Ultrasound Case of the Month

Case: Submitted by Dr. Sam Goldman

This is an 83-year old woman with a history of prior abdominal surgeries presenting to the ED as a transfer from her SNF with increasing abdominal distention. Patient has not had a bowel movement in four days although endorses passing occasional flatus. She denies emesis though endorses nausea, hiccupping, and burping. She denies any abdominal pain, fevers, chills, dysuria or urinary frequency. 

Diagnosis:

Small Bowel Obstruction

Image was acquired with the curvilinear probe, but any high penetration probe (eg curvilinear of phased array probe) can also be used.  Multiple regions of the abdomen should be interrogated when evaluating for SBO.

What are we looking for with abdominal US for SBO?

When evaluating for an SBO, we are looking for fluid filled small bowel loops >2.5-3cm in width. You maybe more likely to see an increase in intestinal contents (fluid and echogenic materials) and you may see to-and-fro or whirling of the intestinal contents. In more severe cases, you may see bowel wall thickening (greater than 3mm) and free fluid which is extraluminal. pSBO may be more difficult to evaluate with the US machine.   

What do we see in this video?

  • Dilated loops of bowel > 2.5cm measured outer wall to outer wall (most sensitive and specific finding). 
  • Bidirectional flow of bowel contents (to and fro or whirling)
  • Visualization of plicae circularis (“keyboard sign”)

How good is U/S for Detecting SBO?

Ultrasound is superior to abdominal plain films and approaches the sensitivity and specificity of CT scan in many cases. 

Sensitvity Specificity
Abdominal Films 66-77% 50-57%
CT 92% 93%
Ultrasound 88% 96%

Faculty Reviewer: Dr. Kristen Dwyer

References

(Mallo RD, et al. Computed tomography diagnosis of ischemia and complete obstruction in small bowel obstruction: a systematic review. Journal Gastrointestinal Surgery. 2005. May-Jun;9(5):690-4.)

(Ogtata M, et al. Prospective Evaluation of Abdominal Sonography for the Diagnosis of Small Bowel Obstruction. Annals of Surgery. 1996. 23(3):237-241.) 

Additional resources:

Podcast on US of SBO from www.ultrasoundpodcast.com: Episode 36 - Small Bowel Obstruction - Ultrasound Podcast

Great view of Plicae Circularis (“Keyboard Sign”) from Emory University

Tales From the Community: A Bike Wipeout

 

A 35yo male is biking when he crosses are area of sand on the road. The bike fishtails and he falls onto his left shoulder. He was helmeted and denies head trauma, neck pain, or LOC. The patient is holding his left arm close to his side and across his chest. On physical exam there is a prominent acromion and coracoid anteriorly.

 

What Injury does this mechanism and presentation correlate with?

Posterior Shoulder Dislocation

 

Incidence

Posterior Shoulder dislocations account for only 2-4% of all shoulder dislocations. Most commonly they are associated with or caused by seizure, electrical shock, FOOSH or a direct blow to the shoulder, as occurred in this patient. Given the atypical presentation, they are missed in up to 50% of cases on initial presentation.

 

Presentation

On presentation the patient will usually presents with the arm adducted and internally rotated. More so than in an anterior shoulder dislocation, movement, especially abduction or external rotation is very painful. A prominent acromion and coracoid are palpable, with the humeral head displaced posteriorly.

 

Radiographs:

The deformity can be very subtle on the Anterior/Posterior view and most reliably visualized on the Axillary or Transscapular Y views. On the anterior/posterior view classically shows a “light bulb sign”.  This occurs when the humeral head is forced into internal rotation as it dislocates posteriorly, giving it the appearance of a light bulb.

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Another characterstic sign on radiograph after a posterior shoulder dislocation is the “Trough Sign”. This may be present when the dislocation results in a Reverse Hill-Sachs deformity. Radiographs will show a loss of overlap of the humeral head and glenoid fossa.

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Reduction

In general, Traction - CounterTraction is the most efficacious means to reduce this dislocation. In addition to the traction, gentle pressure to the humeral head in the posterior and lateral directions can be helpful to disengage the humeral head from the posterior glenoid. In our case above, gentle pressure to the humeral head quickly disengaged the humerus from the glenoid and under procedural sedation the patients shoulder was reduced on first attempt.

Dispo

Similar to anterior dislocations after a posterior shoulder dislocation is reduced, the patient is placed in a sling and swath and discharged with orthopedic follow-up and instructions for non-weight bearing and to keep the shoulder in the sling at all times.

 

Complications

The “Reverse Hill-Sachs” lesion mentioned above is one of the complications of a posterior shoulder dislocation. This “lesion” is an osteochondral impression fracture in the anteromedial portion of the humeral headand is known by many names: enoche fracture, McLaughin lesion or reverse Hill-Sachs lesion. In posterior dislocations the shoulder rotates internally causing a anteromedial fracture while in an anterior shoulder dislocation which can lead to a Hill-Sachs deformity which is in the posteriorlateral humeral head.

