Solid-state esophageal pressure sensor for the estimation of pleural pressure: a bench and first-in-human validation study.

Background: Advanced respiratory monitoring through the measurement of esophageal pressure (Pes) as a surrogate of pleural pressure helps guiding mechanical ventilation in ICU patients. Pes measurement with an esophageal balloon catheter, the current clinical reference standard, needs complex calibrations and a multitude of factors influence its reliability. Solid-state pressure sensors might be able to overcome these limitations.

Objectives: To evaluate the accuracy of a new solid-state Pes transducer (Pes). We hypothesized that measurements are non-inferior to those obtained with a properly calibrated balloon catheter (Pes).

Methods: Absolute and relative solid-state sensor Pes measurements were compared to a reference pressure in a 5-day bench setup, and to simultaneously placed balloon catheters in 15 spontaneously breathing healthy volunteers and in 16 mechanically ventilated ICU patients. Bland-Altman analysis was performed using mixed effects modelling with bootstrapping to estimate bias and upper and lower limits of agreement (LoA) and their confidence intervals.

Results: Bench study: Solid-state pressure transducers had a positive bias (P - P) of around 1 cmHO for the absolute minimal and maximum pressures, and no bias for pressure swings. Healthy volunteers: the solid-state transducer revealed a bias (i.e. Pes - Pes) [upper LoA; lower LoA] of 1.59 [8.21; - 5.02], - 2.32 [4.27; - 8.92] and 3.91 [11.04; - 3.23] cmHO for end-expiratory, end-inspiratory and ΔPes values, respectively. ICU patients: the solid-state transducer showed a bias (Pes-Pes) [upper LoA; lower LoA] during controlled/assisted ventilation of: - 0.15 [1.41; - 1.72]/- 0.19 [5.23; - 5.62], 0.32 [3.45; - 2.82]/- 0.54 [4.81; - 5.90] and 0.47 [3.90; - 2.96]/0.35 [4.01; - 3.31] cmHO for end-expiratory, end-inspiratory and ΔPes values, respectively. LoA were ≤ 2cmHO for static measurements on controlled ventilation.

Conclusions: The novel solid-state pressure transducer showed good accuracy on the bench, in healthy volunteers and in ventilated ICU-patients. This could contribute to the implementation of Pes as advanced respiratory monitoring technique.

Trial Registration: Clinicaltrials.gov identifier: NCT05817968 (patient study). Registered on 18 April 2023.