Im a HCA on a surgerical ward (we have alot of pneumothoraces). We've just had a new registrar start on the ward who suggested we use a technique of nitrogen washout (putting patient on high flow oxygen) for treatment of a small pneumothorax. It was the first time the technique has ever been used on this ward, the nurses said. Can anyone explain to me what a 'nitrogen washout' is exactly? And why its so uncommonly used?