Neostigmine does not prolong the duration of analgesia produced by caudal bupivacaine in children undergoing urethroplasty.

CONTEXT: Neostigmine extends the duration of analgesia produced by caudal bupivacaine in children.

AIMS: To study the effect of different doses of caudal neostigmine on the duration of postoperative analgesia.

SETTINGS AND

DESIGN

A randomized, double-blind study was conducted in 120 boys aged 1-12 years undergoing urethroplasty under combined general and caudal anesthesia.

MATERIALS AND

METHODS

Children were administered 1.875 mg/kg bupivacaine alone (Group B) or with 2, 3 or 4 microg/kg of neostigmine (groups BN 2, BN 3 or BN 4 respectively) as caudal drug (0.75 ml/kg). Children with a pain score of 4 or more (OPS and NRS) postoperatively were administered rescue analgesic. Time to first analgesic and the number of analgesic doses administered in the 24h were recorded.

STATISTICAL ANALYSIS: Parametric data were analyzed using ANOVA. Kaplan-Meier survival curves for the time to first analgesic administration were plotted and compared using log rank analysis. Chi-square test was used to analyze the incidence data.

RESULTS

The median [IQR] time to first analgesic in Group B (540 [240-1441] min) was similar to that in Groups BN 2 (450 [240-720]), BN 3 (600 [360-1020]) and BN 4 (990 [420-1441]). Significantly more patients in Groups B (9 [34.6%]) and BN 4 (13 [44.8%]) required no supplemental analgesic for 24h than those in Groups BN 2 and BN 3 (4 [13.8%] and 4 [13.3%]). The number of analgesic doses required in 24h in the four groups was similar.

CONCLUSION

Addition of neostigmine to 1.875 mg/kg of caudal bupivacaine did not prolong the analgesia following urethroplasty in children.