Criteria Analysis for Ventilatory Support Adjustment of Mechanical Ventilation

Study Overview
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Brief Summary
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The indications for mechanical ventilation (MV) include excessive work of breathing, with or without evidence of respiratory muscle fatigue. The setting of the MV is still a challenge because it is based on criteria understudied, often subjective and observer-dependent. Despite several studies, to our knowledge has never been done before is the precise definition of the optimal range of ventilatory support. Novel and recognizable diagnostic techniques will be applied. No single parameter of the breathing pattern has good accuracy for the adjustment of ventilatory support. Non-invasive measures such as P0.1 and rate of muscle relaxation may have good accuracy for the adjustment of ventilatory support.

Detailed Description
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Use of excessive pressure support

Official Title
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Criteria Analysis for Ventilatory Support Adjustment of Mechanical Ventilation

Conditions
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Acute Mechanical Ventilatory Failure

Intervention / Treatment
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* Procedure: Variation of the level of pressure support during the mechanical ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients under invasive mechanical ventilation for 48h patients without the objective of complete rest of the respiratory muscles. This decision will be on the discretion of the attending physician, spontaneous breathing, clinically stability. Exclusion Criteria: Previous disease of the central nervous system that can lead to respiratory changes. Previous disease of the peripheral nervous system that can lead to respiratory changes Previous muscular disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Pressure Support Titration<br>The analysis of the diagnostic accuracy of the breathing pattern variables, P 0.1 and the rate of tracheal muscle relaxation. | Procedure: Variation of the level of pressure support during the mechanical ventilation<br>* The pressure support of the patient was changed form the baseline to 20 cmH20 and then stepwise decreased to 2 cmH20,<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measuring muscular force | Muscular force measured by inspiratory force in centimeters of water (cmH2O) | From the baseline ventilation to the minimum level of pressure support. Around 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measuring inspiratory drive | Inspiratory drive measured in cmH2O in the first 100 milliseconds of the inspiration | From the baseline ventilation to the minimum level of pressure support. Around 3 hours | 
| Measuring endurance | Endurance measured by the maximal relaxation rate (cmH2O/10ms) | From the baseline ventilation to the minimum level of pressure support. Around 3 hours |