Pleural Pressure and Optimal Positive End-Expiratory Pressure Based on Esophageal Pressure Versus Chest Wall Elastance

2013 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Gaurav Gulati ◽  
Aileen Novero ◽  
Stephen H. Loring ◽  
Daniel Talmor
Keyword(s):  
Chest Wall ◽  
Esophageal Pressure ◽  
Pleural Pressure ◽  
Positive End Expiratory Pressure ◽  
Chest Wall Elastance

scholarly journals Determinants of the esophageal-pleural pressure relationship in humans

2020 ◽  
Vol 128 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Iacopo Pasticci ◽  
Paolo Cadringher ◽  
Lorenzo Giosa ◽  
Michele Umbrello ◽  
Paolo Formenti ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Supine Position ◽  
Body Position ◽  
Esophageal Pressure ◽  
Lateral Position ◽  
Pleural Pressure ◽  
Absolute Value ◽  
Gravitational Forces ◽  
Chest Wall Elastance

Esophageal pressure has been suggested as adequate surrogate of the pleural pressure. We investigate after lung surgery the determinants of the esophageal and intrathoracic pressures and their differences. The esophageal pressure (through esophageal balloon) and the intrathoracic/pleural pressure (through the chest tube on the surgery side) were measured after surgery in 28 patients immediately after lobectomy or wedge resection. Measurements were made in the nondependent lateral position (without or with ventilation of the operated lung) and in the supine position. In the lateral position with the nondependent lung, collapsed or ventilated, the differences between esophageal and pleural pressure amounted to 4.4 ± 1.6 and 5.1 ± 1.7 cmH2O. In the supine position, the difference amounted to 7.3 ± 2.8 cmH2O. In the supine position, the estimated compressive forces on the mediastinum were 10.5 ± 3.1 cmH2O and on the iso-gravitational pleural plane 3.2 ± 1.8 cmH2O. A simple model describing the roles of chest, lung, and pneumothorax volume matching on the pleural pressure genesis was developed; modeled pleural pressure = 1.0057 × measured pleural pressure + 0.6592 ( r2 = 0.8). Whatever the position and the ventilator settings, the esophageal pressure changed in a 1:1 ratio with the changes in pleural pressure. Consequently, chest wall elastance (Ecw) measured by intrathoracic (Ecw = ΔPpl/tidal volume) or esophageal pressure (Ecw = ΔPes/tidal volume) was identical in all the positions we tested. We conclude that esophageal and pleural pressures may be largely different depending on body position (gravitational forces) and lung-chest wall volume matching. Their changes, however, are identical. NEW & NOTEWORTHY Esophageal and pleural pressure changes occur at a 1:1 ratio, fully justifying the use of esophageal pressure to compute the chest wall elastance and the changes in pleural pressure and in lung stress. The absolute value of esophageal and pleural pressures may be largely different, depending on the body position (gravitational forces) and the lung-chest wall volume matching. Therefore, the absolute value of esophageal pressure should not be used as a surrogate of pleural pressure.

scholarly journals Respiratory mechanical effects of surgical pneumoperitoneum in humans

2014 ◽  
Vol 117 (9) ◽  
pp. 1074-1079 ◽  
Author(s):  
Stephen H. Loring ◽  
Negin Behazin ◽  
Aileen Novero ◽  
Victor Novack ◽  
Stephanie B. Jones ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Pleural Pressure ◽  
Abdominal Pressure ◽  
Positive End Expiratory Pressure ◽  
Before And After ◽  
Show Evidence ◽  
Obese Subjects

