The effects of age, epinephrine, and operative site on duration of caudal analgesia in pediatric patients.

The effects of age, operative site (penoscrotal or inguinal), and the addition of epinephrine 1:200,000 to bupivacaine on duration of postoperative analgesia after caudal block were prospectively and blindly evaluated in 341 children aged 13 months to 17 yrs. At the conclusion of the surgical procedures under halothane/N2O/O2 anesthetics (n = 419), caudal blocks were performed with 0.5 ml/kg of either 0.25% bupivacaine or 0.25% bupivacaine with 1:200,000 epinephrine injected at a rate of 0.5 ml/sec. The duration of analgesia was noted by parents or nurses who had been instructed how to identify, in a standard manner, the onset of postoperative pain. The mean duration of analgesia was significantly longer in young children (P less than 0.001), in children having penoscrotal operations (P less than 0.001), and when epinephrine was added to bupivacaine (P less than 0.001). There were no major complications. The authors conclude that duration of analgesia is significantly influenced by age, operative site, and the addition of epinephrine 1:200,000 to bupivacaine.