Comparative study of epidural fentanyl and epidural fentanyl with magnesium sulphate for post-operative analgesia in patients undergoing lower limb surgeries

Background: Control of post-operative pain is a major concern for the patients and also for the treating physicians. Various analgesic agents such as opioids, nonopioids through various routes such as oral, intravenous, neuraxial, regional for the management of postoperative pain exist. Magnesium has anti-nociceptive properties with additional enhancement of opioid anti-nociception when used epidurally. Materials and methods: The study was a randomized open labelled controlled trail, conducted in the department of anaesthesiology, Govt. Mohan Kumaramangalam Medical College and Hospital, Salem, Tamil Nadu. The data collection for the study was done between June 2016 to June 2017. The study population included people who were undergoing lower limb surgery for various disease conditions. The key outcome variables assessed were highest sensory blockade, time taken for highest sensory level (min), duration of surgery (min), time for regression to L1 (min), duration of analgesia (min). Results: Duration of analgesia was longer in the Magnesium sulphate group, with analgesia lasting for 143.4 +39.57 minutes which was statistically significantly higher compared to Epidural Fentanyl group with 107 (±25.82) minutes. The mean time for regression to L1 was 118 minutes and 119 minutes in group F and FM respectively, there is no statistically significant between two study groups (P value>0.05). There was no statistically significant difference between the groups in the time taken for the highest sensory level (P value>0.05), the duration of surgery and the time taken for the highest sensory level (P value>0.05). Conclusion: Magnesium being a relatively harmless and inexpensive molecule, a non-competitive, N-methyl-D-aspartate receptor antagonist with its anti-nociceptive properties has a huge role to play in the coming years for postoperative analgesia.