← The OB/GYN Resident Survival Guide
The OB/GYN Resident Survival Guide
#13: How to Identify & Manage a Shoulder Dystocia (and the largest baby I've ever delivered)
00:14:05
Loading summary
Transcript45 lines
- [00:01]
A
Hello and welcome back for another episode. Today I'm going to teach you how to identify and manage a shoulder dystocia. I am recording this ill and with a sore throat, so if I don't
- [00:15]
B
sound like myself or if I sound unpleasant, please forgive me. Before we start, I wanted to invite you to join in on a one hour training I'm hosting over the next two weeks called the Intern's Guide to
- [00:29]
A
Managing Labor Induction and Augmentation.
- [00:33]
B
During the training, I'm going to teach you how to counsel patients about labor induction. I'll review how to calculate and actually apply the Bishop score as well as do a deep dive on all the induction methods including medication dosing frequency and contraindications.
- [00:49]
A
At the end there will be a Q and A, so you can ask any question you want.
- [00:53]
B
It doesn't have to be related to the actual topic and I think it'll be super helpful for any incoming interns or students that are hoping to match into OB GYN and want a little bit of an edge up as you go into your OB GYN rotations and sub is. So if that sounds like a fit
- [01:10]
A
for you, you can click the link
- [01:11]
B
in the show notes or visit subscribepage IO interntraining. All right, back to the scheduled program. Let's start with the definition of shoulder dystocia.
- [01:23]
A
A shoulder dystocia is defined as the failure to deliver the fetal shoulder or
- [01:28]
B
shoulders with gentle downward traction on fetal
- [01:32]
A
head, requiring additional obstetric maneuvers to affect
- [01:35]
B
delivery, AKA a size discrepancy between the shoulders and pelvic inlet that obstructs delivery and this can present with the anterior shoulder lodging behind the pubic symphysis or the posterior shoulder lodging behind the sacral promontory. The incidence of Shoulder Dystocia is 0.2 to 3% in Vertex presenting fetuses and
- [02:00]
A
the recurrence rate is anywhere between 1
- [02:04]
B
and 16%, with the majority of studies reporting at least a 10% recurrence rate. Those numbers might not be super reliable given that many patients with a history of shoulder dystocia and associated complications will actually choose not to labor and electively undergo cesarean delivery. Risk factors for shoulder dystocia include maternal diabetes and suspected fetal macrosomia. However, the majority of dystocias occur in non diabetic patients with normal sized babies, so it's generally unpredictable and unpreventable. That being said, the ACOG do support the consideration of offering elective cesarean delivery
- [02:48]
A
to two categories of patients, the first
- [02:51]
B
being diabetic patients with babies estimated to be 4,500 grams or greater or non diabetic patients with babies estimated to weigh 5,000 grams or greater. And those are important categories to remember because they may come up on your shelf exam or creogs.
- [03:08]
A
Now, how do we diagnose it?
- [03:09]
B
Slash Call the Shoulder Dystocia if you
- [03:12]
A
listen to episode number eight, Vaginal Delivery Basics, you'll remember me explaining that after the fetal head delivers, it restitutes or
- [03:21]
B
rotates externally, meaning that an occiput anterior fetus will go from face down looking
- [03:27]
A
at the floor, to then facing the right or left wall, depending on how the trunk is oriented. After head restitutes, you apply downward traction
- [03:37]
B
with your hands on the head, which
- [03:39]
A
helps that anterior shoulder to deliver. So a shoulder dystocia should be called if the anterior or posterior shoulder failed to deliver with that gentle traction.
- [03:50]
B
Another side note for the interns listening, you are not likely going to be
- [03:54]
A
the one that calls the dystocia because typically if the senior or supervising attending sees that you're struggling, they will step in to assess whether or not just a little bit more traction is required or if there's truly a dystocia present. Okay, now to the actual practical stuff. What do we actually do when the shoulder dystocia is identified?
