scholarly journals End-expiratory esophageal pressure versus lower inflection point in acute lung injury

Critical Care ◽  
2013 ◽  
Vol 17 (S2) ◽  
Author(s):  
A Yaroshetskiy ◽  
D Protsenko ◽  
E Larin ◽  
O Ignatenko ◽  
B Gelfand
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflection Point ◽  
Esophageal Pressure ◽  
Lower Inflection Point

Sigmoidal equation for lung and chest wall volume-pressure curves in acute respiratory failure

2003 ◽  
Vol 95 (5) ◽  
pp. 2064-2071 ◽  
Author(s):  
Cécile Pereira ◽  
Julien Bohé ◽  
Sylvaine Rosselli ◽  
Emmanuel Combourieu ◽  
Christian Pommier ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Chest Wall ◽  
Respiratory System ◽  
Inflection Point ◽  
Significant Contribution ◽  
Esophageal Pressure ◽  
Constant Flow ◽  
Lower Inflection Point ◽  
Mechanically Ventilated ◽  
Volume Pressure Curves

To assess incidence and magnitude of the “lower inflection point” of the chest wall, the sigmoidal equation was used in 36 consecutive patients intubated and mechanically ventilated with acute lung injury (ALI). They were 21 primary and 5 secondary ALI, 6 unilateral pneumonia, and 4 cardiogenic pulmonary edema. The lower inflection point was estimated as the point of maximal compliance increase. The low constant flow inflation method and esophageal pressure were used to partition the volume-pressure curves into their chest wall and lung components on zero end-expiratory pressure. The sigmoidal equation had an excellent fit with coefficients of determination >0.90 in all instances. The point of maximal compliance increase of the chest wall ranged from 0 to 8.3 cmH2O (median 1 cmH2O) with no difference between ALI groups. The chest wall significantly contributed to the lower inflection point of the respiratory system in eight patients only. The occurrence of a significant contribution of the chest wall to the lower inflection point of the respiratory system is lower than anticipated. The sigmoidal equation is able to determine precisely the point of the maximal compliance increase of lung and chest wall.

Using Esophageal Pressures to Improve Oxygenation and Compliance in Acute Lung Injury

2018 ◽  
pp. 163-169
Author(s):  
Connie Wang ◽  
Edward Bittner
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
New England ◽  
Transpulmonary Pressure ◽  
Standard Of Care ◽  
Esophageal Pressure ◽  
Optimal Level ◽  
Balloon Catheters ◽  
Alveolar Collapse

The New England Journal of Medicine article, “Using Esophageal Pressures to Improve Oxygenation and Compliance in Acute Lung Injury,” showed that ventilator adjustments guided by using esophageal pressure for estimation of transpulmonary pressure demonstrated significant improvement in oxygenation and compliance for patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The study randomized patients with ALI or ARDS to either a positive end expiration pressure (PEEP) adjustment according to measurement of either esophageal pressures or ARDS network standard-of-care recommendations. Esophageal balloon catheters helped to determine the optimal level of PEEP that would sustain oxygenation but still prevent alveolar collapse or overdistention.

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.

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