What are the main symptoms of end stage respiratory failure?

Wide range.... There are a wide range of symptoms depending on if the respiratory failure results in carbon dioxide elevation or just low oxygen levels. Low oxygen levels can cause shortness of breath at rest when end-stage, fatigue, mental status change whereas high carbon dioxide levels can cause confusion, sleepiness. The skin can look blue especially at the fingertips, toes, lips. Coma and death can occur.