Ultrasound

Clinical Image of the Month: September 2018

Welcome back to another Clinical Image of the Month from the case files of the Brown EM Residency.

 

The Case

The patient is a 39-year-old female, G2P1, without significant PMH, who arrives in the critical care room from triage. She is lethargic with an undetectable blood pressure and a moderate amount of vaginal bleeding. A cordis was placed emergently and she received 2U pRBCs. Her mental status responded quickly to the transfusion, along with her systolic blood pressure. The first detectable blood pressure was captured in the 60’s and continued to steadily improve.   

During resuscitation, her husband tells you that they believe she is seven weeks pregnant based on her LMP, however, she has not had an evaluation or ultrasound yet during this pregnancy.  She recently took an at-home pregnancy test that was positive. She had some vaginal spotting last week that resolved. She otherwise has no history of abnormal bleeding, but does report strong cramping during menstrual periods. No history of sexually transmitted infections. This episode of vaginal bleeding began this morning and was associated with moderate pain and abdominal cramping. She has been changing pads hourly to manage the vaginal bleeding; she reports blood clots but no passage of tissue.

She otherwise reports some recent weakness and fatigue in addition to SOB and chills. Denies chest pain, back pain, urinary symptoms.

Vital Signs:

T 98.1, HR 110s, RR 20, BP 64/49, SpO2 98% on RA

Repeat blood pressure (after 2U pRBC) 89/73

 

Pertinent physical exam:

Alert and oriented x3. Diaphoretic, anxious, pallor.

Soft abdomen with suprapubic tenderness to palpation without rebound or guarding

External os dilated <5mm. Patient passing multiple large clots and copious bright red blood from cervical os on speculum exam.

An emergent bedside transvaginal ultrasound was obtained:

Cervical Ectopic Gif.gif

Figure 1: Transvaginal ultrasound clip

 Figure 2: Transverse view of the cervix on transvaginal ultrasound

Figure 2: Transverse view of the cervix on transvaginal ultrasound

What’s the diagnosis?

CERVICAL ECTOPIC PREGNANCY

Cervical ectopic pregnancies represent less than 1% of all ectopic pregnancies.  Prior dilatation and curettage, caesarean section and in vitro fertilization all increase risk for implantation of the blastocyst into the intracervical wall. According to one review, the incidence of cervical pregnancy is 0.1% among in vitro fertilization pregnancies. They can present with painful or painless vaginal bleeding. If detected early, cervical ectopic pregnancies can be treated similar to a tubal ectopic with methotrexate. If hemorrhaging, there is a high risk for maternal mortality and therefore a hysterectomy would be necessary to control bleeding.  There may be some role for uterine artery embolization prior in an attempt to decrease bleeding and therefore decrease the likelihood for hysterectomy. Don’t forget to administer Rhogam if indicated.


 

ULTRASONOGRAPHIC FINDINGS

Incomplete abortion may also present with products of conception residing within the cervix. For this reason, it may be difficult to ascertain the difference between a spontaneous miscarriage versus cervical ectopic pregnancy. The ‘sliding scan’ on transvaginal ultrasound is seen when the gestational sac, in an intrauterine pregnancy that is aborting, slides against the endocervical canal. This sliding is not seen on a cervical ectopic pregnancy due to the implantation into the endocervical wall.

Case conclusion

The ultrasound was reviewed with radiology and OB/GYN specialists and the decision was made to administer Methotrexate. Due to the persistent vaginal bleeding, the patient was taken urgently to the OR  for dilation and curettage. Intraoperative findings were consistent with an adherent mass arising from the anterior cervix. There was moderate active bleeding from the cervical os. The anterior lip of the cervix was injected with a solution of dilute vasopressin and was grasped with a single tooth tenaculum, with care not to disrupt the mass. A paracervical block was then performed with the dilute vasopressin.  Figure of 8 sutures were placed at 3 and 9 o’clock and tied down to partially occlude the cervical branches of the uterine artery. There was minimal clot in the uterus.  An 18F intrauterine foley balloon instilled with saline was placed to provide tamponade to the cervix. Intrauterine foley was removed on POD#2.  She was discharged on POD#3.

At her two-week outpatient follow-up appointment with OB/GYN, the patient had minimal pain and light bleeding. She was started on Depo-Provera to prevent pregnancy for six months due to the administration of MTX. Outpatient labwork trended her beta-HCG to zero.

