Transcription:
Treatment of Elevated Blood Pressure in Children

Dr. Michael Smith (Host):  Welcome to Transformational Pediatrics. I’m Dr. Michael Smith and our topic is, “Treatment of Elevated Blood Pressure in Children.” My guest is Dr. Doug Blowey. He is the Associate Professor of Pediatrics and Pharmacology and Children’s Mercy and also the Director of the Hypertension Clinic. Dr. Blowey, welcome to the show.

Dr. Doug Blowey (Guest):  Thank you very much for having me.

Dr. Smith:  What are some of the challenges that you face in monitoring and treating hypertension in, specifically, hospitalized children?

Dr. Blowey:  There are several challenges. The first one is the most basic one which is really having a nice way and place or process to identify those children that actually do have high blood pressure measurements. Children get their blood pressure measured multiple times during a hospitalization by various different people. A lot of times they just get put into a computer system or written down and nobody really identifies when those measures are abnormal and they’re not abnormal. I think the first one is just for that process to be able to recognize when a blood pressure that is measured is actually abnormal. As you know, compared to an adult person where one size kind of fits all, one number is good for everybody, in children, we’re dealing from neonates - premature babies - to 18-year-olds in our hospital. What normal blood pressure is varies across the age spectrum, so one size doesn’t fit all. It is a complex process of defining who actually has high blood pressure. It is a process issue, really. The second challenge, really, is making sure that the people that are measuring the blood pressure are doing it the appropriate way. There are clear guidelines about how you should measure blood pressure. There’s a lot of issues that go into the technique of measuring blood pressure that will impact the reading that we get. We get concerned when we get high reading they’re falsely elevated readings because of technical issues such as we’re not measuring the blood pressure in the appropriate extremity; we’re not using the appropriate size of the blood pressure cuff to ensure appropriate measurement; the patient isn’t comfortable at rest. In the hospital, we do a lot of things to patients. We cause discomfort and pain. Some of the kids are having anxiety because family isn’t there and somebody walks in to do something and they get upset. That can affect the blood pressure. There are a lot of technical issues that we have to overcome to decide if that blood pressure we’re getting is actually a true reflection of the patient’s blood pressure. Those are probably the two biggest challenges that we have. Some of the things that we’ve done and other groups have done, too, is to try and simplify identifying what blood pressures are abnormal. Rather than just writing them down in a chart or putting them in a computer system, that we have developed processes that will allow us to flag abnormal blood pressure values for the patient’s particular age and gender. So, you don’t have to memorize everything you can just kind of see this blood pressure falls outside normal. We can flag it for just a little bit abnormal or really abnormal and then process to identify the doctor based on how many times that happens and the sequence of events that goes from there.

Dr. Smith:  Let’s talk a little bit more about measuring blood pressure in hospitalized kids because in the adult population, there are studies that have shown that using the automatic blood pressure cuffs that you see all over the hospital, that those are quite reliable, at least in the adult population. Is that true for children or would you prefer physicians and nurses to actually take the blood pressure themselves?

Dr. Blowey:  Sure. As you mention, the oscillometric or the automated type devices, are prevalent and there’s a reason. They are easy to do, it doesn’t require much training and they’re fast. The reality is, they are going to be used.  That’s just how it is. However, in children, the oscillometric blood pressure or automated blood pressure doesn’t do the same thing as the old fashion manual blood pressure. The other point about this is, all of those blood pressure normal values that we talked about are actually based on manual blood pressure readings not oscillometric.  When you look at the difference between oscillometric blood pressure measurements and manual blood pressure measurements, there clearly is a difference. They don’t correlate very well sometimes and they are all over the place meaning they systematically overestimate or underestimate and the spread is all over the place. It’s really hard to know. We feel that if the oscillometric is normal, you’re probably okay. But, if we have high oscillometric blood pressure measurements, our standard or our protocol is to obtain a manual blood pressure because that is really the gold standard.

Dr. Smith:  This, I think, leads into the fact that you are part of an international committee where you are trying to establish some of these guidelines for hospitalized children, correct? Who’s a part of that committee? What are the goals of that committee? How is that going?

Dr. Blowey:  It’s going well. It’s actually an updating of guidelines that have been present. There have been several guidelines for pediatric hypertension that have been present. The most recent one, I believe, was in 1994 or 1997, something like that. It’s called The Fourth Report. The new group that has taken over --The National Heart Institute was doing that before but that has changed and now the American Academy of Pediatrics has taken over the guidelines. It’s a national guideline, he U.S. guidelines, for blood pressure management and there is a group of experts, cardiologists, hypertension specialists, and endocrinologists, involved in hypertension that have published extensively in that area. We’re meeting to update and develop new guidelines for hypertension. What we’re really focusing on is, there are several very key clinical questions. Rather than being a comprehensive, opinion-based document, we focused on four clinical important questions. Those questions really are:  how should we be measuring blood pressure? What is the optimal way of doing it? Looking at it in an evidenced based manner. That’s one question. The other question is, what should the work up be for a patient that has been identified to have hypertension? What is the best way to identify secondary causes? The third question that we’re asking is, if we are treating blood pressure, what is the optimal goal? What is our target and why is it that target? Finally, we’re trying to look and find what evidence there is that treatment – whether it be lifestyle modifications, dietary, exercise, other things, or medications – what is the evidence that it really decreases the indirect measures of cardiovascular risk? This is an important point in pediatrics. In the adult world, unfortunately, the outcome of death and cardiovascular disease is very prevalent. You can do studies and look for those outcomes. Fortunately, kids they don’t have those outcomes. What we know is that, although they don’t have those bad outcomes, we are seeing the early development or the early pathogenesis of atherosclerosis and cardiovascular disease in kids but in indirect ways. Looking at thickening of the heart or left ventricular hypertrophy; looking at thickening of the intima vessels or carotid; looking at some physiologic flow characteristics of the peripheral blood circulation system. We look at those things and we see changes in kids that have hypertension, so we know those are surrogate markers. We’re trying to say, is there any evidence that when we do things do those improve? Those are the four key clinical questions we’re developing and developing some statements for the practitioner.

Dr. Smith:  Is there a timeline that you anticipate having these new guidelines published?  

Dr. Blowey:  Yes. Right now, we’re in the phase of extracting all of the literature. We develop those questions, extract the literature and then we’ll work on putting some consensus guidelines together. I think we’re hoping that by this fall, that they will be ready for publication.

Dr. Smith:  Dr. Blowey, I want to thank you for the work that you are doing – extremely important – and the success that you’re having and that Children’s Mercy is having is really impacting the daily practice and improving the health of children. So, thank you so much for that and I want to thank you for coming on the show.  You’re listening to Transformational Pediatrics with Children’s Mercy Kansas City. For more information you can go to ChildrensMercy.org. That’s ChildrensMercy.org. I’m Dr. Michael Smith. Thanks for listening.