Quantification of pendelluft using EIT: comparison of prevalence across methods

Background Pendelluft refers to the movement of air between lung regions and has been associated with increased lung strain, especially in ventilated patients with breathing effort. Electrical impedance tomography (EIT) is the only available bedside method to measure pendelluft. Several algorithms for pendelluft quantification with EIT exist. Aim To determine and compare pendelluft prevalence with different EIT-based algorithms. Methods Five algorithms were implemented based on original publications, with clarification from respective authors. Thresholds for pendelluft detection per algorithm were based on EIT data from hypoxemic respiratory failure patients under controlled ventilation (n=5, no patient effort). We then applied the algorithms and their thresholds to determine pendelluft prevalence in data from different patient cohorts: post-operative on PSV (n=13), hypoxemic failure early after switch to PSV (n=5), and NIV post-extubation (n=11). As two algorithms require esophageal pressure as input, these could not be applied to all cohorts. Preliminary results Thresholds and prevalence of pendelluft varied between algorithms, although some spatial similarities were found (fig. 1). Discussion Pendelluft prevalence varies widely depending on the algorithm used. This emphasizes the need for consensus on pendelluft definitions and quantification methods, before interpreting the clinical consequences. erjor;12/suppl_17/45/F1 F1 F1