Objective:To study the safety and curative effect of large dose naloxone in patients with acute carbon monoxide(CO) poisoning in pre-hospital.Methods:145 patients with acute CO poisoning were involved in a randomized controlled trial. 69 patients received traditional medication as the control group, 76 patients in the observation group received the scheme that the large dose naloxone was used in pre-hospital on the base of the control group, first,intravenous 2mg naloxone, followed with 12mg naloxone in 5% ...