 

Reviewed by: Dr Kristina McAteer

AEM Early Access 05: The Role of Prehospital ACLS for Potential E-CPR Candidates

Welcome to the fifth episode of AEM Early Access, a FOAMed podcast collaboration between the Academic Emergency Medicine Journal and Brown Emergency Medicine. Each month, we'll give you digital open access to an AEM Article in Press, with an author interview podcast and links to curated FOAMed supportive educational materials for EM learners.

Find previous podcasts and subscribe to this series on I tunes here.

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Dr. Alexis Cournoyer, MD Universite de Montreal, Montreal, Quebec, Canada Hospital du Sacre-Coeur de Montreal, Montreal, Quebec, Canada Institut de Cardiologie de Montreal, Montreal, Quebec, Canada

Dr. Alexis Cournoyer, MD

Universite de Montreal, Montreal, Quebec, Canada
Hospital du Sacre-Coeur de Montreal, Montreal, Quebec, Canada
Institut de Cardiologie de Montreal, Montreal, Quebec, Canada

 

 

 

Listen now: Interview with Dr. Alexis Cournoyer, lead author, interviewed by Dr. Thomas Ross

Open Access Through September 30th. Click below:

Prehospital Advanced Cardiac Life Support for Out-of-Hospital Cardiac Arrest: A Cohort Study. Cournoyer A, et. al

Article Summary:

Objectives: Out-of-hospital advanced cardiac life support (ACLS) has not consistently shown a positive impact on survival. Extracorporeal cardiopulmonary resuscitation (E-CPR) could render prolonged on-site resuscitation (ACLS or basic cardiac life support [BCLS]) undesirable in selected cases. The objectives of this study were to evaluate, in patients suffering from out-of-hospital cardiac arrest (OHCA) and in a subgroup of potential E-CPR candidates, the association between the addition of prehospital ACLS to BCLS and survival to hospital discharge, prehospital return of spontaneous circulation (ROSC) and delay from call to hospital arrival. 

Methods: This cohort study targets adult patients treated for OHCA between April 1010 and December 2015 in the city of Montreal, Canada. We defined potential E-CPR candidates using clinical criteria previously described in the literature (65 years of age or younger, initial shockable rhythm, absence of return of spontaneous circulation after 15 minutes of prehospital resuscitation and emergency medical services witnessed collapse or witnessed collapse with bystander cardiopulmonary resuscitation). Associations were evaluated using multivariate regression models.

Results: A total of 7134 patients with OHCA were included, 761 (10.7%) of whom survived to discharge. No independent association between survival to hospital discharge and the addition of prehospital ACLS to BCLS was found in either the entire cohort [adjusted odds ratio (AOR) 1.05 (95% confidence interval 0.84-1.32), p=0.68] or amongst the 246 potential E-CPR candidates [AOR 0.82 (95% confidence interval 0.36-1.84), p=0.63]. The addition of prehospital ACLS to BCLS was associated with a significant increase in the rate of prehospital ROSC in all patients experiencing OHCA (AOR 3.92 [95% CI 3.38-4.55], p<0.001) and in potential E-CPR candidates (AOR 3.48 [95% CI 1.76-6.88], p<0.001) as compared to isolated prehospital BCLS. Delay from call to hospital arrival was longer in the ACLS group than in the BCLS group (difference=16 min [95% CI 15-16], p<0.001). 

Conclusions:  In a tiered-response  urban emergency medical service setting, prehospital ACLS is not associated with an improvement in survival to hospital discharge in patients suffering from OHCA and in potential E-CPR candidates, but with an improvement in prehospital ROSC and with longer delay to hospital arrival. 

Suggestions for Further Reading: 

Open Access:

RAGE Podcast: E-CPR by Vincent Pellegrino

EM Docs: ECMO in the ED

Subscriptions/Abstracts:

Sanghavi P, Jena AB, Newhouse JP, Zaslavsky AM. Outcomes after out-of-hospital cardiac arrest treated by basic vs advanced life support. JAMA Intern Med 2015;175:196-204. 

Ma MH, Chiang WC, Ko PC, et al. Outcomes from out-of-hospital cardiac arrest in Metropolitan Taipei: does an advanced life support service make a difference? Resuscitation 2007;74:461-9.

Bakalos G, Mamali M, Komninos C, et. al. Advanced life support versus basic life support in the pre-hospital setting: a meta analysis. Resuscitation 2011;82:1130-7.

Stub D, Bernard S, Pellegrino V, et. al. Refractory cardiac arrest treated with mechanical CPR, hypothermia, ECMO and early reperfusion (the CHEER trial). Resuscitation 2014. 

Siao FY, Chiu CC, Chiu CW, et al. Managing cardiac arrest with refractory ventricular fibrillation in the emergency department: Conventional cardiopulmonary resuscitation versus extracorporeal cardiopulmonary resuscitation. Resuscitation 2015;92:70-6. 

Faculty Editors/Reviewers: Dr. Gita Pensa and Dr. Kristy McAteer 

Podcast credits: Used under creative commons license: intro music by freemusicarchive.org , sound effect from freesound.org, exit music by bensound.com