Anesthetic is one of the world’s most widely used drugs — doctors now have a clearer understanding of how it works.
The fact that I not only don’t recall the cuts that removed it, but also anything about the procedure, even before they officially knocked me out, is one of the remarkable things about anesthetic. “The long standing theory of anesthesia was that it put the body to sleep, it’s what the anesthetist tells you and it’s quite a comforting thought, but it’s not quite true; after all we can be easily wakened from sleep.” We therefore knew other things must be happening as well.
The common anesthetic propofol actually affects t he movement of a protein in the brain. This protein is part of the process your brain cells (neurons) use to talk to each other. If it’s gone, so too is their ability to communicate.
“Our brain has 100 billion neurons and a trillion points of chemical communication and the likelihood is that many of these are impaired by general anesthetic causing the brain to lose what’s called synaptic co-ordination across these billions of different points. “This not only causes you to lose consciousness, but also lose behavioral responses, the sensation of pain and the ability to form memories, triggering the type of short-term memory-loss that you experienced.
Since then, other studies have shown similar responses involving anesthetic drugs and other brain chemicals.
“Effectively the brain becomes detached from the body during anesthetic.” It’s actually a bit more like a coma than a sleep.
The fact that we only found this mechanism six years ago is even more fascinating considering the first operation with anesthetic was carried out by Japanese surgeon, Seishu Hakakoa in 1804. He used a mix of sedating herbs that had taken over 20 years to perfect. He called it Mafutsusan, which in Japanese translates ‘to make go away.’
Today we make things go away via two different forms of anesthetic injectables like propofol and inhaled ones like the drug sevoflurane. Usually both are used during surgery. Being able to determine the correct levels and cocktail of drugs to ensure you feel no pain, but are exposed to the lowest level of anesthetic possible, is a skill that take years to learn.
This is because we don’t all respond to anesthetic in the same way; “Redheads, for example, need a higher dose of anesthetic to be effective but older people generally need less than younger ones.” If someone is unfortunate enough to already be on a lot of painkillers, they need a little more, as do people who drink more alcohol.” Studies also suggest that smokers might need more than non-smokers.
At this point though we have to discuss the elephant in the room — the fact that up to 0.2 percent of people undergoing anesthetic don’t go completely under and instead become aware of what’s happening during surgery.
One potential reason for this; the brains of these people differ in structure from the rest of the population — they have more grey matter (a type of tissue) at the front of the brain and very strong neural connections which might need higher doses of anesthetic to switch them off.
Talking of switching off — it might also surprise you to know that “there’s no reversal agent to an anesthetic.” We just wait for it to work its way out of the brain and the results to wear off.
At this point, some of us bounce back better than others. I, as the nurses on the ward will attest, vomit — profusely. This is a common side effect, particularly in women, those who suffer from motion sickness and non-smokers. Other post-operative reactions to anesthesia can include low blood pressure, emotional reactions like crying, reduced reflexes and foggy thinking. Most of these disappear within hours, but you’re not completely back to normal for 24 hours — which is why you’re told not to drive or make important decisions shortly after your surgery.
“We think how each individual reacts is genetic. Not that it’s inherited from your parents, but that your genomics determine how you react to everything about the surgery.”
“Some people are hyper-inflamers which increase their responses, while others under-react and don’t mount a sufficient healing response which also makes them more susceptible to post-surgical complications like infection.”
This inflammatory reaction is now also thought to be behind one of the most potentially debilitating after effects of surgery — post-surgical delirium — which can have long-term effects on cognition, particularly in the elderly. This was previously blamed on anesthesia, but researchers suspect that it’s actually triggered by the brain’s reaction to the trauma of surgery.
This discovery is just one that shows we still have a lot to learn a bout anesthetic, and the more we do, the better the drugs will become — but right now, we do not know one thing for certain. “Prior to its development there was no way of preventing the unimaginable suffering and pain that people would have to go through if they needed surgery.”
“Now we can go into hospital, have an operation that can be quite invasive and be assured that we won’t feel a thing.” “I guess, I’m biased, but I think it’s a modern miracle.”
HOW TO PREPARE FOR A GENERAL ANESTHETIC:
“If you’ve had past anesthetic and recovered well that’s a pretty good sign you’ll do OK this time, too.” But if you’re coming up for a bigger operation, or you’re older than you were when you last had surgery, start preparing as if you were going to run a marathon.”
- Get your body in shape — during the six weeks before surgery.
- Quit smoking: if you can, cut back on alcohol, eat a good diet and start some mind of daily exercise.
- The more muscle mass: you have, the stronger your heart and lungs are and the better your circulation is, the better you’ll handle both anesthesia and surgery.
- If you’ve had nausea and vomiting: In the past, make sure the medical team know this so they can give you medication to reduce it.
- The liver: is the organ responsible for clearing anesthetic from our system.. To help it focus on this job, it’s also suggested that you avoid alcohol and high-fat meals for a day or two after anesthetic.
- Anesthesia and painkillers: used during some surgeries can also lead to constipation after surgery. Chewing gum can help with this — but check with your doctors that it’s right for you.
