During general anesthesia, a surgical patient needs to be given a combination of drugs that ensures four basic things: 1) immobility 2) muscle relaxation 3) hypnosis, and 4) amnesia. The first two are the chief concerns of the surgeon, but the most pressing one for the patient is the last one. I get asked by patients about it almost every day. "I'm not gonna remember, am I?" My answer is always the same - not if I can help it.
I have been an anesthesiologist for a decade now, and I have yet to have an incident of intraoperative awareness that I know of. However, it is a well documented phenomenon, and one that is a big problem for people who have experienced it. I have interviewed a few patients who remembered being awake during surgery, and though a few were nonchalant about it, most were absolutely horrified by the experience, and for good reason. Imagine it - you're having surgery, you can't move, and you are (supposedly) unconscious. Yet you remember incidents during your operation, including being cut open, or people talking about you. Worse yet, you feel pain but can't do anything about it. Just thinking about it is nauseating, and I wouldn't wish it on my worst enemy.
There are a few things I want to discuss regarding this phenomenon. First, how often does it happen? Second, when does it happen? Third, how (in the world?!?!) could any anesthesiologist let it happen?
Incidence:
There have been numerous studies documenting how often recall under general anesthesia occurs, and they vary. Some cite an incidence of up to 0.9% - almost 1 in a hundred. That's a lot. There was a more recent study from the University of Illinois at Chicago that looked at almost 180,000 patients over a three year period that had undergone general anesthesia. They found an incidence of recall of about 0.006%, or 1 in about 14,500. That's not a lot - but try telling that to the one person out of that 14,500 who was awake during surgery. I'm more inclined to believe the more recent study, as anesthetic techniques have changed over the years and we have a wide range of drugs at our disposal to ensure amnesia.
When (and how) it happens:
Type of surgery
Not all general anesthetics are the same from the standpoint of recall. There are some cases where the risk of being aware during anesthesia is significantly higher than in others:
1. Cardiac surgery - A lot of the first documented widespread episodes of intraoperative awareness were during open heart surgery. I don't remember the statistics, but it's more than the 0.9% cited in previous studies on all general anesthetics.
2. C-sections under general anesthesia. General anesthesia presents a unique dilemma during a c-section. Of course, the woman in such a situation needs to be asleep to get her baby out. The problem is afterwards; the gases used in general anesthesia tend to relax the uterus. This may be a good thing when the obstetricians are trying to remove the baby, but afterwards, those relaxing properties prevent the uterus from contracting, and this can increase the risk of bleeding. So the anesthesiologist is limited in how much anesthetic gas they can use.
3. Trauma surgery - The problem here is the condition trauma patients are in when they arrive to the OR. They are unstable, with low blood pressures. Most of the anesthetic drugs we give tend to lower the blood pressure, so if a patient comes in with a blood pressure of 60 over 40, for example, the last thing we should do is make it even lower with anesthetic drugs.
4. Emergency surgery, of any kind. The same logic applies here as in trauma surgery. A person having emergent surgery is unstable and tolerates even a small amount of anesthesia very poorly.
Type of patient
Not everyone is at the same risk for remembering stuff during anesthesia. If you fit into one of these categories, be aware that your risk is greater:
1. Users of alcohol and drugs. This makes total sense, doesn't it? If someone drinks a lot of alcohol or uses drugs of any kind, they have a greater tolerance to anesthesia. This doesn't just apply to street drugs like heroin or cocaine. It applies to prescription pain meds (like Vicodin or Oxycontin) and prescription sedatives/anti-anxiety drugs (like Valium or Xanax). People who use these drugs are just a little different from the rest of us. For one, their livers are turbocharged and spit out anesthetic drugs quickly. For another, their brain cells have fewer receptors for anesthesia drugs, so it takes more drug to affect those brain cells.
2. People on antidepressants. See above. These drugs tend to make the liver metabolize drugs faster.
3. People who have had similar episodes before. Another intuitive one. If, for some reason a patient was aware during anesthesia even though everything sounded OK medically, there's probably something going on with that patient. We don't know exactly how these anesthetic gases work; as such, it's hard to predict how or why some people just aren't as affected by them as others.
4. People who have been told that they might be aware during anesthesia. No one is sure why that is; I suppose you could look at it as a self-fulfilling prophecy kind of thing.
5. Redheads. What?!?!? Seriously? It has always been a unwritten rule, especially among the older anesthesiologists, that redheads need more anesthesia for reasons no one knows. I always dismissed these old geezers as a bunch of idiots, but a study came out in one of our major journals in the last few years, and it backed it up. Granted, the study was very small, but it did show that redheads needed significantly more inhaled anesthetic gas (up to 20% more!) to maintain the same level of anesthesia as non-redheads. Believe what you may, I guess. I'm just putting it out there...