Faculty Reviewer: Dr. Alyson McGregor


  

References:

Samal SK and Rathod S. Cervical Ectopic Pregnancy. J Nat Sci Biol Med 2015 Jan-Jun; 6(1): 257–260.

Tolandi Togas. UpToDate: Ectopic pregnancy: Clinical manifestations and diagnosis

Zhou A, Young D, Vingan H. Uterine artery embolization for cervical ectopic pregnancy. Radiol Case Rep. 2015 Dec; 10(4): 72-75.


  

Shoutout to resident physician Will Galvin who managed this case in critical care! Check back for the next Clinical Image of the Month.

The ‘To-and-Fro’ of Gentle (Sound) Waves: POCUS in SBO

Images credit: Natasha Gill MD, Matin Shah, MD

It’s the beginning of your shift, and there are seven patients waiting to be seen. Jane is up first. She is a 46-year-old female who comes in with acute, progressive abdominal pain, bloating, and bilious emesis for several days.

She tells you that her abdominal pain is very severe, diffuse, and constant. She has a history of MDD, seizure disorder, cholecystectomy, and a chronic ventral hernia.

On presentation vitals are stable (Temp 36.1°C | Pulse 74 | Resp 19 | SpO2 98% | BP 136/94). Her abdominal exam is distended and diffusely tender in all quadrants with hypoactive bowel sounds.

Back at your station, what tests do you order?

You might say basic labs, X-ray and a CT because you are concerned for a small bowel obstruction (SBO). Did you consider a bedside ultrasound?

Did you know that a meta-analysis published in Academic Emergency Medicine in 2013 showed that a bedside ultrasound had a pooled sensitivity of 97% and specificity of 90% compared to CT scan of 87% and 81%, respectively, for diagnosing SBO?

How did you interpret these clips and images below?

  Figure 1:  “To-and-fro” movement of the bowel contents.

Figure 1: “To-and-fro” movement of the bowel contents.

Fig2A.png
  Figure 2: A.  Dilated bowel loops measuring 3.38 cm.  B.  Keyboard sign

Figure 2: A. Dilated bowel loops measuring 3.38 cm. B. Keyboard sign

What is the keyboard sign?

  • The inner wall of the small intestine is lined with numerous folds of mucus membrane called plica circularis (or valves of Kerckring). These are especially prominent in the distal duodenum and jejunum, and rare in the ileum. In small bowel obstruction, these finger-like projections become more prominent and look like a keyboard.

What are some ultrasound findings of SBO, and which one is the most sensitive and specific?

  • Dilated fluid-filled small bowel loops greater than 2.5 cm is the most sensitive and specific

  • “To-and-fro” movement of the bowel contents due to increased peristalsis or increased intestinal contents

  • Keyboard sign

If you saw no peristalsis, bowel wall thickening (more than 3mm), and/or fluid-filled loops with extra luminal free fluid, would it change your management?

These ultrasound findings are concerning for bowel ischemia which is associated with a higher mortality rate and larger portion of bowel resection, therefore requiring prompt surgical evaluation.

Granted there are some limitations to using ultrasound, recent literature shows that it is a promising adjunct for the evaluation of SBO.

A prospective study in the ED by Unluer et al showed that four relatively inexperienced EM residents had a sensitivity of 97.7% and a specificity of 92.7% to detect SBO using ultrasound.

Pros and Cons of Ultrasound to Detect SBO

Benefits

  • Lower cost than CT

  • Can be performed at bedside

  • Can be performed rapidly and with high accuracy (even in less experienced operators)

  • No side effects from radiation or possible contrast reactions

Limitations

  • Operator dependent

  • May be difficult to identify:

    • Location of obstruction

    • Partial SBO

    • Specific cause of obstruction

What are some extrinsic, intrinsic, and intraluminal causes of SBO?

