Evaluating for an ectopic pregnancy using point-of-care ultrasound (POCUS)
After reviewing this lesson, you will know how to evaluate for an ectopic pregnancy using point-of-care ultrasound.
After reviewing this lesson, you will know how to evaluate for an ectopic pregnancy using point-of-care ultrasound.
This video was taken from our POCUS Essentials course taught by Viveta Lobo, MD who is an attending emergency medicine physician and Associate Director, Emergency Ultrasound Fellowship at Stanford University Medical Center in California, USA.
Video Transcript
[00:00:00] Now that we've reviewed what a normal pelvic study should look like and how to definitively evaluate for intrauterine pregnancy, let's talk about an ectopic pregnancy. When evaluating for an ectopic pregnancy, you may not always actually identify the ectopic pregnancy. You often will only see secondary signs of a ruptured ectopic pregnancy. Let's look at this image. Here, you're looking at the short-axis of the uterus using an endocavitary probe.
[00:00:30] Surrounding your uterus, you should notice the anechoic structure that is free fluids surrounding your uterus. The right clinical setting of a pregnant patient, with lower abdominal pain or vaginal bleeding, with an unidentifiable definitive IUP and free fluid, like this, on their pelvic study, I would be very concerned for a ruptured ectopic pregnancy. What if I told you that that same patient had a beta quant number of 1,500?
[00:01:00] A beta quantification number is a lab value that is routinely used to monitor the progression in an early pregnant female. A value of 1,500 is a relatively low number. One might be tempted to think that because the number is relatively low, they probably just have a very early intrauterine pregnancy that is not identifiable on ultrasound as yet. That would be an incorrect correlation. The literature shows that there is no reliable correlation between a beta quant number
[00:01:30] and your gestational age or your expected ultrasound findings. So, don't use your beta quant number on ruling out an ectopic pregnancy. Here, we're looking at the short-axis of your uterus using an endocavitary probe. If I told you that this patient had a positive pregnancy test, I would be concerned because within the uterus, I don't see any identifiable intrauterine pregnancy. However, if you look out to the right side outside the uterus, you do see what looks like a gestational sac with
[00:02:00] fetal material and even cardiac activity present. This was an ectopic pregnancy in the right fallopian tube. How about this image? Once again, we're looking at a short-axis view of your uterus and we've moved our probe to look at the left side of the pelvic cavity. Here, we should expect to find our left ovary. We don't see any identifiable gestational sac or a definitive IUP within the uterus. However, within the left ovary, we notice a gestational sac with hyperechoic
[00:02:30] material within it. This was an ectopic pregnancy found within the left ovary. How about this image? Once again, we're looking at a short-axis view of your uterus and surrounding your uterus, you'll notice anechoic material with some hyperechoic material within it. This is actually free fluid around your uterus with hyperechoic clots. This is a very concerning finding for a ruptured ectopic pregnancy. Here's your ultrasound pearl. If you have a patient where you have a very high suspicion
[00:03:00] for a ruptured ectopic pregnancy but on the ultrasound exam cannot actually identify the ectopic pregnancy, move your low-frequency probe up to the right upper quadrant, as if performing a fast view. If you see free fluid around the liver, like this, that would be consistent with a ruptured ectopic pregnancy. Remember, a ruptured ectopic pregnancy is going to bleed into your peritoneal space, so you may find a positive fast exam. So to summarize, let's review an algorithm on how
[00:03:30] to assess the early pregnant female, who presents with abdominal pain and / or vaginal bleeding, in order to rule out an ectopic pregnancy. If you have a patient with a positive pregnancy test, you should perform a bedside ultrasound study. Either you will see a definitive IUP in which case you've ruled out your ectopic and you're done or you will not see a definitive IUP. If you don't see a definitive IUP, you should be considering one of the following options: either you visualized your ectopic pregnancy and will now
[00:04:00] consult your OB / GYN consultant for further management or you have secondary findings that are concerning for ruptured ectopic pregnancy such as free fluid in the pelvis or a positive fast exam. Again, you would consult your OB / GYN consultant for further definitive management. Your third option would be very early gestational age. If this is the case, your patient would require close follow-up and monitoring and a repeat ultrasound within one week, to [00:04:30] identify their definitive IUP.