Sunday, September 18, 2011
Saturday, September 17, 2011
The White Stuff: An informal look at propofol
In 2009 Michael Jackson passed away under tragic and unfortunate circumstances. The reason? It was an overdose of the anesthetic drug propofol. For over 20 years, propofol has been one of the most commonly used anesthetic drugs on earth, and if you had surgery during that time, it was more than likely used to put you to sleep. But until that June day two years ago, nobody outside of medicine had ever heard of it, and pundits were all over the TV in the days following Michael Jackson's death, speculating on how it might have killed him. That is a story for another blog entry. What I do want to do, however, is give a little insight into this mysterious drug, which even now I am asked about at least once a week. It is important because like I said, it is the single most common induction drug used today in anesthesia, and a little information goes a long way in reassuring anyone about to undergo anesthesia.
First of all, what is propofol? It is different from all of the other sedative drugs used in anesthesia today. It is not a benzodiazepine, like the more familiar drugs Valium or Klonopin. Nor is it a barbiturate, like sodium thiopental (Pentothal). Both of these drugs have known mechanisms of action; they make certain inhibitory substances in the nervous system more potent. Propofol is in its own unique class of drugs; it is what is known as a "hindered phenol".
No, I don't really know what that means either. Nor are people in general completely sure of how propofol works. It is thought that like other sedatives, it potentiates the action of certain inhibitory substances, or neurotransmitters, in the central nervous system.
Enough about that. Propofol is a relatively new drug, having just come along in the last twenty-five years or so. Unlike most other drugs, which are mixed in saline or water, propofol is mixed in a lipid emulsion, with a substance, lecithin, that is similar to egg whites. As such, propofol has a unique place in the pantheon of drugs because of its snow-white color. It is often offhandedly referred to by non-anesthesiologist medical personnel as "milk of amnesia," a moniker I find annoying, albeit understandable. Propofol does a few things that make it so valuable and useful for anesthesiologists:
It acts for a short time and is metabolized quickly. Propofol is given in a large dose in the beginning of an anesthetic to put patients to sleep, and it causes almost immediate unconsciousness. Within five to ten minutes, though, that large dose has completely worn off and the patient will awaken unless they are given more anesthetic.
It can cause that unconsciousness, yet can wear off quickly without lingering side effects.In fact, propofol, when used for sedation (or misused, like MIchael Jackson's physician did), needs to be given through a pump, continuously. Shortly after the propofol stops, the patient wakes up and has little if any of the "hangover" feeling that characterized many sedative drugs before it. That is a great, and very useful quality to have in a drug.
Propofol, however, has a couple of properties that can make it extremely dangerous if not used correctly. First, it can cause blood pressure to drop significantly, especially in someone who is dehydrated - like a patient having surgery, who has been instructed not to eat or drink for at least 8 hours before their procedure. If that drop in blood pressure isn't treated in some way and is allowed to continue for any period of time, it can cause significant damage to vital organs. Elderly people are especially susceptible to this.
But the most significant - and now, the most notorious - property of propofol is that it decreases breathing, and can cause it to stop completely if given in large enough doses. If that sounds alarming, it can be. Propofol is a very safe drug in the hands of anesthesia providers who are trained in how to manage the airway and breathe for the patient who cannot do so on their own. But for someone not trained in airway management, propofol can be an extremely dangerous drug indeed. Almost all medical personnel are trained in basic or advanced life support, which does involve learning how to maintain an airway in a patient who is not breathing, but very few are trained with advanced airway management skills that are critical to know when such drugs as propofol are being given.
Doctors from specialties outside anesthesiology, like GI doctors and cardiologists, use mild sedation for a lot of their procedures, and have recently petitioned for the privilege of using propofol. All have been turned down by the governing society of anesthesia, the American Society of Anesthesiologists. They are certainly capable doctors in their area of expertise; they just don't necessarily have the skills in resuscitation and airway management to help a patient who stops breathing from an accidental overdose of propofol. That's not their fault; their training focuses on their particular area of expertise. Anesthesiologists do resuscitation and airway management for a living.
Again, it bears repeating that of the millions of surgeries performed in the United States each year under general anesthesia, propofol is used to put patients to sleep in, oh, 99.9% of them. Propofol is used, safely, in almost all of those as well, because it is given by an anesthesia provider who is vigilantly watching the patient with the help of multiple monitors, and has been trained for years in its proper use.
First of all, what is propofol? It is different from all of the other sedative drugs used in anesthesia today. It is not a benzodiazepine, like the more familiar drugs Valium or Klonopin. Nor is it a barbiturate, like sodium thiopental (Pentothal). Both of these drugs have known mechanisms of action; they make certain inhibitory substances in the nervous system more potent. Propofol is in its own unique class of drugs; it is what is known as a "hindered phenol".
No, I don't really know what that means either. Nor are people in general completely sure of how propofol works. It is thought that like other sedatives, it potentiates the action of certain inhibitory substances, or neurotransmitters, in the central nervous system.
