Grant: Catalyst Grant: Breathing as One - Boehringer Ingelheim Canada COPD Grant

There are more than 2.5 million diagnosed cases of Chronic Obstructive Pulmonary Disease (COPD) in Canada. These patients have difficulties to breathe and regularly present episodes of worsening respiratory difficu lties which require hospitalization (exacerbation). At St Michael's Hospital, almost one patient everyday visits the Emergency Department for such a disease. To relieve their shortness of breath, noninvasive ventilation delivered with a full face mask (NIV) is recommended and efficient, but needs expertise and close monitoring; often, it is poorly tolerated. Another noninvasive device provides a heated and fully humidified high flow of gas with controlled oxygen concentration through nasal cannula (HFNC). This is a promising alternative. It decreases the work of breathing of patients with shortness of breath, avoid hyperoxygenation , is well tolerated but has not been properly evaluated in patients with COPD exacerbation. The aim of this study is to compare the physiologic effects and tolerance of HFNC and NIV in patients with COPD exacerbation admitted in the emeroencv department or the intensive care unit. Patients admitted to Emergency Department or Intensive Care Unit of St. Michael's Hospital for exacerbation of COPD, hypercapnia and requiring NIV or HFNC as per treating staff will be enrolled. After written consent, they will be treated by sessions of NIV and HFNC in a randomised order (cross- over study). The work of breathing, the breathing pattern, the level of C02 in the blood and the tolerance of the technique will all be assessed noninvasively. Estimated duration of participation for each patient is about 1h30. This research is highly innovative: 1) there are no similar studies in the acute settings, 2) we use only noninvasive measurements which make the study feasible and minimally interfering with the real course of the patient, and 3) HFNC is sometimes already used in clinical practice for this indication but has never been properly evaluated. Our hypothesis is unique as physiological effects of HFNC have never been compared to that of NIV. Showing that HFNC is as efficient as NIV could immensely benefit patients and the health care system in terms of cost saving, reducing time spent in the ED or ICU, simplicity of used requiring less training and improving patients' comfort. COPD is a worldw ide Pl:Jblic health issue with more than 2.5 million of Canadians suffering from this disease. If our hypothesis of equivalence between NIV and HFNC is confirmed, our results could: 1) improve the treatment tolerance for millions of _patients suffering from COPD; 2) justify a larger study (multicenter randomized trial) to compare effects of HFNC and NIV on mortality and qualitv of life.