Diagnosis and management of ectopic pregnancy using bedside transvaginal ultrasonography in the ED: a 2-year experience

Abstract

Objectives

The objective of this study was to describe diagnosis and management of ectopic pregnancy using bedside transvaginal ultrasound (US) in an established emergency US program.

Methods

This was a retrospective study on patients presenting over a 2-year period performed at a level I urban academic emergency department (ED). The ED sees 78 000 patients annually and has a residency and active US program. Patients were eligible for inclusion if they were pregnant, seen in the ED for a first-trimester complication, and underwent a bedside emergency US suggesting an ectopic pregnancy. Emergency department US logs were reviewed for findings suggestive of ectopic pregnancy. Medical records were reviewed for history, physical examination findings, laboratory results, additional diagnostic testing, management, hospital course, and a discharge diagnosis by the admitting obstetric service (OB). Patients with incomplete data were excluded from analysis. Statistical analysis consisted of descriptive statistics.

Results

Seventy-four patients ranging in age from 16 to 39 years (mean, 25 years) were included in the study. Eight patients with incomplete data were excluded from analysis. Emergency-physician US diagnoses included definite ectopic pregnancy (6/74), probable ectopic pregnancy (28/74), and possible ectopic pregnancy (40/74). Forty-seven (64%) of these patients were eventually diagnosed with definite ectopic pregnancy by the OB. During initial consultation, the OB disagreed with the diagnosis of ectopic pregnancy in 15 (32%) of the 47 eventual patients with ectopic pregnancy, calling them miscarriages. Other eventual diagnoses included 9 (12%) patients with possible ectopic pregnancy, 11 (14%) patients with miscarriage, and 7 (9%) with intrauterine pregnancy. Emergency sonologists found tubal rings in 9 (19%) patients with eventual ectopic pregnancy, complex adnexal mass in 29 (61%) patients, and a large amount of echogenic fluid in the cul-de-sac in 10 (21%) patients. Six (13%) patients had live ectopic pregnancy. The OB ordered a radiology US in 10 cases but did not change the diagnosis or management. β-Human chorionic gonadotropin (β-hCG) levels ranged from 41 to 59 846 mIU/mL (mean, 4602 mIU/mL), but for live ectopic pregnancy, the range was 2118 to 59 846 mIU/mL (mean, 36 341 mIU/mL). Seventeen (36%) patients had β-hCG levels of lower than 1000 mIU/mL. Of 47 eventual ectopic pregnancies, 29 (62%) patients underwent operative intervention, 17 (36%) patients received methotrexate, and 1 patient left against medical advice. Five (11%) of these patients with definite ectopic pregnancy were initially managed by emergency physicians with follow-up ED visits and serial US examinations without OB consultation.

Conclusion

Our study demonstrates that with increased experience, emergency sonologists can accurately diagnose ectopic pregnancy. Furthermore, patients at risk for ectopic pregnancy should not be denied US examinations if their β-hCG levels fall below an arbitrary discriminatory zone.

Introduction

Ectopic pregnancy is a high-risk condition that occurs in approximately 2% of all pregnancies [1]. The prevalence of ectopic pregnancy is much higher in the emergency department (ED) compared with the general population, accounting for approximately 8% of all pregnant ED patients [2], [3], [4], [5]. In the United States, the incidence of ectopic pregnancy has increased from 4.5 per 1000 pregnancies in 1970 to 19.7 per 1000 in 1992, accounting for 9% of pregnancy-related maternal deaths [2], [5]. Forty percent of ectopic pregnancies are missed on initial ED evaluation, and ectopic pregnancy remains the leading cause of pregnancy-related death in the first trimester [3], [6], [7], [8]. Early diagnosis of ectopic pregnancy is crucial to prevent major complications and their sequelae.

Clinical criteria alone are not adequate to distinguish between patients with ectopic pregnancy and miscarriage. Pelvic ultrasound (US) is the test of choice in the initial evaluation of patients with possible ectopic pregnancy. Ultrasound has been shown to be an accurate and rapid method of ruling out ectopic pregnancy. The portability, accuracy, and noninvasive features of US make it an ideal tool for use by trained emergency physicians. Emergency physicians have been using bedside pelvic US in the evaluation of patients with first-trimester complications for more than a decade. Prior studies have shown that emergency physician–performed bedside pelvic US is safe and decreases length of stay, overall cost, and morbidity [9], [10]. The objective of our study was to describe diagnosis and management of ectopic pregnancy using bedside transvaginal US in an established emergency US program and to focus toward identifying ectopic pregnancy and not simply ruling in an intrauterine one.