Enough about that. Propofol is a relatively new drug, having just come along in the last twenty-five years or so. Unlike most other drugs, which are mixed in saline or water, propofol is mixed in a lipid emulsion, with a substance, lecithin, that is similar to egg whites. As such, propofol has a unique place in the pantheon of drugs because of its snow-white color. It is often offhandedly referred to by non-anesthesiologist medical personnel as "milk of amnesia," a moniker I find annoying, albeit understandable. Propofol does a few things that make it so valuable and useful for anesthesiologists:
It acts for a short time and is metabolized quickly. Propofol is given in a large dose in the beginning of an anesthetic to put patients to sleep, and it causes almost immediate unconsciousness. Within five to ten minutes, though, that large dose has completely worn off and the patient will awaken unless they are given more anesthetic.
It can cause that unconsciousness, yet can wear off quickly without lingering side effects.In fact, propofol, when used for sedation (or misused, like MIchael Jackson's physician did), needs to be given through a pump, continuously. Shortly after the propofol stops, the patient wakes up and has little if any of the "hangover" feeling that characterized many sedative drugs before it. That is a great, and very useful quality to have in a drug.
Propofol, however, has a couple of properties that can make it extremely dangerous if not used correctly. First, it can cause blood pressure to drop significantly, especially in someone who is dehydrated - like a patient having surgery, who has been instructed not to eat or drink for at least 8 hours before their procedure. If that drop in blood pressure isn't treated in some way and is allowed to continue for any period of time, it can cause significant damage to vital organs. Elderly people are especially susceptible to this.
But the most significant - and now, the most notorious - property of propofol is that it decreases breathing, and can cause it to stop completely if given in large enough doses. If that sounds alarming, it can be. Propofol is a very safe drug in the hands of anesthesia providers who are trained in how to manage the airway and breathe for the patient who cannot do so on their own. But for someone not trained in airway management, propofol can be an extremely dangerous drug indeed. Almost all medical personnel are trained in basic or advanced life support, which does involve learning how to maintain an airway in a patient who is not breathing, but very few are trained with advanced airway management skills that are critical to know when such drugs as propofol are being given.
Doctors from specialties outside anesthesiology, like GI doctors and cardiologists, use mild sedation for a lot of their procedures, and have recently petitioned for the privilege of using propofol. All have been turned down by the governing society of anesthesia, the American Society of Anesthesiologists. They are certainly capable doctors in their area of expertise; they just don't necessarily have the skills in resuscitation and airway management to help a patient who stops breathing from an accidental overdose of propofol. That's not their fault; their training focuses on their particular area of expertise. Anesthesiologists do resuscitation and airway management for a living.
Again, it bears repeating that of the millions of surgeries performed in the United States each year under general anesthesia, propofol is used to put patients to sleep in, oh, 99.9% of them. Propofol is used, safely, in almost all of those as well, because it is given by an anesthesia provider who is vigilantly watching the patient with the help of multiple monitors, and has been trained for years in its proper use.
Thursday, September 15, 2011
To-do list: the responsibilities of the anesthesiologist
This is the first part of unraveling the mystery of what exactly we anesthesiologists are doing while our patients are asleep. Everyone who has had general anesthesia knows the experience. You go into the room and you may vaguely recall seeing the inside of the OR, getting onto the OR table and lying down, and then...you're done. What happens in between? The answer to that question is more complex than meets the eye. Some of our tasks are obvious; some are less so. Either way, a lot of things that happen in an awake person without them even thinking about it don't happen at all under anesthesia. That is where the anesthesiologist takes over. Literally.
ABC. This is the most obvious and yet far-reaching task of the anesthesiologist, and it stands for Airway-Breathing-Circulation. In an awake person, the airway is maintained by muscle tone in the mouth and throat, muscle tone which decreases dramatically under anesthesia. Airway refers to giving the patient a means by which to exchange oxygen with the outside world. That can be a lot of things; usually it is a breathing tube placed in the mouth and windpipe, called, unsurprisingly, an endotracheal tube. There are several other airway devices placed in the mouth that can also be used for this purpose, or even a mask hooked up to tubing and an anesthesia machine will do. Of the members of the anesthesiologist's mighty triumvirate of ABC, A (airway) is king. Without it, nothing else matters.
Breathing. Duh. Of course we need to breathe, right? Yes , and we do so just fine while awake; the problem is that general anesthesia, and most sedatives for that matter, decrease the body's desire to breathe, and some drugs stop breathing completely. In my first post on this blog, I mentioned that each general anesthetic literally involves giving enough drugs to kill a person. It put off a few people who read it, but I'll explain myself here. Any drug that slows down breathing can be extremely dangerous, because it requires vigilance to administer it. If you were to give someone drugs to slow or stop their breathing and then just walk away, you'd kill them. But that's not the case at all in anesthesia. A trained anesthesia professional is sitting right there, using a mask to help the patient breathe, or more commonly, hooking their breathing tube up to an anesthesia machine that breathes for them.
