Comparison of Transdermal Fentanyl Patch and Intravenous Fentanyl for Postoperative pain relief in patients undergoing major abdominal surgeries under general Anaesthesia

Abstract

Pain is a common feature for many disease processes which has association with actual or impending tissue damage. Acute postoperative pain, moderate-to-severe is still a problem, despite the progress in pain management. New technologies in pain management are being used as alternatives to IV routes because of its limitations. The transdermal route is a novel system which uses iontophoresis for the drug delivery directly via the skin by a low-intensity electrical field. Among opioids, fentanyl is the most common and because of its low molecular weight, smaller structure, high lipid solubility and high analgesic potency it could be a good choice for transdermal use. Objectives: The primary objective of this study is to evaluate the efficacy of fentanyl dermal patch with intravenous fentanyl for postoperative analgesia in major abdominal surgeries under general anaesthesia. The secondary objective is to assess the side effects associated with transdermal fentanyl patch. Methods: 50 patients of ASA I and II posted for elective abdominal surgeries, randomly allocated into two groups, IV group (n=25), received intravenous fentanyl and TFP group (n=25), receiving 25mcg/hr Duragesic patch applied on upper arm 10 hours before the surgery and were monitored for pain by VAS scale and for side effects i.e, respiratory depression, pruiritis, nausea and vomiting. The patients received inj. Paracetamol 1gm as rescue analgesia when the VAS score> 5. The pain scores, time for rescue analgesia, the complications were noted and analysed by using Windows SPSS 17 version. Results: Pain intensity scores showed a statistically significant difference between the two groups, with VAS score lower in TFP (3.80±0.12) when compared to I.V (4.67±1.18). The mean time interval for the first rescue analgesia was significantly greater in TFP (345.50±33.34) than in I.V (58.10±12.88). The side effects i.e, respiratory depression, pruritis, nausea and vomiting were significantly lower with TFP. Conclusion: Transdermal patch of fentanyl of 25 microgram/hour put 10hours prior to surgery provides an effective, safe and non-invasive method of postoperative pain relief after major abdominal surgery.