Department of Anesthesiology

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Are anaesthetics toxic to the brain?

TitleAre anaesthetics toxic to the brain?
Publication TypeJournal Article
Year of Publication2011
AuthorsHudson AE, Hemmings HC
JournalBr J Anaesth
Volume107
Issue1
Pagination30-7
Date Published2011 Jul
ISSN1471-6771
KeywordsAged, Anesthetics, General, Animals, Brain, Cognition Disorders, Disease Models, Animal, Humans, Postoperative Complications
Abstract

It has been assumed that anaesthetics have minimal or no persistent effects after emergence from anaesthesia. However, general anaesthetics act on multiple ion channels, receptors, and cell signalling systems in the central nervous system to produce anaesthesia, so it should come as no surprise that they also have non-anaesthetic actions that range from beneficial to detrimental. Accumulating evidence is forcing the anaesthesia community to question the safety of general anaesthesia at the extremes of age. Preclinical data suggest that inhaled anaesthetics can have profound and long-lasting effects during key neurodevelopmental periods in neonatal animals by increasing neuronal cell death (apoptosis) and reducing neurogenesis. Clinical data remain conflicting on the significance of these laboratory data to the paediatric population. At the opposite extreme in age, elderly patients are recognized to be at an increased risk of postoperative cognitive dysfunction (POCD) with a well-recognized decline in cognitive function after surgery. The underlying mechanisms and the contribution of anaesthesia in particular to POCD remain unclear. Laboratory models suggest anaesthetic interactions with neurodegenerative mechanisms, such as those linked to the onset and progression of Alzheimer's disease, but their clinical relevance remains inconclusive. Prospective randomized clinical trials are underway to address the clinical significance of these findings, but there are major challenges in designing, executing, and interpreting such trials. It is unlikely that definitive clinical studies absolving general anaesthetics of neurotoxicity will become available in the near future, requiring clinicians to use careful judgement when using these profound neurodepressants in vulnerable patients.

DOI10.1093/bja/aer122
Alternate JournalBr J Anaesth
PubMed ID21616941
PubMed Central IDPMC3159425
Grant ListR01 NS056315 / NS / NINDS NIH HHS / United States