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

Abstract Background Although 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. Methods The 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pressure curves were analyzed in five points, at 0, 25%, 50%, 75% and 100% of the relative volume of pleural effusion withdrawn in particular patients. Results There 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 The median total volume of withdrawn pleural fluid was 1800 (IQR 1500–2400) ml.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). Conclusions In 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 registration ClinicalTrial.gov, registration number: NCT02192138, registration date: July 1st, 2014

Pleural pressure pulse in patients with pleural effusion: A new phenomenon registered during thoracentesis with pleural manometry

Pleural manometry enables the assessment of physiological abnormalities of lung mechanics associated with pleural effusion. Applying pleural manometry, we found small pleural pressure curve oscillations resembling the pulse tracing line. The aim of our study was to characterize the oscillations of pleural pressure curve (termed here as the pleural pressure pulse, PPP) and to establish their origin and potential significance. This was an observational cross-sectional study in adult patients with pleural effusion who underwent thoracentesis with pleural manometry. The pleural pressure curves recorded prior to and during fluid withdrawal were analyzed. The presence of PPP was assessed in relation to the withdrawn pleural fluid volume, lung expandability, vital and echocardiographic parameters, and pulmonary function testing. A dedicated device was developed to compare the PPP to the pulse rate. Fifty-four patients (32 women) median age 66.5 (IQR 58.5–78.7) years were included. Well visible and poorly visible pressure waves were detected in 48% and 35% of the patients, respectively. The frequency of PPP was fully concordant with the pulse rate and the peaks of the oscillations reflected the period of heart diastole. PPP was more visible in patients with a slower respiratory rate (p = 0.008), a larger amount of pleural effusion, and was associated with a better heart systolic function assessed by echocardiography (p < 0.05). This study describes a PPP, a new pleural phenomenon related to the cyclic changes in the heart chambers volume. Although the importance of PPP remains largely unknown, we hypothesize that it could be related to lung atelectasis or lower lung and visceral pleura compliance

Pleural pressure pulse in patients with pleural effusion: A new phenomenon registered during thoracentesis with pleural manometry

Pleural manometry enables the assessment of physiological abnormalities of lung mechanics associated with pleural effusion. Applying pleural manometry, we found small pleural pressure curve oscillations resembling the pulse tracing line. The aim of our study was to characterize the oscillations of pleural pressure curve (termed here as the pleural pressure pulse, PPP) and to establish their origin and potential significance. This was an observational cross-sectional study in adult patients with pleural effusion who underwent thoracentesis with pleural manometry. The pleural pressure curves recorded prior to and during fluid withdrawal were analyzed. The presence of PPP was assessed in relation to the withdrawn pleural fluid volume, lung expandability, vital and echocardiographic parameters, and pulmonary function testing. A dedicated device was developed to compare the PPP to the pulse rate. Fifty-four patients (32 women) median age 66.5 (IQR 58.5–78.7) years were included. Well visible and poorly visible pressure waves were detected in 48% and 35% of the patients, respectively. The frequency of PPP was fully concordant with the pulse rate and the peaks of the oscillations reflected the period of heart diastole. PPP was more visible in patients with a slower respiratory rate (p = 0.008), a larger amount of pleural effusion, and was associated with a better heart systolic function assessed by echocardiography (p < 0.05). This study describes a PPP, a new pleural phenomenon related to the cyclic changes in the heart chambers volume. Although the importance of PPP remains largely unknown, we hypothesize that it could be related to lung atelectasis or lower lung and visceral pleura compliance