Current thinking regarding potential neurotoxicity of general anesthesia in infants

Purpose of review: Numerous preclinical studies have shown that general anesthetics adversely influence the development of young brains. These adverse effects are dose-dependent occurring in specific stages of brain development. Histologic examinations show increased apoptosis, pathological neurogenesis and dendritic formation after exposure in infant animals to virtually all general anesthetics at a clinically effective dose which are associated with memory and behavioral changes at adulthood. Recent findings: Clinical research into the long-term effects of anesthesia during early childhood on brain development is mainly limited to retrospective cohort studies, with conflicting results. Only recently, the interim analysis of a prospective randomized clinical trial examining the effects of general anesthesia has been published. In this GAS-study the influence up to 1h of general anesthesia versus regional anesthesia in young infants has been assessed on the neurocognitive functioning at the age of 2 years. No differences were found between the two groups. However, the primary outcome analysis which is the 5-year outcomes will not be complete until 2018. Summary: Pending clear evidence, anesthesiologists should discuss the indication of anesthesia for surgery and diagnostic procedures with caregivers and parents taking into consideration the risks and benefits of the planned procedure.