For paediatric circumcision, under general anaesthesia, the addition of clonidine 2 microg x kg(-1) to low volume (0.5 ml x kg(-1)) caudal anaesthetics has a limited clinical benefit for children undergoing circumcision.

No abstract

Fifty boys presenting for day case circumcision were allocated randomly to receive either caudal analgesia or dorsal nerve block (DNB) to provide postoperative pain relief. Analgesia was assessed by a single, unbiased observer utilising a three-point scale. Subsequently, parents completed a simple questionnaire. Subjects in the DNB group micturated earlier (P less than 0.05) and stood unaided earlier (P less than 0.025) than patients in the caudal group. The incidence of vomiting was significantly lower in the DNB group (P less than 0.05). There was no significant difference in the duration of analgesia, although that produced in the DNB group tended to wane sooner. It is concluded that DNB provides satisfactory analgesia following circumcision and has specific advantages when compared with caudal analgesia.

SummarySerum hupivacaine concentrations were measured in 12 children who underwent elective herniotomy and who received analgesia in the form of wound infiltration. Mean ( S D ) peak concentration was 0.36 (0.14) pgLglml and time to peak concentration was 14.6 (7.2) Local anaesthetic techniques are used widely to provide postoperative analgesia in children who undergo day-case herniotomy. Wound infiltration with bupivacaine has been shown to provide analgesia comparable to that associated with caudal block' or ilioinguinal block.2 Bupivacaine may produce toxic effects at plasma concentrations greater than 4 ~g / m l~.~ although the rate of increase of plasma concentration is an important f a~t o r .~.~ Both caudal and ilioinguinal blocks have been shown to result in concentrations well below 4 pg/mI.' Bupivacaine concentrations have been measured following subcutaneous injection: but this does not mimic the conditions of wound infiltration and this information is not available for this age group.The purpose of this study was to measure serum bupivacaine concentrations after wound infiltration for postoperative analgesia in children who underwent day-case herniotomy . MethodThe study was approved by the District ethics committee and informed consent was obtained from one or both parents. Twelve children aged between 2 and 10 years admitted for elective unilateral herniotomy as day-cases were studied. No premedication was given and general anaesthesia was induced by inhalation of halothane or by the intravenous route (following application of EMLA cream). Maintenance of anaesthesia was by spontaneous ventilation of 67% nitrous oxide in oxygen and halothane delivered by a T-piece or Bain coaxial system.A 20-gauge cannula was inserted into a vein on the dorsum of the hand either for intravenous induction or after inhalational induction, and was used for blood sampling. A baseline (2 ml) sample was taken prior to surgery. Before skin closure, the wound edges were infiltrated with 1.25 mg/kg of bupivacaine without adrenaline as either the 0.25% solution in children under 16 kg or as the 0.5% solution in those of greater weight. Further venous blood samples were taken at 5, 10, 15, 20, 30, 45 and 60 minutes after the completion of wound infiltration. The patency of the cannula was maintained with heparinised saline and the deadspace was aspirated on each occasion. Samples were placed in plain tubes and centrifuged to yield approximately 1 ml of serum which was stored at -70°C.Bupivacaine concentrations were measured by high pressure liquid chromatography using dichloromethane for the extraction and p-chlorodisopyramide as internal standard. Interassay coefficient of variation was 5.1% and intra-assay coefficient of variation was less than 10%. ResultsThe ages and weights of patients are shown in Table 1. A complete set of results was not obtained for all patients because of sampling difficulties. The serum bupivacaine concentrations in one patient were somewhat higher than the others. Consequently, the median an...