Local Anesthetic Systemic Toxicity rare in children but may prove fatal

New research revealed that local anesthetic (LA) systemic toxicity (LAST) is rare but may frequently exhibit neurological and cardiac signs in children. The study was published in the journal BMC Pediatrics.

Local anesthetics in the pediatric population can produce severe systemic toxicity after intravenous absorption from the injection site (topical, or subcutaneous). These can occur within an hour or sometimes many hours later and can be fatal. Despite the dosages, children should be monitored for an hour after LA administration. As the factors associated with systemic reactions are poorly understood, researchers conducted a study to characterize the clinical profile of pediatric local anesthetic (LA) systemic toxicity (LAST) and to identify determinants of life-threatening outcomes.

The French Pharmacovigilance Network received spontaneous reports, which were then retrieved and reviewed on a case-by-case basis by the following standards:

The elements that can result in a life-threatening reaction like persistent seizures or cardiorespiratory arrest, were determined by multivariate logistic regression analysis.

Key findings:

• Among 512 cases retrieved, 64 LAST cases included neonates 11%, infants 30%, children 36%, and adolescents 23%.
• The anesthetics involved mainly were lidocaine (47%), lidocaine + prilocaine (22%), and ropivacaine (14%).
• Toxicity profiles were neurological (58%), cardiac (11%), or mixed (20%), and seven patients (11%) developed methemoglobinemia.
• LAST was life-threatening for 23 patients (36%) and two died.
• In 26 patients (41%), the doses were above recommendations and were not different between life-threatening and non-life-threatening cases.
• A life-threatening outcome was independently linked with the usage context (general and orthopedic surgery, p = 0.006) and the kind of LA agent (lidocaine, p = 0.016).

Thus, according to the comparatively small number of instances reported over more than 30 years at a national level, LAST in children appears to be a rare occurrence. Most of them occur in less than an hour after administration. Hence early management requiring special care is essential.

Further reading: Schweitzer-Chaput, A., Callot, D., Bouazza, N. et al. Local anesthetics systemic toxicity in children: analysis of the French pharmacovigilance database. BMC Pediatr 23, 321 (2023).https://doi.org/10.1186/s12887-023-04126-7