Post extubation respiratory failure occur in 30% of extubated patients. More than 50% of them required reintubation. Noninvasive positive pressure ventilation (NIV) had been reported as an effective tool to prevent post extubation respiratory failure. Recently, high flow oxygen nasal cannula (HFNC) had been successfully used to prevent post extubation respiratory failure and prevent reintubation. The results from recent randomized controlled trials, comparing HFNC with NIV for prevent post extubation respiratory failure among post cardiac surgery and high risk patients, showed no significant different in the treatment outcome.comparable with NIV among post cardiothoracic surgery and high risk for reintubated patients.