Friday, March 20, 2009

Blood Pressure Cuff Size and Pregnancy

We have been discussing the importance of blood pressure cuff sizes, especially for people of size.

When a too-small cuff is used, blood pressure readings are falsely elevated, sometimes by really sizable amounts. This can lead to medications and interventions that are unnecessary and which can carry significant side effects.

Blood Pressure Cuff Size And Pregnancy

In pregnancy, being vigilant about blood pressure cuff size is even more important, yet using the wrong cuff size (miscuffing) seems even more common in pregnancy.

Anecdotally, fat women report that obstetrics providers often don't carry the full range of cuff sizes and tend to be very cavalier about using the correct size, even more so than non-pregnancy healthcare providers. Even hospital labor wards don't always use the correct size consistently.

Yet it is particularly critical to have an accurate reading of blood pressure in pregnancy due to concerns about hypertensive disorders of pregnancy (like pre-eclampsia), which can be very serious indeed.

Unfortunately, many "obese" women are incorrectly diagnosed with BP issues and subjected to interventions like medications, inductions, and sometimes even unnecessary cesareans because of use of the wrong BP cuff size.

Hypertensive Disorders of Pregnancy/Pre-Eclampsia

Hypertensive Disorders of Pregnancy is one of the most common (and potentially serious) complications of pregnancy.

The term "hypertensive disorders of pregnancy" is an umbrella term used to cover a multitude of blood pressure issues that happen in pregnancy. The terminology for it varies a lot (toxemia, pregnancy-induced hypertension, gestational hypertension, etc.), but that's a discussion for another day. The main issue here is what is commonly known as "pre-eclampsia."

Pre-eclampsia is a rise in blood pressure after 20 weeks gestation in a previously normotensive woman, accompanied by protein in the urine. If it is accompanied by altered lab results (like elevated liver enzymes, uric acid, or low platelets), it becomes really serious.

Severe pre-eclampsia can become truly life-threatening to both mother and baby, sometimes very quickly, and is one of the leading causes of maternal mortality in the world. Thus, doctors take BP issues in pregnancy very seriously indeed, and with good reason.

Outside of pregnancy, a borderline BP number is not pursued that vigorously, but in pregnancy many OBs get nervous about even borderline blood pressures and often will start very aggressive interventions very quickly.

Furthermore, because "obese" women do tend to have higher rates of pre-eclampsia, doctors tend to be even more interventive with women of size at the first suggestion that there might be BP issues.

Therefore, it is extremely important for pregnant women of size to have accurate BP data....yet miscuffing seems to be particularly common in obstetrics.

As a result, pregnant "obese" women need to be particularly vigilant about checking cuff size.

My Anecdotal Stories

Sadly, in 3 out of my 4 pregnancies, miscuffing was an issue at some point or other. That's how common it is, especially in pregnancies of women of size.

Pregnancy #1:

Normally I am quite vigilant about cuff size, and during prenatals I always asked about whether they were using a large cuff.

However, during labor my mind was busy concentrating on coping with contractions and I didn't always ask about cuff size. As a result, at one point the nurse took my BP, became quite alarmed, and was about to initiate several big interventions as a result.

Luckily, I surfaced enough to ask if she had used the large cuff; she said she couldn't find it and it wouldn't make much difference anyhow. We fought about it for quite a while; she was really resistant to getting the larger cuff, and stated strongly that it didn't matter that much and we really needed to start these interventions sooner than later.

I became quite assertive and insisted she go get the large cuff. She huffed out (she was quite mad!) and finally managed to "find" one and re-took my BP.

It was totally normal, as my blood pressure had been throughout all my pregnancy.

During that entire hospital stay, very few staff members understood the importance of a large cuff, and many resisted the idea of getting one. Even when they were willing to get one, they often had trouble finding one, despite being in a hospital setting where they should be plentiful. The resistance to using the correct-sized cuff was considerable, both on an individual and institutional basis.

