Diagnosis of Ectopic Pregnancy in the Emergency Department

Ralph Wang/Brian ChinnockUCSF/Fresno DEM

learning objectives

• understand the problem of EP

• become familiar with roles of US and bHCG

• learn how to perform bedside pelvic US

• integrating BPU into your practice

• recognize common pitfalls of BPU

key points

• r/o EP by identifying IUP (with caveat)

• IUP is defined by GS + YS surrounded by myometrium

• interrogate the uterus thoroughly

• bedside US is the test of choice in unstable patients

• TVS and TAS are complementary

who are we talking about?

• pregnant patients in the 1st trimester

• UPT + (with exceptions)

• VB +/or pelvic pain

• no prior US with IUP • does this patient have an ectopic pregnancy?

• 3-13% prevalence in ED studies

• EP was leading cause of 1st trimester mortality (10%)

• increased pre-rupture detection = declining mortalityBarnhart, K. T. Clinical practice. Ectopic pregnancy N Engl J Med 2009

advances in diagnostic modalities

• pelvic ultrasound

• ICT = high resolution (5-8Mhz)

• serum bHCG

basic strategy

• identify location of pregnancy

• identification of IUP = r/o EP

• rate of heterotopic = 1/30000 >1/5000*

• IVF rate = 1/100

ididentify location of pregnancy

ididentification of IUP = r/o EP

rarate of heterotopic = 1/30000 >1/5000*

IVIVF rate = 1/100

possible findings

• IUP (GS + YS) = discharge

• EP (-IUP, FF, adnexal mass) = ob/gyn

• indeterminate (-IUP) = correlate with bHCG

• abnormal IUP

• molar pregnancy

the intermediate result

• approx 10-20% of all pts

• location of pregnancy is unknown

• ddx = early IUP, miscarriage,

• approx 10-20% of all pts

• location of pregnancy is unknown

• ddx = early IUP, miscarriage, EP

narrowing the differential

• enter bHCG/DZ concept

• correlate bHCG to indeterminate result

• bHCG = gestational age

• DZ = level of bHCG at which operator is certain to see IUP (if IUP exists)

• enenteter r bHbHCGCG/D/DZ Z Z Z coconcncepepepeptt

• correlate bHCGCGCGCG t t t to indeterminate result

• bHbHCGCG = = g g gesestatatitiononononalal a agegege

• DZ = level of bHbHbHbHCG at which opopoperator is s certain to see IUP (i(i(i(if f f f IUIUIUIUP P P P exexisisisistststs))))

Gestational Age bHCG IUP visualized by US

3w 25-50

5w 1000-2000 gestational sac

5-6w >2000 GS+YS

6w >5000 GS+FP

7w >10000 cardiac activity

8w >100000

intermediate result

• bHCG<DZ: IUP, EP, embryonic demise

• bHCG>DZ: EP, embryonic demise

Kadar, N.Combined use of serum HCG and sonography in the diagnosis of ectopic pregnancy AJR American journal of roentgenology 1983

, IUP

USI

IUP - D/CEP - C/S OB

intermediate - correlate bHCG with DZI

low B - F/U 48hhi B - C/S OB

Moore, C. Ultrasound in pregnancy. Emerg Med Clin North Am. 2004

problems with protocol

• RUS unavailability

• increased ED LOS

• transport of unstable patients

• sending patients home with EP***

EPPU for EP

• US at the bedside performed by EP

• focused question: do I see an IUP ?

• components:

• transabdominal

• RUQ of FAST

• transvaginal

getting ready - 4P’s

• probe selection

• patient pee’s - bladder should be emptied for TVS

• position - pelvic exam

• probe cover - cover the ICT with condom

TASTAS

B

A

TAS

U V

TAS

TVS sagittal

TVS US

Ucul-de-sac

ES

full bladder

TVS coronal

interrogation - visualize the entire uterus

TVS - left adnexa TVS

recognizing IUP

• IUP =

• GS +YS or FP +

• surrounded by myometrium

gestational sac

pseudogestational sac

• EP may present with pseudo-GS (10%)

• NO DDSS, irregular border, may contain echogenic material

• yolk sac?

psuedogestational sac

GS + YS + surrounded IUP = GS + YS in uterus

location, location

• GS should be within uterus

• beware peripherally placed GS

• may represent interstitial EP

• 5mm rule

• importance of TAS

fetal pole

ectopic location

• majority (97%) tubal

• interstitial/cervical 2%

• ovarian 1%

EP

• empty uterus

• secondary signs

• free fluid (large FF, blood)

