Please see be sure to review Resources at the end of this post. The Resources section contains ten links on all aspects of emergency care for women relating to obstetrics and gynecology and each contains essential information on using the information that can be gained from obstetric POCUS.
To get started we’ll watch two videos from Western Sono:
All of the posts of the series Learning Ultrasound are excerpts from the book Point-Of-Care Ultrasound for Emergency Physicians — “The EDE Book”. I purchased the e book two years ago. The e book is only available on Apple devices. The e book is only about $15 and it is simply the best there is on learning to perform point of care ultrasound (POCUS). You need to buy it now.
I have posted these Learning Ultrasound series, temporarily, for a friend who does not currently have access to an Apple device. In the Resources section following this post, I have posted links to outstanding obstetrical POCUS YouTube videos.
In this post we will go over the often difficult technical points of conducting the point of care obstetric ultrasound exam from Point-Of-Care Ultrasound for Emergency Physicians — “The EDE Book”.
What follows are excerpts from the above book:
Obstetrical Point of Care Ultrasound Scan (POCUS)
Obstetrical Ultrasound differs from all the other POCUS indications because it seeks to rule in because it seeks to rule in a benign condition – intrauterine pregnancy (IUP) – rather rule out a malignant one – ectopic pregnancy. While the detection of an ectopic pregnancy by ultrasound is challenging, the detection of an IUP is quite straight forward. This makes it an appropriate goal for obstetric POCUS. By its very presence, an IUP dramatically decreases the probability of ectopic pregnancy.
The diagnosis of ectopic pregnancy is one that we would like to make it more accurately. For decades, the data suggested that over 40% of women with this condition were undiagnosed at first contact. While these numbers are no doubt improving as [Obstetric POCUS] makes inroads into emergency medicine, there is still much room for improvement, particularly for such a such a potentially lethal condition.
Although previous chapters have stressed the primacy of clinical skills over labs and imaging, ectopic pregnancy is the exception to this rule. We all know how unreliable history is for the date of the last menstrual and pregnancy symptoms; the ‘classic triad’ of delayed menses, vaginal bleeding, and pain is incomplete in up to a quarter of ectopic pregnancies. The physical exam suffers from even worse limitations: the most skillful gynecologists are unable to detect more than half of ectopic pregnancy are unable to detect more than half of ectopic pregnancy masses on physical exam, even under general anesthesia. In fact, when an adnexal mass is felt, it is often the corpus luteum of pregnancy. Not infrequently, this mass is not on the same side of as the ectopic pregnancy.
Luckily, in this area where are primary tools – history and physical are unreliable, we have a lab test ([serum*] the beta-HCG) that is extraordinarly sensitive and extension of the physical [Obstetrical POCUS] that is readily available and highly accurate.
* The urine beta-HCG can, for a number of reasons, can be falsely negative. See Best Case Ever (BCE 68) Ectopic Pregnancy Pitfalls in Diagnosis from Emergency Medicine Cases.
A good rule of thumb to follow in emergency medicine is to assume that every premenopausal women who comes to your department with an abdominal or pelvic complaint has an ectopic until proven otherwise. A negative [serum] beta-HCG will rule this out in most cases. For those who have a positive beta-HCG, an [obstetrical POCUS] can greatly improve our diagnostic accuracy and accelerate disposition by detecting the presence of an intrauterine pregnancy (IUP). While the rate of ectopic pregnancy for all comers is around is 1 in 80, the rate of heterotopic pregnancy (a twin gestation where one embryo is in the uterus and the other one is elsewhere) is 1 in 30,000. By detecting an IUP, therefore, the risk of ectopic pregnancy is vastly reduced. It is worth noting, however, that both these rates are trending upward as chlamydia and fertility treatments become more wide spread. In some areas with endemic chlamydia, the heterotopic pregnancy rate is 1 in 4,000. For women who have undergone some kind of fertility enhancement (e.g., clomiphene in vitro fertilization), the heterotropic rate can be as high as 1%. Even if [obstetric POCUS] detects an IUP in these patients, it is still mandatory to obtain an elective ultrasound to “clear” the adnexa.
*See Two Cases of Heterotopic Pregnancy: Review of the Literature and Sonographic Diagnosis in the Emergency Department [PubMed Abstract] [Full Text HTML] [Full Text PDF]. J Ultrasound Med. 2015 Mar;34(3):527-30. doi: 10.7863/ultra.34.3.527.
Resources On The Management Of Early Pregnancy Loss
Posted on June 23, 2016
Resources For Ultrasound Diagnosis of Interstitial Ectopic Pregnancy
Posted on June 12, 2016
A Great Website for DIY Surgical Practice Models That Students Can Build
Posted on April 11, 2016
What a Positive POCUS OB Study Is and What it Means — YouTube Video From Westernsono
Posted on June 7, 2015
How To Find The Ovaries on Pelvic Ultrasound–A YouTube Video From Gulf Coast Ultrasound
Posted on June 4, 2015
An Outstanding Free Book On Ultrasound In Obstetrics and Gynecology
Posted on January 22, 2015