I managed to stave off the risky interventions that are standard with high blood pressure, but only because I knew about the importance of cuff sizes and was ready to be quite assertive about it.

Pregnancy #2:

In my second pregnancy and labor, I was extremely vigilant about checking on BP cuff size. Because I always asked and because my labor support people asked for me as well when I was preoccupied in labor, I did not have any cuff size issues in this pregnancy......until after the baby was born.

It was only postpartum that the cuff size issue arose....because I was doped out on drugs, post-cesarean, and my support people had gone home to get some sleep.

A nurse came in in the middle of the night to check on me and take my vitals. I was so wiped out and groggy from drugs I didn't bother to ask about cuff size. She took my BP and commented that it was really up.

[It is unusual....but possible....to have normal BP throughout pregnancy and all of labor, and yet still develop pre-eclampsia after the baby is born. That's why they are careful to monitor BP throughout the postpartum period too.]

Fortunately, I surfaced enough to ask whether or not she had used the large cuff. She said no, it was broken, and it didn't really matter that much anyhow. It's a little blurry now but I think she told me I wasn't fat enough for it to be that important anyhow, that the regular cuff fit around my arm just fine.

I think I pointed out that it's not whether the cuff fits or not, it's the size of the cuff/bladder in proportion to your arm size that makes the difference, and that she needed to get the larger cuff.
At that point, she got really snotty. She asked me where I had gotten my medical degree from, implying that she was the medical professional and I was just a lowly ignorant patient, and what did I really know about it anyhow.

[This is typical of medical bullying; when you don't do what they want you to do, they bring out the old "*I* am the medical professional and know more than you," and try to intimidate you into submission.]

I still insisted. She rolled her eyes and snapped that she had so many patients to check on, she couldn't take the time to go get the other cuff, yadda yadda. I still insisted. She was pissed.

Eventually, she did come back with a larger cuff she somehow "managed" to find....and of course, my blood pressure was just fine.

Pregnancy #3:

In this pregnancy, I wanted to avoid the hospital and OBs from the get-go. I chose a homebirth midwife, but she did not own a large BP cuff.

She had not attended many women of my size before so she was not fully familiar with the importance of a large cuff, but she was very open to learning about it from me. We both agreed we needed to have accurate readings to make sure I stayed low-risk enough for a homebirth. I was nearing 40 at that point and the risk for blood pressure issues goes up with age, so even though I'd never had an issue with blood pressure before, we still needed to watch carefully in this pregnancy. After listening to the evidence, she agreed that a larger cuff would be important.

It's been quite a while so I'm a bit hazy on the details of how we got one, but she either bought one or we managed to borrow one. Either way, we managed to find a way to get a large BP cuff so we could have accurate readings.

Fortunately, my BP stayed normal throughout the pregnancy, despite my age. But if I had not been so familiar with cuff size issues, she would not have known that it was so important for someone of my size and I probably would have gotten risked out for no good reason. Luckily, she was open to learning about it.

I did transfer to the hospital during that labor and had my VBAC in the hospital after all. Fortunately, I never had an issue that time with cuff size at the hospital. I always asked, and they either always had the right cuff already, or were willing to go get it without arguing about it. That was a refreshing change!

Pregnancy #4:

This was the only pregnancy that I did not have cuffing issues. I selected a homebirth midwife for this pregnancy (a different one than with #3), but because she is a woman of size herself, she knew about the importance of a larger cuff and already owned one.

I can't tell you what a relief it was to just sit back in prenatals and in labor and know that I didn't have to be so constantly vigilant about blood pressure cuff sizes! She not only had the proper cuff size, but she also knew how to take it properly in all the "little" details (which a lot of medical workers don't do correctly either.....things like having you seated with back support, legs uncrossed, raising the arm to the correct height, not talking to you while taking the BP, etc.).

My baseline BP was a little higher in this pregnancy because of my age (early 40s) but with the correct cuff we were able to document that it stayed normal throughout.

