Nitrous Oxide: Correct Use and Indications in Pediatric Dentistry

You're listening to The Dr. Phil Klein Dental Podcast from Viva Learning.com. Welcome to the show. I'm Dr. Phil Klein. Today we'll be discussing the most up-to-date information on the use of nitrous oxide in both pediatric and family dentistry. We'll be talking about indications for nitrous oxide, its mechanism of action, and its contraindications. Our guest is Dr. Juan Yepes, a full professor in the Department of Pediatric Dentistry at Indiana University and an attending at Riley Children's Hospital in Indianapolis, Indiana. Dr. Yepes, it's a pleasure to have you on Dental Talk. It's a pleasure to be here, Phil. Thank you so much. So to begin this podcast, what are some of the indications for the use of nitrous oxide? Well, it's a very interesting question, and I will try to keep it to the point. Definitely nitrous oxide, which by the way, about 85% of the pediatric dentists, we use nitrous oxide as a sedation technique. It's probably the most frequently used sedation technique in these days in dentistry. So the indications are children as well as adults. And if I refer to children, I just want to make sure that sometimes I... forgot to include adults in my answer, but definitely the indication is the pre-cooperative patient. Sedation will be obtained with using nitrous oxide in the proper way. So in the patient who is pre-cooperative, the use of nitrous oxide will help to calm down the patient, will help to make the patient more cooperative, will help even sometimes to use less lidocaine. So there are multiple situations in pediatric dentistry as well as adult dentistry that nitrous oxide is an excellent helper. In your practice, what proportion of your patients do you use nitrous on? I mean, you're very competent with its use. Do you think that dentists that are more competent with using nitrous oxide are using it more actively than other dentists? Yes, absolutely. Honestly. In my private practice, I probably use nitrous oxide in 9 out of 10 patients. It's probably the single most effective sedative technique that I use in my office. I don't want to say, Phil, that I use nitrous oxide in every single patient, but it's very close to every single patient. It really helps. So it helps you and it helps the patient, right? And your staff, everybody. Yes, and you forgot also it helps parents. And the parents. When we are working in these days, it's very common to have the parents in the operatory. So when the parents witness that the child is more calm, the child is more cooperative, happy parents, happy appointment. So, you know, the collateral effects of nitrous oxide, they go all the way to the parents. And when they see the child is more cooperative and we can complete the treatment. without a lot of disruptions so um definitely it's a good helper for higher dental team yeah sometimes i forget i'm talking to a pediatric dentist like yourself because as an endodontist retired i didn't really have to deal with the parents there was no well i mean we did do some root canals on some very young patients considering that most of our clients or most of our patients were much older but yeah we never really saw the parents in the operatory So I don't have a lot of experience with that. But that is a good point. If the patient's relaxed, then the parents are relaxed. So let's talk about the contraindications. What are some of the contraindications to the use of nitrous oxide? You know, this is a very interesting question. And before I go over the contraindications, I just want to add one sentence to your previous comment. Sometimes in pediatric dentistry, patients are so close that I can feel the cheek of mom or dad next to me. So close that I move a little bit and I can... mean, I can feel the breath of the partens next to me. And I know you probably never in your practice when you were in active dentistry, you probably never, never, ever have a partens so close to you. Never. No, that's frightening. It's actually frightening to me. I like that. So, Phil, to answer this question in an easy way, there are some contraindications for the use of nitrous oxide. I, you know, not to, it's not my intention to go very deep here and just... provide a whole physiopathology paragraph. I just want to name some of the most common contraindications and then we may actually can expand it if you want it. Definitely pregnancy is one of the contraindications of nitrous oxide. One more contraindication that we don't see that in pediatric dentistry is patients with COPD. If it's a dentist who sees patients, adult patients with COPD, remember emphysema and chronic bronchitis. Definitely nitrous oxide is not a good helper. And there is a whole reason for that. Just for the time that we have some time limitations today, patients with COPD are not really good patients for nitrous oxide. Let me tell you a couple of more than that. Sometimes in pediatric dentistry, we see that. Number one, a patient with an active median otitis. And I know you may are... trying to recall your brain, I can tell you that you are trying to understand what is the connection between the middle ear and the use of nitrous oxide. Well, the connection is what happened. Nitrous oxide get entrapped into spaces with air that we have in our body. And we have a space with air, which is the middle ear. And nitrous oxide can stay there. So if a patient