- [04:15]
B
The first thing you need to do
- [04:17]
A
is call it meaning announce to the room that there's a shoulder dystocia and ask someone to start the timer because we want to know what the duration of the shoulder dystocia is by the end of the procedure. Then you want to tell the patient to stop pushing so that you can perform all of these subsequent maneuvers.
- [04:35]
B
Now, there are no randomized control trials
- [04:39]
A
to actually guide us on the best
- [04:41]
B
order to perform these maneuvers.
- [04:43]
A
However, the first two of them that
- [04:45]
B
I'm going to talk about are the easiest and least invasive as well as very effective, so it makes sense to start there.
- [04:52]
A
Maneuver number one is McRoberts. This is where two assistants on either side of the patient each grab a leg and hyperflex the thigh back against the abdomen, and this tilts the pubic symphysis cephalad and flattens the lumbar lordosis, both of which can free the impacted shoulder. The second maneuver is the application of supra pubic pressure, and this can be done at the same time as McRoberts. I'll usually call for them both at the same time, and this is where another assistant uses their fist or palm to apply downward and Lateral pressure on the fetal anterior shoulder. Now, in order for them to do this properly, you need to tell them which direction to direct the lateral pressure, either to the patient's right or to their left. And the direction should be whichever way the head restituted. So if the head is facing the maternal right, they should be pushing in that direction to relieve the impacted shoulder. And what that does is it abducts and rotates the anterior shoulder inward. Maneuver number three is posterior arm delivery. And this is where you insert your hand into the vaginal canal, all the way in farther than you think, so that you can feel the fetal hand on the posterior arm when you grasp it. Then you can flex at the elbow gently and sweep the arm across the chest, up towards the head and out of the vagina. If you don't have the space to do this, you can consider making an episiotomy. And that stands for any of the maneuvers.
- [06:24]
B
The next two maneuvers are considered rotational maneuvers.
- [06:27]
A
There is the Rubin maneuver, and this is where you place your hand on the back surface of the posterior shoulder and then rotate the shoulder anteriorly towards the face, curving it inward. The wood screw maneuver is the opposite. Instead of putting your hand on the back of the posterior shoulder, this time you put your hand on the front of it over the clavicle, and try rotating it away from the fetal face.
- [06:53]
B
So those were maneuvers number four and five.
- [06:56]
A
Maneuver number six is the application of an axillary sling. This is where you take a size 12 or 14 French catheter, a soft catheter, and thread it under the axilla of the posterior arm to create a sling. You then apply moderate traction to the sling to try and get that posterior shoulder to deliver.
- [07:17]
B
Then we have maneuver number seven, Gaskin all fours.
- [07:21]
A
And this is really only feasible if the patient does not have an epidural. Because in order to do this, the patient needs to be able to mobilize onto their hands and knees so that you can then apply downward traction on
- [07:33]
B
the posterior shoulder or upward traction on the anterior shoulder.
- [07:38]
A
All right, those are your seven maneuvers. But what happens if none of them work? Well, then, unfortunately, you have to just repeat them all. And if you've repeated them several times and the shoulder is still impacted, you have no choice but to move towards the last resort options. So one option is to intentionally break the clavicle. And you do this by pulling the anterior clavicle outward, thus decreasing the bisacromial diameter. The next two options, I truly hope that I will never have to perform and that you will never have to perform these due to the associated high morbidity and mortality for the fetus. The Zavanelli maneuver is cephalic replacement followed by C section, meaning you push the head back into the vaginal canal and emergently go to the OR to deliver that baby by C section. Like I said, high morbidity, high mortality. If you don't do the Zavanelli, you can try an abdominal rescue where you don't replace the head back into the vagina, but you still take the patient to the operating room, you do the ex lab, you perform a hysterotomy, and you manually through the hole you've made in the uterus dislod shoulder from above to facilitate a vaginal delivery from below.
