Transcript for:
Lecture on Fetal Heart Rate Patterns

Hi, I'm Meris with Level Up RN. And in this video,  I'm going to be talking to you about fetal heart   rate patterns. We're going to talk about normal  fetal heart rate patterns, what we expect to see,   what kind of things are okay, and then we're  also going to talk about some abnormal findings   and the causes of those things and what we should  do about them. So I'm going to be following along   with our Maternity Nursing Flashcards in the  Labor and Delivery section. If you have a set,   I would invite you to follow along  with me. And if you don't have one,   you can get a set for yourself on our website,  leveluprn.com. Okay. Let's get started.   So first off, let's talk about normal findings for  fetal heart rate. These are things that we expect   to see or things that are okay to see. So first  and foremost, let's just talk about the heart rate   itself. The normal fetal heart rate baseline is  going to be between 110 and 160 beats per minute.   So we want to first check and see what the rate  is of the fetal heart rate so that we can see,   is this in the right range? Is it too  slow, too fast, that sort of thing.   Now when we talk about accelerations, if you  have seen the video about the nonstress test,   I talk about what accelerations are in that video.  But accelerations are what they sound like. It's   where the fetal heart rate accelerates from its  baseline level, and that's going to be by at least   15 beats a minute. So it's going to increase  by 15 beats per minute, and that's going to be   sustained for at least 15 seconds. So that's  what an acceleration is. And this is a good   thing. This is actually really reassuring that the  baby is getting enough oxygen and things are okay   because accelerations happen in response to fetal  movement and just kind of the impact of the world   around them. Things like vaginal exams also can  cause acceleration. So these are good. These   are normal. These are reassuring. We like them. Now, decelerations, decelerations are also what   they sound like, but we have a couple of different  types. So in this case, when we're talking about   things that are okay or normal, we're talking  about early decelerations. And what this means   is that it's in relation to a contraction. So  when we talk about early or late, we're talking   about where does it happen in relation to the  patient's contraction? So an early deceleration   is going to be a mirror image like a flipped image  of the contraction. So the contraction is going   to come up like this. It's going to peak and come  back down. The deceleration is going to come down   like this. It's going to bottom out and then come  back up. But the peak of the contraction and the   very bottom of the deceleration are going  to match up. They are happening in sync,   so they should look just like flipped versions of  one another. Now, an early deceleration, this is   going to be benign. This is not something where  we need to intervene. This is typically because   of head compression. So that early deceleration  in fetal heart rate is going to be caused by   head compression, compression of the fetal head.  And like I said, that mirroring is going to be   the most important thing to understand when  you're looking for, is it early or is it late?   Now, variability, variability has to do with, how  does the heart rate change second to second? So we   should see fluctuations of the fetal heart rate by  6 to 25 beats per minute around the baseline. So   that's why if you ever look at a fetal heart rate  tracing, most of the time you're not just seeing   a straight line across that's showing you it's  120 beats a minute, and it's just really staying   there. That is not normal. So the variability  indicates that we have a healthy nervous system.   A healthy nervous system of the baby is going to  be demonstrated with this moderate variability.   Remember that variability is a term that can  be used-- you have to qualify it. You have to   say how much there is. So you can have absolute  variability. You can have minimal variability.   You can have marked variability. But what we  want is to see moderate. Moderate variability   is the reassuring type of variability. So now let's move on to abnormal findings.   So from this point out, we're talking about things  that are not normal, not expected, and probably   not okay. So first up, we're talking about fetal  bradycardia. Now, remember that 110 to 160 is the   normal baseline. So fetal bradycardia is going to  be anything that is less than that 110. However,   it has to be sustained for greater than or equal  to 10 minutes. So we're not going to call it   fetal bradycardia if we have a drop in the heart  rate and then 30 seconds later it comes back up,   right? That would probably be more a deceleration.  But why does this happen? Well, there's a lot of   reasons that fetal bradycardia can happen. If we  have prolonged cord compression, we're not getting   enough blood to the baby. That's going to increase  the blood pressure. It's going to decrease the   heart rate. Umbilical cord prolapse, same kind  of situation there. Anesthetic medications,   so medications given to mom can affect baby.  So that has to be a consideration as well.   And fetal heart abnormalities, of course, could  cause that as well. But if I am not-- if my heart   is not beating appropriately, I am not oxygenating  my body appropriately, right? I'm not getting that   good oxygen-rich blood where it belongs. So when  you think fetal bradycardia, you've got to think,   "This baby isn't getting enough oxygen." That's  a big problem. So things that we can do for it,   side-lying position is always a good choice,  repositioning the uterus so that it may not be   on the umbilical cord, for instance, can be  helpful, oxygen, IV fluids, but most importantly,   we need to notify the provider, right?  That's going to be really important,   but we want to stay at the bedside with mom too. Now, on the flip side, fetal tachycardia. So   that's going to be anything above 160 beats  a minute, sustained for 10 minutes or longer,   right? So same parameters, just on  the opposite side of the spectrum.   Now what can cause this? A big one is maternal  fever. So if mom has a fever or an infection,   then that's going to affect mom's metabolic  rate, which in turn is going to affect baby,   also, fetal hypoxia, right? If I'm not getting  enough oxygen, my heart rate is going to start   to go up to try and compensate for that. Maternal  hypothyroidism, again, anything that's affecting   mom's metabolic rate will also affect babies. And  then cocaine use, cocaine use, it's a stimulant   for mom. Therefore, it's a stimulant for baby.  