There has been documented evidence of tracheostomies for over two millennia, the majority being descriptions of relieving acute upper airway obstructions in an emergency. Refinement of anaesthetic and surgical techniques resulted in the increased frequency and success of the procedure and in the latter half of the 20th century they were being used increasingly as adjuncts to long-term respiratory support for patients who had either lost their upper airway or who had limited bulbar function and reduced ability to clear secretions via coughing and expectorating. (Source: Surgery (Medicine Publishing))