Adjunct analgesic drugs to local anaesthetics for neuroaxial blocks in children.

PURPOSE OF REVIEW: This article reviews various adjunct drugs used in the context of neuroaxial blocks in children and to provide a literature and evidence-based suggestion for the rational use of such adjuncts.

RECENT FINDINGS: Contrary to plain local anaesthetics, preservative-free morphine and clonidine, ketamine in neonatal rodents has been found to enhance apoptosis in the spinal cord. Dexmedetomidine has been shown to be equally effective as clonidine as an adjunct to caudal blocks. Systemic dexamethasone is as effective as if it is co-administered together with the local anaesthetic in the context of neural blockade.

SUMMARY: Alpha-2 adrenoceptor agonists currently represent the most versatile and well-tolerated adjunct for neuroaxial blockade in children. Preservative-free morphine may be indicated in certain situations but the risk for respiratory depression and other disturbing side-effects must be taken into account. Preservative-free ketamine is an effective adjunct to caudal blockade in children but the use should be restricted to children older than 1 year of age. All other drugs must still be regarded as experimental and should not be used outside clinical trials.