is having middle otitis, active infection of the ear, Nitrous oxide can increase the pressure, and that can cause some discomfort. So generally speaking, patients with active infection of the ears, it's not a good idea to use nitrous oxide. And then to finish, let me just add one more, which is also not very common. Patients who are in active therapy with bleomycin. I know bleomycin is a medication that is used for chemotherapy. And we don't see too many patients taking bleomycin. And it's a whole physiopathology. reason why patients who are active in therapy with gliomycin are not good candidates for nitrous oxide. And I want to finish before you keep going. Obviously, patients who are not willing to place the hose over the nose. I mean, patients who are with a completely disrupted behavior, there is no way that they are going to have the nitrous oxide hose over the nose. So it's wasting time if we try to do that. So in your pediatric practice, what happens if you see a patient who has asthma? I mean, that's not COPD, but what about asthma? Is that a contraindication? Good question. Asthma is not a contraindication of nitrous. Studies show that really the nitrous oxide is not an irritant for the airway because, you know, if you assume that nitrous is very irritant to the airway, you may can trigger an asthma attack. But nitrous is safe to use in patients with asthma. Now, there is common sense, which... Obviously, if you have a patient with acute, severe asthma or maybe having an asthma attack, I probably will not use nitrous. Obviously, it's unlikely that a patient with an asthma attack will be in the dental chair. In fact, if you have an asthma attack in the dental chair, you're supposed to stop providing dental treatment. So asthma, per se, is not a contraindication for the use of nitrous oxide. Remember, Phil, that we use nitrous oxide in combination with oxygen. The concentration of oxygen that you are breathing right now in your studio is about 20 to 21% of oxygen. That's what you are breathing right now. When we use nitrous oxide, we deliver concentration of oxygen who are 30%, 40%, almost double. the oxygen that you have right now in your room. So in some way, a patient with asthma will get more oxygen than normally will get from the environment. You've been doing this for a while, and a lot of your patients, as you mentioned, you use nitrous oxide. What are some of the potential side effects that clinicians should be aware of when administering nitrous oxide, and what have you seen in your years of practice? You know, Phil, I think this is probably the most critical question from our conversation. the side effects. But let me, I just step back and explain briefly that one of the ways to avoid the side effects is to use nitrous oxide correctly. And sometimes we don't keep that in our mind and we kind of skip some steps. And the consequence is that we may see the side effects. So I will go in the side effects in a minute, but we both need to... kind of being the same page in the way that when we are going to use nitrous oxide, we need to explain to the parents. We need to explain to the patient. He needs to be aware. We need to explain what the patient is going to feel. And then we start initially with 100% oxygen for a few minutes, one to two minutes. And we go 100% oxygen, two to four liters per minute. Then slowly, in capital letters, underlined, highlighted, slowly we are going to... by increment, we are going to start the nitrous oxide. We will start at 10% for maybe a minute. Then we go 20% for a minute, 30% for a minute. And then during that time, we are active monitoring our patient. If we do that, we actually are going to be more efficient in terms of we are going to obtain the effect that we are looking with nitrous oxide. Now, going to your question, the side effects. Generally speaking, it's not a good idea to go over 50% in the concentration of nitrous oxide. Several machines who are available in the market, not several, probably all the machines available in these days, they don't let you to go more than 50% of nitrous oxide, even if you want it. But what happens is if you go over 50%, and some textbooks, they even go 40% and higher. is when you start to potentially, you can see the side effects. Studies show that the side effects of nitrous oxide are between 1% to 10%. That means that maybe one patient out of 10 will have some of the side effects, but they are usually related with the higher concentrations of nitrous oxide. The most common side effects are nausea and vomiting. It's interesting. In a textbook that I'm the associate editor, McDonald, which is Dentistry for the Child and Adolescent, I'm one of the associate editors of the textbook. It's from our institution here in Indiana. We have a chapter in nitrous oxide, and we recommend to have a container every time that we use nitrous oxide to have a container next to you in case that the patient is having nausea and vomiting, because that can happen. But again, they are directly related with the concentration of nitrous oxide. So when you treat a patient, let's say a 10-year-old boy sits down in the chair. Do you administer the nitrous and base your percentage of oxygen to nitrous based on the experience you've had with this patient, by their weight, by their anxiety levels? If they are very anxious, do you ramp them up over time, not just at that visit like you