scholarly journals Novel method of transpulmonary pressure measurement with an air-filled esophageal catheter

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Paul Bernard Massion ◽  
Julien Berg ◽  
Nicolas Samalea Suarez ◽  
Gilles Parzibut ◽  
Bernard Lambermont ◽  
...  
Keyword(s):  
Balloon Catheter ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Protective Ventilation ◽  
Pleural Pressure ◽  
Good Precision ◽  
Pressure Measurements ◽  
Reproducible Method ◽  
Assisted Modes

Abstract Background There is a strong rationale for proposing transpulmonary pressure-guided protective ventilation in acute respiratory distress syndrome. The reference esophageal balloon catheter method requires complex in vivo calibration, expertise and specific material order. A simple, inexpensive, accurate and reproducible method of measuring esophageal pressure would greatly facilitate the measure of transpulmonary pressure to individualize protective ventilation in the intensive care unit. Results We propose an air-filled esophageal catheter method without balloon, using a disposable catheter that allows reproducible esophageal pressure measurements. We use a 49-cm-long 10 Fr thin suction catheter, positioned in the lower-third of the esophagus and connected to an air-filled disposable blood pressure transducer bound to the monitor and pressurized by an air-filled infusion bag. Only simple calibration by zeroing the transducer to atmospheric pressure and unit conversion from mmHg to cmH2O are required. We compared our method with the reference balloon catheter both ex vivo, using pressure chambers, and in vivo, in 15 consecutive mechanically ventilated patients. Esophageal-to-airway pressure change ratios during the dynamic occlusion test were close to one (1.03 ± 0.19 and 1.00 ± 0.16 in the controlled and assisted modes, respectively), validating the proper esophageal positioning. The Bland–Altman analysis revealed no bias of our method compared with the reference and good precision for inspiratory, expiratory and delta esophageal pressure measurements in both the controlled (largest bias −0.5 cmH2O [95% confidence interval: −0.9; −0.1] cmH2O; largest limits of agreement −3.5 to 2.5 cmH2O) and assisted modes (largest bias −0.3 [−2.6; 2.0] cmH2O). We observed a good repeatability (intra-observer, intraclass correlation coefficient, ICC: 0.89 [0.79; 0.96]) and reproducibility (inter-observer ICC: 0.89 [0.76; 0.96]) of esophageal measurements. The direct comparison with pleural pressure in two patients and spectral analysis by Fourier transform confirmed the reliability of the air-filled catheter-derived esophageal pressure as an accurate surrogate of pleural pressure. A calculator for transpulmonary pressures is available online. Conclusions We propose a simple, minimally invasive, inexpensive and reproducible method for esophageal pressure monitoring with an air-filled esophageal catheter without balloon. It holds the promise of widespread bedside use of transpulmonary pressure-guided protective ventilation in ICU patients.

scholarly journals Novel method of transpulmonary pressure measurement with an air-filled esophageal catheter

2021 ◽  
Author(s):  
Paul B Massion ◽  
J Berg ◽  
N Samalea ◽  
G Parzibut ◽  
B Lambermont ◽  
...  
Keyword(s):  
Balloon Catheter ◽  
Transpulmonary Pressure ◽  
Pressure Change ◽  
Esophageal Pressure ◽  
Protective Ventilation ◽  
Suction Catheter ◽  
Reproducible Method ◽  
Novel Method ◽  
Flush Device

Abstract Background There is a strong rationale for proposing transpulmonary pressure-guided protective ventilation in acute respiratory distress syndrome (ARDS). The reference esophageal balloon catheter method requires complex in vivo calibration and dedicated ventilator with auxiliary pressure port. A simple, inexpensive, accurate and reproducible method of measuring esophageal pressure would greatly facilitate the measure of transpulmonary pressure to individualize protective ventilation in the intensive care unit. Results We propose an air-filled esophageal catheter method without balloon, using disposable catheter and transducer that allows reproducible esophageal pressure measurements, and that does not require any specific ventilator equipment. We use a 49 cm-long thin low compliance polyvinyl 10 Fr suction catheter, positioned in the lower third of the esophagus and connected to an air-filled disposable blood pressure transducer bound to the monitor. To guarantee air transmission, the transducer is pressurized by an air-filled infusion bag allowing its integrated flush device to deliver continuous air flow and to obtain a stable esophageal waveform. Calibration requires simple zeroing the transducer open to atmospheric pressure. Esophageal pressures recorded on the monitoring are expressed in mmHg and need to be converted in cmH2O. We tested our novel method in 10 consecutive intubated patients with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. We calculated the target transpulmonary pressures for protective lung and diaphragm ventilation, both in passive and spontaneously breathing conditions. Esophageal to airway pressure change ratio was close to one in both conditions (median [P25;P75] = 0.94 [0.92;1.00] and 0.98 [0.96;1.01]). We adjusted ventilator settings towards recommended pressure targets to limit atelectrauma, barotrauma, inspiratory effort and lung stress, by modifying positive end-expiratory pressure, tidal volume, or inspiratory pressure accordingly. Conclusions We propose a simple, inexpensive and reproducible method for esophageal pressure monitoring with an air-filled esophageal catheter without balloon. It holds the promise of widespread bedside use of transpulmonary pressure-guided protective ventilation in patients with ARDS.

