Sevoflurane PharmacokInetics in ARDS

Study Overview
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Brief Summary
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The main objective of this study is to compare the pharmacokinetic models of sevoflurane-induced sedation during ARDS depending on the lung imaging phenotype (focal vs nonfocal phenotypes) The authors hypothesized that sevoflurane used for inhaled sedation could have distinct pharmacokinetic profiles depending on lung imaging phenotypes (focal vs nonfocal) during ARDS in ICU patients.

Detailed Description
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Adult patients admitted to the ICU within 12 hours of moderate-severe ARDS onset and under sedation with sevoflurane will be enrolled in the study with inclusion criteria. They will be enrolled, depending on their morphotype (focal or nonfocal), as routinely assessed in participating centers using CT-scan, chest x-ray and/or lung ultrasound. These patients will receive inhaled sevoflurane as a standard practice of sedation that is routinely used in participating ICUs. After inclusion, the mechanical ventilation protocol must be initiated within two hours (if not already being used). In both groups, deep sedation followed by neuromuscular blockade must be initiated within four hours of inclusion. Adult patients admitted to the ICU within 12 hours of moderate-severe ARDS onset and under sedation with sevoflurane will be enrolled in the study with inclusion criteria. They will be enrolled, depending on their morphotype (focal or nonfocal), as routinely assessed in participating centers using CT-scan, chest x-ray and/or lung ultrasound. These patients will receive inhaled sevoflurane as a standard practice of sedation that is routinely used in participating ICUs. After inclusion, the mechanical ventilation protocol must be initiated within two hours (if not already being used). In both groups, deep sedation followed by neuromuscular blockade must be initiated within four hours of inclusion. Blood sample will be collected at different times after the onset of sevoflurane administration and after its cessation.

Official Title
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Sevoflurane pharmacokInetics During Inhaled Sedation Relies on the Morphotype of ARDS in ICU Patients

Conditions
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Acute Respiratory Distress Syndrome

Intervention / Treatment
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* Drug: Deep sedation by Sevoflurane on the Morphotype of ARDS in ICU patieNts


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 years Presence for ≤ 12 hours of all of the following conditions, within one week of a clinical insult or new or worsening respiratory symptoms : a PaO2/FiO2 < 200 mmHg with positive end-expiratory pressure (PEEP) ≥ 8 cmH2O (or, if arterial blood gas not available : SpO2/FiO2 ratio that is equivalent to a PaO2/FiO2 < 200 mmHg with PEEP ≥8 cmH2O, and a confirmatory SpO2/FiO2 ratio between 1-6 hours after the initial SpO2/FiO2 ratio determination) b Bilateral opacities not fully explained by effusions, lobar/lung collapse, or nodules c Respiratory failure not fully explained by cardiac failure or fluid overload; need objective assessment (e.g., echocardiography) to exclude hydrostatic edema if no risk factor present Exclusion Criteria: Lack of informed consent Continuous sedation with inhaled sevoflurane at enrollment Currently receiving ECMO therapy Chronic respiratory failure defined as PaCO2 > 60 mmHg in the outpatient setting Home mechanical ventilation (non-invasive ventilation or via tracheotomy) except for CPAP/BIPAP used solely for sleep-disordered breathing Body mass index > 40 kg/m2 Chronic liver disease defined as a Child-Pugh score of 12-15 Expected duration of mechanical ventilation < 48 hours Tidal volume of 6 mL/kg predicted body weight (PBW) below 200 mL Decision to withhold life-sustaining treatment; except in those patients committed to full support except cardiopulmonary resuscitation Moribund patient, i.e. not expected to survive 24 hours despite intensive care Burns > 70% total body surface Previous hypersensitivity or anaphylactic reaction to sevoflurane Medical history of malignant hyperthermia Suspected or proven intracranial hypertension Know pregnancy - Pregnancy testing will be systematically performed to rule out pregnancy in female patients of reproductive age Enrollment in another interventional ARDS trial with direct impact on sedation and PEEP Endotracheal ventilation for greater than 120 hours (5 days) PaO2/FiO2 (if available) > 200 mmHg after meeting inclusion criteria and before start of the study

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: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Inhaled sedation with sevoflurane, will be vaporized via the miniaturized Anesthesia Conserving Device (AnaConDa-S®, Sedana Medical, Uppsala, Sweden). Sevoflurane infusion rate will be adapted from manufacturer's instructions in order to reach a target of expired sevoflurane fraction (FEsevo) of 0.8-1.1. Mechanical ventilation will be protocolized in both arms, based on recent results of a RCT from our group, in which 90-day survival was improved in patients with nonfocal ARDS when an individualized ventilation strategy was applied, compared to the ARDSNet strategy (PEEP set according to FiO2). We will recommend sites wait at least 12 hours before proning, as in the PROSEVA study. In both groups, patients will receive cisatracurium besylate for neuromuscular blockade, and deep sedation will be protocolized to Richmond Agitation-Sedation Scale (RASS) of -4 to -5 (Ramsay of 5-6, or Riker of 1-2) before starting, and during, the cisatracurium besylate infusion.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Nonfocal ARDS<br>ARDS patient with nonfocal lung imaging phenotype | Drug: Deep sedation by Sevoflurane on the Morphotype of ARDS in ICU patieNts<br>* Pharmacokinetic of inhaled sevoflurane used for sedation<br>|
| Experimental: Focal ARDS<br>ARDS patient with focal lung imaging phenotype | Drug: Deep sedation by Sevoflurane on the Morphotype of ARDS in ICU patieNts<br>* Pharmacokinetic of inhaled sevoflurane used for sedation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 5 minutes after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 30 minutes after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 1 hour after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 6 hours after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 24 hours after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 48 hours after the detection by the monitor of sevoflurane (0.1%) in the breathing circuit | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 5 minutes after the cessation of sevoflurane administration | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 30 minutes after the cessation of sevoflurane administration | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 1 hour after the cessation of sevoflurane administration | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 4 hours after the cessation of sevoflurane administration | 
| Plasma concentrations of sevoflurane | Plasma concentrations of sevoflurane | 6 hours after the cessation of sevoflurane administration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma concentration of hexafluoroisopropanolol | Plasma concentration of hexafluoroisopropanolol | Until sedation can be definitely interrupted or until day 7 | 
| Fraction of inspired sevoflurane | Fraction of inspired sevoflurane | Until sedation can be definitely interrupted or until day 7 | 
| Fraction of expired sevoflurane | Fraction of expired sevoflurane | Until sedation can be definitely interrupted or until day 7 | 
| Dose of sevoflurane | Dose of sevoflurane (mg/l) | Until sedation can be definitely interrupted or until day 7 | 
| Infusion duration of sevoflurane | Infusion duration of sevoflurane (min) | Until sedation can be definitely interrupted or until day 7 | 
| Infusion rate of remifentanil | Infusion rate of remifentanil | Until sedation can be definitely interrupted or until day 7 | 
| Values of a bispectral index | Values of a bispectral index | Until sedation can be definitely interrupted or until day 7 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Nonfocal Acute respiratory distress syndrome, Focal Acute respiratory distress syndrome, Sevoflurane, Pharmacokinetics, Mechanical ventilation