- [08:53]
B
Now, before we do an episode recap, I wanted to share a little bit about what this looks like in real life. I have assisted with probably over a dozen, maybe close to two dozen shoulder dystocias in the last five years. Don't ask me why or how. It's just like they flock to me and I don't love it. In fact, the largest baby that I delivered vaginally that unsurprisingly had a shoulder Dystocia was 11 pounds and 4 ounces. This patient was already laboring when I came onto my shift and the documented estimated fetal weight was only 3,900 grams. However, she was also very obese, so I suspect those measurements were very limited due to her habitus, which does happen. So in that scenario, I was surprised, but normally we try to take precautions so that a shoulder dystocia is actually not a huge surprise. Of course, because it can happen in any patient, it's impossible to be prepared every single time. However, if we know that this baby is going to be large, that gives us a little bit of information so that we can be prepared. In that scenario, any patient with a large estimated fetal weight should be discussed at the morning and evening sign out and shoulder precautions put in place, meaning that at the time of delivery, everyone in the room is already anticipating for this to happen and is prepared. Just in case. The nurses will place step stools on either side of the bed so that they are ready to perform McRoberts and superpubic pressure as needed. And I will also make sure that the patient is positioned right at the edge of the bed so that I'm not having to reach up the bed to perform the maneuvers and so that the bed doesn't get in my way when I'm performing downward traction during delivery. In the real world, all the maneuvers kind of happen all at once. When I identify that there's a shoulder, I'll call out to the room. Shoulder, start the timer, and then I'll tell the patient to stop pushing. By then the nurses are already doing McRoberts, and if they're not, I'll ask them to and then I'll also say suprapubic pressure to the window or to the door. I find that saying right or left can be confusing sometimes because the assistant doesn't know if I mean my right or the patient's right. So landmarks are just a little bit easier to work with. As they're doing this, I'm cycling through the posterior arm, wood screw, and Reuben maneuvers within a matter of seconds, and I'll ask them to take a break with the suprapubic pressure intermittently as needed. But generally I'm not spending more than 10 to 15 seconds on one maneuver because getting this baby out as quickly as possible is essential. So I'm trying a lot of things within a short period of time. From personal experience, I've actually found that delivering the posterior arm is a lot harder than performing Wood screw and Ruben maneuvers.
- [11:47]
A
So I'll usually actually start with those
- [11:49]
B
and then if they fail, I will go for the posterior arm. And you have to put your hand a lot farther in than you think. And depending on how lodged they are in there, it sometimes feels near impossible to sweep that arm up and out. Also, I've never actually done a posterior sling. There was one time that I was going to, so I called out to the room for a Foley catheter. However, the bedside nurse didn't know what it was for, so she brought in the whole urethral Foley kit with a bag attached and I didn't have time to set it up or explain to her what I actually wanted it for, so I didn't end up using it. All right, let's do a quick summary of what we reviewed today. The definition of a shoulder dystocia is
- [12:32]
A
the failure to deliver the fetal shoulder or shoulders with gentle downward traction on the fetal head due to a size discrepancy between the shoulders and pelvic inlet. Next, diabetes and suspected fetal macrosomia are risk factors. However, the majority of shoulder dystocias will occur in non diabetic patients with normal sized infants. That being said, ACOG supports the consideration of elective cesarean delivery in diabetic patients with estimated fetal weights of 4,500 grams or greater, or to non diabetic patients with estimated fetal weights of 5000 grams or greater. When you identify a shoulder dystocia, you need to call it out to the room so everyone is aware and tell the patient to stop pushing. There are seven primary maneuvers that you can attempt to relieve the shoulder Dystocia 1. McRoberts 2 suprapubic pressure, 3 posterior arm delivery 4. Rubin 5. Wood screw, 6 axillary sling and 7 Gascon all fours. If none of those work, repeat them all. Your last resort steps include intentional clavicle fracture, the Zavanelli maneuver, or abdominal rescue. That's everything for today. As usual, all of my references and the links I talked about in the episode will be in the PODC show notes and I hope to see you live for the one hour training that I talked about at the start of today's episode. Take care and have a great week.