Trauma in the pregnant patient is scary, but thankfully not very common. About 1 in 15 pregnant women sustain some type of significant injury. About half are from car crashes (most commonly if unrestrained), and 25% each are from assault (frequently domestic) and falls. Unfortunately, trauma is the leading cause of non-obstetric fetal death.
What makes this type of trauma problematic is two-fold, literally. First, you have two patients. And second, neither one has “normal” physiology. The mother has made numerous adaptations to accommodate the pregnancy, and the fetus is essentially a small parasite, totally dependent on her.
Let’s look at the impact of some of the more important maternal adaptations:
Total blood volume increases by about one liter. This would seem to be good, but since it is mainly dilutional with no real increase in total RBCs, and this is coupled with a lower mean blood pressure. Trauma professionals can easily underestimate blood loss.
Going into the third trimester, the uterus can compress the IVC when the mother is lying supine. but it is quite frequently forgotten. One of the first maneuvers when you suspect an advanced pregnancy is to bump the patient to her left. Do this even if the blood pressure is normal.
The pelvic veins are huge. Disruption from pelvic fractures or penetrating injury can lead to massive bleeding.
The stomach is probably full, and under pressure from below. This increases aspiration risk in women who have decreased mental status or need intubation.
And don’t forget the fetus:
The fetal/placental/uterine complex is one large, non-compressible unit with multiple shear planes within it. Blunt force will stress those planes, and may result in disruption of the uterus from pelvic veins (massive bleeding), or separation of the placenta from the uterus (abruption).
The fetus is totally dependent on the mother for survival, but the placenta will protect the mother first, shutting down fetal circulation if she becomes hypotensive or hypoxic.
The baby was designed to come into this world at full term. We have developed the technology to sustain life in smaller and more premature babies. The magic number of weeks keeps slowly decreasing, but preemie survival without complications is a challenge.
Tomorrow, we’ll move on and get to the fun stuff, predicting outcome after trauma in pregnancy.
Here’s an image of the Lucas automated CPR device. Here’s a question for you: can you use the Lucas chest compression device in a pregnant patient?
The official company answer is “no.” Obviously, this is one those areas that is tough to get research approval on, and the number of pregnant patients who might need it is very small. So basically, we have little experience to go on.
That being said, the reality is that prehospital agencies can and do use it for these patients on occasion. There is only one published case report that I could find (see reference below). The thing that makes using this device a little more challenging is that, to optimize blood pressure, late term pregnant patients need to have the uterus rolled off of the vena cava. This means tipping the patient to her left.
As you can see from the picture above, the design of the Lucas makes this a bit difficult. However, it can be done, either by tipping the board the patient is on or wedging something under the right side of the back plate.
And as always, make sure that you adhere to your local policies and procedures, or have permission from your medical director to use this device in this particular situation.
Reference: Cardiac arrest and resuscitation with an automatic mechanical chest compression device (LUCAS) due to anaphylaxis of a woman receiving caesarean section because of pre-eclampsia. Resuscitation 68(1):155-159, 2005.
Your preparation. You should already have full personal protective gear on, right? Right? Your existing gear is just fine. You do not need to change to sterile gown and gloves. The time wasted is probably not worth the low risk of infection in the rare event that the mother survives.
You need at least one assistant, preferably two. They will pass you instruments and provide retraction. Continue CPR throughout the procedure.
At the same time, call your OB and neonatal colleagues, if you haven’t already. If you don’t have any at your hospital, don’t sweat it. If you do, don’t wait for them to arrive.
Patient preparation. Have someone quickly insert a foley catheter.
Do not use sterile technique. It just slows things down. The bladder needs to be empty so you can quickly and easily get to the uterus.
The procedure. Here’s the blow by blow:
Splash some betadine on the skin. The mother is probably not going to survive, so infection is not a concern.
Make a midline, vertical incision from mid-epigastrium to pubis. Extend down to the midline fascia.
Enter the peritoneal cavity near the umbilicus. Extend the incision along the full length of the skin incision using scissors.
Use the scalpel to make a 4cm vertical incision near the top of the uterus. Insert your 2nd and 3rd fingers into the uterus, directed downwards. Use them to protect the fetus from the scissors as you use them to extend the uterine incision downwards.
Rupture the membrane with a clamp and deliver the baby. Remember, the membrane is tough! Insert your hand deep into the lower uterus under the baby’s head. Flex the body as you gently push upwards to deliver the head first. Suction the mouth and nose, then deliver the shoulders and body.
Cut and clamp the cord. Hand off the baby to another team for suctioning and resuscitation.
Continue to try to revive the mother. If circulation is restored, move immediately to an OR for delivery of the placenta, control of the bleeding that was killing her in the first place, and hopefully, closure.
Here’s a video that shows how quickly the procedure can be done (with a few edits). Just watch the first 47 seconds!
Most emergency departments do not have a separate perimortem C-section pack sitting on the shelf. And when you finally need it, that is not the time to make one up. Most emergency departments have some type of major cutdown or mini-laparotomy tray available. Here is the absolute minimum required. Make sure these are on your existing tray.
Large scalpel – note that this should be a disposable type that is opened and dropped onto the tray
3 large retractors for the helpers
Multiple large clamps and hemostats
Yup, that’s all the heavy equipment you really need!
The perimortem C-section (PMCS) is a heroic procedure designed to salvage a viable fetus from a moribund mother. Interestingly, in some mothers, delivery of the fetus results in return of spontaneous circulation.
The traditional teaching is that PMCS should be started within 4-5 minutes of the mother’s circulatory arrest. The longer it is delayed, the (much) lower the likelihood that the fetus will survive.
The reality is that it takes several minutes to prepare for this procedure because it is done so infrequently in most trauma centers. Recent literature suggests the following management for pregnant patients in blunt traumatic arrest (BTA):
Cover the usual BTA bases, including securing the airway, obtaining access and rapidly infusing crystalloid, decompressing both sides of the chest, and assessing for an unstable pelvis
Assess for fetal viability. The fundus must measure at least 23 cm.
Assess for a shockable vs non-shockable rhythm. If shockable, do two cycles of CPR before beginning the PMCS. If non-shockable, move straight to this procedure.
Bottom line: Any time you receive a pregnant patient in blunt arrest, have someone open the C-section pack while you assess and try to improve the mother’s viability. As soon as you complete the three tasks above, start the procedure! You don’t need to wait 4 minutes!
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