Eight patients with chronic severe and refractory hypoxemia were treated with a new transtracheal oxygen catheter. All patients demonstrated an arterial oxygen partial pressure of less than 55 mm Hg on high-flow nasal cannula therapy. Refractory hypoxemia was successfully treated in all eight patients following initiation of transtracheal oxygen therapy at 2.5 to 6.0 L/min. Arterial oxygen partial pressure was 50% greater and oxygen flow requirements were 72% less with transtracheal oxygen. There were no complications related to the procedure and oxygen flow rates up to 6 L/min were well tolerated. Although four patients died, four remain clinically stable with adequate oxygenation at up to 20 months' follow-up. All eight patients experienced an improvement in quality of life with transtracheal oxygen.