Methods for Determination of Individual PEEP for Intraoperative Mechanical Ventilation Using a Decremental PEEP Trial.

(1) Background: Individual PEEP settings (PEEP IND ) may improve intraoperative oxygenation and optimize lung mechanics. However, there is uncertainty concerning the optimal procedure to determine PEEP IND . In this secondary analysis of a randomized controlled clinical trial, we compared different methods for PEEP IND determination. (2) Methods: Offline analysis of decremental PEEP trials was performed and PEEP IND was retrospectively determined according to five different methods (EIT-based: RVD I method, Global Inhomogeneity Index [GI], distribution of tidal ventilation [EIT VT]; global dynamic and quasi-static compliance). (3) Results: In the 45 obese and non-obese patients included, PEEP IND using the RVD I method (PEEP RVD ) was 16.3 ± 4.5 cm H 2 O. Determination of PEEP IND using the GI and EIT VT resulted in a mean difference of -2.4 cm H 2 O (95%CI: -1.2;-3.6 cm H 2 O, p = 0.01) and -2.3 cm H 2 O (95% CI: -0.9;3.7 cm H 2 O, p = 0.01) to PEEP RVD , respectively. PEEP IND selection according to quasi-static compliance showed the highest agreement with PEEP RVD ( p = 0.67), with deviations > 4 cm H 2 O in 3/42 patients. PEEP RVD and PEEP IND according to dynamic compliance also showed a high level of agreement, with deviations > 4 cm H 2 O in 5/42 patients ( p = 0.57). (4) Conclusions: High agreement of PEEP IND determined by the RVD I method and compliance-based methods suggests that, for routine clinical practice, PEEP selection based on best quasi-static or dynamic compliance is favorable.