Circulation. Almost all of the drugs used in general anesthesia also decrease the blood pressure, some more than others, but the important thing is that the anesthesiologist maintains the blood pressure. It has to be high enough that vital organs like the brain, heart, kidneys, etc. get enough blood to function well, but low enough that the patient doesn't bleed too much or suffer a stroke. This all has to be done against the backdrop of some interloper (oh, those surgeons!) performing painful and intentional trauma on the body, which understandably causes a great deal of stress on the body and a strong adrenaline rush. That's why we give anesthesia in the first place. It is a balancing act often determined by many things, including the patient's health and the kind of surgery being performed. Ultimately, circulation, namely blood pressure, tells us how we're doing. Too much anesthesia and the patient's blood pressure is dangerously low. Too little, and it's high. And the patient moves. And...the patient remembers. Which leads me to my next point...
Make sure the patient doesn't remember. This seems obvious, right? But in older times, it was not unheard of to use the anesthetic technique of giving only a small amount of anesthesia combined with a muscle relaxant to keep the patient from moving. So the patients were immobile for the surgery, but if the anesthetist underestimated how much drug to give by even a little, well, that's where the nightmare stories on news shows came about, with patients hearing their surgeons talking during their operation or feeling pain but unable to tell anyone. Part of any general anesthetic is to ensure complete amnesia of everything that happens during the surgery.
Make sure the patient doesn't move. This is another painfully obvious job here, but it bears repeating. it is unreasonable to ask any surgeon to have to hit a moving target with their scalpels or sutures.
Protect the nerves. What do I mean here? When you're asleep, you're immobile, of course, during the duration of the surgery. Though it's necessary for the surgeons, it is not normal in real life, and that presents its own set of problems. When you you go to bed at night, you don't stay in the same position. You start on your back, switch to one side, maybe switch again to the other side, even go to your stomach. You have to, or you'll get numb from lying in the same position for hours. That's where the anesthesia problem lies. There are certain parts on the body where nerves are very superficial to the skin, and those parts are especially susceptible to being injured when placed in the same position for too long.
First among these is that spot on the inside of your elbow, the funny bone, known in medical terms as the ulnar groove. If that is pressed on too vigorously while the patient is lying still for their surgery, it can cause injury to the 4th and 5th fingers on that hand - numbness, tingling, and even permanent weakness. It's the anesthesiolgist's job to make sure that doesn't happen. Vulnerable spots like the funny bone are padded heavily while under anesthesia, to ensure too much pressure isn't placed on them. Other key places to protect and pad during anesthesia are the back of the forearm (radial nerve) and the outside of the knee (peroneal nerve).
Protect the eyes. An awake person has many ways to protect their eyes. Cover them with their hand, maybe, or even just close the eyes tightly. If a small speck gets in the eye, it reflexively starts making tears to wash the offending thing out. Under anesthesia, all such defenses are gone, so the anesthesiologist must again take over. They will often put a mild lubricant in the eye, some sort of artificial tears, to make sure the eye stays moist. Then, the eyes are taped closed, to make sure they don't accidentally open and expose the eyeball. Some people even put plastic shields over the taped eyes, like a pair of wraparound sunglasses, to make sure the eyes aren't harmed. The eyes, so valuable and vulnerable, are
watched VERY carefully during surgery.
These are some of the high points. There are more, but you get the idea. The bottom line is that the patient, while under anesthesia, is as defenseless as a little baby, and regardless of what kind of operation is being done, needs to be protected in even basic ways. That is the task of your anesthesiologist.
ABC. This is the most obvious and yet far-reaching task of the anesthesiologist, and it stands for Airway-Breathing-Circulation. In an awake person, the airway is maintained by muscle tone in the mouth and throat, muscle tone which decreases dramatically under anesthesia. Airway refers to giving the patient a means by which to exchange oxygen with the outside world. That can be a lot of things; usually it is a breathing tube placed in the mouth and windpipe, called, unsurprisingly, an endotracheal tube. There are several other airway devices placed in the mouth that can also be used for this purpose, or even a mask hooked up to tubing and an anesthesia machine will do. Of the members of the anesthesiologist's mighty triumvirate of ABC, A (airway) is king. Without it, nothing else matters.
Breathing. Duh. Of course we need to breathe, right? Yes , and we do so just fine while awake; the problem is that general anesthesia, and most sedatives for that matter, decrease the body's desire to breathe, and some drugs stop breathing completely. In my first post on this blog, I mentioned that each general anesthetic literally involves giving enough drugs to kill a person. It put off a few people who read it, but I'll explain myself here. Any drug that slows down breathing can be extremely dangerous, because it requires vigilance to administer it. If you were to give someone drugs to slow or stop their breathing and then just walk away, you'd kill them. But that's not the case at all in anesthesia. A trained anesthesia professional is sitting right there, using a mask to help the patient breathe, or more commonly, hooking their breathing tube up to an anesthesia machine that breathes for them.
