Clonidine versus other adjuncts added to local anesthetics for pediatric neuraxial blocks: a systematic review and meta-analysis

Abstract

BackgroundClonidine is a common adjunct to local anesthetics for pediatric neuraxial block; however, the pros and cons between clonidine and other adjuncts remain unclear. Thus, we performed this meta-analysis of randomized controlled trials to assess the efficacy and adverse effects between clonidine and other adjuncts added to local anesthetics.Materials and methodsThe systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Randomized controlled studies were searched in Cochrane (to present), Medline (1946 to present), Embase (1974 to present), and Biosis (1995 to present). Relative risks (RRs), standard mean difference (SMD), and associated CIs were calculated using RevMan statistical software to assess continuous and dichotomous data. Heterogeneity in studies was measured by forest plots and I2 values. Subgroup analysis was performed for continuous and dichotomous variables, while meta-regression was applied for continuous data with high I2 values.ResultsA total of 15 randomized controlled studies met the inclusion criteria. There was a longer duration of postoperative analgesia in the clonidine group than for other adjuncts (SMD=1.54, p=0.005, I2=96%). The number of patients requiring rescue analgesia was lower in the clonidine group without the addition of epinephrine (RR=0.55, p=0.0002, I2=0), while the RR for the comparison with epinephrine was significant (p=0.62, I2=95%). The duration of motor block was longer in the clonidine group (mean difference [MD]=1.06, p<0.00001, I2=0). The clonidine group also had a lower incidence of postoperative nausea and vomiting (PONV; RR=0.49, p<0.00001, I2=0). Postoperative bradycardia, hypotension, and urinary retention were not significantly different between clonidine and other adjuncts (p>0.05).ConclusionClonidine, compared with other adjuncts, added to local anesthetics for neuraxial block, provides a longer duration of postoperative analgesia with lower incidence of PONV. However, the duration of motor block may also be prolonged by clonidine.

Analgesic Effects of Regional Analgesic Techniques in Pediatric Inguinal Surgeries: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

“…Studies have shown that adding clonidine and epinephrine to local anesthetics prolonged the analgesic effects of peripheral nerve blocks for pediatric surgeries. 94,95 Fourth, the study included trials that combined peripheral nerve block and surgical site infiltration as interventions without further analysis. Additional surgical site infiltration might have affected the analgesic effect of II-IHB and TAPB.…”

Scorpion venom peptide, BmK AGAP as an adjuvant to lidocaine in sciatic nerve block causes dose-dependent increase intensity of sensory block and prolog duration of analgesia in rat.

“…With the introduction of several adjuvants, local anesthetic systemic toxicity has become rarer. However, reports indicate that some of these adjuvants prolong motor and sensory blocks, induce dose-dependent purities, urinary retentions and nausea [14]. The findings of this study showed BmK AGAP as an adjuvant to lidocaine in sciatic nerve block to increase and prolong the duration of analgesia without significant adverse effects.…”

Analgesic efficacy of Clonidine as an adjuvant in ultrasound-guided rectus sheath block for midline incisional hernia repair – A randomized double-blind controlled trial

“…Clonidine, alpha 2 adrenoreceptor agonist, has been very commonly used as an adjuvant with LA for epidural anesthesia,[ 8 9 ] peripheral nerve blocks,[ 6 10 ] abdominal plane block,[ 11 12 ] and local infiltration. [ 13 ] Clonidine acts by binding to presynaptic C fiber and post synaptic dorsal horn neurons and shows analgesics action by depressing the release of c-fibers, transmitter, and hyperpolarizing post synaptic dorsal horn; thus, significantly prolonging the sensory and motor block.…”