Long-term Outcome and Lung Capacity in Survivors of ARDS Due to Influenza A (H1N1) v2009 The RESPIFLU Study

Study Overview
=================
Brief Summary
-----------------
Influenza A (H1N1) v2009 infection was responsible throughout the world of viral pneumonia and severe pulmonary edema requiring rescue therapeutics such as extracorporeal oxygenation. To date, no data exist on the outcome of patients having developed acute respiratory distress syndrome (ARDS) due to influenza A (H1N1) v2009, and in particular in patients with very severe lung injury requiring extracorporeal oxygenation. Although data exist on long-term outcome of survivors of ARDS, the patients included in the observational studies were heterogeneous with various underlying disease. Moreover, no study compared the outcome of survivors of ARDS according to the need or not of extracorporeal oxygenation. We therefore conducted this prospective case-control study to compare the long term pulmonary and extra pulmonary function in 2 groups of patients, one with severe ARDS due to H1N1 requiring extracorporeal oxygenation (case), and the second with ARDS due to H1N1 but without need for extracorporeal oxygenation (control). Eighteen case patients with inclusion and without non-inclusion criteria were selected from our national registry, and 32 controls (with inclusion and exclusion criteria) were matched on age, sex, and body mass index. All 48 patients will be contacted and asked to participate. Patients will be evaluate at least 9 months after ICU discharge, looking for health-related quality of life, measured by the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36), post traumatic stress disorder, assessed by the Impact of Event Scale Anxiety, and depression, assessed by the Hospital and Depression Score. Pulmonary function testing, including VO2 max test on a static bike will be performed. Muscle weakness will be clinically evaluated by the medical council research (MRC) test, with an additional electromyography if the result of the test was <48/60. A CT-scan will be performed, looking for lung abnormalities (fibrosis...). Albumin and prealbumin will be measured to evaluate the nutritional status. Primary outcome measurement is carbon monoxide diffusion capacity. The primary hypothesis is that patients with extracorporeal oxygenation will have a carbon monoxide diffusion capacity lower than patients without extracorporeal oxygenation (15% difference between groups). Inclusion of 13 patients in the case group and 26 patients in the control group will allow testing this hypothesis with a statistical power of 80% (standard deviation 15%). Secondary outcome measures will be the quality of life, the presence or not of post-traumatic stress disorders, of anxiety and/or depression, the results of pulmonary function testing, of the CT-scan, and of muscle testing. All results will be compared in patients with and without extracorporeal oxygenation.

Official Title
-----------------
Long-term Outcome and Lung Capacity in Survivors of ARDS Due to Influenza A (H1N1) v2009 The RESPIFLU Study

Conditions
-----------------
Influenza, Pneumonia, Viral, Pulmonary Fibrosis, Quality of Life, Stress Disorders, Post Traumatic

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients from 18 to 65 year-old Survivors of ARDS due to influenza A (H1N1) v2009 infection developed during the winter 2009-2010 Influenza A (H1N1) infection confirmed by RT-PCR Written consent Need or not for extra corporeal lung oxygenation Exclusion Criteria: Pre existing pulmonary disease Asthma Diabetes mellitus Immunodepression Cancer Severe obesity (BMI >35 kg/m²) Neuromuscular disease Pre existing cardiac disease Chronic renal failure Liver failure Stroke Pregnancy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 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 |
| --- | --- |
| Extra corporeal oxygenation<br>Survivors of ARDS due to influenza A (H1N1)2009 infection who needed an extracorporeal oxygenation at the time of infection | |
| No extracorporeal oxygenation<br>Survivors of ARDS due to influenza A (H1N1) 2009 infection who did not need an extracorporeal oxygenation at the time of infection | |

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Carbon monoxide diffusion capacity |  | At least 9 months after ICU discharge | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Health-related quality of life |  | At least 9 months after ICU discharge | 
| Pulmonary function testing |  | At least 9 months after ICU discharge | 
| Post traumatic stress disorder |  | At least 9 months after ICU discharge | 
| Anxiety and depression |  | At least 9 months after ICU discharge | 
| Muscle weakness |  | At least 9 months after ICU discharge | 
| Lung abnormalities on CT scan |  | At least 9 months after ICU discharge | 
| Alveoli-arterial gradient of oxygen during effort |  | At least 9 months after ICU discharge |