Episode 36 – Small Bowel Obstruction


This episode has been updated with a english subtitled version.  For now, you must download the file and use a player featuring subtitles such as VLC Player.  We’re working on a different solution for future subtitled episodes.  There is also a transcription featured below, as well as a link to download a PDF of the transcription. 

Want to learn how to ultrasound for small bowel obstruction? 

Well, it’s your lucky day!  Mike and Matt back at you for a great podcast on SBO.

Want to learn about all things ultrasound in a castle? 

Well…April’s gonna be your lucky month….if you register soon enough, that is.  Listen to this podcast for more info on both.




below you will find the transcription of this podcast provided by Daniel Lakoff.  You can Download PDF Here.


Ultrasound Podcast with Mike and Matt on Small Bowel Obstruction

Summary by Elizabeth Dei Rossi, MD

Different modalities can be used for diagnosing SBO

  • CT scan is considered gold standard
    • sensitivity of 92% and a specificity of 93%
    • Mallo RD et al. CT diagnosis of ischemic and complete obstruction in SBO: a sys review. J Gastrointest Surg 2005
    • Abd xray is often used a rapid test in the ER but has very poor sensitivity/specificity
      • Looks for air fluid levels
      • sensitivity of 66-77% and specificity of 50-57%
      • Shrake PK, Rex DK, Lappas JC, et al. (1991) Radiographic evaluation of suspected small bowel obstruction.  Am J Gastroenterology 86:175-178
      • Ultrasound can be used for diagnosis of SBO
        • Sensitivity of 88% and specificity of 96%
        • Ogata M et al Prospective Evaluation of Abdominal Sonography for the diagnosis of bowel obstruction. Annals of surgery in 1996
        • can see SBO without air


Ultrasound findings in patients with SBO

  • Fluid filled bowel
  • Dilated bowel with back and forth peristalsis


Bedside ultrasonography of the detection of small bowel obstruction in the emergency department by Timothy B Jang, Danielle Schindler, and Amy H Kaji

  • Methods
    • Residents were given 10 min of training with 5 scans performed then patient’s with suspected small bowel obstruction had an US and XRAY, CT scan was used as the gold standard
    • Using a phased array probe bilateral colic gutters, epigastric and suprapubic areas were assessed for dilated loops of bowel with peristalsis (big loops of bowel with movement back and forth of bowel)
    • Results
      • Dilated bowel on US had a sensitivity of 91% and a specificity of 84%
      • Xray had a sensitivity of 46% and specificity of 67%
      • Some tips from Dr. Timothy Jang
        • Decreased peristalsis is a late finding and therefore not something for which to look
        • If you see dilated bowel also consider non-SBO etiologies like ileus
        • Study didn’t assess for transition point
        • Look for gallstones if you see dilated bowel (gallstone ileus)
        • In SBO bowel wall thickening is a prognostic sign and may suggest diagnosis like IBD and colitis

In summary US is potentially a quicker study without side effects of radiation that has a better sensitivity and specificity than XRAY.  Develop your own practice with this information: maybe use to rule out low risk patients.


CastleFest 2013

  • Some of the speakers and their topics include
    • Mike Stone speaking teaching on nerve blocks with the help of a cadaver lab
    • Mike Blaivas instructing on TEE
    • Scott Weingart lecturing on critical care
    • Vicki noble
    • Matt Dawson
    • Many small group sessions
    • Registration open at castlefest2013.com