First Trimester Emergency Pelvic Ultrasonography

Transcription

1 First Trimester Emergency Pelvic Ultrasonography Joel M. Schofer, MD, RDMS, FAAEM Lieutenant Commander, Medical Corps, United States Navy Emergency US Director, Emergency Department, Naval Medical Center Portsmouth

2 INTRODUCTION

3 Why We Order Pelvic Ultrasounds? 89% - Ectopic pregnancy 4% - Cyst 4% 4% 3% 4% - Torsion 3% - Abscess 89%

4 No Thanks...Radiology Will Do My Scans ED pelvic US shortens length of stay Improves throughput More costeffective

5 The Radiology Timeline Order US Pelvis Quantitative HCG ordered Ultrasound tech paged Argument regarding HCG Ultrasound tech arrives Bladder filled Patient to US Ultrasound performed Interpretation sent to ED IUP identified/patient notified Patient discharged TOTAL: Time 0 Time 5 minutes Time 10 minutes Time 30 minutes Time 70 minutes Time 85 minutes Time 100 minutes Time 120 minutes Time 150 minutes Time 160 minutes Time 180 minutes TIME 3 HOURS

6 Emergency Physician Pelvic US Timeline Order US ED Performed US IUP identified Patient notified Patient Time 0 Time 5 minutes Time 10 minutes Time 15 minutes Time 25 minutes discharged

7 Basic Goals of Emergency Pelvic US Identify an IUP Exclude an ectopic pregnancy

8 Secondary Goals of Emergency Pelvic US Detect signs of an ectopic pregnancy Estimate viability of an IUP Find other causes of pelvic pain and bleeding Masses Gestational trophoblastic disease Evaluate for multiple pregnancies

9 Indications for Emergency Pelvic US Pregnant Pelvic or abdominal pain Vaginal bleeding Uterine size not consistent with dates Shock Dizziness Syncope Pelvic mass

10 ANATOMY

11 Sonographic Anatomy Uterus and ovaries are mobile organs Anterior cul-de-sac between bladder and uterus Posterior cul-de-sac or pouch of Douglas between uterus and rectosigmoid Most dependent area so most common location of free fluid

12 TECHNIQUE

13 Transabdominal vs Endovaginal Scanning Transabdominal Endovaginal Wide Field of View Very Wide field of View High depth of view Shallow depth Low Freq, Low Resolution High Freq, High resolution Comfortable with orientation New orientation

14 Transabdominal Scanning Utilize abdominal probe Scan with bladder full, but don t wait for it Probe just above pubic bone Indicator toward patient s right or head

15 Transabdominal - Sagittal View

16 Transabdominal - Transverse View

17 Transabdominal Scanning - Ovaries/Adnexa Lateral to uterus Anteromedial to iliac vessels Normal ovaries not always seen Start in sagittal plane Slide probe away from ovary to visualize it Utilize bladder as sonographic window Try scanning directly over it if unsuccessful

18 Scanning for Ovaries/Adnexa

19 Endovaginal Scanning Have patient empty bladder Ultrasound gel on tip of endocavitary probe Cover with condom or sheath Surgilube on tip of condom/ sheath Scan after pelvic exam complete Patient may insert probe herself

20 Endovaginal Scanning - Sagittal View

21 Endovaginal Scanning - Sagittal View

22 Endovaginal Scanning Begin with probe indicator toward ceiling Identify uterus Scan from side to side Check pouch of Douglas by pulling out transducer and aiming probe tip down

23 Pouch of Douglas

24 Endovaginal Scanning - Coronal View

25 Endovaginal Scan Video Demonstration

26 Calculating Fetal Heart Rate

27 Endovaginal Scanning - Ovaries/Adnexa Return probe indicator to up position Scan lateral to uterus Ovaries between uterus and iliac vessels

28 Endovaginal Scanning - Ovaries/Adnexa Hypoechoic structures with anechoic follicles Look like chocolate chip cookies Palpate them with the probe

29 Ovary and Free Fluid

30 I Can t Find the Ovaries! Sometimes you can t find them Use your free hand on lower abdomen Paint the adnexa with sound

31 NMCP Pelvic Ultrasound Protocol Uterus long view - REQUIRED Uterus short view - REQUIRED M-Mode tracing of fetal heart rate - REQUIRED Cul-de-sac for free fluid - REQUIRED Gestational age - suggested Bilateral adnexa - suggested