• complex adnexal mass

• pseudogestational sac

• EP still possible without secondary signs

Normal FF Free Fluid

TAS - ectopicTAS eecctoppicc ectopic pregnancy

ectopic Morison’s pouch

• FF in RUQ scan predicts need for OR for ruptured EP

• Moore, C. Free Fluid in Morison's Pouch on Bedside Ultrasound Predicts Need for Operative Intervention in Suspected Ectopic Pregnancy Academic Emergency Medicine 2007

abnormal

• large GS without YS, or FP

molar pregnancy

outcomes of EPPU

IUP70%

Demise~50%

IUP~30%

EP15%

Unknown3%

Indeterminant20%

Embrionic demise8%

EP2%

Molar preg<1%

N=1490pts w/ 1st trimester symptoms

Mateer, J. R. Outcome analysis of a protocol including bedside endovaginal sonography in patients at risk for ectopic pregnancy. Ann Emerg Med 1996

risk of ectopic according to subclass

• empty uterus = strongest predictor for EP

• normal GS (no yolk sac) = EP very unlikely

accuracy of EPPU

in 10 trials of EPPU TVS, 1 miss (heterotopic)excellent specificity = when we detect IUP > almost always correct

safe to discharge pts with IUP

McRae, A. Diagnostic accuracy and clinical utility of emergency department targeted ultrasonography in the evaluation of first-trimester pelvic pain and bleeding: a systematic review.

CJEM 2009

ED LOS

4 studies showing 1-2hr decreased LOS if EP identifies IUP

MICHAEL BLAIVAS, MD. Do Emergency Physicians Save Time When Locating a Live Intrauterine Pregnancy with Bedside Ultrasonography? ACADEMIC EMERGENCY MEDICINE 2000

perform EPPUI

IUP - D/CEP - C/S OB, RUS

indeterminate - RUSI

compare BHCG with DZ

Moore, C. Ultrasound in pregnancy. Emerg Med Clin North Am.2004

pitfalls - errors in thinking

• “lets wait for the bHCG before performing the US”

• “I’ve never sent home a pt with EP”

“lets wait for the bHCG”

•EP mean bHCG below DZ

•if only pt with bHCG>DZ scanned - miss 1/3-1/2 EPs

•discriminatory zone and bHCG only apply to IUP, not EP

•IUP and EP can be visualized below DZ

Kohn, M. A. Beta-human chorionic gonadotropin levels and the likelihood of ectopic pregnancy in emergency department patients with abdominal pain or vaginal bleeding. Academic emergency medicine. 2003

pitfalls

• heterotopic pregnancy

• cornual ectopic pregnancy

• pseudo-gestational sac

• state of the bladder

• TVS vs TAS - performing one without the other (see image)

summary

• EPPU for possible EP is a valuable screening tool

• In most instances, IUP rules out EP, dec LOS

• definition IUP = GS + YS surrounded by myometrium

• bedside US is test of choice in unstable pts

• TAS and TVS are complimentary studies

selected bibliography

1. Barnhart, K.T., Clinical practice. Ectopic pregnancy. N Engl J Med, 2009. 361(4): p. 379-87

2. Blaivas, M., et al., Do emergency physicians save time when locating a live intrauterine pregnancy with bedside ultrasonography? Academic emergency

medicine : official journal of the Society for Academic Emergency Medicine, 2000. 7(9): p. 988-93.

3. Mateer, J.R., et al., Outcome analysis of a protocol including bedside endovaginal sonography in patients at risk for ectopic pregnancy. Annals of emergency

medicine, 1996. 27(3): p. 283-9.

4. Moore, C. and S.B. Promes, Ultrasound in pregnancy. Emerg Med Clin North Am, 2004. 22(3): p. 697-722.

5. Moore, C., et al., Free Fluid in Morison's Pouch on Bedside Ultrasound Predicts Need for Operative Intervention in Suspected Ectopic Pregnancy. Academic

Emergency Medicine, 2007. 14(8): p. 755-758.

6. Tayal, V., Outcome of Patients with an Indeterminate Emergency Department First-trimester Pelvic Ultrasound to Rule Out Ectopic Pregnancy. Academic

Emergency Medicine, 2004. 11(9): p. 912-917.

7. Kohn, M.A., et al., Beta-human chorionic gonadotropin levels and the likelihood of ectopic pregnancy in emergency department patients with abdominal pain or

vaginal bleeding. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine, 2003. 10(2): p. 119-26.

8. Adhikari, S., M. Blaivas, and M. Lyon, Diagnosis and management of ectopic pregnancy using bedside transvaginal ultrasonography in the ED: a 2-year

experience. The American journal of emergency medicine, 2007. 25(6): p. 591-6.

9. Shih, C.H., Effect of emergency physician-performed pelvic sonography on length of stay in the emergency department. Annals of emergency medicine, 1997.

29(3): p. 348-51; discussion 352.

10. McRae, A., H. Murray, and M. Edmonds, Diagnostic accuracy and clinical utility of emergency department targeted ultrasonography in the evaluation of first-

trimester pelvic pain and bleeding: a systematic review. CJEM : Canadian journal of emergency medical care = JCMU : journal canadien de soins médicaux

d'urgence, 2009. 11(4): p. 355-64.