PEEP titration guided by ventilation homogeneity: a feasibility study using electrical impedance tomography

Abstract

IntroductionLung protective ventilation requires low tidal volume and suitable positive end-expiratory pressure (PEEP). To date, few methods have been accepted for clinical use to set the appropriate PEEP. The aim of this study was to test the feasibility of PEEP titration guided by ventilation homogeneity using the global inhomogeneity (GI) index based on electrical impedance tomography (EIT) images.MethodsIn a retrospective study, 10 anesthetized patients with healthy lungs mechanically ventilated under volume-controlled mode were investigated. Ventilation distribution was monitored by EIT. A standardized incremental PEEP trial (PEEP from 0 to 28 mbar, 2 mbar per step) was conducted. During the PEEP trial, "optimal" PEEP level for each patient was determined when the air was most homogeneously distributed in the lung, indicated by the lowest GI index value. Two published methods for setting PEEP were included for comparison based on the maximum global dynamic compliance and the intra-tidal compliance-volume curve.ResultsNo significant differences in the results were observed between the GI index method (12.2 ± 4.6 mbar) and the dynamic compliance method (11.4 ± 2.3 mbar, P > 0.6), or between the GI index and the compliance-volume curve method (12.2 ± 4.9 mbar, P > 0.6).ConclusionsAccording to the results, it is feasible and reasonable to use the GI index to select the PEEP level with respect to ventilation homogeneity. The GI index may provide new insights into the relationship between lung mechanics and tidal volume distribution and may be used to guide ventilator settings.

Recruitment Maneuvers and PEEP Titration

“…98 Electrical impedance tomography has the potential for bedside use to estimate regional alveolar collapse and overdistention. [98][99][100][101][102][103] To date, experience with electrical impedance tomography in North America is limited.…”

Visualisation of Time-Variant Respiratory System Elastance in ARDS Models

“…Therefore, true minimal E drs can only be determined after a stabilisation period is provided at each PEEP level. Setting PEEP at minimum elastance theoretically benefits ventilation by maximising recruitment, reducing work of breathing and avoiding overdistension [3][4][5]9]. …”

Electrical impedance tomography: A new monitoring of regional distribution of lung ventilation (principle of work and clinical application)

“…23 Zatvorena endotrahealna sukcija za posledicu ima manji gubitak plućnog volumena i sporiji oporavak, dok otvorena endotrehealna sukcija dovodi do većeg gubitka plućnog volumena, ali bržeg oporavka i vraćanja respiratornih parametara na početne vrednosti pre sukcije koji su praćeni EIT--om. 1…”