explained, but over time, do you try to get them to a higher concentration of nitrous so that it's more effective? Interesting question. If we have a 10-year-old or if we have a 5-year-old, We, in both situations, in the patient's 10-year-old and the patient's 5-year-old, we are not going to go higher than 50%. We go exactly in the same protocol. We start with 100% oxygen. Then we start slowly to increase the concentration of nitrous oxide, initially 10%, then 15%, 20%, 25%, 30%. And then around 35% is when we are starting to stop. Sometimes we go 40%. Generally speaking, we don't go over 50%. But we apply the same protocol for the five-year-old and for the 10-year-old. And also, you know, following your second question, and the patient comes back, we don't actually go higher just because we already had a session with the patient that went well or maybe didn't went very well or didn't go very well. But we are still following the same protocol. We don't... use previous experience to continue increasing the concentration of nitrous oxide. And as I explained, a lot of the machines, if not all of the machines who deliver nitrous oxide, they don't let you to go over 50% of nitrous oxide. Yeah. So what is the minimum therapeutic level of nitrous oxide that you could administer and still gain the benefit of it without going to like 35, 40%? Yeah, it's an excellent. I have patients that I know with 10 to 50% of nitrous oxide. 10 to 15% of nitrous oxide is perfect. You can see the kid is relaxed. You can see that the kid is more cooperative. You can see that the, you know, one interesting effect of nitrous oxide that you can suggest to the patients, and it seems like patients who are under the nitrous oxide influence, they seem to respond more active to your suggestions. Open your mouth. Open wide. So sometimes 10 to 15% is perfect. Now, some patients may be 20% to 25%, maybe some patients 30% to 35%. It's very individual -dependent. So when you ramp it up, as you said, one minute, then one minute, and one minute, you keep ramping it up. Do you evaluate and monitor what state they're in before you go to the next level so you don't have to give as much concentration? Yes, yes. We evaluate the patient. We look at the patient cooperative level. We look at the eyes of the patient. We talk with the patient, and with experience, and I know the experience is difficult to apply into a protocol, we know when we need a little bit more. Also, when we are going to provide the injection, sometimes during that specific time, we can go a little bit higher, and we need to remind the patient all the time that please breathe through your nose. And remember, if I tell you that as an adult, you probably will follow my command. breathe through your nose. But if you have a five-year-old who is a five-year-old, and sometimes five-year-olds, they don't breathe all the time through the nose. So that's a factor that you need to also include in the equation at the time that you decide I'm going higher or not. You need to make sure that the patient is breathing through the hose. Yeah, and if they have a cold or sinus infection, you just reschedule them because that's not going to work if they can't breathe through their nose. Yeah, absolutely. I forgot to mention in the contraindication, which is a relative contraindication, a patient who is having a cold, a runny nose, or maybe an obstruction in the nose, obviously nitrous oxide is not going to work. Right. And I assume you record in the chart the level of nitrous you're at. So if that patient behaves very comfortably in the chair or feels very comfortably in the chair at 25%, you'd record that in the chart. Not just only we record that, but it's mandatory. to record the time that you start oxygen, the time that you start the nitrous oxide, the time that you close the nitrous oxide. And remember, after you close the nitrous oxide, it's important that the patient will breathe 100% oxygen for about two or three minutes. There is also a physiopathology reason that if you close abruptly, close the nitrous oxide, that can cause a problem relative. short hypoxia, and that can cause some nausea, that can cause some dizziness. So it's important when we close the nitrous oxide to leave the patient for about two or three minutes breathing 100% oxygen. But all these times are recorded in the chart. as well as the concentration of nitrous oxide that was used. Right. Do you move to pure oxygen at the end of the procedure, or do you try to ride that full oxygen dosage so that it coincides with the last two minutes of your treatment? Yeah, as soon as I believe that the procedure is almost done, not necessarily at the end of the procedure. To give you an example, I am doing a stainless steel crown in a child. I'm placing a crown. So as soon as the crown is cemented, I probably will close the nitrous oxide and just leave the patient with 100% oxygen, knowing that it's still two or three more minutes because I need to hold the crown, need to wait until the crown is fully cemented. I need to clean, use the dental floss. But I know that now the critical time of my treatment is over. And the critical time is when I'm prepping the tooth, when I'm doing the injection, that at these particular times is when I want the effects of nitrous oxide to be my best friends. As soon as I did the critical part of my treatment, then I can close the nitrous oxide. Remember, nitrous