Patterns of pleural pressure amplitude and respiratory rate changes during therapeutic thoracentesis

Abstract

BackgroundAlthough the impact of therapeutic thoracentesis on lung function and blood gases has been evaluated in several studies, some physiological aspects of pleural fluid withdrawal remain unknown. The aim of the study was to assess the changes in pleural pressure amplitude (Pplampl) during the respiratory cycle and respiratory rate (RR) in patients undergoing pleural fluid withdrawal.MethodsThe study included 23 patients with symptomatic pleural effusion. Baseline pleural pressure curves were registered with a digital electronic manometer. Then, the registrations were repeated after the withdrawal of consecutive portions of pleural fluid (200 ml up to 1000 ml and 100 ml above 1000 ml). In all patients the pleural pressure curves were analyzed in five points, at 0, 25%, 50%, 75% and 100% of the relative volume of pleural effusion withdrawn in particular patients.ResultsThere were 11 and 12 patients with right sided and left sided pleural effusion, respectively (14 M, 9F, median age 68, range 46–85 years). The most common cause of pleural effusion were malignancies (20 pts., 87%). The median total volume of withdrawn pleural fluid was 1800 (IQR 1500–2400) ml. After termination of pleural fluid withdrawal Pplampl increased in 22/23 patients compared to baseline. The median Pplampl increased from 3.4 (2.4–5.9) cmH2O to 10.7 (8.1–15.6) cmH2O (p < 0.0001). Three patterns of Pplampl changes were identified. Although the patterns of RR changes were more diversified, a significant increase between RR at baseline and the last measurement point was found (p = 0.0097).ConclusionsIn conclusion, therapeutic thoracentesis is associated with significant changes in Pplampl during the respiratory cycle. In the vast majority of patients Pplampl increased steadily during pleural fluid withdrawal. There was also an increase in RR. The significance of these changes should be elucidated in further studies.Trial registrationClinicalTrial.gov, registration number: NCT02192138, registration date: July 1st, 2014.

Independent Lung Ventilation-Experimental Studies on a 3D Printed Respiratory Tract Model

“…Air mass flow was measured by Mass Flow Meter SFM3000 (Sensirion, Switzerland), while for pressure monitoring the manometer was used with a 50 Hz sampling rate, constructed by IBBE PAS (Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland). The manometer is an enhanced version of the device (IBBE PAS) dedicated to pleural pressure measurement and has been successfully used in over 60 patients up to the present [ 23 , 24 ]. The main part of the device is the Smiths Medical DPT-8003 pressure transducer, and its measuring range is equal to □+/− 300 cm H 2 O).…”

Physiologic Basis of Symptoms in Pleural Disease

“…The same group examined the change in Ppl amplitude in 23 patients, measured by the change in Ppl on inspiration and expiration, throughout thoracentesis. 49 They found that as fluid was removed there was a significant increase in median Ppl amplitude from 3.4 to 10.7 cm H 2 O. The clinical significance and physiologic basis of this finding is not immediately clear.…”

Pleural manometry: techniques, applications, and pitfalls

“…(Figure 2). The custombuilt system allows accurate measurements at very high frequencies which is useful when patients have high respiratory rates, which occurs towards the end of the pleural drainage (10). It can show positive and negative Ppl of each individual respiratory cycle.…”