So what are we going to do about that? Well, we   need to treat the underlying cause if that is the  case, so giving an antipyretic for mom's fever,   for instance. IV fluids and oxygen, of course, are  going to be helpful if they are indicated for that   purpose. But there's a line here that I would  like to draw your attention to if you have this   card as well. Fetal tachycardia accompanied  by decreased variability is indicative of   severe fetal distress, so heart rate goes up, but  variability goes down. That's a really bad, scary   thing. We need to be thinking about immediate  interventions to get this baby earthside.   Okay. Up next, we're going to talk about late  and variable decelerations. We already talked   about early decels, right? Those are those exact  mirror images of the contractions. Those are okay.   They're caused by head compression. That's all  right. But when we talk about late and variable,   these are not normal findings. So a late  deceleration is not going to be that perfect   mirror image of the contraction. Instead, it's  going to be offset slightly. So what you're   going to see is that the contraction comes up and  goes down, but the base of that deceleration of   the heart rate is going to come after the peak  of the contraction. So it's later than the peak   of the contraction. That's a late deceleration. So  that can also have a prolonged return to baseline,   meaning that it takes longer for it to  kind of come back up to where it should be.   So those are the scary ones that we don't like  to see. And the biggest cause here is going to be   uteroplacental insufficiency. You can sometimes  hear this just called placental insufficiency.   But essentially, we have decreased blood  flow coming to the baby, which in turn is   going to lead to fetal hypoxia. And that's  where we see that drop in fetal heart rate.   So we have a cool chicken here right here on  this card. We have a cool chicken that I want   to point out because I love this one. I think  it's very helpful. It's how to treat any sort of   deceleration, but specifically, the late one here  we're talking about is LION. And I would actually   say it's LIONS, but I'll get there in a second. So  LION is for left-lying positions. We're going to   turn mom onto the left side. I is for IV fluids.  We're going to administer IV fluids per order.   O is for oxygen, and you can also remember the  O means to discontinue oxytocin. O for oxytocin,   discontinue it. And then N for notify provider.  So those are the letters in LION to remember   treatments for late decels. I would say that  the S is to prep for surgery. So if we have   late decels and we're not able to resolve  them, doing these other LIONS interventions,   then preparing for surgery, delivery via  C-section is going to be the next thing to do.   Moving on to variable decelerations. Variable  decelerations, I remember V for variable and they   kind of look like a V. They have a very sharp,  dramatic drop and usually a pretty quick recovery.   So the fetal heart rate tracing, when you see  a variable decel, it's going along. It drops.   It comes back up, and it keeps going along. Now,  the cause of variable decels, that's going to be   umbilical cord compression. So cord compression is  going to lead to increased fetal blood pressure,   which then is going to lead to decreased fetal  heart rate. So with this one, we need to get the   baby off of the cord. So how can we do that? Well,  we can put mom in the Trendelenburg position.   Trendelenburg is where the head is down, and the  feet are up. So if you have a patient laying flat,   then you're going to tip them like this, and  hospital beds have the ability to do that.   You're going to put the head down, feet up. That's  going to use gravity to shift the uterus, shift   the baby, potentially shifting the baby off of the  cord. Another one would be knee-chest position,   again, to try and move the contents of the uterus  around to get baby off of the cord. Now, again,   we're going to administer oxygen, discontinue  oxytocin, notify the provider. That's all   important stuff all of the time, right?  But amnioinfusion may be indicated. And   this is for patients who have oligohydramnios,  meaning they have too little amniotic fluid.   Well, that amniotic fluid works as a buffer and  a cushion, so it would be between baby and the   cord and providing all of this nice, cushioned  environment. If I don't have enough, then if   that cord is underneath baby, there is no cushion  there. So we can do an amnioinfusion, which again,   is what it sounds like. We are infusing synthetic  amniotic fluid into the uterus to provide that   sort of cushioning environment as well. Now, this card is my favorite one to sum up   everything we just talked about. This is the  VEAL chop card. So we have it spelled out here,   right for you, in big letters. And it's a very  clear card so that you can see exactly what we're   talking about. So VEAL chop, and I want you  to write it out vertically, not horizontally,   vertically, VEAL and chop so that the  letters line up. So V is for variable,   and the C is going to be for cord compression.  They line up. Then we have the E is for early,   so early deceleration lines up with  the H, which is for head compression.   The A is accelerations, which lines up with the  O, which means, okay. This is okay. This is a good   thing. We're not worried about it. And then L is  for late as in late decelerations, which lines up   with the P for placental insufficiency. So when  you use this mnemonic right here, when you use   this, you can line up and see the cause of each  different kind of fetal heart rate variation. So I   hope that review was helpful for you. But now I'm  going to give you some quiz questions so that you   can test your knowledge and see if you picked up  on some of the really key points of this video.   Okay. So first up, I want you to tell me what  is the normal baseline for fetal heart rate?   Think about that, normal  baseline for fetal heart rate.   For which fetal heart rate pattern  would you want to place the mom   in Trendelenburg or knee-chest position?   What does moderate variability in the fetal  heart rate indicate? What does moderate   variability indicate about the fetus?   Lastly, I want you to think about  and tell me what is the cause   of late decelerations? So what is the  underlying cause of a late deceleration?