Randomized Comparative Study to Evaluate the Effectiveness of Ropivacaine 0.125% Versus 0.2% with Fentanyl in Epidural Labor Analgesia

Background: Minimum effective concentration of local anesthetics for providing optimal labor epidural analgesia and the strategies aiming to reduce their consumption are continuously being searched. Objectives: The objective of this study was to evaluate the efficacy of 0.125 % and 0.2 % ropivacaine both mixed with fentanyl 2 mcg/ml for epidural labor analgesia. Materials and Methods: A total of 80 parturients in active labor were randomly assigned to two groups of 40 each, to receive an epidural injection of 15 ml ropivacaine 0.125 % with fentanyl (2 mcg/ml) in group R1 and 15 ml of ropivacaine 0.2 % with fentanyl (2 mcg/ml) in group R2 as initial bolus dose. Same dose regimen was used as subsequent top-up dose on patients demand for pain relief. The duration and quality of analgesia, motor block, top-up doses required consumption of ropivacaine and fentanyl and feto-maternal outcome in both groups were compared. Results: Effective labor analgesia with no motor blockade was observed in both groups with no failure rate. Onset of analgesia was significantly faster in group R2 (75 % parturients in 0-5 min) as compared to group R1 (25 % parturients in 0-5 min), P less than 0.001. Duration of analgesia after initial bolus dose was also significantly longer in group R2 (132 56.81 min) than in group R1 (72.25 40.26 min), P less than 0.001. Mean VAS scores were significantly less in group R2 than in group R1 at 5, 60, and 90 min, P less than 0.01. Requirement of top-up doses was significantly less in group R2 (0.05 0.22) as compared to group R1 (0.80 0.65), P less than 0.001. Consumption of ropivacaine was comparable in both the groups (33.75 12.16 mg in group R1 and 31.50 6.62 mg in group R2 P greater than 0.05), but consumption of fentanyl was significantly more in group R1 (54.00 19.45) as compared to group R2 (31.50 6.62), P less than 0.001. There were no significant changes in hemodynamics, nor adverse effects related to neonatal or maternal outcomes in both groups. Conclusion: It was concluded that both the concentrations of ropivacaine (0.2 % and 0.125 %) with fentanyl are effective in producing epidural labor analgesia. However, 0.2 % concentration was found superior in terms of faster onset, prolonged duration, lesser breakthrough pain requiring lesser top-ups, and hence a lesser consumption of opioids. Key words: Epidural labor analgesia, labor analgesia, ropivacaine 0.2 % versus 0.125 %, fentanyl