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Updated: Jun 29, 2026

Monitoring Lung Function with Electrical Impedance Tomography in the Intensive Care Unit
Published on: September 6, 2024
Ability of dynamic airway pressure curve profile and elastance for positive end-expiratory pressure titration
Alysson R Carvalho1, Peter M Spieth, Paolo Pelosi
1Clinic of Anesthesiology and Intensive Care Therapy, Medical Faculty, University Hospital Carl Gustav Carus, Dresden, Germany.
Objective:
To evaluate the ability of three indices derived from the airway pressure curve for titrating positive end-expiratory pressure (PEEP) to minimize mechanical stress while improving lung aeration assessed by computed tomography (CT).
Design:
Prospective, experimental study.
Setting:
University research facilities.
Subjects:
Twelve pigs.
Interventions:
Animals were anesthetized and mechanically ventilated with tidal volume of 7 ml kg(-1). In non-injured lungs (n = 6), PEEP was set at 16 cmH(2)O and stepwise decreased until zero. Acute lung injury was then induced either with oleic acid (n = 6) or surfactant depletion (n = 6). A recruitment maneuver was performed, the PEEP set at 26 cmH(2)O and decreased stepwise until zero. CT scans were obtained at end-expiratory and end-inspiratory pauses. The elastance of the respiratory system (Ers), the stress index and the percentage of volume-dependent elastance (%E (2)) were estimated.
Measurements And Main Results:
In non-injured and injured lungs, the PEEP at which Ers was lowest (8-4 and 16-12 cmH(2)O, respectively) corresponded to the best compromise between recruitment/hyperinflation. In non-injured lungs, stress index and %E (2) correlated with tidal recruitment and hyperinflation. In injured lungs, stress index and %E (2) suggested overdistension at all PEEP levels, whereas the CT scans evidenced tidal recruitment and hyperinflation simultaneously.
Conclusion:
During ventilation with low tidal volumes, Ers seems to be useful for guiding PEEP titration in non-injured and injured lungs, while stress index and %E (2) are useful in non-injured lungs only. Our results suggest that Ers can be superior to the stress index and %E (2) to guide PEEP titration in focal loss of lung aeration.
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