I had my home waterbirth after all and it was wonderful.

Other Women's Stories

I have collected stories on my website of pregnant women of size who were almost forced into immediate cesareans because of high blood pressure readings brought on by miscuffing. Here are two. (If you have additional stories, I urge you to submit them to me for documentation on my website.)

L's Story:

I came within an hour of having an emergency c/s at week 33 with my son. They even went as far to have the surgical resident (who would be assisting my regular OB) and the anesthesiologist speak with me. They were just waiting for my regular OB to get to the hospital and see me before they prepped me.

When he did come in and see me, the first thing he did was take my BP. When he reached for the BP cuff, he said, "Is this the cuff they're using to check your pressure with?" I said yes, then he went out and yelled up one side and down the other to the nursing staff about jeopardizing his patient and baby because they didn't use the large cuff. It made a huge difference! The readings went from [about] 180/104 to [about] 114/63. Surgery cancelled!

Usually I'm much more alert than that and demand the large cuff. I had requested it several times in the hospital and the nurses kept saying it didn't matter...[even after delivery] the jerks still wanted to use the small cuff!!!

A's Story:

Having gone through two pregnancies with elevated BP, it became kind of crucial to me to have it done correctly.

When I was pregnant with [my daughter], I would have it done at my OB/GYN office, and have it either normal or slightly elevated. Then I would get to my perinatologist's office and have it skyrocketed.

The first issue was the cuff---until I insisted I get the right sized cuff (my OB didn't even own one, but I made sure the girl ran next door to borrow one from another doctor for each of my visits---the peri didn't have one and was the only doctor in the building).

The second thing was my OB always had me either sit in a chair and not speak while they did it, or they did it with me lying down. The peri always did it...on the exam table, legs dangling, no back support, while they were chatting with me. Finally, upon the recommendation of the peri, I got a unit for home. From that point on, I refused to let the peri's office do it. I would do it myself while I was out in the car, and bring them my reading.

Twice they suggested my OB take [my daughter] by c-section immediately due to high BP. Thank gosh my OB relied more on his own records than on the recommendation of the peri.

Oh, and I had to fight with the insurance company to get a large-sized cuff for my home unit.

And these are the stories of the women whose misreadings were discovered.

How many "obese" women have been pushed into cesareans they didn't need because they were miscuffed and the error was never discovered? How many have had to get magnesium sulfate (good for pre-eclampsia treatment but it makes you feel like total crap) because they were miscuffed and the error never discovered?

Let's be fair; some women of size do truly experience pre-eclampsia and need these interventions as a result. You certainly cannot say that all fat women's experiences with pre-eclampsia in pregnancy have been spurious.

But because miscuffing is such a common mistake in women of size, chances are very high that some fat women have been diagnosed and treated in error. And because all of these interventions carry significant risks, that's a pretty big mistake to make, whether it's from ignorance or from laziness. It really highlights just how important cuff size is, especially in pregnancy.

Summary

Over the many years that I have been running my website on plus-sized pregnancy and reading stories from other pregnant women of size, this issue of blood pressure cuff sizes keeps coming up again and again.

Despite all the many years of research and training out there for medical professionals on the importance of the correct BP cuff size, miscuffing is consistently still a problem....both outside of pregnancy and in it. However, I have to say miscuffing seems particularly pervasive in obstetrics.

Because hypertensive disorders of pregnancy are a very serious potential complication of pregnancy and because the threshold for intervention is very low when a baby is involved, accurate blood pressure readings are particularly important during pregnancy.

This is even more critical for "obese" women, because many providers assume fat women are automatically going to develop pre-eclampsia anyhow, and because using the wrong blood pressure cuff is such a common error.

You would think that this would mean that attention to the proper cuff size would be particularly strong in obstetrics, but in reality, many women find that there is even less attention to it in obstetric offices and on labor wards.