32 Dating a Pregnancy Not as important as identifying an IUP or ectopic More important if dates unknown or uterine size doesn t correlate with gestational age More accurate during 1st trimester than later

33 How to Date a Pregnancy Measure gestational sac if no fetal pole Measure crown-rump length if fetal pole Maximal length of fetus After 1st trimester use biparietal diameter Measure skull through thalamus Leading edge to leading edge

34 Gestational Sac

35 Crown Rump Length

36 Biparietal Diameter

37 COMMON FINDINGS

38 Intrauterine Pregnancy Found in 70% of patients with 1st trimester pain/bleeding Can see 5 week pregnancy with endovaginal scan Abdominal scan findings lag by 7-10 days

39 Intradecidual Sign Seen at 4-5 weeks Small sac in endometrium Few mm in diameter Not a reliable indicator of an IUP

40 Gestational Sac Appears at 5 weeks Can be seen in all patients with quant HCG > 2,000 Not a reliable indicator of an IUP Could be a pseudogestational sac

41 Pseudogestational Sac

42 Double Decidual Sign Gestational sac with double echogenic ring Present in half of IUP s Not 100% accurate Some consider it a definitive sign of an IUP YOU DON T!

43 Double Decidual Sign

44 Yolk Sac First structure that develops in gestational sac Circular structure at edge of gestational sac Visualized at 5-6 weeks by EV scan Disappears by 12 weeks First definitive sign of an IUP

45 Yolk Sac

46 Fetal Pole Starts as thickening of yolk sac at 5-6 weeks Visible by 6 weeks Once 5 mm, should have heart beat Alive at 5

47 Fetal Pole with Cardiac Activity

48 Multiple Pregnancies Outside of the normal realm of emergency US Require OB follow-up 25% of twin pregnancies become singleton pregnancies by 2nd trimester

49 Ectopic Pregnancy % incidence in symptomatic ED patients Most common cause of maternal morbidity

50 Definitive Ectopic Pregnancies Live extrauterine embryo Extrauterine gestational sac with embryo or yolk sac

51 Live Extrauterine Gestation

52 Extrauterine Gestational & Yolk Sac

53 Nonspecific Signs of Ectopic Pregnancy Highly suggestive if uterus empty Free fluid Tubal ring Complex mass

54 Free Pelvic Fluid Suggestive of ectopic pregnancy Sole abnormal finding in 15% of ectopics The more free fluid, the more likely an ectopic is present Echogenic fluid or clots increases chance

55 Empty Uterus, Pelvic Free Fluid

56 Grading the Amount of Free Fluid Small free fluid = confined to pouch of Douglas and covers < 1/3rd of posterior uterus Anything more almost always associated with ectopic pregnancy

57 Large Free Fluid from Ectopic

58 Tubal Ring Nearly diagnostic of ectopic pregnancy Concentric hyperechoic structure in adnexa Thicker, brighter border than a cyst

59 Tubal Ring

60 Tubal Ring Plus Free Fluid

61 Complex Mass Mixture of cystic and solid components Represents tubal hematoma, trophoblastic tissue, or distorted gestational sac

62 Adnexal Doppler Flow - Ring of Fire

63 US Findings and Likelihood of Ectopic Any free fluid - 52% Complex pelvic mass - 75% Moderate-large free fluid - 86% Tubal ring - 95% Mass and free fluid - 97% Hepatorenal free fluid - nearly 100%

64 Indeterminate Ultrasound No IUP or ectopic identified Occurs in 15% of patients with quant HCG > 1,000 20% of these patients will have an ectopic ORDER A COMPREHENSIVE STUDY!

65 Spontaneous Abortion Complete expulsion of pregnancy US should show empty uterus except for small blood/clot

66 Incomplete Abortion POC present in failed pregnancy Synonymous with embryonic demise, blighted ovum, and retained POC Empty gestational sac > 20 mm Fetal pole > 5 mm without cardiac activity (endovaginal, alive at five ) Fetal pole > 10 mm without cardiac activity (transabdominal) Endometrial stripe >= 10 mm ORDER A COMPREHENSIVE ULTRASOUND!

