PUB - Publikationen an der Universität Bielefeld

Background and goal of the study: Several different techniques are applied to prolong postoperative analgesia in children after caudal block. We have compared the preoperative caudal administration of bupivacaine plus clonidine to the sandwich technique, i.e. the pre- and postoperative caudal administration of plain bupivacaine, regarding the duration of analgesia after hypospadia repair. Materials and methods: Prospective, randomized, observer, patient and parents blind study. Approval of the ethics board was obtained. Inhalational induction and maintenance with halothane and nitrous oxide. Group BC: preoperative caudal block with 0.5 mL kg−1 bupivacaine 0.2% with 2 μg kg−1 clonidine. Group BB: caudal block with 0.5 mL kg−1 bupivacaine 0.2% before and after the procedure (sandwich technique). Duration of analgesia (t) is the interval between the start of the procedure and the first postoperative administration of analgesics. Statistics: Mann-Whitney U Test. Results and discussion: Group BC: 15 patients, median age 17 m, Group BB: 13 patients, median age 25 m (see Figure). The difference in t was: tBB = 12.1 [10-13.6] h (median [lower-upper quartile]) vs. tBC = 6.5 [5-4-6.75] h with P = 0004. Conclusion: Many adjuvants prolong the duration of epidural blocks significantly. Most of these drugs are not evaluated sufficiently for epidural use in children. Safe application of these drugs requires the proof of nonneurotoxicity and the establishment of reliable dose effect relationships. The sandwich technique may be considered as an alternative to the application of adjuvants as long as these requirements are not met.