Therefore, it's critical that pregnant women of size:
  • know their own arm size (in centimeters!) and which cuff size they need

  • ask about cuff size EVERY TIME blood pressure is taken in pregnancy, labor, or postpartum (and double-check the range printed on the cuff if they are borderline in size)

  • train their partners and labor support personnel to ask about cuff size for them during labor if they are too preoccupied

  • learn to be assertive about proper cuff size and not allow themselves to be bullied or dissuaded from the proper cuff

  • consider purchasing their own cuff and bringing it to every appointment and to the hospital if they are supersized, borderline in arm size, or if they have very heavyset arms
Blood pressure cuff size is an important issue for people of size everywhere, but it is particularly critical for pregnant women of size to be proactive about cuff size.

10 comments:

Ms. Heathen said...

I'm wondering, how resistant are doctors to you bringing your own cuff? I've been thinking about getting one, but if I'm going to shell out all that money out of my very tight budget I want to know they're going to use it on me in the doctor's office. I'm not quite sure I'd be able to use it myself to get accurate readings.

Hypertension is a big problem in my family, I'd like to be able to spot it and get it treated accurately. I wouldn't want to be put on too strong a medicine if I need to regulate my BP.

As an aside, if you carry a purse, it's a good idea to have a cheap flexible tape measure tucked into a side pocket. You never know when you'll have to measure yourself to fit something, and you can't even trust people in clothing stores to do that right. I own about six, and they all end up in my purse because I forget that I already put one in.

Shotgun Mary said...

I had read about this before on your website and kind of stashed it in the back of my head. Throughout this pregnancy (my first) my blood pressure has been quite a bit higher than it normally is. At my nurse practitioner's office I always run 110/70 or thereabouts. When I visit my midwife I'm 140/90+. I ran into my NP the other day and she asked me if the MW was using the correct cuff size. I had totally spaced it. I emailed my MW right away and I'll be interested to see how things go at my next appt. I'm right on the border line 34 cm one arm and 36cm the other but my NP suspects that the size is the difference. I'll be more on top of it from now on!

Anonymous said...

Thanks for this article - I am pregnant myself and about to graduate from nursing school. It's really scary the difference a inaccurate BP can make.

Thanks for raising awareness - i will advocate for my patients to get the right size cuffs. staff do get busy bu thaht doesn't make it right.

Anonymous said...

I never even realised that cuff size could be an issue before I started reading this.

However, it DOES explain my family's perpetual low pressure.

Next year, I'm going to begin training as a paramedic. I have no idea if British ambulances carry the largest sizes of cuff as standard, but even if I have to buy them myself I can guarantee mine will.

NavelgazingMidwife said...

As a fat woman, pregnant and otherwise, I have had my share of cuff horror stories... including the time I was in the ER for a broken toe and the new tech kept trying to use the small cuff on my 350 pound arm. I was so disgusted, I just let him keep trying, he getting to the point where he used MEDICAL TAPE to try and keep the velcro closed. I was crying by this point and his supervisor came by and was HORRIFIED by what he was doing. He'd ignored my explanation for getting the large cuff over and over, so I thought I'd just let him make an ass of himself. I hadn't really thought about the humiliating part of it for my Self.

Anyway, now as a fat midwife, I REALLY have the understanding of cuff size and the importance of being prepared. I had a great cuff set when I first started that included not only a large cuff, but a THIGH cuff for women over about 350-370 pounds.

Okay, so what do you do if you have a dorky provider that remains an ass and won't go get you a large cuff? HAVE THEM PUT IT ON YOUR LOWER ARM! The small cuff can be put on your lower arm, the bladder lying over the main veins in your upturned arm (palm to the ceiling). The provider listens to the pulse beats ON THE INNER WRIST (not in the usual antecubital spot inside the elbow). It is just as easy to hear the beats in the wrist as it is the upper spot.

I have done this trick with automatic cuffs a lot.