67 Signs of Abnormal Pregnancies Embryonic bradycardia (HR < 120) Especially if HR < 90 Too large or small yolk sac (subtle) Distorted gestational sac (subtle) Subchorionic hemorrhage

68 Subchorionic Hemorrhage

69 Inevitable Abortion Expulsion of POC in progress Open cervix US may show separated gestational sac lying low within uterus

70 Nabothian Cysts Small cervical cysts Usually noted when looking at pouch of Douglas during endovaginal scan

71 Pelvic Masses All require follow-up imaging 3% have malignant potential 1 in 1,300 masses in pregnancy will require surgery

72 Corpus Luteum Cyst Secrete progesterone to support pregnancy Thin-walled cyst surrounded by normal ovarian parenchyma Usually < 5 cm in diameter, but may be larger Usually regress by 18 weeks gestation

73 Corpus Luteum Cyst

74 Hemorrhagic Corpus Luteum Cyst Internal echogenic debris and septae

75 Theca Lutein Cyst Large corpus luteum cyst in patient with very high HCG levels Gestational trophoblastic disease Ovarian hyperstimulation Large, multiseptated cystic mass Resolve once abnormal stimulus removed

76 Theca Lutein Cyst

77 Uterine Leiomyomas or Fibroids Solid uterine masses Usually hypoechoic May be calcified or have cystic degeneration Grow in early pregnancy Regress in late pregnancy

78 Teratoma or Dermoid Cyst Most common complex mass May contain fat, skin, hair, teeth, etc. Prone to torsion and rupture

79 Mucinous and Serous Cystadenomas Ovarian neoplasms Multicystic masses

80 Idiots Guide to Adnexal Masses Just get a comprehensive ultrasound...

81 Adnexal Torsion Almost always in setting of enlarged ovary or ovarian mass Rare in normal ovary Most patients have pelvic free fluid Doppler US misses up to 60% of torsion Blood flow difficult to visualize in cystic masses even without torsion

82 Idiots Guide to Adnexal Torsion Ovarian enlargement or adnexal mass makes torsion more likely Normal-sized ovaries and absence of free fluid makes torsion highly unlikely Just get a comprehensive ultrasound...

83 Gestational Trophoblastic Disease Intrauterine echogenic mass with diffuse small hypoechoic vesicles Grape-like appearance Quant HCG > 100,000 May be confused with incomplete abortion early in pregnancy Theca lutein cyst in 50% of cases

84 Molar Pregnancy

85 CLINICAL USE

86 HCG Discriminatory Zone Level at which we should see an IUP with endovaginal ultrasound Ranges from 1,000 to 2,000 NMCP discriminatory zone = 2,000 NO QUANT NEEDED IF IUP WITH CARDIAC ACTIVITY PRESENT!

87 Rosen s Ectopic Pregnancy Algorithm

88 Counseling Patients on US Findings 25% of early pregnancies have bleeding 40-50% will lose their pregnancy 15-24% rate of fetal loss if heart beat seen Lower as pregnancy progresses Even a normal US carries risk of fetal loss

89 PITFALLS

90 Pitfalls of Basic Pelvic Ultrasound Only scanning those above the HCG discriminatory zone Can t detect 3-5 week pregnancies Not designed to detect all pelvic pathology or fetal anomalies Stopping the workup of pelvic pain prematurely because of an IUP Not ordering comprehensive US on pelvic masses, fetal demise, or when no IUP/ectopic found Using US to rule out torsion Don t get distracted - FOLLOW THE PROTOCOL! Retroverted uterus (10%) makes transabdominal scanning difficult Mobility of uterus and ovaries Pseudogestational sac - YOLK SAC IS EARLIEST DEFINITIVE IUP!

91 Fry Baby

92 Interstitial Pregnancy 2-5% of ectopics Occurs in cornua of uterus Brisk bleeding and lethal when they rupture Easily mistaken for an IUP because surrounded by myometrium Occurs at margin of uterine wall Asymmetric myometrium with < 5-8 mm thickness

93 Cornual/Interstitial Ectopic Pregnancy

94 And Another

95 Heterotopic Pregnancy IUP and an ectopic Up to 1 in 8,000 pregnancies Higher if on ovulation inducing medication or undergoing in vitro fertilization 1 in 100 pregnancies

96 SUMMARY

97 Summary of Emergency Pelvic US Follow the protocol Learn to answer the question: Is there an IUP or not? Yolk sac is earliest definitive IUP M-Mode to calculate fetal heart rate If in doubt, radiology study or OB consult

98 Questions?