Ventilation-Perfusion Matching in Early-stage Prone Position Ventilation

Study Overview
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Brief Summary
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Prone positioning has been widely used in critical care medicine to improve oxygenation in patients with acute respiratory distress syndrome (ARDS). This study aimed to compare the effect of pronation on lung ventilation-perfusion matching between COVID19-associated acute respiratory distress syndrome (CARDS) and ARDS from other etiologies (non-CARDS) using electrical impedance tomography (EIT).

Detailed Description
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In this prospective study, both COVID19-associated ARDS (CARDS) patients and patients with ARDS from other etiologies (non-CARDS) were enrolled. Electrical impedance tomography (EIT) was used to evaluate the changes in ventilation and perfusion between supine and prone positions. Baseline values of the area of DeadSpace, shunt, ventilation-perfusion matching (VQmatch) were identified at the time of enrollment. Within the defined VQmatch region, the global inhomogeneity index (VQmatch-GI) was calculated to assess the degree of uniformity within the region. Prone position was applied immediately after the baseline data were collected. After 2 hours of proning, another EIT examination was conducted. Parameters such as DeadSpace, shunt, VQmatch, and other common measurements before and after pronation were taken and compared to evaluate the effect of prone positioning on CARDS and non-CARDS patients.

Official Title
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Ventilation-Perfusion Matching in Early-stage Prone Position Ventilation: A Comparison Between COVID-19 ARDS and ARDS From Other Etiologies

Conditions
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Acute Respiratory Distress Syndrome

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Above the age of 18 Diagnosed with ARDS based on the Berlin Definition of ARDS Under mechanical ventilation Exclusion Criteria: Contraindications to EIT examination and prone position Refusal of signing the informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| COVID19-associated ARDS (CARDS)<br>This group included COVID19 patients with acute respiratory distress syndrome. Patients were put under prone position while their pulmonary function was measured using EIT before and after proning. | |
| Non-COVID19-associated ARDS (non-CARDS)<br>This group included patients with acute respiratory distress syndrome from other etiologies. Patients were put under prone position while their pulmonary function was measured using EIT before and after proning. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| DeadSpace | The area of Deadspace will be assessed using electrical impedance tomography | 3 months | 
| Shunt | Shunt will be assessed using electrical impedance tomography | 3 months | 
| Ventilation-perfusion matching (VQmatch) | VQmatch will be assessed using electrical impedance tomography | 3 months | 
| Global inhomogeneity index (VQmatch-GI) | Within the defined VQmatch region assessed by electrical impedance tomography, the global inhomogeneity index (VQmatch-GI) was calculated to assess the degree of uniformity within the region. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ventilation | The ventilation of the lungs is assessed by electrical impedance tomography before and after prone positioning. | 3 months | 
| Perfusion | The perfusion of the lungs is assessed by electrical impedance tomography before and after prone positioning. | 3 months | 
| Center of Ventilation (CoV) | The center of ventilation of the lungs is assessed by electrical impedance tomography before and after prone positioning. | 3 months | 
| Standard deviation of regional ventilation delay | The standard deviation of regional ventilation delay of the lungs is assessed by electrical impedance tomography before and after prone positioning. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Acute Respiratory Distress Syndrome, ICU, COVID19, Electrical impedance tomography