Depending on whether the woman has large ankles or not, the same can be done around the ankle, the bladder going on the inner side with the tubes laying right over the inner ankle bone. Listening to the pulse beats is heard right above the inner ankle bone. I use this ankle trick for women in labor and in bed for a long time, especially if they have to have BPs done every 15 minutes, epidural or not. Women can tolerate the ankle cuffing much more than a continuous upper arm cuffing.

I cannot agree with WRM enough that BO cuff size is SO important to us fat women. Teach your doulas and partners to watch out for it in labor (usually once in the hospital, you keep the same cuff throughout, so making sure it is large just the once is enough). And it is WAY worth our stating, clearly but not demanding, that the large cuff needs to be used. If they insist on coming at you with the (too) small cuff, tell them they need to do it on your lower arm. They may have never heard of this, but you will be demonstrating your knowledge of your own body and taking a stand on being your own best care provider.

Thanks for such a great post!

Well-Rounded Mama said...

Ms. Heathen, I don't usually have to bring my own cuff (although I do own one) but when I have brought one, they've been very open to it.

I actually bought two cuffs for myself; a large one that can screw into the dr's BP apparatus, and an automatic home monitor with a large cuff I can use myself at home. Both have been useful.

Shotgun Mary, I will be interested to hear if this makes a difference in your readings since you are right on the cusp of that cutoff.

Both Anonymous commenters, THANK YOU for listening and being open to learning about this, and for making sure your future patients get the right cuff. It's amazing just how resistant some staff are about it (the next post is about that), so it's great to have staff who will be vigilant about it. Thank you.

Hi Navelgazing Midwife, welcome to my blog! I've read yours off and on for many years. Thank you for sharing your story; I'm sure it's only one of many you could share between your own experiences and your clients' experiences!

I do know about forearm readings; I wrote about it in a previous post. While forearm readings can be used in a pinch, they are not that accurate either and tend to overestimate BP, so if your client is borderline at all, it's probably not as good a choice as getting the correctly-sized cuff. It's certainly better than nothing or than using a regular cuff on a fat arm....but it's not the ideal either and does overestimate pressures to some degree.

You can read the study references on that on my original post about BP cuff size, http://wellroundedmama.blogspot.com/2009/03/importance-of-blood-pressure-cuff-size.html.

Well-Rounded Mama said...

Navelgazing Midwife, I got interrupted and hit "publish" before I finished that last comment. Oops!

Yes, if a healthcare worker comes at you with a regular cuff and won't/can't get a proper-sized one, forearm readings are better than doing a regular reading on a fat arm. Very true.

However, forearm readings aren't accurate enough to use on a regular basis and may not be a very good choice for someone with borderline pressures, since they tend to overestimate BP to some degree too.

Forearm readings are a tool you can use if you have to, but best choice is to insist on the proper cuff size, which certainly a hospital SHOULD have somewhere. The hard part is getting them to get it sometimes, which is what my next post is about.

But thanks for reiterating that a forearm pressure is another option if there truly are no other choices.

Sarah B. said...

I have two logistical questions:

1- once I've measured my arm circumference, how to do I know what size cuff to use? I don't even know what sizes they come in! What formula should I use?

2- Where can one buy one's own cuff to bring to the doctor's office?

THANK YOU!!!!

Well-Rounded Mama said...

Sarah B, those are good questions.

I answered those in the first post I wrote on the BP cuff size topic, which you can find at http://wellroundedmama.blogspot.com/2009/03/importance-of-blood-pressure-cuff-size.html.

It has info for you to figure out your cuff size from, and a link to a page where you can buy your own cuff from Amplestuff, if you'd like.

Or you can read about it all summarized in one place on my website, www.plus-size-pregnancy.org on the BP cuff size page.

Anonymous said...

I've never been pregnant, but I've had an awful time with almost every medical office I've been in recently doing the blood pressure reading wrong (with clothes on, lying down, while talking to me, etc.)!

I know someone that is teeny-tiny, and it often seems that she gets strange blood pressure readings. Does she need to get the medical professionals to use a different cuff.