Good Practice in Postoperative and Procedural Pain Management ...

5.5 General surgery and urology (minorand intermediate)5.5.1 Sub-umbilical surgeryThis category has been included because many studieshave used a combination of different surgical proceduresfrom the sub-umbilical area as the operativemodel, for example, repair of inguinal hernia, orchidopexy,orchidectomy, circumcision, phimosis, hypospadias,hydrocoele, vesico-ureteric reflux, testiculartortion, appendicectomy. Postoperative pain is unlikelyto be equivalent following each of these different procedures(97), but they are not uniformly distributedbetween studies and the numbers of individual proceduresin each study are often low, thereby making itimpractical to look at each procedure in isolation.Refer to other pages in this section for more informationon specific procedures, see also section 5.1 for thegeneral management of postoperative pain.RecommendationLA should be used when feasible: wound infiltration,transversus abdominis plane (TAP) block, ilio-inguinalnerve block, and caudal analgesia are effective in theearly postoperative period following sub-umbilical surgery:Grade A (98–103).EvidenceThe majority of studies compared differing drug combinationsin central or peripheral nerve blockade. Caudalepidural neuraxial block was the most commonlystudied technique and demonstrated good efficacy inall studies with a low failure and serious complicationrate. This is in agreement with large case series of thistechnique (104–107). Efficacy was equivalent irrespectiveof the local anesthetic agent used, and there waslittle difference in the rate of side effects, caudal analgesiahas been used with either general anesthesia orsedation for surgery (100,102,107–109). The optimalconcentration and volume of LA has not been elucidated,but concentrations of levobupivacaine and ropivacainebelow 0.2% have been associated with lowerefficacy in some studies (110–112).Caudal neuraxial analgesic additives 1 : with LA: theaddition of caudal S-ketamine, neostigmine, clonidine,dexmedetomidine, midazolam, buprenorphine, fentanyl,and morphine increased analgesic efficacy and prolongedthe duration of the block, with little reported increase inside effects in most studies (113–123). In contrast, otherstudies show that there is no benefit to adding midazolam,magnesium, or sufentanil to LA via the caudal route(124–126). Clonidine, S-ketamine, and buprenorphinewere more effective when given by the caudal route comparedwith the intravenous route (115,120,127). In directcomparisons, either caudal clonidine or midazolam werebetter than morphine (113,128).Without LA: a combination of S-ketamine andclonidine demonstrated better analgesic efficacy thanS-ketamine alone via the caudal route (129). The useof such adjunctive analgesia requires further researchto better identify safety profile, risk–benefit and dose;see also section 6.3 for a further discussion of neuraxialanalgesia.Ilio-inguinal nerve block was shown to be effective,but overall efficacy was generally lower than in studiesof caudal block (98,130). The use of ultrasound toplace the ilio-inguinal block improved the quality ofthe block, decreased supplementary opioid use, anddecreased the amount of local anesthetic used (131).No benefit was seen from adding clonidine to the localanesthetic in ilio-inguinal nerve block (100,132).TAP block is feasible with initial reports of goodefficacy. An ultrasound-guided technique was shownto be effective in the intraoperative and early postoperativeperiod, though efficacy was less when comparedwith ultrasound-guided ilio-inguinal nerve block foringuinal surgery (103).LA wound infiltration/instillation is effective in theearly postoperative period, it was equivalent to ilioinguinalblock with no further benefit from using themin combination in one study (98,101).1 Note on caudal additives: not all additives have undergone rigoroussafety testing and concerns regarding potential toxic effects have beenexpressed. See Section 6. 3ª 2012 Blackwell Publishing Ltd, Pediatric Anesthesia, 22 (Suppl. 1), 1–79 39