oxide, they are a bunch of reports in the literature that it's not a good idea for the staff, it's not a good idea for the office members to breathe nitrous oxide. And sometimes, you know, if the kid is not having very well adjusted the nitrous oxide in the nose, or if you leave the nitrous oxide for a long time, we never know that we may actually are breeding nitrous oxide. This is a cholerous gas, so we don't know. And there are some reports that occupational hazard with nitrous oxide is associated with infertility, and it's associated with a bunch of different things. So we want to minimize the amount of nitrous oxide. getting out of the system and one of the ways is as soon as i finish the critical time i stop the nitrous oxide right and there's no harm in having the patient breathe 100 oxygen if anything it'll make them feel a little bit better when they leave the office oh yes it's going to make the feel the patient feel really good now remember we breathe 21 of oxygen so breathing 100 of oxygen is is three times more of the usual concentration of oxygen so you know there are some places that they have oxygen bars right You go and they connect you with oxygen. Absolutely. You never went to the nitrous bars then, huh? Just the oxygen bars? I'm only kidding. You know, in the history of nitrous, in the old days, when nitrous came into dentistry, it's pretty interesting studies of dentists during the lunchtime. Just look it up with nitrous. We didn't really understand the effects of it. I think what happened is, you know, neurological problems developed and so forth from too much nitrous, without a doubt. What exactly is the mechanism of action? You don't have to go in too much depth here because I have some more questions I want to ask you before we end the podcast. But tell us about the mechanism of action of nitrous oxide. Yeah, that's a good question. And I discuss this question all the time with my residents here in my residency program and sometimes with the parents because they ask me. We really don't know. We really don't know exactly the mechanism. However, probably the best evidence is like... the nitrous oxide interacts with the endogenous opioid systems. Without getting into many details, the strongest evidence suggests that nitrous oxide releases encephalins, which is kind of an endogenous opioids that we produce in our brain. Interesting, listen to this. 30% of nitrous oxide is equivalent to 10 to 15 milligrams of morphine. So in a very, just one sentence, Nitrous oxide, once getting to the lungs, it gets into the bloodstream, it goes into the brain, will stimulate the release of endogenous opioids that we produce. And all the effects are connected with this internal release of the opioids. The somnolence, that less gag reflex, more cooperative, are all connected with the release of these endogenous opioids. In fact, as I mentioned, 30% of nitrous oxide is equivalent to 10 to 50 milligrams of morphine. So in some way, nitrous oxide releases endogenous morphine. Right. Whatever the mechanism is, it seems to work. Is there any potential of the patient falling asleep during long procedures under nitrous? That happens to me. I don't want to say often, but once in a while, I have kids who are extremely susceptible to nitrous oxide. It's 2 p.m., plus they just had lunch, plus they used to take a nap after lunch in the school. So all this combination together with mouth open, breathing nitrous oxide, yes, some patients at some point and, you know, just recently happened with one of my patients completely fall asleep. that, you know, at the beginning was even a challenge for us. Believe me, it was a challenge for us to wake up the patient. So that means that we always need to monitor that. You know, in some dental offices, well, we're supposed to use eye protection always when we are working in dentistry. It's important, and in my office, we like to use eye protection that I can see the eyes of the patient because sometimes the eye protection that some dental offices, they use are dark glasses. And if you are using nitrous oxide in a young kid, you cannot really kind of see the kid's eyes. So it's not a good idea to keep stimulating the patient because then you are not really going to use the benefits of nitrous oxide. But definitely, you want to make sure that the kid is awake. That's an excellent point. That's an excellent point about eye protection for the patient. I never thought about that, that you actually, in this case specifically, you should be looking at the child's eyes to know what state they're in when administering nitrous oxide. Very good point. So there's a lot of systems out there. You know, we hear about scavenger systems that are developed by these companies to make sure that any nitrous that could escape is recaptured so that the staff and the rest of the team doesn't breathe this stuff in. Can you give us some recommendations regarding the different nitrous oxide systems available on the market today? Yeah, there are many systems available in the market. In terms of the nasal device, definitely the double mask type is probably the most efficient type of a scavenger. We call it the double mask. Or in some textbooks, they call that mask in within the mask. It's almost like having two masks. And that actually makes very efficient the scavenger, which is how we suction the air that the patient is exhaling, and we suction