By DR Jeremy Beckett
This is a very controversial topic at the moment, and unfortunately leaves us with more questions than answers. Let’s start with a facetious multiple choice question to highlight the point:
Question: Does having an anaesthetic damage your brain?
I’m going to answer (G) — all of the above! As you can see, there is a lot of grey in this subject.
Post-operative cognitive dysfunction (POCD)
We have known about POCD for some years. It is described as “a mild but possibly long-lasting fogginess” following an anaesthetic. This may include short term memory impairment and difficulty concentrating. Up to half of patients (young and old) display some evidence of this in the first week after a procedure and perform worse on intellectual testing. Most of them get better, but three months after the procedure as many as 10-15% of people will still exhibit some of this fogginess. The worry is that even a year after the procedure a small percentage of patients will still not have fully recovered their intellectual functioning, and a small number of elderly people seem to develop a condition resembling Alzheimer’s Disease.
No one has been able to identify exactly what causes this problem, nor how it can be prevented. It seems to be the elderly and the very young (under 4 years of age) who are most sensitive. We know that the problem is more prominent after open heart surgery (or coronary artery bypass surgery), but it’s not clear why that is, nor which other procedures are worse than others.
Problems in children?
The new concern relates to some evidence suggesting that children who undergo general anaesthetic before the age of four are more likely to suffer learning and behavioural difficulties. This is a worrying finding, and obviously needs a lot more research!
What can be done?
It’s very hard to deal with a problem that we know so little about. The research is continuing and hopefully we will learn more in the coming years. We need to keep a balanced view.
In the meantime, someone who needs an anaesthetic procedure (like a child with acute appendicitis) is still better to have the procedure, which is potentially life-saving, than worrying about the possibility of POCD. However, we should probably try to avoid anaesthetic procedures that are less urgent or may not be clinically necessary (including cosmetic procedures, wart removals, ingrown toenail surgery or minor dental work).
Dr Jeremy Beckett works in regional Western Australia in general practice, emergency medicine and anaesthetics.