacuation for persistent chest discomfort, incessant cough, complication, rapidly falling pleural pressure, or end-expiratory pleural pressure lower than-20 cm H2O (latter two only in the manometry group). We performed a modified intention-to-treat analysis. The primary outcome was overall procedural chest discomfort through 5 minutes post-procedure. This trial was registered at clinicaltrials.gov, NCT02677883. Findings: Between March 4, 2016 and September 8, 2017, 191 patients were screened. One hundred twenty-eight eligible subjects were randomized with four excluded from the final analysis of 62 subjects per group due to manometer malfunction (n=2), inability to access effusion due to pleural tumor burden (n=1), and inability to remain seated (n=1). There was no difference in the primary outcome of overall procedural chest discomfort between groups (mean difference 2.4, 95% CI-5.7-10.5; p = 0.78). Six asymptomatic pneumothoraces ex-vacuo occurred in the control group; no serious complications occurred in either group. Interpretation: Measurement of pleural pressure during large-volume thoracentesis does not alter procedure-related chest discomfort. This is the first study to directly assess the impact of pleural manometry on important patient-centered clinical outcomes during thoracentesis, and does not support its routine use. Funding: Centurion Medical Products PANEL: RESEARCH IN CONTEXT Evidence before this study Chest discomfort, reexpansion pulmonary edema, and pneumothorax ex-vacuo complicating thoracentesis have been associated with development of excessively negative pleural pressure in the setting of nonexpandable lung. Routine pleural manometry during aspiration has been advocated as potentially protective against these complications, but prospective comparative studies are lacking. Added value of this study This is the first prospective, randomized trial of routine pleural manometry during therapeutic thoracentesis for important clinical and patient-centered outcomes. Manometry did not reduce chest discomfort and there were no serious complications in either group. Implications of all the ava...

Management of Malignant Pleural Effusions—What Is New

“…While conceptually appealing, a recent RCT confirmed that there is no role for routine manometry during large-volume thoracentesis in reducing pain. 45 One explanation for these observations is that the pleural pressure is usually measured intermittently, not continuously; the pleural pressure is measured after the drainage is interrupted so as to measure the true intrapleural pressure rather than the negative pressure generated by suction bottles or gravity. This could lead to periods of "blind time" in between the measurements during which the pleural pressures could drop precipitously without being detected by the proceduralists.…”

Physiologic Basis of Symptoms in Pleural Disease

“…Several studies addressed whether chest pain is associated with excessive negative Ppl and if it is preventable by routine use of manometry. 36,42,47 Feller-Kopman et al recorded Ppl at end expiration in 169 patients undergoing thoracentesis. 36 Eleven percent of patients developed chest discomfort during thoracentesis.…”

“…Most recently, Lentz et al performed a two-center single blind randomized controlled trial of thoracentesis performed with and without pleural manometry. 47 The primary outcome was development of postprocedure chest discomfort at 5 minutes. No difference was found in patients undergoing thoracentesis guided by manometry versus control.…”

“…A major limitation of the Lentz et al study was that the majority of patients had < 1,500 mL of fluid drained and it is unclear if manometry would be useful in patients undergoing large-volume thoracentesis. 47 Overall, while routine use of manometry has not been demonstrated to improve complications in patients undergoing thoracentesis, it continues to provide useful insight into the physiologic changes that occur in the presence of pleural effusion, the identification of patients with unexpandable lung, and options for pleural palliation. For the latter, patients with unexpandable lung should not be offered pleurodesis, but can have significant improvement in their symptoms after placement of indwelling pleural catheters.…”

Advances and Controversies in Thoracentesis and Medical Thoracoscopy

“…10 A separate multicenter, single-blinded randomized controlled trial using pleural manometry showed that pleural pressure monitoring during large-volume thoracentesis did not alter procedure-related chest discomfort nor change patient-centered outcomes such as breathlessness, volume removed, or time required for the procedure. 11 Together these studies may suggest that thoracentesis performed without using vacuum bottles to drain and without the use of pleural manometry may be reasonable. Additional studies are underway to evaluate gravity versus suction for large-volume thoracentesis (NCT03591952) and gravity versus vacuum-based drainage of indwelling tunneled pleural catheter systems (Newton; NCT03831386).…”