///2015 Abstract Details
2015 Abstract Details2019-08-02T16:54:43-05:00

A Non-Opioid Adjunct Equally or More Potent than Fentanyl for Labor Epidural Analgesia With Less Side Effects

Abstract Number: BP-06
Abstract Type: Original Research

Peter H Pan MSEE, MD1 ; Kenneth Nelson MD2; Vernon Ross MD3; Jessica Booth MD4; Lynn Harris BSN5; James Eisenach MD6

Introduction: Addition of opioid to epidural local anesthetic (LA) reduces LA dose by 20%, but at the expense of side effects & regulatory compliance. Epidural neostigmine (N) also reduces LA dose(1). Here we compared in a double-blind RCT the dose dependent effect of N to a standard dose of fentanyl (F) added to bupivacaine (B) for labor PCEA.

Method: After IRB approval, 215 ASA 1-2 & laboring parturient (cervix dilation≤5cm & Wt<115Kg) requesting labor epidural analgesia were consented & randomized to receive 1 of 4 epidural drug solutions. All 4 gps received 0.125% B with addition of either F (2μg/ml) or N (2, 4, or 8 μg/ml). A lumbar epidural catheter was inserted & tested with 3mL 1.5% lidocaine with 5 μg/mL epinephrine. Study solution (15mL) was administered as initial epidural loading dose, followed by PCEA with the same study solution at 6 mL/hr, a demand of 5 mL & 10-min lock-out. Top ups for breakthrough pain were provided at patient’s request as routine. The primary outcome was the total LA consumption, defined as the total PCEA use and top-ups (expressed as 0.125% B equivalents) divided by the infusion duration. A priori analysis determined a group size of 35 was needed in order to have 80% power at α=0.05 to detect a 20% difference in the primary outcome. Data are presented as mean±SD, median[IQR] or % as appropriate, with P<0.05 as significant.

Results: Of 215 subjects consented 151 were evaluable after 64 excluded due to delivery before study began or failed inclusion criteria. Demographics, maternal & fetal outcomes & labor characteristics were similar among gps. Total LA consumption, PCEA use & top ups did not differ among gps(Table 1). APGAR scores, mode of delivery & time from analgesia initiation to complete cervical dilation or delivery were similar among gps. Average maximum scores for Bromage motor scale, nausea & sedation were similar among gps but pruritus score was higher(P<0.001) in the gp with F than the gps with N.

Conclusion: Addition of neostigmine from 2 to 8 μg/mL reduces epidural B requirement comparable to 2 μg/mL of fentanyl in labor PCEA. The lack of significant dose response difference from 2 to 8 μg/mL of N suggests that lower doses should be examined. These data confirm the lack of increased nausea and less pruritus from epidural N in this setting & offer guidance to the clinical application of neostigmine as a non-opioid adjuvant to labor analgesia.

1.AnesthAnalg 2009;109:524-31

Supported in part by NIH GM48085 

SOAP 2015