Circulation. Almost all of the drugs used in general anesthesia also decrease the blood pressure, some more than others, but the important thing is that the anesthesiologist maintains the blood pressure. It has to be high enough that vital organs like the brain, heart, kidneys, etc. get enough blood to function well, but low enough that the patient doesn't bleed too much or suffer a stroke. This all has to be done against the backdrop of some interloper (oh, those surgeons!) performing painful and intentional trauma on the body, which understandably causes a great deal of stress on the body and a strong adrenaline rush. That's why we give anesthesia in the first place. It is a balancing act often determined by many things, including the patient's health and the kind of surgery being performed. Ultimately, circulation, namely blood pressure, tells us how we're doing. Too much anesthesia and the patient's blood pressure is dangerously low. Too little, and it's high. And the patient moves. And...the patient remembers. Which leads me to my next point...
Make sure the patient doesn't remember. This seems obvious, right? But in older times, it was not unheard of to use the anesthetic technique of giving only a small amount of anesthesia combined with a muscle relaxant to keep the patient from moving. So the patients were immobile for the surgery, but if the anesthetist underestimated how much drug to give by even a little, well, that's where the nightmare stories on news shows came about, with patients hearing their surgeons talking during their operation or feeling pain but unable to tell anyone. Part of any general anesthetic is to ensure complete amnesia of everything that happens during the surgery.
Make sure the patient doesn't move. This is another painfully obvious job here, but it bears repeating. it is unreasonable to ask any surgeon to have to hit a moving target with their scalpels or sutures.
Protect the nerves. What do I mean here? When you're asleep, you're immobile, of course, during the duration of the surgery. Though it's necessary for the surgeons, it is not normal in real life, and that presents its own set of problems. When you you go to bed at night, you don't stay in the same position. You start on your back, switch to one side, maybe switch again to the other side, even go to your stomach. You have to, or you'll get numb from lying in the same position for hours. That's where the anesthesia problem lies. There are certain parts on the body where nerves are very superficial to the skin, and those parts are especially susceptible to being injured when placed in the same position for too long.
First among these is that spot on the inside of your elbow, the funny bone, known in medical terms as the ulnar groove. If that is pressed on too vigorously while the patient is lying still for their surgery, it can cause injury to the 4th and 5th fingers on that hand - numbness, tingling, and even permanent weakness. It's the anesthesiolgist's job to make sure that doesn't happen. Vulnerable spots like the funny bone are padded heavily while under anesthesia, to ensure too much pressure isn't placed on them. Other key places to protect and pad during anesthesia are the back of the forearm (radial nerve) and the outside of the knee (peroneal nerve).
Protect the eyes. An awake person has many ways to protect their eyes. Cover them with their hand, maybe, or even just close the eyes tightly. If a small speck gets in the eye, it reflexively starts making tears to wash the offending thing out. Under anesthesia, all such defenses are gone, so the anesthesiologist must again take over. They will often put a mild lubricant in the eye, some sort of artificial tears, to make sure the eye stays moist. Then, the eyes are taped closed, to make sure they don't accidentally open and expose the eyeball. Some people even put plastic shields over the taped eyes, like a pair of wraparound sunglasses, to make sure the eyes aren't harmed. The eyes, so valuable and vulnerable, are
watched VERY carefully during surgery.
These are some of the high points. There are more, but you get the idea. The bottom line is that the patient, while under anesthesia, is as defenseless as a little baby, and regardless of what kind of operation is being done, needs to be protected in even basic ways. That is the task of your anesthesiologist.
Tuesday, September 6, 2011
To sleep or not to sleep, Part II
So, just as promised, I want to go over the pros and cons of conscious sedation, so that if given the choice, you as a patient can make an informed decision about whether not to go completely to sleep for your surgery. First, I just want to more clearly define what I mean by "conscious sedation."
Conscious sedation refers to a level of anesthesia that is more than being completely awake, but less than being completely asleep. It is often referred to as "twilight" anesthesia, and the technical term for it is Monitored Anesthesia Care, called MAC for short. When patients receive MAC anesthesia, their consciousness is depressed somewhat. They have amnesia and are sedated enough that they may respond to very strong noxious stimuli but not much if at all to weaker stimuli. As opposed to a general anesthetic where the patient's breathing is significantly slowed down and their blood pressure can also decrease quite a bit, conscious sedation depresses these functions only mildly, if at all.
With that in mind, let's go over the good and bad of having conscious sedation.
The Good:
1. You're more awake during the surgery. In most cases, the amount of sedation you receive for such a case is enough that you don't remember anything, but not so much that you're totally out of it. Patients will sometimes remember hearing voices and the beeping sounds of monitors, but will note that they didn't really care about them and weren't worried or concerned about hearing them.
2. You wake up faster afterwards. The most common sedative administered during conscious sedation is propofol. Yes, that's the same drug that was misused by Michael Jackson, but in the hands of trained anesthesia professionals, it is a very safe drug. One of its best qualities is that it only lasts a few minutes, so during sedation it is given continuously into the IV via a small pump. When the surgery is done, the pump is discontinued, and the patient wakes up within a few minutes. There is little or none of the groggy feeling that so often accompanies general anesthesia.