the air out of the office. So the double mask systems, which are several in the market, are probably the most efficient systems. Now, in terms of, and I always look this as a pediatric dentist, I look at the system size. We work in small phases, so it's important that... we are going to get to our office is small in size. They come in different sizes. So it's not a good idea to use a large device in a young kid with a small face. So double mask is also, and I prefer to use the one who are kind of plastic clear so we can see how well the device is fitted within the nose. The size, you know, some systems which I used in the past are huge. And what happened is with the huge systems, is difficult to work in the maxillary front teeth. So you also want a system that you always will have a problem if you have a plastic in the nose, but you want to minimize that using a system who is smaller. In that way, you can keep the system over the nose and then you can work in the anterior maxilla. So definitely... Double mass is probably the most effective type of scanning. Right. Now, what system do you use in your practice? Yeah, the system that I'm using in my practice right now is the Air Technique systems. It's a double nasal hood, so it's a double mass system. And that's the one that I have been using since Air Technique came with this product into the market. Now, there's a reservoir that is on this hood, right? Yes. That allows the exhaled... to be taken out through the scavenger hoses yes is that something innovative or that that's available on most systems no no that's very innovative that's not available in other systems and one of the good advantage of that is that it's very efficient in sending out the nitrous oxide and not having any leak and that allows not actually to decrease the potential concentration of nitrous oxide in the environment so this is a very innovative i like it and i think so that is a one more safe mechanisms when we are working with nitrous oxide. Yeah. So does Air Technique sell the entire system? Because I know some doctors move their units from one operatory to another. Some have them fixed. What are the recommendations? And I guess it depends on the practice, of course. Yeah, depending on the practice. In my office, I have both systems. I have nitrous oxide attached to the unit. And I have also the mobile, the one that you mentioned that it comes over four wheels and then you can move around the office. In my office in Open Bay, in both extremes of the Open Bay, I have four dental chairs in the Open Bay. In both extremes, I have connections with nitrous oxide. So we use the mobile unit in case that we have a patient in any of the extremes that we are going to need nitrous oxide. Remember, nitrous oxide decreases the GAC reflex. So sometimes when we are going to take x-rays, it's a good idea, especially to the patients who they have a pretty strong GAC reflex, nitrous oxide will help. Phil, I need to add that I am extremely satisfied with the use of the double hood scavenging circuit, sell buyer techniques. I have an excellent results. I use it today. I will use it tomorrow without any question. I think so all the specifications of the system are extraordinarily adapted to work with children and adolescents. You know, the double scavenger or double mask, the design. The plastic, easy to adapt to the patient, is not really bulky. So I only have good things about that. I think we covered it very well, or you did. I was just asking the questions, but you really did answer a lot of questions regarding some of the thoughts that should be going through the clinician's mind when they're administering nitrous. And as someone who never used nitrous before, I ask you, Dr. Yepes, is that something that you think is absolutely essential, especially in a pediatric practice, of course? Even for the GP that treats everybody, children and adults, do you think that nitrous is essential to a practice today? Yes, without any question. Not just only in pediatric practices. I think nitrous oxide is an excellent helper in adult dentistry. Absolutely. No question about that. Even myself, when I go to see my dentist, which is wonderful. My dentist is a wonderful dentist. I love her. She's very kind. She explains everything, but I am. really a chicken when i go to see my dentist and right which is typical that's typical of one professional to another it's interesting you you say that she explains everything like like you should know what's going on but i guess it's nice to hear it from the person who's doing work right it's very gentle but the other day and this is real life the other day i asked her um do you use nitrous and she told me no i'm thinking to have nitrous here and i say oh my god the day that you have nitrous i will be the number one candidate especially when they are doing the scaling cleaning my teeth i i really get a lot of anxiety of listen this down of the curette cleaning my teeth i hate that so honestly i will be the first patient so yes to answer your question i don't see really any reason i think some nitrous oxide is as important as having a dental mirror right or or a carpal of lidocaine right yeah an explorer yeah that's right very good all right Dr. Yepes it's a pleasure to have you back on the show we enjoyed your previous podcast this one was excellent and we look forward to more in the future thank you so much thank you phil