General anesthesia affecting on developing brain: evidence from animal to clinical research.

As the recent update of General anaesthesia compared to spinal anaesthesia (GAS) studies has been published in 2019, together with other clinical evidence, the human studies provided an overwhelming mixed evidence of an association between anaesthesia exposure in early childhood and later neurodevelopment changes in children. Pre-clinical studies in animals provided strong evidence on how anaesthetic and sedative agents (ASAs) causing neurotoxicity in developing brain and deficits in long-term cognitive functions. However pre-clinical results cannot translate to clinical practice directly. Three well designed large population-based human studies strongly indicated that a single brief exposure to general anesthesia (GAs) is not associated with any long-term neurodevelopment deficits in children's brain. Multiple exposure might cause decrease in processing speed and motor skills of children. However, the association between GAs and neurodevelopment in children is still inconclusive. More clinical studies with larger scale observations, randomized trials with longer duration exposure of GAs and follow-ups, more sensitive outcome measurements, and strict confounder controls are needed in the future to provide more conclusive and informative data. New research area has been developed to contribute in finding solutions for clinical practice as attenuating the neurotoxic effect of ASAs. Xenon and Dexmedetomidine are already used in clinical setting as neuroprotection and anaesthetic sparing-effect, but more research is still needed.