Pneumoperitoneum for laparoscopic surgery is known to stiffen the chest wall and respiratory system, but its effects on resting pleural pressure in humans are unknown. We hypothesized that pneumoperitoneum would raise abdominal pressure, push the diaphragm into the thorax, raise pleural pressure, and squeeze the lung, which would become stiffer at low volumes as in severe obesity. Nineteen predominantly obese laparoscopic patients without pulmonary disease were studied supine (level), under neuromuscular blockade, before and after insufflation of CO2 to a gas pressure of 20 cmH2O. Esophageal pressure (Pes) and airway pressure (Pao) were measured to estimate pleural pressure and transpulmonary pressure (Pl = Pao − Pes). Changes in relaxation volume (Vrel, at Pao = 0) were estimated from changes in expiratory reserve volume, the volume extracted between Vrel, and the volume at Pao = −25 cmH2O. Inflation pressure-volume (Pao-Vl) curves from Vrel were assessed for evidence of lung compression due to high Pl. Respiratory mechanics were measured during ventilation with a positive end-expiratory pressure of 0 and 7 cmH2O. Pneumoperitoneum stiffened the chest wall and the respiratory system (increased elastance), but did not stiffen the lung, and positive end-expiratory pressure reduced Ecw during pneumoperitoneum. Contrary to our expectations, pneumoperitoneum at Vrel did not significantly change Pes [8.7 (3.4) to 7.6 (3.2) cmH2O; means (SD)] or expiratory reserve volume [183 (142) to 155 (114) ml]. The inflation Pao-Vl curve above Vrel did not show evidence of increased lung compression with pneumoperitoneum. These results in predominantly obese subjects can be explained by the inspiratory effects of abdominal pressure on the rib cage.

scholarly journals Effects of High-Frequency Chest Wall Oscillation on Pleural Pressure and Oscillated Flow

2008 ◽  
Vol 42 (6) ◽  
pp. 485-491 ◽  
Author(s):  
Tal Zucker ◽  
Neil M. Skjodt ◽  
Richard L. Jones
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Pulse Pressure ◽  
High Frequency ◽  
Esophageal Pressure ◽  
Wall Pressure ◽  
Pleural Pressure ◽  
Significant Difference ◽  
Esophageal Balloon ◽  
Wall Oscillation

Abstract The effectiveness of high-frequency chest wall oscillation (HF-CWO) is directly related to the level of oscillated flow (vosc) in the airways. We used the Vest™ system to investigate the effects of HFCWO on chest wall and pleural pressures and we correlated these pressures to the resultant vosc. We also compared the latest HFCWO device with it predecessor. Different combinations of vest inflation pressure (background pressure) and oscillation frequency were randomly applied to 10 healthy volunteers. Chest wall pressure was determined using an air-filled bag under the vest and pleural pressure was estimated using an esophageal balloon. Reverse plethysmography was used to measure vosc at the mouth and a spirometer was used to measure changes in end-expired lung volume. We found a significant correlation between chest wall and pleural pressure with approximately one-third of the chest wall pressure transmitted into the pleural space. Mean esophageal pressure remained negative at all background pressure/frequency combinations. There was a significant correlation (p<0.0001) between the esophageal pulse pressure and vosc, which was highest at 15Hz regardless of the background pressure. The end-expired lung volume correlated with mean chest wall pressure. There was no significant difference between the two Vest™ systems. Since vosc dictates the effectiveness of HFCWO and since vosc is dependent on esophageal pulse pressure, which in turn is dependent on chest wall pulse pressure, it follows that the effectiveness of HFCWO is influenced by the ability to generate an effective chest wall pulse pressure.

Effects of Prone Positioning on Transpulmonary Pressures and End-expiratory Volumes in Patients without Lung Disease

2018 ◽  
Vol 128 (6) ◽  
pp. 1187-1192 ◽  
Author(s):  
Abirami Kumaresan ◽  
Robert Gerber ◽  
Ariel Mueller ◽  
Stephen H. Loring ◽  
Daniel Talmor
Keyword(s):  
Chest Wall ◽  
Prone Position ◽  
Airway Pressure ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Driving Pressure ◽  
Prone Positioning ◽  
Volume Increase ◽  
Mechanically Ventilated ◽  
Chest Wall Elastance