Regional differences in alveolar density in the human lung are related to lung height

2015 ◽  
Vol 118 (11) ◽  
pp. 1429-1434 ◽  
Author(s):  
John E. McDonough ◽  
Lars Knudsen ◽  
Alexander C. Wright ◽  
W. Mark Elliott ◽  
Matthias Ochs ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Regional Differences ◽  
Volume Fraction ◽  
Transpulmonary Pressure ◽  
Pleural Pressure ◽  
Lung Inflation ◽  
Residual Capacity ◽  
Alveolar Duct ◽  
The Difference

The gravity-dependent pleural pressure gradient within the thorax produces regional differences in lung inflation that have a profound effect on the distribution of ventilation within the lung. This study examines the hypothesis that gravitationally induced differences in stress within the thorax also influence alveolar density in terms of the number of alveoli contained per unit volume of lung. To test this hypothesis, we measured the number of alveoli within known volumes of lung located at regular intervals between the apex and base of four normal adult human lungs that were rapidly frozen at a constant transpulmonary pressure, and used microcomputed tomographic imaging to measure alveolar density (number alveoli/mm3) at regular intervals between the lung apex and base. These results show that at total lung capacity, alveolar density in the lung apex is 31.6 ± 3.4 alveoli/mm3, with 15 ± 6% of parenchymal tissue consisting of alveolar duct. The base of the lung had an alveolar density of 21.2 ± 1.6 alveoli/mm3 and alveolar duct volume fraction of 29 ± 6%. The difference in alveolar density can be negated by factoring in the effects of alveolar compression due to the pleural pressure gradient at the base of the lung in vivo and at functional residual capacity.

In vivo estimation of tracheal distensibility and hysteresis in normal adults

1987 ◽  
Vol 63 (6) ◽  
pp. 2482-2489 ◽  
Author(s):  
V. Hoffstein ◽  
R. G. Castile ◽  
C. R. O'Donnell ◽  
G. M. Glass ◽  
D. J. Strieder ◽  
...  
Keyword(s):  
Lung Volume ◽  
Transpulmonary Pressure ◽  
Lung Parenchyma ◽  
Esophageal Pressure ◽  
Transmural Pressure ◽  
Variable Degree ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Direct Measurements

We used the acoustic reflection technique to measure the cross-sectional area of tracheal and bronchial airway segments of eight healthy adults. We measured airway area during a slow continuous expiration from total lung capacity (TLC) to residual volume (RV) and during inspiration back to TLC. Lung volume and esophageal pressure were monitored continuously during this quasi-static, double vital capacity maneuver. We found that 1) the area of tracheal and bronchial segments increases with increasing lung volume and transpulmonary pressure, 2) the trachea and bronchi exhibit a variable degree of hysteresis, which may be greater or less than that of the lung parenchyma, 3) extrathoracic and intrathoracic tracheal segments behaved as if they were subjected to similar transmural pressure and had similar elastic properties, and 4) specific compliance (means +/- SE) for the intrathoracic and bronchial segments, calculated with the assumption that transmural pressure is equal to the transpulmonary pressure, was significantly (P less than 0.05) smaller for the intrathoracic segment than for the bronchial segment: (2.1 +/- 2.0) X 10(-3) cmH2O-–1 vs. (9.1 +/- 2.1) X 10(-3) cmH2O–1. Direct measurements of airway area using acoustic reflections are in good agreement with previous estimates of airway distensibility in vivo, obtained by radiography or endoscopy.

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.

Measurement of pleural pressure in neonates

1982 ◽  
Vol 52 (2) ◽  
pp. 491-494 ◽  
Author(s):  
M. I. Asher ◽  
A. L. Coates ◽  
J. M. Collinge ◽  
J. Milic-Emili
Keyword(s):  
Body Position ◽  
Balloon Catheter ◽  
Esophageal Pressure ◽  
Indirect Measurement ◽  
Pleural Pressure ◽  
Internal Diameter ◽  
Term Neonates ◽  
Esophageal Balloon ◽  
Airway Opening ◽  
Pressure Changes

The indirect measurement of pleural pressure in neonates is obtained from measurements of esophageal pressure (Pes) with either a liquid-filled catheter or an esophageal balloon-catheter system. The purpose of this investigation was to assess the validity of the water-filled esophageal catheter by comparing the simultaneous changes in Pes and airway opening pressure (Pao) during occluded respiratory efforts. Equal changes in Pes and Pao under this condition indicate that Pes is a valid measurement of pleural pressure. In six healthy unsedated term neonates (aged 2–3 days) we measured Pes in the lower third of the esophagus with a water-filled catheter of eight French gage (FC), which has a 2-mm internal diameter. During occlusions, changes in Pes and Pao were almost identical in magnitude and timing in each body position studied (right lateral, prone, and supine). We conclude that the water-filled 8-FG esophageal catheter gives an accurate measurement of pleural pressure changes in healthy neonates.

scholarly journals Development of a compact stand-alone esophageal pressure measurement device

