Why a correctly-fitting blood pressure cuff is important for children

In this Contemporary Pediatrics® interview, Tammy Brady, MD, PhD, vice chair for clinical research, Department of Pediatrics, Johns Hopkins University School of Medicine, medical director, Pediatric Hypertension Program, Johns Hopkins Children's Center, details why a blood pressure cuff fitting correctly is important for children. Brady outlines what the blood pressure cuff market looks like today and why some lables can be misleading.

Transcript (edited for clarity):

Contemporary Pediatrics®:

When are blood pressure cuffs primarily used, and what is important to know for screening settings?

Tammy Brady, MD, PhD

Blood pressure cuffs are often linked to a device, and they're used to screen blood pressure in children and adults to look for hypertension. It's really important to make sure that those cuffs fit appropriately, because if they are too large or too small, it could provide inaccurate readings. One thing that many people don't recognize when using an automated device is you need to use the cuff that comes with the device. You can't use an off-brand cuff because the accuracy of the device is linked to the cuff. So, those are some things that are really important and may be overlooked in many screening settings.

Contemporary Pediatrics:

In the pediatric population, how prevalent are these cuffs and are they the primary source for a blood pressure reading?

Brady:

Blood pressure measurement using a cuff is really the only way that we can recommend measuring blood pressure at this time. There are a lot of things in the market these days, cuffless devices, etc., but those aren't really ready for primetime. So, for children, adolescents, young adults, all comers, really the best way to screen for hypertension is to measure blood pressure with a cuff device. I think one of the big challenges in pediatrics is that these cuffs are often labeled qualitatively. They're named as child, small adult, large adults, and even a thigh cuff. So many people who are in charge of measuring blood pressure may look at the cuff, look at the description, and use that. They'll say, "Well, this is a 5-year-old child, I need to use a child cuff." But there have been a lot of studies, especially using the National Health and Nutrition Survey (NHANES) data, in particular, that show even in kids between 6 to 11 years of age, there's a large proportion of those children who need adult and even large adult cuffs.

Contemporary Pediatrics:

How can a pediatrician or parent find the right-sized cuff for a child if labels are not always accurate based on age?

Brady:

For pediatricians or people performing in-office blood pressure measurement, really the best way to do this is to just measure the mid-arm circumference. Almost every pediatric office is going to have a measuring tape because measuring head circumference is part of the physical exam for infants. I recommend, and actually in my practice, every single patient who sits in my chair that I'm going to measure blood pressure in, gets a mid-arm circumference measurement. It takes less than 15 seconds, and I use that measurement to choose the cuff. I ignore the label and I look at what the marking says in terms of what arm circumference that cuff is appropriate for. And then I make sure that that cuff fits snugly. A snug cuff and an appropriately-fitting cuff should have no more than two finger breadths fitting underneath the cuff when it's on. And many parents and children often tell me that I put the cuff on a little more snugly than they're used to, but that's really the best way to do it. Then if you're trying to monitor your blood pressure at home, this can be a little challenging in children because there are very few devices that have been tested for accuracy in children. Some of the devices for adults have been tested in individuals above 12, so 13 and up. For people who are in that age range and you find a product that's been tested for accuracy, again, I just recommend asking your pediatrician with the arm circumference is so you can make sure that device comes with a cuff that has an arm circumference appropriate for your arm circumference.

Contemporary Pediatrics:

What can happen when a blood pressure cuff does not fit as it is intended to, and can age effect these outcomes?

Brady:

If the cuff is too small, that will give you an erroneously high reading. That could give you a wrong diagnosis of high blood pressure, which will lead you to extra visits, extra testing, potentially subspecialist referral, potential medication. The younger you are, you are more likely to undergo more testing because the current pediatric guidelines state that if you are under 6 or you have other risk factors like a family history of hypertension, then you should really do a deeper dive to look for secondary forms. So, it could have bigger implications the younger you are, if you don't use the correct cuff size. Also, if you use too large of a cuff, you could miss hypertension. In the pediatric age group, hypertension is often due to something else, and that something else is often the kidney, the heart, or even an endocrine disorder. So, you are missing an opportunity to identify one of those disorders early on, which then leads to a missed opportunity for early treatment and prevention of adverse outcomes.

Contemporary Pediatrics:

What does the blood pressure cuff market look like for the pediatric population?

Brady:

The limitations of what's available on the market really came to the forefront, I think, with COVID, when we were trying to do what we could with telehealth. When I took a look to see what was available on the market that 1) had been accuracy tested for kids, and 2) had provided cuffs in a variety of sizes, in the US, I was really left with just 2 devices. One of the biggest challenges, I think, is in finding cuffs that are suited for people with extra-large arms, above 19 inches or so, that can be really hard to find. And then similarly, for the really small arms, which is what we see in our little ones, that can be really hard to find a cuff that fits appropriately and that's affordable. So, I think it is a big challenge and it's something that I hope device manufacturers will help remedy. As we are doing a better job of identifying children with hypertension, we're identifying kids who have those secondary conditions that I mentioned, and those kids really do need a little extra help for monitoring at home, and they're really left with very few resources to do so.