Comparison Of Onset And Duration Of Blockade And Post Operative Analgesia Of Isobaric Ropivacaine 0.75% With Fentanyl And Isobaric Ropivacaine 0.5% With Fentanyl In Female Patients Undergoing Lower Abdominal Surgeries Under Epidural Anaesthesia - A One Year Hospital Based Randomised Controlled Trial

Abstract

Background and objective : Epidural anaesthesia is increasingly becoming popular as the neuraxial block of choice for lower abdominal and lower limb surgeries due to various advantages over sub arachnoid block. Ropivacaine, a newer amide local anaesthetic with excellent sensory blockade with less dense motor block and a much more cardiostable profile compared to bupivacaine is increasingly replacing the latter as the drug of choice in epidural anaesthesia. Opioids especially the highly lipid soluble fentanyl, provide synergistic action with local anaesthetics and are popular adjuvants for epidural block. The present study was done to compare the onset and duration of sensory block and post operative analgesia between 0.75% ropivacaine with 50 mcg fentanyl and 0.5% ropivacaine with 50 mcg fentanyl in female patients undergoing lower abdominal surgeries under epidural anaesthesia. Methods: The present one year randomised clinical trial was undertaken at Department of Anaesthesiology, KLES Dr. Prabhakar Kore Charitable Hospital, Belagavi from January 2015 to December 2015. A total of 80 female patients undergoing lower abdominal surgeries under epidural anaesthesia were randomly allocated into two groups using a computer generated randomization chart as follows :Group A received 15 ml of 0.75% ropivacaine and 50 mcg fentanyl by epidural route, (n=40) while Group B received 15 ml of 0.5% ropivacaine and 50 mcg fentanyl by epidural route, (n=40) Results : The demographic data was comparable in both the groups. The mean time of onset of sensory block in this study was significantly faster in group A( 8.8+ 1.33 min) than in Group B( 14.8 + 0.97 min ).The duration of sensory block was significantly longer in group A (150 + 11.09 min) than in Group B (137.2 + 9.93 min). The time of onset of motor block in this study was significantly faster in group A (14.4 + 2.05 min.) than in Group B(19.1 + 1.03 min ). The duration of motor block was significantly longer in group A (164.7 + 13.77 min.) than in Group B(152.2 + 9.49 min). The time for rescue analgesia was significantly delayed in Group A (190.7 + 15.91 min ) as compared to Group B (163.7 + 8.37 min ). The total analgesic consumption was significantly lower in Group A (206.27 + 73.54 mcg ) than Group B (266.63 + 63.43 mcg ). There was a significant fall in heart rate, SBP and DBP in group A as compared to group B. No major side effects complications were encountered during the study. Conclusion: Our study showed that 0.75% ropivacaine with fentanyl is significantly more potent than 0.5% ropivacaine with fentanyl in terms of onset and duration of sensory and motor block , however the overall sensory and motor block was found to be comparable. Also 0.75% ropivacaine with fentanyl provides significantly prolonged analgesia and significantly lower analgesic requirement in 24 hours than 0.5% ropivacaine with fentanyl. The haemodynamic parameters including HR, SBP and DBP are more stable with 0.5% ropivacaine with fentanyl than 0.75% ropivacaine with fentanyl. Thus 0.5% ropivacaine with fentanyl can be used as an alternative to 0.75% ropivacaine with fentanyl for epidural anaesthesia without any major side effects/complications.