Medicine’s biggest mystery: How do general anaesthetics work?

Despite being one of the most common medical procedures used all over the world for the past 180 years, we have not been able to really understand how general anaesthetic works… until now. Australian researchers believe they now understand a lot more about the impacts of general anaesthetics on the body.

What are general anaesthetics?

General anaesthetics are used to send people to sleep so that they are unaware of surgery and unable to feel pain. It is typically used for long or very painful operations.

How do they work?

Until recently, scientists did not fully understand how general anaesthetics worked. They knew that they disturb the passage of signals along the nerves so that we don’t process or recognise any stimulation to the body. Doctors had little knowledge as to what that disturbance actually was.

New research

Researchers at the University of Queensland, Australia, have have discovered exactly what propofol does to our bodies, besides inducing sleep. Propofol is the most commonly used general anaesthetic. Professor Bruno van Swinderen and his team carried out research into how propofol affects synaptic release. Synaptic release is the way in which nerve cells communicate with each other. This is how they made their discovery.

Scientists understand that the propofol restricts the movement of an important protein which leads to decreased communication between neurons in the brain.  It is believed that this widespread disruption to the brain’s communication pathways is what makes surgery possible.

This discovery is groundbreaking in understanding the impacts of general anaesthetic. The findings also help to understand human behaviour when patients come round from an operation. Many people experience grogginess and disorientation after being put to sleep. We now know that this is because the majority of brain activity has been shut down by the drug.

What does this mean for the future?

This discovery will help doctors to understand why more vulnerable patients are at risk when undergoing operations. Older patients or patients suffering from Alzheimer’s or Parkinson’s have been known to come round from operations with permanent cognitive impairment. We now know this is because of the serious disturbance that propofol causes in our brains. This explains why such patients take longer to recover from being put to sleep.

This new research could help improve recovery rates as scientists may be able to create drugs that accelerate recovery. Professor van Swinderen’s work is likely to spark a further interest into exactly how anaesthetics work and different drugs for use in operations.