Naloxone antagonism after narcotic-supplemented anesthesia

Narcotic-supplemented balanced anesthesia is increasing in popularity; however, the narcotic must frequently be antagonized postoperatively. Authorities differ in their recommendations as to dose and as to mode and duration of administration of the narcotic antagonist. In the present study of 58 patients undergoing narcotic-supplemented anesthesia, 60 percent of 42 fentanyl patients and 81 percent of 16 morphine patients required postsurgical naloxone for respiratory inadequacy. Naloxone dosage was initially 1.5 mug/kg IV, with repeat IV doses of 1.5 mug/kg, when needed, at 3-minute intervals, until a regular respiratory rate greater than 15 breaths/min was attained. None of the fentanyl patients and only 25 percent (4/16) of the morphine patients required additional naloxone in the recovery room. For the latter, the dose of naloxone previously administered was given IM and proved satisfactory. Additional analgesia was needed by 12 percent (7/58) of the patients during the recovery room stay. Judicious naloxone titration permitted respiratory adequacy to coexist with analgesia after narcotic-supplemented anesthesia.