Abstract Background The effects of prone positioning on esophageal pressures have not been investigated in mechanically ventilated patients. Our objective was to characterize effects of prone positioning on esophageal pressures, transpulmonary pressure, and lung volume, thereby assessing the potential utility of esophageal pressure measurements in setting positive end-expiratory pressure (PEEP) in prone patients. Methods We studied 16 patients undergoing spine surgery during general anesthesia and neuromuscular blockade. We measured airway pressure, esophageal pressures, airflow, and volume, and calculated the expiratory reserve volume and the elastances of the lung and chest wall in supine and prone positions. Results Esophageal pressures at end expiration with 0 cm H2O PEEP decreased from supine to prone by 5.64 cm H2O (95% CI, 3.37 to 7.90; P < 0.0001). Expiratory reserve volume measured at relaxation volume increased from supine to prone by 0.15 l (interquartile range, 0.25, 0.10; P = 0.003). Chest wall elastance increased from supine to prone by 7.32 (95% CI, 4.77 to 9.87) cm H2O/l at PEEP 0 (P < 0.0001) and 6.66 cm H2O/l (95% CI, 3.91 to 9.41) at PEEP 7 (P = 0.0002). Median driving pressure, the change in airway pressure from end expiration to end-inspiratory plateau, increased in the prone position at PEEP 0 (3.70 cm H2O; 95% CI, 1.74 to 5.66; P = 0.001) and PEEP 7 (3.90 cm H2O; 95% CI, 2.72 to 5.09; P < 0.0001). Conclusions End-expiratory esophageal pressure decreases, and end-expiratory transpulmonary pressure and expiratory reserve volume increase, when patients are moved from supine to prone position. Mean respiratory system driving pressure increases in the prone position due to increased chest wall elastance. The increase in end-expiratory transpulmonary pressure and expiratory reserve volume may be one mechanism for the observed clinical benefit with prone positioning.

Liquid-filled esophageal catheter for measuring pleural pressure in preterm neonates

1989 ◽  
Vol 67 (2) ◽  
pp. 889-893 ◽  
Author(s):  
A. L. Coates ◽  
G. M. Davis ◽  
P. Vallinis ◽  
E. W. Outerbridge
Keyword(s):  
Chest Wall ◽  
Precise Measurement ◽  
Esophageal Pressure ◽  
Lung Mechanics ◽  
Pleural Pressure ◽  
Preterm Neonates ◽  
Alveolar Pressure ◽  
Occlusion Test ◽  
Catheter System ◽  
Airway Opening

The precise measurement of esophageal pressure (Pes) as a reflection of pleural pressure (Ppl) is crucial to the measurement of lung mechanics in the newborn. The fidelity of Pes as a measurement of Ppl is determined by the occlusion test in which, during respiratory efforts against an occlusion at the airway opening, changes in pressure (delta Pao) (Pao is assumed to be equal to alveolar pressure) are shown to be equal to changes in Pes (delta Pes). Eight intubated premature infants (640–3,700 g) with chest wall distortion were studied using a water-filled catheter system to measure Pes. During the occlusion test, all patients had a finite region of the esophagus where delta Pes equaled delta Pao, which corresponded to points in the esophagus above the cardia but below the carina. In conclusion, even in the presence of chest wall distortion, a liquid-filled catheter with the tip between the cardia and carina can provide an accurate measurement of Ppl, even in the very small premature infant with chest wall distortion.

scholarly journals Comparison of pleural and esophageal pressure in supine and prone positions in a porcine model of acute respiratory distress syndrome

2020 ◽  
Vol 128 (6) ◽  
pp. 1617-1625 ◽  
Author(s):  
N. Terzi ◽  
S. Bayat ◽  
N. Noury ◽  
E. Turbil ◽  
W. Habre ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Prone Position ◽  
Distress Syndrome ◽  
Porcine Model ◽  
Vertical Gradient ◽  
Esophageal Pressure ◽  
Pleural Pressure ◽  
Positive End Expiratory Pressure

In a porcine model of acute respiratory distress syndrome, we found that static end-expiratory esophageal pressure did not change significantly in prone position compared with supine position at any positive end-expiratory pressure (PEEP) tested between 5 and 20 cmH2O. Prone position was associated with an increased ventral pleural pressure and reduced end-expiratory dorsal-to-ventral pleural pressure (Ppl) vertical gradient, likely due to a more even distribution of mechanical forces over the chest wall.

