Airway Closure During Extracorporeal Membrane Oxygenation: The AiCLOSE Study

Study Overview
=================
Brief Summary
-----------------
About 65,000 Canadians develop acute respiratory failure requiring breathing machines (ventilators) to give oxygen to their lungs. Unfortunately, up to 50% of these individuals will not survive their illness. Mechanical ventilation through breathing machines, though potentially lifesaving, may further injure the lungs and the respiratory muscles. In the patients with the most severe and life threatening forms of respiratory failure a breathing machine alone may not be able to provide enough oxygen to the lungs and vital organs. In these critical situations, patients may require an artificial lung machine, which is referred to as extracorporeal membrane oxygenation (ECMO) to temporarily replace the function of the patient's own lung and supply critical oxygen to the body, while protecting the damaged lungs. How to use the breathing machine safely while a patient is on ECMO is still unknown. Using conventional breathing machine settings while on ECMO can lead to large portions of the lungs or airway to remain collapsed, which can contribute to further lung damage. The investigators have recently discovered a way of detecting if patients on a breathing machine suffer from collapsed airways. Knowing if the most severe patients on ECMO have airway collapse is a pivotal question that the investigators plan to answer in our study. The investigators will use our technique to determine how many patients on ECMO have airway closure and determine if this contributes to a longer time on ECMO and a longer time on a breathing machine, and if this impacts a patient's survival in the intensive care unit.

Official Title
-----------------
Airway Closure During Extracorporeal Membrane Oxygenation: The AiCLOSE Study

Conditions
-----------------
Acute Hypoxemic Respiratory Failure

Intervention / Treatment
-----------------
* Other: Acute hypoxemic respiratory failure patients on VV-ECMO


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Acute hypoxemic respiratory failure VV-ECMO Less than 24 hours from ECMO cannulation Exclusion Criteria: Air leak VV-ECMO as bridge to lung transplantation Status asthmaticus
Sexes Eligible for Study
-----------------
All

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

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

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acute hypoxemic respiratory failure patients on VV-ECMO<br> | Other: Acute hypoxemic respiratory failure patients on VV-ECMO<br>* To describe the prevalence of complete airway closure in patients with acute hypoxemic respiratory failure on VV-ECMO and its association with outcome.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of complete airway closure | Prevalence of complete airway closure during day 1 of VV-ECMO support. | Day 1 of VV-ECMO cannulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of airway closure with patient outcomes | Evaluation of the correlation between the presence of complete airway closure and the level of airway opening pressure and both clinical and physiological outcomes listed below: a. Clinical outcomes i. duration of ECMO support at 90 days ii. duration of mechanical ventilation at 90 days iii. ICU mortality iv. mortality at 90 days v. prevalence of barotrauma vi. daily ECMO support I. sweep gas II. Flow vii. Daily fluid balance b. Physiological outcomes i. time to recovery I. In spontaneous modes of ventilation compliance will be measured by dividing tidal volume by driving pressure ii. time to protective spontaneous breathing (defined as: a. ventilator not continuously triggered by the patient I. Pocc is measured by performing an end-expiratory occlusion maneuver, freezing the ventilator waveform and measuring the drop in airway pressure. iii. lung recruitability iv. right ventricular dysfunction | Up to 90 days from VV-ECMO cannulation | 
| Correlation of the degree of mismatch between clinical PEEP and AOP with patient outcomes | Evaluation of the correlation between the degree of mismatch between clinical PEEP and AOP and patient outcomes listed below: a. Clinical outcomes i. duration of ECMO support at 90 days ii. duration of mechanical ventilation at 90 days iii. ICU mortality iv. mortality at 90 days v. prevalence of barotrauma vi. daily ECMO support I. sweep gas II. Flow vii. Daily fluid balance b. Physiological outcomes i. time to recovery I. In spontaneous modes of ventilation compliance will be measured by dividing tidal volume by driving pressure ii. time to protective spontaneous breathing (defined as: a. ventilator not continuously triggered by the patient I. Pocc is measured by performing an end-expiratory occlusion maneuver, freezing the ventilator waveform and measuring the drop in airway pressure. iii. lung recruitability iv. right ventricular dysfunction | Up to 90 days from VV-ECMO cannulation | 
| Assessment of the distribution of airway closure within the lung and between the two lungs | Assessment of the distribution of airway closure within the lung and between the two lungs by EIT. | Up to 90 days from VV-ECMO cannulation | 
| Assessment of predictors of airway closure | Assessment of body mass index and the degree of obesity as predictors of airway closure. | Up to 90 days from VV-ECMO cannulation |