Evaluation of High Velocity Nasal Insufflation in Management of Respiratory Failure in Patients With Overlap Syndrome

High velocity nasal insufflation (HVNI), a form of HFNC that utilizes a small bore nasal cannula to generate higher velocities of gas delivery than HFNC which uses large bore cannula, has the ability to accomplish complete purge of extra thoracic dead space at flow rates of 35 litres/min and may be able to provide ventilatory support in patients with respiratory failure in addition to oxygenation support in patients with overlap syndrome. This study aims to evaluate the effectiveness of HVNI compared to NIMV in management of respiratory failure in patients with obesity hypoventilation syndrome and overlap syndrome.