Mediastinal and chest wall limitations to asymmetry of lung inflation

2004 ◽  
Vol 96 (3) ◽  
pp. 999-1004 ◽  
Author(s):  
Ken C. Lin ◽  
Anna Dizner-Golab ◽  
Robert L. Thurer ◽  
Stephen H. Loring
Keyword(s):  
Lung Transplantation ◽  
Chest Wall ◽  
Balloon Catheter ◽  
Left Lung ◽  
Lung Ventilation ◽  
Esophageal Pressure ◽  
Pleural Pressure ◽  
Reduced Pressure ◽  
Lung Inflation ◽  
Left And Right

The extent to which inflation of one lung increases pleural pressure around the contralateral lung could affect ventilatory function, e.g., after pneumonectomy or lung transplantation. The rise in contralateral pleural pressure is limited by mediastinal stiffness and other chest wall properties. To estimate these properties, we determined an elastance of asymmetric expansion (EAsym) in 20 supine adults undergoing thoracic surgery requiring endobronchial intubation. Esophageal pressure, measured with a balloon catheter, was used as an estimate of pleural pressure for determining chest wall elastance during symmetric inflation. Pressures measured in the left and right lung airways during sequential asymmetric inflations with known volumes were used to calculate EAsymand elastances of left and right lungs by using a four-element mathematical model. Elastances (means ± SD) were 13.0 ± 8.7 (EAsym), 14.0 ± 7.0 (left lung), 12.2 ± 6.1 (right lung), and 6.7 ± 2.1 cmH2O/l (chest wall). EAsymwas high in three patients with prior cardiac surgery or mediastinal radiation therapy, suggesting that mediastinal stiffening due to scarring and fibrosis reduced pressure transmission between hemithoraxes. Simulations with a previously published model showed that changes in EAsymin the range of values observed could substantially affect lung ventilation after single-lung transplantation for emphysema.

scholarly journals Different contributions from lungs and chest wall to respiratory mechanics in mice, rats, and rabbits

2019 ◽  
Vol 127 (1) ◽  
pp. 198-204 ◽  
Author(s):  
Roberta Südy ◽  
Gergely H. Fodor ◽  
André Dos Santos Rocha ◽  
Álmos Schranc ◽  
József Tolnai ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Respiratory Mechanics ◽  
Esophageal Pressure ◽  
Tissue Mechanics ◽  
Lung Mechanics ◽  
Laboratory Animals ◽  
Forced Oscillation Technique ◽  
Small Laboratory ◽  
Positive End Expiratory Pressure

Changes in lung mechanics are frequently inferred from intact-chest measures of total respiratory system mechanics without consideration of the chest wall contribution. The participation of lungs and chest wall in respiratory mechanics has not been evaluated systematically in small animals commonly used in respiratory research. Thus, we compared these contributions in intact-chest mice, rats, and rabbits and further characterized the influence of positive end-expiratory pressure (PEEP). Forced oscillation technique was applied to anesthetized mechanically ventilated healthy animals to obtain total respiratory system impedance (Zrs) at 0, 3, and 6 cmH2O PEEP levels. Esophageal pressure was measured by a catheter-tip micromanometer to separate Zrs into pulmonary (ZL) and chest wall (Zcw) components. A model containing a frequency-independent Newtonian resistance (RN), inertance, and a constant-phase tissue damping (G) and elastance (H) was fitted to Zrs, ZL, and Zcw spectra. The contribution of Zcw to RN was negligible in all species and PEEP levels studied. However, the participation of Zcw in G and H was significant in all species and increased significantly with increasing PEEP and animal size (rabbit > rat > mice). Even in mice, the chest wall contribution to G and H was still considerable, reaching 47.0 ± 4.0(SE)% and 32.9 ± 5.9% for G and H, respectively. These findings demonstrate that airway parameters can be assessed from respiratory system mechanical measurements. However, the contribution from the chest wall should be considered when intact-chest measurements are used to estimate lung parenchymal mechanics in small laboratory models (even in mice), particularly at elevated PEEP levels. NEW & NOTEWORTHY In species commonly used in respiratory research (rabbits, rats, mice), esophageal pressure-based estimates revealed negligible contribution from the chest wall to the Newtonian resistance. Conversely, chest wall participation in the viscoelastic tissue mechanical parameters increased with body size (rabbit > rat > mice) and positive end-expiratory pressure, with contribution varying between 30 and 50%, even in mice. These findings demonstrate the potential biasing effects of the chest wall when lung tissue mechanics are inferred from intact-chest measurements in small laboratory animals.

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