PEEP Incremental and Decremental Alveolar Recruitment of Critically Ill Corona Virus Disease-19 (COVID-19) Patients

Study Overview
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Brief Summary
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COVID-19 originated from Severe Acut Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection leads to critical condition due to hypoxemic respiratory failure with the background of viral pneumonia. Both alevolar recruitment and the subsequent optimal positive end-expiratory pressure (PEEP) adjustment has a pivotal role in the elimination of atelectasis developed by inflammation in the lung parenchyma The gold standard of the follow up of recruitment manoeuvre is the chest computed tomography (CT) examination. However, reduction of intrahospital transport and the exposure with healthcare workers are recommended because of the extremely virulent pathogen spreading easily by droplet infection. In this case bedside investigations have an utmost importance in the management of hygiene regulations. Electric impedance tomography (EIT) is a non-invasive, radiation free functional imaging technique easily applicable at the bedside.

Detailed Description
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COVID-19 originated from Severe Acut Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection leads to critical condition in 5% of the cases due to hypoxemic respiratory failure with the background of viral pneumonia. 90% of these patients require invasive mechanical ventilation on critical care units. Both alevolar recruitment and the subsequent optimal positive end-expiratory pressure (PEEP) adjustment has a pivotal role in the eliminitaion of atelectasis developed by inflammation in the lung parenchyma. The gold standard of the follow up of recruitment manoeuvre is the chest computed tomography (CT) examination. However, reduction of intrahospital transport and the exposure with healthcare workers are recommended because of the extremely virulent pathogen spreading easily by droplet infection. In this case bedside investigations have an utmost importance in the management of hygiene regulations. Electric impedance tomography (EIT) is a non-invasive, radiation free functional imaging technique easily applicable at the bedside. With the help of EIT, intrathoracic impedance changes, resulting from air and blood volume variations, can be determined by circumferentially attached surface electrodes around the thorax, applying small alternating currents and measuring differences in surface potentials. The calculated difference in potential is utilised to reconstruct impedance images what is employed to assess ventilation and perfusion distribution. Several local and global variances can be estimated just like the ratio fo atelectatic/overdistended alveoli, the ratio of aeration in the anterior/posterior regions, the inhomogeneity of aeration or regional compliance.

Official Title
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PEEP Incremental and Decremental Alveolar Recruitment of Critically Ill COVID-19 Patients Under Electric Impedance Tomography (EIT)

Conditions
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COVID-19, Virus; Pneumonia, Atelectasis

Intervention / Treatment
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* Procedure: alveolar recruitment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: SARS-CoV-2 positivity confirmed by polymerase chain reaction orotracheally intubated patients pressure control ventilation mode sedation level of minimum -4 on the Richmond Agitation Sedation Scale (RASS) Exclusion Criteria: age under 18 pregnancy pulmonectomy, lung resection in the past medical history clinically end stage chronic obstructive pulmonary disease sever hemodynamic instability (vasopressor refractory shock) sever bullous emphysema and/or spontaneous pneumothorax in the past medical history chest drainage in situ due to pneumothorax and/or bronchopleural fistula

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PEEP incremental-decremental alveolar recruitment<br>installing EIT belt over the chest at the level of the 5th intercostal space and adjustment of the default recruitment settings in pressure control ventilation mode: pressure control 15 cmH20, PEEP 10 cmH2O, fraction of inspired oxygen (FiO2) and respiratory rate according to the discretion of the attending physician, recording basal parameters implementation of recruitment: increment phase: increasing PEEP by 3 cmH2O in every two minutes from 10 cmH2O until top of PEEP 25 cmH2O decrement phase: decreasing PEEP by 3 cmH20 in every two minutes from 25 cmH20 until the basal PEEP 10 cmH20 end inspiratory hold manoeuvre at every PEEP level recording closing parameters Repeating the above detailed intervention once daily as long as the patient is controlled ventilation. | Procedure: alveolar recruitment<br>* incremental and decremental positive end-expiratory pressure alveolar recruitment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in lung compliance | Estimation of change in compliance (ml/cmH2O) from the beginning to end of of the incremental/decremental PEEP alveolar recruitment. | 20 minutes | 
| Change in global impedance | Estimation of change in global impedance (%) from the beginning to end of of the incremental/decremental PEEP alveolar recruitment. | 20 minutes | 
| Change in recruitability | Estimation of change in global impedance (%) on a daily manner. | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gas exchange | Change in arterial partial pressure of oxygen (PaO2) (mmHg) following recruitment | 20 minutes and 7 days | 
| Plateau pressure | Change in plateau pressure (cmH2O) following recruitment | 20 minutes and 7 days | 
| End expiratory lung impedance (EELI) | Change in end expiratory lung impedance (%) | 20 minutes and 7 days | 
| Antero-to-posterior ventilation ratio | Change in antero-to-posterior ventilation ratio (%) following intervention | 20 minutes and 7 days | 
| Center of ventilation | Change in center of ventilation (%) following intervention | 20 minutes and 7 days | 
| Global inhomogeneity index | Change in global inhomogeneity index (%) following intervention | 20 minutes and 7 days |