V/Q Matching in Pressure Support Ventilation

Azienda Ospedaliera Universitaria Policlinico Paolo Giaccone Palermo

Status: Enrolling

Conditions: Electrical Impedance Tomography; ARDS; Acute Respiratory Failure

Treatments: Other: Level of pressure support

Study type: Observational

Funder types: Other

Identifiers

NCT05781802

EIT01

Details and patient eligibility

About

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.

Full 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.

Enrollment: 15 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥ 18 years
• Need for invasive mechanical ventilation and ICU admission
• Diagnosis of ARDS at ICU admission or during ICU stay
• Informed consent
• Presence of central line in the internal jugular vein

Exclusion criteria

• Any contraindication to Electrical impedance tomography monitoring (e. g. severe chest trauma or wounds)
• Cardiogenic pulmonary edema
• Pulmonary embolism
• Chronic obstructive pulmonary disease
• Pulmonary fibrosis
• Asthma exacerbation
• Pneumothorax and/or chest drainages
• Pre-existing diaphragmatic function impairment
• Neuro-muscular disease or impairment
• Moribund patients with limitation of care or expected survival <48h according to the treating physician

Trial design

15 participants in 1 patient group

Adult mechanically ventilated patients with ARDS

Description:

Adult mechanically ventilated patients with ARDS (see inclusion/exclusion criteria)

Treatment:

Other: Level of pressure support