High Flow Nasal Cannula Versus Non-Invasive (NIV)in Both Hypoxemic and Hypercapnic Respiratory Failure.

high flow nasal cannula (HFNC) oxygen therapy utilizes an air oxygen blend allowing from 21 % to 1 00% FiO2 delivery and generates up to 60 L/min flow rates The gas is heated and humidified through an active heated humidifier and delivered via a single limb heated inspiratory circuit (to avoid heat loss and condensation) to the patient through a large diameter nasal cannula Theoretically, HFNC offers significant advantages in oxygenation and ventilation over COT. Constant high flow oxygen delivery provides steady FiO2 and decreases oxygen dilution. It also washes out physiologic dead space and generates positive end expiration pressure (PEEP) that augments ventilation The heated humidification facilitates secretion clearance, decreases bronchospasm, and maintains mucosal integrity. This study aims to evaluate the effectiveness of HFNC compared to NIMV in management of Acute hypoxemic and acute hypercapneic respiratory failure