Neurotoxicity of Anesthetic Drugs on Developing Brain
We read with interest the recent review article by Bosnjak et al1 addressing the neurotoxicity of propofol leading to neuronal death followed by long-term memory and learning abnormalities. Over the past few years, several studies focusing on anesthetic neurotoxicity in children have been performed, all for a good reason. However, anesthesiologists should exert diligence when translating animal and basic science research to humans. Along with drug doses and responsiveness as well as evolutionary biology, there are differences in translational medicine that make it challenging to draw conclusions in clinical practice. Translational studies, especially involving stem cells, still lack strong clinical correlation. In addition, the majority of the observational studies on anesthetic neurotoxicity do not fully account for confounding factors, like fluctuations in blood pressure, acid base imbalance, hypoxia and hypercarbia, labor and delivery issues, and neonatal health and management to name a few. As a result, it is too early to make clinical decisions based on current information.
It is imperative to note that learning disability and memory loss are multifactorial. They can only be tested years after the window of vulnerability to neurotoxic effects of anesthetic has closed and may not be directly related to anesthesia received during infancy. These deficits may be linked to child’s environment, educational opportunities, and social support.
We applaud the hard work that has gone into high-quality observational studies. Although many exciting trials are still ongoing, there is need for more evidence. At the same time, a few articles2,3 have addressed the wider issue of what we are trying to achieve with anesthesia.
Anesthesiologists and physicians alike should maintain a balanced perspective on the translational studies.