NCT05781802

V/Q Matching in Pressure Support Ventilation

Assessment of V/Q Matching During Pressure Support Ventilation With Electrical Impedance Tomography

• Status: Unknown
• Phase: —
• Study type: Observational
• Enrollment: 15 (estimated)
• Sponsor: Azienda Ospedaliera Universitaria Policlinico Paolo Giaccone Palermo · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The aim of this study is to describe the effects of different levels of pressure support on ventilation-perfusion matching in patients recovering from ARDS, using electrical impedance tomography.

Detailed description

Spontaneous breathing during mechanical ventilation has been attributed to both protective and negative effects on patient outcomes, largely varying based on the severity of lung injury. Indeed, in severe ARDS the avoidance of spontaneous efforts has an established protective role. However, spontaneous breathing promotes the distribution of tidal volume towards the dependent lung, and low levels of support pressure determine more homogeneous ventilation in patients recovering from ARDS, compared to higher support levels. Physiology supports the potential of spontaneous breathing to increase lung perfusion, through the decrease of intra-thoracic pressure leading to an increased venous return. This mechanism, in absence of right ventricular dysfunction, may lead to increased global lung perfusion. Furthermore, gas exchange improvements in experimental lung injury models during pressure support vs. controlled ventilation have been explained with redistribution of lung perfusion to nondependent lung areas and improvement of V/Q matching even in absence of significant lung recruitment. Electrical impedance tomography has been clinically used as a non-invasive tool to assess V/Q matching in patients with ARDS and to compare V/Q matching prior to and after a cycle of prone position in spontaneously breathing patients with COVID-19. The aim of this study is to describe the effects of different levels of pressure support on ventilation-perfusion matching in patients recovering from ARDS, using electrical impedance tomography.

Conditions

• Acute Respiratory Failure
• ARDS
• Electrical Impedance Tomography

Interventions

Type	Name	Description
OTHER	Level of pressure support	Patients will be evaluated in two different conditions sequentially. The first condition will be at a clinically selected level of pressure support under stable clinical conditions. This condition will be labeled according to P0.1: * In case of P0.1\<2, the clinically selected level of pressure support will be considered "High Pressure support". * In case of P0.1\>2, the clinically selected level of pressure support will be considered "Low Pressure support". After data collection at clinically selected level of pressure support, pressure support level will be transiently increased or decreased (i.e. from high to low/ from low to high) to the lowest/highest clinically tolerated level, aiming at the predefined P01 thresholds, and then kept for 20 minutes under stable clinical conditions. Data collection will be repeated and then the clinically selected level of pressure support restored.

Timeline

• Start date: 2023-02-27
• Primary completion: 2023-12-31
• Completion: 2024-01-01
• First posted: 2023-03-23
• Last updated: 2023-03-27

Locations

1 site across 1 country: Italy