The P0.1 maneuver as an alternative method for assessing the validity of esophageal pressure measurements during assisted ventilation: an exploratory analysis

Background: Transpulmonary pressure, calculated as the difference between airway pressure (Paw) and esophageal pressure (Pes), is an important monitoring parameter during assisted mechanical ventilation, provided Pes is measured via a correctly placed and filled esophageal pressure probe. The reference method to verify Pes accuracy in spontaneously breathing patients requires calculating the ratio of changes in Pes and Paw (ΔPes/ΔPaw) during an inspiratory effort against an occluded airway. We hypothesized that the P0.1 maneuver, a brief and repeatable test, could provide an alternative means to assess ΔPes/ΔPaw during assisted mechanical ventilation. Methods: We performed an exploratory secondary analysis of data from a multicenter prospective observational study (ICEBERG study; NCT05203536). In 35 patients receiving assisted mechanical ventilation, ΔPes/ΔPaw obtained during P0.1 maneuvers (RatioP0.1, experimental method) was compared with ΔPes/ΔPaw from prolonged expiratory occlusion maneuvers (Ratioocc, reference method) using linear regression and Bland–Altman analysis. Results: Among 25 patients with 65 evaluable measurements, RatioP0.1 showed a moderate correlation (R2:0.647, p < 0.0001) with Ratioocc. Bland–Altman analysis demonstrated minimal bias and acceptable agreement between methods. Using the occlusion maneuver as reference, RatioP0.1 identified incorrect Pes measurement with a sensitivity of 93% and a specificity for identifying correct Pes measurement of 71%. Results were consistent across patient subgroups. Conclusions: Our exploratory analysis suggests that the P0.1 maneuver may support semi-continuous screening of esophageal pressure signal validity during assisted ventilation. While abnormal P0.1 values should prompt confirmatory occlusion testing, values within the expected range may help rule out major measurement errors. These findings provide a rationale for prospective validation studies including different ventilator types. Trial registration: clinicaltrials.gov, NCT05203536. Registered 24. January 2022—Retrospectively registered, https://classic.clinicaltrials.gov/ct2/show/NCT05203536