Non-invasive Assessment of Inspiratory Effort and Tidal Distension During Non-invasive Ventilation (INSPIRE)

Summary

The goal of this observational study is to evaluate whether the airway occlusion pressure recorded during a sudden end-expiratory breath-hold (ΔPocc) is correlated with esophageal swing in pressure and the reliability of P0.1, driving pressure, plateau pressure, pressure-muscle index, and diaphragm ultrasound as noninvasive estimates of inspiratory effort and lung distension in hypoxemic patients undergoing NIV.

The main questions this trial aims to answer are:

\- Primary Outcome: whether the airway occlusion pressure recorded during a sudden end-expiratory breath-hold (ΔPocc) is correlated with esophageal swing in pressure and the reliability of various noninvasive estimates of inspiratory effort and lung distension in hypoxemic patients undergoing NIV.

Secondary outcomes will include:

* Statistic metric of association between P0.1, ΔP, PMI and ΔPes
* Statistic metric of association between P0.1, ΔPocc, ΔP, PMI and PaO2/FiO2 ratio
* Statistic metric of association between P0.1, ΔPocc, ΔP, PMI and tidal volume
* Statistic metric of association between P0.1, ΔPocc, ΔP, PMI and DTF%
* Statistic metric of association between P0.1, ΔPocc, ΔP, PMI and Ex/DTF%
* Statistic metric of association between P0.1, ΔPocc, ΔP, PMI and respiratory rate, VAS dyspnea and VAS discomfort.

Participants will undergo the following tasks and treatments:

* Complete written informed consent before enrollment.
* Post-extubation noninvasive ventilation via nose-to-mouth and full-face masks.
* Monitoring of esophageal pressure (in all patients the catheter will be placed before extubation, according to clinical judgment, and its correct position will be verified through a positive pressure occlusion test)
* Continuous recording of airway pressure, flow, and esophageal pressure (Pes), using a dedicated pneumotachograph and pressure transducer.
* Sudden end-inspiratory and end-expiratory occlusion maneuvers, to measure plateau pressure (Pplat) and end-expiratory airway occlusion pressure (ΔPocc), respectively.
* Collection of hemodynamic and arterial blood-gas parameters, performed according to clinical judgment, along with assessments of dyspnea and discomfort using a modified visual analogue scale (VAS).
* Diaphragm ultrasound during occlusion maneuvers, measuring diaphragm displacement, diaphragm thickening fraction (DTF%), and diaphragmatic excursion (Ex) under various conditions.

Conditions

• Respiratory Disease
• Artificial Respiration

Interventions

DIAGNOSTIC_TEST

End-inspiratory Maneuvers

Airway pressure, flow, and esophageal pressure will be continuously recorded in all patients using a dedicated pneumotachograph and pressure transducer: all signals will be acquired and stored. Once a stable ventilation pattern is observed NIV will be administered by setting ventilator in invasive-pressure support ventilation. PEEP and PS-level will by kept constant while expiratory trigger will be adjusted to optimize patient-ventilatory synchrony. Immediately after, sudden end-inspiratory and end-expiratory occlusion maneuvers will be performed to measure plateau pressure and end-expiratory airway occlusion pressure (ΔPocc), respectively. Invasive PSV will be used only to perform the occlusion maneuvers, subsequently, PSV will be delivered in non-invasive PSV mode. Patient's blood-gas parameters and vital signs will be collected, including discomfort assessment. During the occlusion maneuvers, diaphragm ultrasound will be performed, and images will be recorded.

Sponsors & Collaborators

• University of Bari

  lead OTHER

Principal Investigators

• Salvatore Grasso, Prof · Azienda Ospedaliero-Universitaria "Consorziale Policlinico" Bari

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-11-01

Primary Completion

2026-05-01

Completion

2026-06-01

Countries

• Italy

Study Locations