3. Less nausea and vomiting. The stuff that really causes nausea is the combination of narcotics and the inhaled anesthetic gases that are used to maintain general anesthesia. With conscious sedation, there is no inhaled gas and significantly less narcotic being given.
4. Receiving less drugs = fewer side effects . General anesthesia is strong stuff. Even a "routine" general anesthetic involves the administration of some pretty potent medicines, ones that can drastically lower all bodily functions, including blood pressure, heart rate, neurologic function, even immune function. A general anesthetic is much more stressful on the body than conscious sedation.
The Bad:
1. You're more awake during the surgery. Again, the likelihood of remembering much at all during conscious sedation is quite small, but it's much more likely to happen than in general anesthesia. If you're the kind of person who wants to be totally knocked out and doesn't want to know anything, well, conscious sedation is not an optimal choice for you.
2. You may end up getting general anesthesia anyway. Everyone deals with conscious sedation differently. Some people do great with just a little bit of IV sedative and some local anesthetic in their incision. Others get uncomfortable - real uncomfortable. It's uncommon but possible that if you get too uncomfortable during your sedation, the anesthesiologist may have to put you to sleep anyway, defeating the whole purpose of having sedation.
3. Sedative-induced confessions. Yeah, this is a rare sort of thing, but there are some people, when given a small amount of sedative, start confessing like a sentimental college kid on graduation night. People know their tendencies. I know OR personnel I work with who have chosen to have their surgeries at outside hospitals just because they feared what they might say once they had a little sedation.
4. It can actually be more dangerous. This is especially true if you have issues with snoring or sleep apnea. When you are under general anesthesia, you have a breathing tube in your mouth that the anesthesiologist uses to help with your breathing. With conscious sedation, you have small plastic prongs in your nose that give oxygen, but that's about it. When people get sleepy, it is easier for the tissues in their mouth and throat to collapse, blocking the flow of oxygen into the lungs and causing blood oxygen levels to decrease dangerously. The vigilant anesthesia provider, of course, can deal with this accordingly, but even small lapses in vigilance can cause big, big problems. This leads me to the next point...
5. The quality of your conscious sedation experience is very anesthesiologist dependent. If you have an anesthesiologist or nurse anesthetist who is experienced with conscious sedation, and is working with a surgeon who is well aware of the issues faced by the anesthesiologist, things usually go very smoothly. But the problem is with anesthesia providers, like residents, who fail to understand a lot of the complexities that come with giving conscious sedation. I remember being a resident and thinking these cases would be easy; if anything, they are harder than general anesthesics, just for the fact that the patient is partially awake. These conscious sedation cases require, in many ways, more vigilance than general anesthetics.
Ultimately, whether you get general anesthesia or conscious sedation for your surgery depends on several things, including the type of surgery, and the experience/comfort of both your anesthesiologist and surgeon. Most importantly, there needs to be a three-way dialogue, between patient, surgeon, and anesthesiologist in order to arrive at a consensus of the best way to proceed.
Conscious sedation refers to a level of anesthesia that is more than being completely awake, but less than being completely asleep. It is often referred to as "twilight" anesthesia, and the technical term for it is Monitored Anesthesia Care, called MAC for short. When patients receive MAC anesthesia, their consciousness is depressed somewhat. They have amnesia and are sedated enough that they may respond to very strong noxious stimuli but not much if at all to weaker stimuli. As opposed to a general anesthetic where the patient's breathing is significantly slowed down and their blood pressure can also decrease quite a bit, conscious sedation depresses these functions only mildly, if at all.
With that in mind, let's go over the good and bad of having conscious sedation.
The Good:
1. You're more awake during the surgery. In most cases, the amount of sedation you receive for such a case is enough that you don't remember anything, but not so much that you're totally out of it. Patients will sometimes remember hearing voices and the beeping sounds of monitors, but will note that they didn't really care about them and weren't worried or concerned about hearing them.
2. You wake up faster afterwards. The most common sedative administered during conscious sedation is propofol. Yes, that's the same drug that was misused by Michael Jackson, but in the hands of trained anesthesia professionals, it is a very safe drug. One of its best qualities is that it only lasts a few minutes, so during sedation it is given continuously into the IV via a small pump. When the surgery is done, the pump is discontinued, and the patient wakes up within a few minutes. There is little or none of the groggy feeling that so often accompanies general anesthesia.
3. Less nausea and vomiting. The stuff that really causes nausea is the combination of narcotics and the inhaled anesthetic gases that are used to maintain general anesthesia. With conscious sedation, there is no inhaled gas and significantly less narcotic being given.
4. Receiving less drugs = fewer side effects . General anesthesia is strong stuff. Even a "routine" general anesthetic involves the administration of some pretty potent medicines, ones that can drastically lower all bodily functions, including blood pressure, heart rate, neurologic function, even immune function. A general anesthetic is much more stressful on the body than conscious sedation.
