A prospective randomized study was performed for 60 adult male patients presented for external fixation of tibial fractures under general anaesthesia in Al-Diwaniya Teaching Hospital.All subjects according to American Society of Anaesthesiologist (ASA) classification were grade 1,between 20 – 35 of age. Before induction of general anaesthesia,an epidural catheter was inserted.At the end of surgery and recovery ,subjects were allocated into four groups (15 patients in each group): Group 1 ( n=15 ) received 4 ml of epidural saline with 4 ml of 0.75% lidocaine (control group). Group 2 ( n=15 ) received 4 ug|kg epidural neostigmine diluted with normal saline to a total 4 ml volume with 4 ml of 0.75% lidocaine. Group 3 ( n=15 ) received 7 ug|kg epidural neostigmine diluted with normal saline to a total 4 ml volume with 4 ml of 0.75% lidocaine. Group 4 ( n=15 ) received 10 ug|kg epidural neostigmine diluted with normal saline to a total 4 ml volume with 4 ml of 0.75% lidocaine. All patients were assessed for 24 hours postoperatively for hemodynamic recording (heart rate and mean arterial blood pressure monitoring) at fixed intervals (3,6,9,12,24 hr) .For postoperative pain relief , diclofenac suppository was administered in increments of 50 mg on patient demand.The time from the end of surgery to first request, and the number of times diclofenac was requested in the first 24 hours after surgery , were recorded.Degree of sedation and number of postoperative nausea and vomiting were assessed.The aim of this study is to show the impact of addition of epidural neostigmine in three different doses with lidocaine or the use of epidural lidocaine alone on the postoperative analgesia following external fixation of tibial fractures.The result showed that the mean arterial blood pressure (MAP) and heart rate(HR) during the postoperative period showed significant decrease in the four groups compared to the baseline reading. However , the reduction was within 20% of the baseline and thus clinically acceptable and harmless.The postoperative analgesic duration(expressed as the time of first rescue analgesic supplementation of diclofenac suppository given ) , was significantly longer in group 4 in comparison with other groups. The number of times diclofenac was requested during the first 24 hours after surgery were significantly lower in group 4 in comparison with other groups. Also there was no significant difference between the four groups asregarding postoperative nausea and vomiting. As regarding sedation , Group 4 has a significantly higher sedation score than the other groups in the first three hours postoperatively.Thus , it is concluded that postoperative epidural neostigmine in dose of 10 ug/kg, can provide a good postoperative analgesia , without side effect , when added to lidocaine and produces a longer duration of analgesia than lidocaine alone.
