Transpulmonary pressure as a surrogate of plateau pressure for lung protective strategy: not perfect but more physiologic

Mechanical ventilation: past lessons and the near future

“…Experienced clinicians are aware that airway pressures alone may be misleading when the chest wall is stiffened by obesity, surgery, trauma, or disease as well as when the patient makes forceful inspiratory and expiratory efforts. Even measuring transpulmonary pressure with the aid of an esophageal balloon catheter may not be enough [52-54]. A challenging aspect of managing the stresses and strains developed within a mechanically heterogeneous lung is the amplification (or stress focusing) that occurs at the interfaces between fully open and closed lung units [55].…”

“…Concerns regarding ventilator-induced lung injury continue, of course, but deployment of the laboratory-proven and venerated esophageal balloon monitoring of pleural pressure may now enable routine determination of transpulmonary pressure - a value that comes a step closer to the calculation of effective stress upon the lung itself during spontaneous breathing and that helps select the PEEP that must be applied to keep it positive so as to avoid collapse [54] (Figure 7). Direct measurement of functional residual capacity allows estimation of the size of the baby lung, which does not always coincide with estimates based on transpulmonary pressure [67].…”

Year in review in Intensive Care Medicine 2012: III. Noninvasive ventilation, monitoring and patient–ventilator interactions, acute respiratory distress syndrome, sedation, paediatrics and miscellanea

“…The authors concluded that, in some patients with influenza A(H1N1)-associated ARDS, abnormalities of chest wall mechanics may be present: in these patients, titrating PEEP to the end-inspiratory pressure of the respiratory system may overestimate the incidence of refractory hypoxaemia leading to inappropriate use of ECMO. This article was accompanied by an editorial by Richard and Marini [29]. …”

Two Steps Forward in Bedside Monitoring of Lung Mechanics: Transpulmonary Pressure and Lung Volume

“…Al though such data are encouraging, we believe that although clinically feasible, measuring P ES and calculating P TP as a strategy for setting the parameters of ventilator support must be embraced with caution, especially in the setting of lung injury, where the tension of the alveolar microenvironment may only be rough ly represented by the P TP . Additionally, increasing PEEP using P TP monitoring might be consider 'safe' with regard to the mechanics of pulmonary injury, but may be simultaneously associated with hazardous consequences for hemodynamics [17].…”