Intrinsic

  • Crohn’s disease*

  • Neoplasia

  • Intussusception

  • Hematoma

Extrinsic

  • Adhesions*+

  • Neoplasms

  • Hernia (umbilical, inguinal)

  • Endometriosis

Intraluminal (least common)

  • Foreign Body

*Most common cause within categories; +Most common cause overall

Ultrasound Tips to Detect SBO

  • Curvilinear probe set on abdominal mode (may also use phased-array)

  • Scan all four quadrants

  • Scan in two planes

Case Conclusion

Prior to transfer to our institution, Jane had a CT performed at an outside hospital and was diagnosed with SBO. These images, however, were initially not available to view. Instead of repeating the CT scan, a bedside ultrasound was completed and confirmed the diagnosis. The scan took less than 5 minutes. The surgery team was promptly consulted, and CT images were obtained from the other institution. Not only did the ultrasound save time and resources, the patient was also very satisfied with the care she received in the ED. She ultimately underwent a ventral hernia repair with reduction of bowel with underlay mesh repair.

Pearls:

  • Bedside ultrasound can be a quick, inexpensive, and useful tool in detecting SBO

  • Look for dilated fluid-filled small bowel loops greater than 2.5 cm, “to-and-fro” movement (increased peristalsis), and the keyboard sign

  • If there is no peristalsis, bowel wall thickening (more than 3mm), and/or fluid-filled loops with extra luminal free fluid, obtain prompt surgical evaluation

References:

  1. Lim JH. Intestinal obstruction. In: Maconi G, Porro GB, eds. Ultrasound of the gastrointestinal tract. Berlin, Germany: Springer-Verlag, 2007; 27–34.

  2. Meiser G, Meissner K. Sonographic differential diagnosis of intestinal obstruction: results of a prospective study of 48 patients [in German]. Ultraschall Med1985; 6(1): 39–45.

  3. Taylor MR, Lalani N. Adult small bowel obstruction. AcadEmerg Med 2013; 14. Jun;20(6):528-44.

  4. Suri S, Gupta S, Sudhakar PJ, et al. Comparative evaluation of plain films, ultrasound and CT in the diagnosis of intestinal obstruction. Acta Radiol1999; 40(4): 422-8.

  5. Unlüer E, Yavaşi O, Eroğlu O, Yilmaz C, Akarca F. Ultrasonography by emergency medicine and radiology residents for the diagnosis of small bowel obstruction. Eur J Emerg Med. 2010;17(5):260-264.

  6. Wilson SR. The gastrointestinal tract. In: Rumack CM, Wilson SR, Charboneau JW, eds. Diagnostic ultrasound. 3rd ed. St Louis, Mo: Mosby, 2005; 269–320.

Ultrasound Case of the Month: August 2018

The Case

This is an 82 year-old male who presented to the ED with acute chest pain and palpitations. He had a known history of AAA s/p repair. Patient denied abdominal, back, or flank pain. There was no loss of consciousness. An EKG was performed and was consistent with SVT with aberrancy. A bedside abdominal ultrasound was performed and the following images were obtained:

 Figure 1: Proximal axial abdominal aortic ultrasound

Figure 1: Proximal axial abdominal aortic ultrasound

 Figure 2: Longitudinal abdominal aorta ultrasound

Figure 2: Longitudinal abdominal aorta ultrasound

 Figure 3: Distal axial abdominal aorta ultrasound

Figure 3: Distal axial abdominal aorta ultrasound

Diagnosis

Known AAA s/p repair (also SVT with aberrancy)

Case Follow-up

The patient remained HDS and adenosine was given with good effect. He was admitted to medicine, and had no further episodes of SVT. He was discharged home with cardiology follow up.

Discussion

The images were acquired using the curvilinear probe. The probe was placed on the abdomen just superior of the umbilicus and just left of midline. Both longitudinal and axial views were acquired.

Ultrasound is the initial test of choice for suspected AAA in the ED. It has sensitivity of 94-99%, and has been shown to decrease mortality in AAA patients by 20-50% compared to CT--likely due to decreased time to diagnosis.

A normal abdominal aorta is typically < 3cm in diameter. A complete AAA ultrasound should evaluate the aorta from the xiphoid process past the aortic bifurcation. US may be considered positive if the aorta is >3 cm in a patient with clinical concern for AAA,  or > 5 cm without clinical concern.

Faculty Reviewer: Dr. Kristin Dwyer

For an in-depth tutorial on the abdominal aorta ultrasound, check out this video from EM:RAP HD:

Additional Resources

https://cdemcurriculum.com/bedside-ultrasound-aaa-examination/

https://radiopaedia.org/articles/abdominal-aortic-aneurysm

https://www.acep.org/sonoguide/abdominal_aortic_aneurysm.html

http://5minsono.com/aaa/