- Clear contraindication to NIV treatment: respiratory arrest, failure to correct positioning of a face mask, hemodynamic instability due to hypotensive shock, ongoing myocardial ischemia, arrhythmia, massive bleeding from upper gastrointestinal tract, patient uncooperative and upset, inability to protect airways, alterations of deglutition, inability to clear secretion also with external aspiration, multiple organs dysfunction, recent surgery of airways or upper gastrointestinal tract, not-drained pneumothorax, bowel obstruction, active vomit.