Effect Alveolar Recruitment Manoeuver on Stroke Volume a Randomized Study

Study Overview
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Brief Summary
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Objective: to compare the effect of alveolar recruitment manouver through stepwise increase and decrease in airway pressure or sustained 30 secondes 30 cmH2O continuous positive airway pressure on cardiac stroke volume estimated by oesophageal doppler in preload independent anesthetized patients scheduled for surgery.

Detailed Description
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Following anesthesia and preload optimisation guided by cardiac stroke volume, patients will be randomised to one alveolr recruitment manoeuver : stepwise increase and decrease in positive airway pressure sustained 30 secondes 30 cmH2O continuous positive airway pressure The primary objective is the change in cardiac stroke volume.

Official Title
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Hemodynamic Effect of Alveolar Recruitment Manoeuver Through Stepwise Increase and Decrease in Irway Pressure or Sustained 30 Secondes 30 cmH2O Continuous Positive Airway Pressure. A Randomized Study.

Conditions
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Alveolar Recruitment Manoeuver, Anesthesia

Intervention / Treatment
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* Procedure: alveolar recruitment manoeuver


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult patients scheduled for major surgery requiring hemodynamic monitoring written signed informed consent Exclusion Criteria: pregnancy non sinusal heart rate known cardiac right ventricular failure or arterial pulmonary hypertension pneumothorax known pulmonary emphysema

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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomised parallel groups. randomisation between 2 groups equilibated by randomised blocks of 4, 6 or 8
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: CPAP30<br>a 30 secondes 30 cmH2O continuous positive airway pressure applied after the orotracheal intubation will be checked and secured following induction of general anesthesia | Procedure: alveolar recruitment manoeuver<br>* alveolar recruitment manoeuver are recommended during general anesthesia to prevent pulmonary atelectasis<br>|
| Active Comparator: STEP30<br>a stepwise increase (+5 cmH2O) in postivie airway pressure from +5 cmH2O to +30 cmH2O and decrease (-5 cmH2O) from +30 cmH2O to +5 cmH2O applied after the orotracheal intubation will be checked and secured following induction of general anesthesia | Procedure: alveolar recruitment manoeuver<br>* alveolar recruitment manoeuver are recommended during general anesthesia to prevent pulmonary atelectasis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cardiac stroke volume | change in cardiac stroke volume during the alveolar recruitment manoeuver | 1 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| arterial pressure | change in arterial pressure during the alveolar recruitment manoeuver | 1 min | 
| recovery at 3 min | recovery of cardiacstroke volume and arterial pressure 3 min after the end of alveolar recruitment manoeuver | 3 min |