Prediction of Response to Recruitment Maneuvers in Patients With Acute Respiratory Failure

Study Overview
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Brief Summary
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The study will explore the possibility to predict potential for recruitment in acute hypoxemic respiratory failure patients by electrical impedance tomography (EIT) Swisstom BB2 (Swisstom, Landquart, Switzerland) during stepwise increase in positive end-expiratory pressure (PEEP) followed by recruitment maneuver (RM). It will compare data obtained by EIT to those obtained by pressure-volume (P-V) curves on respiratory system mechanics and data on pulmonary gas exchange.

Detailed Description
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The investigators will monitor lung ventilation by EIT during the whole protocol and perform P-V curves and arterial blood gas analysis at every step of the protocol. Participants will be sedated and paralyzed, ventilated in volume-controlled with protective ventilation (tidal volume=6-8 mL/Kg of predicted body weight and respiratory rate set to obtain normal pH) then the protocol will follow 5 steps each lasting 20 minutes to obtain clinical stability: PEEP 5 centimeter of water (cmH2O) PEEP 10 cmH2O Recruitment maneuver followed by PEEP 15 cmH2O PEEP 10 cmH2O PEEP 5 cmH2O

Official Title
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Prediction of Response to Recruitment Maneuvers in Patients With Acute Respiratory Failure

Conditions
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Acute Respiratory Failure

Intervention / Treatment
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* Device: Swisstom BB2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with acute hypoxemic respiratory failure defined by recent known clinical insult or worsening of respiratory symptoms and arterial pressure of oxygen to inspired fraction of oxygen ratio (PaO2/FiO2) ≤300 mmHg Patient on invasive mechanical ventilation Age ≥18 years Written informed consent Exclusion Criteria: Pregnancy Unstable hemodynamic condition requiring blood transfusion or adjustment of inotropics more often than every hour FiO2 ≥80% or clinical suspicion of pulmonary embolism Pneumothorax Chronic obstructive pulmonary disease (COPD) with clinical symptoms of lung emphysema as evidenced by chest radiography or computed tomography or autoPEEP > 5 cmH2O Intracranial hypertension Impossibility to correctly position the EIT belt (e.g., dressings, chest drainage, etc.) Contraindications to EIT (e.g., implantable cardiac defibrillator, pacemaker, instable spinal lesions)

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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Recruitment<br>Lung aeration monitored by Swisstom BB2 during PEEP steps and recruitment maneuver | Device: Swisstom BB2<br>* Electrical impedance tomography lung monitoring uses a dedicated belt placed around patient's thorax to detect change in impedance due to change in aeration within the thorax<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Significant reduction in silent spaces (i.e. non ventilated lung areas) during incremental PEEP steps |  | Within 20 minutes from PEEP increase |