Developmental anesthetic neurotoxicity: from animals to humans?

Several animal studies have demonstrated that most routinely used general anesthetics induce widespread neuroapoptosis and long-term neurocognitive impairment in the immature brain. These findings have generated great interest among pediatric anesthesiologists and other practitioners regarding the safe use of general anesthetics in pediatric patients. Several human retrospective studies failed to confirm whether or not anesthesia exposure during the crucial phase of brain development induces long-term neurocognitive deficits in humans. Since the clinical relevance of the results of general anesthesia in animal experiments is unknown, it is unreasonable to directly utilize the results derived from animals and retrospective human surveys to guide clinical practice at the present time. Clearly, additional prospective randomized controlled trials are needed in humans to determine the effects of general anesthesia on neurodevelopment. In this review, we summarize currently available laboratory and clinical evidence for anesthetic neurotoxicity. Furthermore, we discuss the implications of these results for clinical anesthesia.