The Bad:
1. You're more awake during the surgery. Again, the likelihood of remembering much at all during conscious sedation is quite small, but it's much more likely to happen than in general anesthesia. If you're the kind of person who wants to be totally knocked out and doesn't want to know anything, well, conscious sedation is not an optimal choice for you.
2. You may end up getting general anesthesia anyway. Everyone deals with conscious sedation differently. Some people do great with just a little bit of IV sedative and some local anesthetic in their incision. Others get uncomfortable - real uncomfortable. It's uncommon but possible that if you get too uncomfortable during your sedation, the anesthesiologist may have to put you to sleep anyway, defeating the whole purpose of having sedation.
3. Sedative-induced confessions. Yeah, this is a rare sort of thing, but there are some people, when given a small amount of sedative, start confessing like a sentimental college kid on graduation night. People know their tendencies. I know OR personnel I work with who have chosen to have their surgeries at outside hospitals just because they feared what they might say once they had a little sedation.
4. It can actually be more dangerous. This is especially true if you have issues with snoring or sleep apnea. When you are under general anesthesia, you have a breathing tube in your mouth that the anesthesiologist uses to help with your breathing. With conscious sedation, you have small plastic prongs in your nose that give oxygen, but that's about it. When people get sleepy, it is easier for the tissues in their mouth and throat to collapse, blocking the flow of oxygen into the lungs and causing blood oxygen levels to decrease dangerously. The vigilant anesthesia provider, of course, can deal with this accordingly, but even small lapses in vigilance can cause big, big problems. This leads me to the next point...
5. The quality of your conscious sedation experience is very anesthesiologist dependent. If you have an anesthesiologist or nurse anesthetist who is experienced with conscious sedation, and is working with a surgeon who is well aware of the issues faced by the anesthesiologist, things usually go very smoothly. But the problem is with anesthesia providers, like residents, who fail to understand a lot of the complexities that come with giving conscious sedation. I remember being a resident and thinking these cases would be easy; if anything, they are harder than general anesthesics, just for the fact that the patient is partially awake. These conscious sedation cases require, in many ways, more vigilance than general anesthetics.
Ultimately, whether you get general anesthesia or conscious sedation for your surgery depends on several things, including the type of surgery, and the experience/comfort of both your anesthesiologist and surgeon. Most importantly, there needs to be a three-way dialogue, between patient, surgeon, and anesthesiologist in order to arrive at a consensus of the best way to proceed.
Monday, September 5, 2011
To sleep or not to sleep?
Anesthesia is always presumed to be the state of being asleep while you are having surgery, and since the advent of modern general anesthesia in the 1840s, that is more or less how it has been. But now, with the advent of new anesthetic techniques, as well as the presence of new drugs, it is not always necessary to have then patients completely asleep in order to have their surgery.
For a lot of operations, it really isn't an option to be asleep or not, such as open heart surgery or a liver transplant. But amazingly, just about every operation you can think of has been done without general anesthesia. Brain surgery, gallbladder removal, total knee and hip replacement, breast implants, facelifts, hysteroscopy - all have been done with minimal sedation, to the satisfaction of everyone involved. Just for the sake of sorting out then debate of being under general anesthesia or not, I thought I'd go through the pros and cons of general anesthesia versus being awake in some form.
Pros of general anesthesia:
1. It's a lot easier and quicker from the patient perspective. This is obvious. You go in the OR, get some drugs to relax you, and then all of a sudden, you're in the recovery room and your surgery is done. There is a lot to be said for that. Along those lines,
2. The chances of you moving during the surgery are slim to none. It may not matter to you because you won't remember it anyway, but if you're fidgeting around during the surgery, it is difficult for your surgeon and in some cases can be dangerous.
3. No drug induced confessions. The medicines used to keep people sleepy during conscious sedation make some people very chatty. Sometimes during that state of mind, people will say things that maybe they shouldn't. If you're the type of person who is a talkative drunk, for example, opt for the general anesthesia route.
4. You are much less likely to remember anything. I guess you can never guarantee anything, but the chances of remembering anything while under general anesthesia are very small.
Cons of general anesthesia:
1. It's a little more dangerous. General anesthesia involves significantly depressing your level of consciousness. With that comes decreasing your blood pressure and your breathing. Any time you decrease these parameters, the chances of something bad happening go up a little bit. now the chances of something bad happening to a healthy person undergoing a "routine" general anesthetic are very small, but not impossible. Every general anesthetic involves some degree of risk.
2. In all likelihood you'll be in more pain afterwards. During the general anesthetic you get medications to keep you motionless and comfortable. When the surgery is done, those medicines are discontinued, and you wake up. The trouble is that the pain relief properties of those medicines stops too. When you get conscious sedation, the surgeon almost always has to give local anesthetic into the area where the surgery is taking place, and so you wake up a little more comfortable.
3. Nausea. Vomiting. The gases used to keep you asleep during a general anesthetic have, as one of their common side effects, the tendency to make people puke. On one hand, a lot of people, if they get sick, do so in the recovery room and don't remember it. But a lot more get sick hours afterward, or even in the next day or two after surgery. Besides making the patient feel miserable, vomiting, if it happens often and/or vigorously enough, can affect the success of the surgery, causing wounds to open up or bleed in the worst case scenario.
