Prevention and minimizing serious complications during difficult airway management is an important goal for anesthesia providers. Using the high flow cannula oxygenation systems it is possible to improve the clinical outcomes, increase patient safety and reduce the rate of complications. A possible mechanism of this method can be explain by 'Aventilatory Mass Flow' which is a physilogical phenomenon. Several methods can be used to implement apneic oxygenation such as nasopharyngeal catheter, nasal cannula, face mask, Venturi mask, transtracheal endobronchial catheters, dual blade laryngoscopes and High Flow Nasal Cannula Oxygenation (HFNCO) systems. However each method has some restrictions. In this review we aim to focus on the important features of HFNCO systems including the indications, contraindications and possible complications.