Abstracts and Programme: EUROANAESTHESIA 2011: The European Anaesthesiology Congress: Best Abstracts - Runner-up Session 1
Background and Goal of Study: Caudal anaesthesia provides safe and effective perioperative analgesia for children undergoing surgery. To prolong neuroaxial analgesia, additives are used and clonidine is one of the most popular additives for caudal anaesthesia worldwide. Aim of the present quantitative systematic review was to assess the efficacy and safety of the combined use of clonidine and local anaesthetics in comparison to caudal local anaesthetics alone.
Materials and Methods: All randomised controlled trials investigating caudally administered clonidine in addition to local anaesthetics in comparison to local anaesthetics alone were included in this review. The systematic search, data extraction, critical appraisal and pooled analysis were performed according to the PRISMA statement. Relative risk (RR), mean difference (MD) and the consecutive 95% confidence intervals (CI) were calculated using the Revman® as statistical software.
Results and Discussion: Twenty randomised controlled trials (published between 1994-2010) including 993 patients met the inclusion criteria. There was a longer duration of postoperative analgesia in children receiving clonidine in addition to local anaesthetic (MD: 3.72 hours; 95% CI: 2.61 - 4.84; P < 0.00001). A subgroup analysis investigating the influence of the most common used clonidine doses (1μg/kg, 2μg/kg) in addition to long lasting local anaesthetics showed a slightly longer analgesic effect in trials administering 1μg/kg clonidine in addition to long lasting local anaesthetics. Furthermore, there was a lower number of patients requiring rescue analgesics in the clonidine group (RR: 0.72; 95% CI: 0.57 - 0.90; P = 0.003). The pooled data analysis showed a lower RR for PONV in children receiving clonidine in addition to local anaesthetics (RR: 0.80; 95% CI: 0.56 - 1.12; P=0.19). The incidence of complications (e.g. respiratory depression) remained very low and was not different to caudal local anaesthetics alone.
Conclusion(s): There is considerable evidence that caudally administered clonidine in addition to local anaesthetics provides extended analgesia (around 4 hours) with a decreased incidence for analgesic rescue requirement and little adverse effects compared to caudal local anaesthetics alone. However, these results were limited by clinical heterogeneity due to different clonidine doses and the use of various types and doses of local anaesthetics.