(O-K1) Using Linear Probe Point-of-care Ultrasound to Identify Early Intrauterine Pregnancies in an Emergency Department

Saturday, September 9, 2023

9:45 AM - 9:57 AM EEST

Location: Elafos A

Oral Presenter / Co-Author(s)

Soheil Saadat, MD PhD

Research Specialist
University of California, Irvine
Orange, California, United States

Primary Author(s)

MG

Megan E. Guy, MD

Ultrasound Fellow
University of California, Irvine
Orange, California, United States

Co-Author(s)

EH

Edmund Hsu, MD

Ultrasound Fellow
University of California, Irvine
Orange, California, United States
AL

Albert Lee, MD

Ultrasound Fellow
UC Irvine
orange, California, United States
RG

Ryan Gibney, MD

Interim Ultrasound Director
University of California, Irvine
Orange, California, United States
BN

Brenda Nash, RDMS

Ultrasound Sonographer and Coordinator
University of California, Irvine
Orange, California, United States
NP

Nora Perez-Moreno, RDMS

Ultrasound Coordinator
University of California, Irvine
Orange, California, United States

Principal Investigator(s)

SL

Shadi Lahham, MD, MS

Emergency Attending Physician
Kaiser Permanente
Anaheim, California, United States

Co-Author(s)

MN

Michelle Nguyen, BS

Research coordinator
University of California, Irvine
Orange, California, United States
IN

Isabelle Nepomuceno, BS

Research Coordinator
University of California, Irvine
Orange, California, United States
ET

Erinna Thai, BS

Research Coordinator
University of California, Irvine
Orange, California, United States
AN

Andy Nguyen, MD

Attending Physician
Desert Valley Hospital
Victorville, California, United States
Jonathan Rowland, MD (he/him/his)

Attending
UT MD Anderson Cancer Center
Houston, Texas, United States
MW

Matthew Whited, MD

Attending Physician
University of California, Irvine
Orange, California, United States
JB

Jessa Baker, MD

Attending Physician
University of California, Irvine
Orange, California, United States
CF

Chanel Fischetti, MD

Clinical Instructor of Emergency Medicine
Harvard Medical School
AK

Ami Kurzweil, MD (he/him/his)

Ultrasound Program Director
Eisenhower Health

Faculty Advisor(s)

JF

John Christian Fox, MD

Ultrasound Fellowship Director
University of California, Irvine
Orange, California, United States

Objectives: The purpose of this study is to determine whether a linear probe alone can identify first trimester IUP.

Background: There are over 5 million Emergency Department visits annually for vaginal bleeding in early pregnancy. The current standard of care for visualizing first trimester pregnancy is with transabdominal ultrasound with a curvilinear probe or transvaginal ultrasound with an endovaginal probe. To date, no previous studies have evaluated the use of linear probe point-of-care ultrasound (LPUS) to assess intrauterine pregnancy (IUP) in first trimester patients presenting to the Emergency Department.

Methods: A team of undergraduate researchers from the Emergency MedicalResearch Associates Program (EMRAP) screened women in their first trimester of pregnancy with a BMI < 35. If a patient chooses to participate, they signed a HIPAA and Consent form. Forms come in both English and Spanish•A linear probe ultrasound was performed before obtaining a transvaginal ultrasound•An EM physician will perform the two ultrasounds and complete a collection sheet.

Results: With 95% confidence for the linear probe to detect an intrauterine pregnancy:sensitivity is between 15.2%-64.6%. Due to low sensitivity, the study is not clinically useful to detect intrauterine pregnancies.

Conclusions: The distribution of BMI and gestational age was not uniform in our sample; therefore, we are not able to study the accuracy of LPUS according to BMI or gestational age. Further studies are required to identify whether LPUS is a reliable tool
to rule out pregnancy in low BMIs. As a negative pilot study, this data is inconclusive. Considering a 95% confidence interval, we are 97.5% confident that the true sensitivity is below 67.7%, which is not clinically useful in detecting IUP. Our findings did not support the idea that LPUS can reliably detect an IUP during the first trimester.

References (Optional):

Funding (Optional): n/a