2018 ◽  
Vol 4 (1) ◽  
pp. 355-358 ◽  
Author(s):  
Andre J. Richter ◽  
Christian Schnabel ◽  
Peter Spieth ◽  
Emdund Koch
Keyword(s):  
Mechanical Ventilation ◽  
Pressure Measurement ◽  
Optimal Parameter ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Pleural Pressure ◽  
Pressure Transducers ◽  
Alveolar Collapse ◽  
Technical Details ◽  
Protective Mechanical Ventilation

AbstractMechanical ventilation requires optimal parameter setting for every single patient. For instance sufficient positive end-expiratory pressure (PEEP) may ensure oxygenation and prevent overdistension of lungs or alveolar collapse. To find optimal PEEP, transpulmonary pressure (airway pressure minus pleural pressure) guides as an indicator for both, chest wall mechanics and lung characteristic. Since measurement of pleural pressure is impractical in clinical routine, esophageal pressure can be used to estimate pleural pressure and may help to assure protective mechanical ventilation. We developed a PESO (derived from PESO = esophageal pressure) measurement system, which provides a compact stand-alone device to measure the esophageal pressure during mechanical ventilation of patients. In addition to the esophageal pressure, air way pressure is also measured to provide the synchronized data independent of the ventilator manufacturer. The device works with two commercial pressure transducers, whose signals are conditioned and digitized with an Arduino Nano microcontroller, which samples data with 62 kHz and transmits averaged data with 100 Hz to a mobile tablet PC, which acts as process, display and record unit. The compact system provides a working time of 5 hours. Therefore, the system supports the progress for mechanical ventilation research. This paper describes technical details as well as functionality.

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.

Volume-related and volume-independent effects of posture on esophageal and transpulmonary pressures in healthy subjects

2006 ◽  
Vol 100 (3) ◽  
pp. 753-758 ◽  
Author(s):  
George R. Washko ◽  
Carl R. O'Donnell ◽  
Stephen H. Loring
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Healthy Subjects ◽  
Balloon Catheter ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Wide Range ◽  
Ventilator Management ◽  
Volume Characteristics ◽  
Independent Effects

Ventilator management decisions in acute lung injury could be better informed with knowledge of the patient's transpulmonary pressure, which can be estimated using measurements of esophageal pressure. Esophageal manometry is seldom used for this, however, in part because of a presumed postural artifact in the supine position. Here, we characterize the magnitude and variability of postural effects on esophageal pressure in healthy subjects to better assess its significance in patients with acute lung injury. We measured the posture-related changes in relaxation volume and total lung capacity in 10 healthy subjects in four postures: upright, supine, prone, and left lateral decubitus. Then, in the same subjects, we measured static pressure-volume characteristics of the lung over a wide range of lung volumes in each posture by using an esophageal balloon catheter. Transpulmonary pressure during relaxation (Plrel) averaged 3.7 (SD 2.0) cmH2O upright and −3.3 (SD 3.2) cmH2O supine. Approximately 58% of the decrease in Plrel between the upright and supine postures was due to a corresponding decrease in relaxation volume. The remaining 2.9-cmH2O difference is consistent with reported values of a presumed postural artifact. Relaxation volumes and pressures in prone and lateral postures were intermediate. To correct estimated transpulmonary pressure for the effect of lying supine, we suggest adding 3 cmH2O (95% confidence interval: −1 to +7 cmH2O). We conclude that postural differences in estimated transpulmonary pressure at a given lung volume are small compared with the substantial range of Plrel in patients with acute lung injury.

Effect of ventilatory frequency on regional transpulmonary pressure in normal adults

1981 ◽  
Vol 51 (3) ◽  
pp. 678-685 ◽  
Author(s):  
W. Hida ◽  
S. Suzuki ◽  
H. Sasaki ◽  
Y. Fujii ◽  
T. Sasaki ◽  
...  
Keyword(s):  
Balloon Catheter ◽  
Transpulmonary Pressure ◽  
Dynamic Compliance ◽  
Local Dynamic ◽  
Ventilatory Frequency ◽  
Catheter System ◽  
Residual Capacity ◽  
Resistive Component ◽  
Normal Adults ◽  
Zero Frequency

The relation between the ventilatory frequency and the elastic (delta Pel) or resistive (delta Prs) components of changes of the regional pleural pressure (delta PL) was studied at functional residual capacity (FRC) in six normal adults. The regional delta PL was measured simultaneously at three levels in the esophagus using a three-balloon-catheter system. Elastic components of regional delta PL normalized by overall tidal volume (delta Pel/delta V) increased with frequency at all three balloon positions; the percentages of delta Pel/delta V at 60 breaths/min to those at zero frequency were 107, 119, and 157% in the upper, middle, and lower balloon, respectively. The resistive component of regional delta PL normalized by overall air flow (delta Prs/delta V) did not show significant dependence on frequency at any of the three positions and was almost the same everywhere. It is suggested that the increase of local delta Pel with frequency might reflect mainly the frequency dependence of local dynamic compliance (Cdyn) and that the change of the local Cdyn with frequency might be larger in dependent than in upper lung.

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