April 2024 If you have ever had general anesthesia, the type that, “puts you to sleep”, you most likely received various types of inhaled gases to accomplish this state of unconsciousness. The inhaled anesthetic, isoflurane, is commonly used to cause loss of consciousness before and during surgery.  Anesthetics that affect targeted receptors in the brain can have post-anesthesia side effects. Delirium and memory loss are common short-term complications of general anesthesia, and some evidence suggests that longer-term memory loss may occur in some people.

This is a major clinical interest as many elderly patients experience post-operative cognitive dysfunction (POCD). In Dr. Maroon’s latest article, entitled, Impact of Isoflurane on Glutathione: Oxidative Stress Mapping Platform from Longitudinal MR Spectroscopic Study, lead researcher, Dr. Pravat Mandal, uses a unique method to monitor the effects of the anesthesia gas isoflurane on the brain antioxidant glutathione.

What they found was that glutathione was depleted due to oxidation in the presence of isoflurane compared to control levels not exposed to isoflurane, by using a specialized MRI scanner. This novel platform provides a method for non-invasively monitoring of glutathione levels in the brain of patients before and after undergoing surgery using inhaled anesthetics. Such observations will contribute to the understanding of the memory impairment that sometimes can be profound and long lasting following general anesthesia.

Why is this Important?

Glutathione is a master antioxidant produced in the human cell cytoplasm and is the most abundant antioxidant produced. Because the brain consumes a large amount of oxygen this leads to a high production of reactive oxygen species, 0r free radicals. The antioxidative capacity of glutathione is important to keep brain homeostasis and counter the free radial’s destructive effects.

A possible explanation for the cognitive and memory dysfunction that occasionally occurs after general anesthesia may be due to depletion this important antioxidant in the brain.  More work is needed to determine is this is the pathway that can lead to this condition, but proving a unique method, by using MRI spectroscopic scanner, to quantitate the change in glutathione is an important step.

See Video Interview – Dr Maroon discusses the the Importance of Glutathione in the Brain