HWN Suggests

Small Bowel Obstruction - A Likely Story?

Small bowel obstruction (SBO) often presents with murky historical and physical features but quick bedside ultrasound exists as a modality that may expedite a patient's workup, with limited training and good sensitivity. Uptake of US for SBO in US EDs has not been quick…

Bedside Ultrasound in the ED- this modality is gaining momentum as it can provide a very rapid rule in/rule out, but it is still not recommended in core EM texts or become commonplace in many EDs.

read full article

Featured

  How useful are plain abdominal films for bowel obstruction?

From the literature assessed, plain abdominal films and chest radiographs have limited added diagnostic value for patients with abdominal pain and suspected small bowel obstruction.

 NG tubes for small bowel obstruction: More pain than evidence

In my mind, the use of NG tubes for bowel obstruction is an anachronism. I grew up hearing about literature that said NG tubes provide no benefit, but are routinely rated as among the most painful things we do to our patients. In my mind, this was a classic example of a medical myth that had been relegated to the history of medicine, side by side with things like leeches and trephination. However, every time I admit a patient with a bowel obstruction, the issue of NG tubes is raised, so I guess we need a quick blog post.

 Sounding the Bowel

Bowel obstruction is a relatively common clinical entity, accounting for 15% of all emergency department admissions for abdominal pain, which equates to approximately 300,000 patients per year in the United States. The current workup includes a plain film X-ray, which can include up to three views, and can be followed by CT imaging if deemed necessary. Abdominal X-rays are fairly rapid and relatively inexpensive, but have very poor specificity and sensitivity, quoted in the literature as being 50-67% and 46-77%, respectively. CT imaging is considered the gold standard in imaging modalities, with a sensitivity of 92% and specificity of 93-100%. When rapid and accurate diagnosis is required, particularly in those who require early operative intervention, point-of-care ultrasound (POCUS) can be a useful imaging modality.

 The truth about Small Bowel Obstruction

Small bowel obstruction (SBO) is a very common problem for patients; treated by many different types of medical providers, including primary care, emergency medicine, internal medicine, and surgery. In the United States alone, there are an estimated 300,000 laparotomies performed annually for SBO, and about one third of these obstructions are complicated by intestinal ischemia, with significantly higher morbidity and mortality resulting.

Articles of Interest

CT of Small Bowel Obstruction

CT can identify small bowel obstruction and its significant time-sensitive complications, ischemia and perforation.

EM@3AM: Small Bowel Obstruction

NG placement is recommended for intractable vomiting, severe abdominal distension, and high risk of aspiration. Otherwise, NG tubes do not improve outcomes.

Episode 23 – SBO and Mesenteric Ischemia

While ultrasound can diagnose SBO, there is little evidence to suggest that we can identify transition points or strangulation/necrosis. As such, there can still be a role for CT scan, particularly in first time SBO to identify a transition point.

POCUS Cases 5 – Small Bowel Obstruction

Dr. Simard explains the limitations of x-rays for small bowel obstruction, the three signs of small bowel obstruction on POCUS including the “keyboard sign”, the most important literature on the topic and the limitations of using POCUS for the diagnosis of small bowel obstruction.

POCUS: Small Bowel Obstruction

Often difficult to differentiate SBO from ileus (visualization of a transition point favors SBO).

Review of Small-Bowel Obstruction: The Diagnosis and When to Worry

In the Western world, the major cause of SBO is adhesions. The next two most frequent causes are hernias and malignancies. These three etiologies account for more than 80% of all causes of SBO. Other etiologies include Crohn disease, intussusception, volvulus, gallstones, foreign bodies, bezoars, trauma, and iatrogenic problems.,

Small bowel obstruction: Diagnosis by ultrasonography

Although highly accurate, both the CT and the MRI have the distinct disadvantages of not being able to performed at the bedside, as well as being time consuming, more costly, and in the case of CT, carrying the side effects of radiation and possible contrast reactions. Ultrasound is a bedside testing modality that has recently arisen as a viable alternative.

Small-Bowel Obstruction, Evaluation and Management of

Over the centuries, the management of SBO has evolved. Early treatments included bloodletting and ingestion of heavy metals. Advancements brought intestinal tube decompression and operative interventions.

Ultrasound Case of the Month

Using a curvilinear transducer, scan the patient’s abdomen with the marker towards the patient’s right. Move your probe up and down interrogating all 4 quadrants of the abdomen. SBO can be identified by looking for the following signs...

Resources

Core EM

Plain X-rays perform poorly in making or ruling out the diagnosis. CT is the most widely accepted imaging modality but US (both formal and ED) has better performance characteristics

SAEM

Bowel obstruction should be considered as a potential surgical emergency when a patient presents with acute abdominal pain. It occurs when the normal flow of intestinal contents is interrupted. The most common causes are adhesions, followed by tumors and hernias. Other causes include strictures, intussusception, volvulus, Crohn Disease, foreign bodies, and gallstones. Obstruction is classified as small bowel obstruction (SBO) or large bowel obstruction (LBO) based on the level of obstruction. LBO is more commonly caused by malignancy...

Diagnosing Small Bowel Obstruction in the ED: A Role for Ultrasound?

Of course there are limitations with this small study. There was a disproportionately high prevalence of SBO in the study population (33 out of 76 patients – 43%), bringing into question its external validity. The doctors performing the US exams volunteered themselves, indicating they were enthusiasts – potentially introducing what the authors describe as ‘ultrasound-interest’ bias.