HPI: 34yo female presents with abdominal pain located in the RLQ. Found to have + pregnancy test on arrival with LMP approximately 1 month ago. No vaginal bleeding. HCG in 500s.
Imaging: Formal pelvic ultrasound reveals "cyst-like structure" in endometrium without a fetal pole. No adnexal masses. Normal ovarian blood flow. No significant free fluid.
Event: Patient has syncope in the ER.
Bedside Ultrasound in the RUQ:
hat structures do you see?
What is abnormal about this ultrasound?
Bedside Ultrasound in the suprapubic view:
Where is the uterus?
Is there a gestational sac?
What is abnormal about this ultrasound?
Diagnosis: Ruptured ectopic pregnancy
Ultrasound Education:
A FAST exam is indicated in any clinical situation in which there is concern for intra-abdominal free fluid or hemorrhage. It is used most often in blunt and penetrating cardiac and abdominal trauma, but is also used when investigating ectopic pregnancy. A moderate amount of free fluid in the abdomen is highly suggestive of an ectopic in the right clinical situation and a FAST exam can reduce the time to diagnosis and treatment of ectopic pregnancy.
This patient has a "pseudo-sac" which is a small collection of intrauterine fluid without presence of a yolk sac, fetal pole, or double-decidual sign (where the decidua lining the uterine cavity meets the decidua lining the gestational sac). However early pregnancies can appear similar to a "pseudo-sac".
During the FAST exam, the patient lies supine, such that fluid will first accumulate in Morrison's pouch as seen on this ultrasound. The 4 views of the FAST exam include:
1) RUQ (Morrison's pouch)
2) LUQ (Splenorenal recess)
3) Suprapubic area
4) Subxiphoid area (pericardium)
Additional resources:
-Free fluid in Morison's pouch on bedside ultrasound predicts need for operative intervention in suspected ectopic pregnancy. https://www.ncbi.nlm.nih.gov/pubmed/17554008
-Use of a beta-hCG discriminatory zone with bedside pelvic ultrasonography https://www.ncbi.nlm.nih.gov/pubmed/21310509
-Accuracy of first-trimester ultrasound in diagnosis of intrauterine pregnancy prior to visualization of the yolk sac: a systematic review and meta-analysis https://www.ncbi.nlm.nih.gov/pubmed/25393076