4. Grogginess. In theory, most young healthy people will metabolize the inhaled gases and IV narcotics from a general anesthetic within 6 hours after the anesthetic is finished, but everyone is different. Some people can feel out of it for a day after anesthesia, or even longer. A lot of people don't like that "drugged up" feeling.
5. Loss of control. What's good for one person stinks for another. Many people like the idea of being taken to a happy place for an hour or two while some surgeon does stuff to them and they don't even have to know that any of it even happened. Others can't stand the idea of not knowing what's going on, not being in total control of the situation. Know anyone like that? Are you someone like that? If the words "control freak" have ever been used to describe you, this aspect of general anesthesia will not appeal to you at all.
6. You receive more drugs. If you're having conscious sedation, you get either a nerve block from the anesthesiologist or local anesthetic from the surgeon, and then the anesthesiologist gives you a small amount of sedative through the IV, not enough to make you completely asleep, but enough to make you feel relaxed and comfortable. General anesthesia involves a lot. There's a sedative, narcotics, anesthetic gas, muscle relaxants, etc. More drugs = more side effects.
Next blog I'll go through conscious sedation - what exactly it means, and its pros and cons.
For a lot of operations, it really isn't an option to be asleep or not, such as open heart surgery or a liver transplant. But amazingly, just about every operation you can think of has been done without general anesthesia. Brain surgery, gallbladder removal, total knee and hip replacement, breast implants, facelifts, hysteroscopy - all have been done with minimal sedation, to the satisfaction of everyone involved. Just for the sake of sorting out then debate of being under general anesthesia or not, I thought I'd go through the pros and cons of general anesthesia versus being awake in some form.
Pros of general anesthesia:
1. It's a lot easier and quicker from the patient perspective. This is obvious. You go in the OR, get some drugs to relax you, and then all of a sudden, you're in the recovery room and your surgery is done. There is a lot to be said for that. Along those lines,
2. The chances of you moving during the surgery are slim to none. It may not matter to you because you won't remember it anyway, but if you're fidgeting around during the surgery, it is difficult for your surgeon and in some cases can be dangerous.
3. No drug induced confessions. The medicines used to keep people sleepy during conscious sedation make some people very chatty. Sometimes during that state of mind, people will say things that maybe they shouldn't. If you're the type of person who is a talkative drunk, for example, opt for the general anesthesia route.
4. You are much less likely to remember anything. I guess you can never guarantee anything, but the chances of remembering anything while under general anesthesia are very small.
Cons of general anesthesia:
1. It's a little more dangerous. General anesthesia involves significantly depressing your level of consciousness. With that comes decreasing your blood pressure and your breathing. Any time you decrease these parameters, the chances of something bad happening go up a little bit. now the chances of something bad happening to a healthy person undergoing a "routine" general anesthetic are very small, but not impossible. Every general anesthetic involves some degree of risk.
2. In all likelihood you'll be in more pain afterwards. During the general anesthetic you get medications to keep you motionless and comfortable. When the surgery is done, those medicines are discontinued, and you wake up. The trouble is that the pain relief properties of those medicines stops too. When you get conscious sedation, the surgeon almost always has to give local anesthetic into the area where the surgery is taking place, and so you wake up a little more comfortable.
3. Nausea. Vomiting. The gases used to keep you asleep during a general anesthetic have, as one of their common side effects, the tendency to make people puke. On one hand, a lot of people, if they get sick, do so in the recovery room and don't remember it. But a lot more get sick hours afterward, or even in the next day or two after surgery. Besides making the patient feel miserable, vomiting, if it happens often and/or vigorously enough, can affect the success of the surgery, causing wounds to open up or bleed in the worst case scenario.
4. Grogginess. In theory, most young healthy people will metabolize the inhaled gases and IV narcotics from a general anesthetic within 6 hours after the anesthetic is finished, but everyone is different. Some people can feel out of it for a day after anesthesia, or even longer. A lot of people don't like that "drugged up" feeling.
5. Loss of control. What's good for one person stinks for another. Many people like the idea of being taken to a happy place for an hour or two while some surgeon does stuff to them and they don't even have to know that any of it even happened. Others can't stand the idea of not knowing what's going on, not being in total control of the situation. Know anyone like that? Are you someone like that? If the words "control freak" have ever been used to describe you, this aspect of general anesthesia will not appeal to you at all.
6. You receive more drugs. If you're having conscious sedation, you get either a nerve block from the anesthesiologist or local anesthetic from the surgeon, and then the anesthesiologist gives you a small amount of sedative through the IV, not enough to make you completely asleep, but enough to make you feel relaxed and comfortable. General anesthesia involves a lot. There's a sedative, narcotics, anesthetic gas, muscle relaxants, etc. More drugs = more side effects.
Next blog I'll go through conscious sedation - what exactly it means, and its pros and cons.
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