死马当活马医

Explanation: Knowing that things have no analogy seeking drugs, still hold the event hope to actively save. It also refers to a final attempt. 　　Usage: Complex sentence; as object, clause; with a compliment 　　Source: Qing Gu Zhangsi "Folk record" Volume 13: "Knowing is not to save, heal tentatively said, 'dead horse a living horse doctor'."