Recent studies are showing interest in how the brain responds to anesthesia, and by extension, sedation therapy for medical procedures. As a board certified Sedation Dentist, I often put patients under for more complicated and often painful procedures, such as full mouth extractions and reconstruction, extensive gum lifts, and restorative procedures. The reason for this, much like general anesthesia, is that many medical procedures are simply too long and/or painful to be endured by a conscious patient — both for their comfort and our mutual safety. Stress from pain can lead to shock and that can lead to complications such as adrenal overload and heart failure. It also helps the doctor and his staff from being injured or injuring a thrashing or difficult patient. All of these scenarios are something nobody, patient nor doctor, wants.
Until recently, there has been very little research on what happens to our brains when sedation and anesthesia wear off. Of course, as many of you know, anesthesia and sedation derail the brain’s pain and consciousness processing — allowing the patient to painlessly endure surgery with little to no memory of the procedure.
Our bodies are incredible machines, and very little short of traumatic, permanent injury or death can truly change how it functions. When a patient returns to consciousness, they retain all of their faculties and all functions return to normal as soon as the body is done processing the sedative or anesthesia. As it turns out, according to this article from Science Daily, that much like computers, our brains ‘reboot’ when we come out of anesthesia. It is not a straightforward process — there are various points where our brains stop to check function and then proceed to the next point.
When we are awake, our brains function on different wavelengths, and when we are unconscious, these wavelengths often slow down. When regaining consciousness, our brains go through the steps mentioned above to recover full awareness, and the electrical impulses that transmit between our neurons and synapses (brain pathways) must go through a series of ‘hubs’ before recovery is achieved. So, again, the analogy to a computer rebooting or booting up is apt. When a computer starts up, it goes through several posts before the operating system starts up and becomes accessible to the user. Likewise, our brains have a pathway to recovering consciousness that likely involves the mind going through various checkpoints to ensure everything is in working order before consciousness is regained.
In theory, we may not have our higher faculties when we initially come out of anesthesia, thus causing us to be unable to communicate, interact, or interact in ways that are far more primal than would be normally expected. However, the brain disallows this — likely as an ancient survival mechanism — and it may be that those in unconscious states such as deep comas or may have had a traumatic injury may be stuck in this process because one of the pathways to consciousness is irrevocably damaged or altered.
Anesthesia and sedation do take some time to shake off, even after a patient regains consciousness. This is why doctors and dentists always advise hiring a cab or having a friend or loved one take you home after a surgery that requires you to “go under”. The new research offers interesting insights into how our brains function in the face of unconsciousness and the recovery thereof. In time, this may give us better knowledge and lead to better understandings of the distinctions between consciousness and unconsciousness, as well as provide better treatments for pain management and recovery from comas and unconsciousness caused by traumatic injury.
While it is still early on in the research and we have just identified these hubs and networks, it does present an interesting case study on what consciousness is exactly, where it begins, and where it ends. It will also help us better understand how the mind and body regain consciousness after anesthesia or sedation.