A New Focus for PoCUS
Elective Resident Clinical Pearl – December 2016
Heather Flemming, PGY4 Emergency Medicine, Dalhousie University, Saint John, New Brunswick
Reviewed by Dr. David Lewis
A 70 year old female presents to the emergency department with central abdominal pain and one episode of vomiting. Her vital signs are stable, but she appears uncomfortable.
You bring the ultrasound machine to the bedside to assess her abdominal aorta. Your exam is challenged by the presence of bowel gas, causing scattering of your ultrasound beam, but is ultimately negative for an abdominal aortic aneurysm. You note that the patient has a midline scar, which she states is from a remote hysterectomy. With increased suspicion for bowel obstruction, you move the curvilinear probe across the abdomen and generate the following images: (Video Below)
The images demonstrate dilated loops of bowel and alternating peristalsis (a ‘to and fro movements’ of bowel contents). This confirms your suspicion for a small bowel obstruction (SBO).
Discussion:
Bedside ultrasound is a useful tool in evaluating any patient with abdominal pain, and has shown to be more sensitive and more specific than abdominal xray in diagnosing SBO1. Additional advantages of ultrasound include lack of radiation to the patient, bedside availability and potential to improve ED flow2. Treatments, such as nasogastric tube insertion, and early consultation to general surgery can be expedited by rapid identification. In individuals with recurrent sub-acute SBO, PoCUS may become the investigation of choice, reducing radiation exposure for this group of patients.
Pearls for performing a bedside ultrasound for SBO:
Multiple regions of the abdomen should be assessed, including the epigastrium, bilateral colic gutters, and suprapubic regions2. (Image 2).
Image 2 (overlapping survey of all quadrants)
Typical SBO ultrasound finding include:
- ≥3 bowel loops dilated >25mm (Measurements taken at 90° to bowel wall)
- Transition point – dilated peristalsing small bowel visualized adjacent to non-peristalsing collapsed bowel
- Increased intraluminal fluid
- Abnormal peristalsis: Hyperdynamic, alternating or absent peristalsis
- Abdominal free fluid may also be present
Credit: ACEP.org
References
- Jang, Timothy B. Schindler, Danielle. Kaji, Amy H. Bedside ultrasonography for the detection of small bowel obstruction in the emergency department. Emerg Med J 2011 28:676-678.
- Chao, Gharahbaghian. Tips and Tricks: Clinical Ultrasound for Small Bowel Obstruction – A Better Diagnostic Tool? https://www.acep.org/content.aspx?id=100218
- A video on Ultrasound in Small Bowel Obstruction by the Academy of Emergency Ultrasound can be found here: https://vimeo.com/69551555
