A double-blind study on analgesic effects of fentanyl combined with bupivacaine for extradural labor analgesia.

Background: The intermittent technique of labor extradural analgesia has been showing promising results over other techniques. This study was done to assess and compare the efficacy of two different doses of fentanyl mixed with low doses of bupivacaine in intermittent labor extradural analgesia.

Materials And Methods: 90 ASA grade I-II parturients in active labor with a cervical dilatation of 3-7 cm were randomly allocated to three different groups: Group A: 10 ml bupivacaine 0.125% + fentanyl 10 μg (1 μg/ml)Group B: 10 ml bupivacaine 0.125% + fentanyl 20 μg (2 μg/ml)Group C: 10 ml bupivacaine 0.125% (the control group) All patients were preloaded with 10-15 ml/kg Lactated Ringer's solution. Labor analgesia was maintained by intermittent boluses of the drug combination.

Results: The mean time of the onset of analgesia was significantly lower (P<0.05) and the duration of analgesia was significantly higher (P<0.01) in Group B when compared with Groups A and C (P<0.001). Patient satisfaction was considerably better in Group B (P<0.01). However, in both groups, the progression of labor was found to be slightly more prolonged than Group C. The level of the sensory and motor block was comparable in both the groups and was at the T8-T10 level; it was comparable and the level of motor blockade (Bromage score = 0, 1) in each group was also not significant (P>0.05).

Conclusion: The addition of fentanyl (2 μg/ml) to bupivacaine 0.125% decreases the time of the onset of analgesia and increases the duration of analgesia and level of maternal satisfaction during labor as compared to fentanyl (1 μg/ml).