Change in the Phase III Slope of the Volumetric Capnography by Prone Positioning in Acute Respiratory Distress Syndrome

Study Overview
=================
Brief Summary
-----------------
This study evaluates the effects of prone positioning on homogenization of ventilation.

Detailed Description
-----------------
After initiation of mechanical ventilation and assessing the eligibility of the patient, informed consent will be taken from the closest kin. If eligible, following steps will be performed which are part of standard ARDS patient care. Low-flow Pressure Volume curve and assessment of airway opening pressure Calculation of recruitment to inflation ratio Optimizing Positive End-Expiratory Pressure Afterwards, phase III slope of the patient will be recorded at four timepoints: Supine 1 (immediately before turning to prone position) Prone 1 (immediately after prone position) Prone 2 (at the end of the 16-24 hour prone cycle) Supine 2 (immediately after turning to supine position)

Official Title
-----------------
Assessment of the Effects of Prone Positioning Among ARDS Patients on Ventilation Homogenization by the Phase Iii Slope of the Volumetric Capnography

Conditions
-----------------
Acute Respiratory Distress Syndrome, Ventilation Perfusion Mismatch, Respiratory Failure

Intervention / Treatment
-----------------
* Procedure: Prone Positioning


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: ARDS criteria met intubated and mechanically ventilated as a result of respiratory failure PaO2/FiO2 <200 Exclusion Criteria: age older than 18 Chronic pulmonary disease, pneumothoraces, intraabdominal hypertension (> 12 mmHg), pregnancy, not expected to survive >24 hours, hemodynamic instability

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Baseline slope of phase iii<br>Severe ARDS patients who are intubated and mechanically ventilated and will undergo prone positioning | Procedure: Prone Positioning<br>* Patients will be turned to prone position and they will be left in prone position for a duration of at least 16 hours to a maximum of 24 hours. This duration is recommended by the ARDS guidelines.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in phase iii slope of the volumetric capnograph | phase iii slope is associated with the ventilation homogeneity | 16 to 24 hours (according to time spent in the prone position) | 
| correlation of the phase iii slope with the recruitment to inflation ratio | recruitment to inflation ratio is a simple bedside tool that indicates a higher possible recruitable lung with higher applied Positive End-Expiratory Pressure | 16 to 24 hours (according to time spent in the prone position) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| correlation of the phase iii slope with the Partial pressure of the arterial oxygen/ Fraction of inspired O2 concentration (PaO2/FiO2) ratio | PaO2/FiO2 is markedly reduced in ARDS patients as a consequence of aeration loss | 16 to 24 hours (according to time spent in the prone position) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Acute Respiratory Distress Syndrome, Volumetric Capnography, phase iii slope, prone