Johnston J R, McCaughey W
Anaesthesia. 1980 Feb;35(2):155-7. doi: 10.1111/j.1365-2044.1980.tb03795.x.
Epidural injection of morphine 2 mg in 10 ml was used as a method of analgesia in treatment of fractured ribs in six patients. This method was effective and appears to have advantages over the use of bupivacaine, both in terms of duration of action and lack of side effects such as hypotension.