Labor Epidural Analgesia: Comparison of Two Different Intermittent Bolus Regimes

BACKGROUND: Optimal labor analgesia can be provided with epidural by addition of opioid to the local anesthetic. AIMS: The aim of this study is to compare the efficacy of labor epidural bolus regimes 20 mL of 0.1% ropivacaine with 40 μg fentanyl versus 15 mL of 0.1% ropivacaine with 15 μg fentanyl as epidural bolus dose. SETTINGS AND DESIGN: This was prospective double-blinded randomized study. MATERIALS AND METHODS: After approval from the Institutional Ethical Committee, 50 consenting parturients in active labor were allotted into two groups by closed envelope technique. Group A received 20 mL of 0.1% ropivacaine with 40 μg fentanyl, whereas Group B received 15 mL of 0.1% ropivacaine with 15 μg fentanyl as an epidural bolus dose. The onset, duration of analgesia, motor block, top-up doses required, consumption of ropivacaine, and fentanyl and fetomaternal outcome were compared. STATISTICAL ANALYSIS USED: Numerical variables are expressed as a mean and standard deviation and categorical variables are expressed as frequency and percentages. To obtain the association between categorical variables and different doses Fischer's exact test was applied. To compare clinical parameters between different drug doses independent two-sample t-test were applied. Mann–Whitney U-test applied for nonparametric data. Results: Effective labor analgesia with no motor blockade was observed in both groups with no failure rate. Duration of analgesia was significantly longer in Group A (166.8 ± 54.64 vs. 100.2 ± 32.39 min P < 0.001). The onset of analgesia was faster in Group A (88% vs. 16% within 7 min, P < 0.001). CONCLUSION: Labor epidural analgesia with larger volume boluses produces faster onset and prolonged duration of analgesia.