Case # 17: Par for the Course

An 80 year old man presents to a rural emergency room at 3am with abdominal pain. His past medical history is significant for mild hemophilia A. Six hours prior to arrival, he was driving a golf cart when he struck a pole and the steering wheel hit his stomach.

He initially had no symptoms but began to have abdominal pain while trying to sleep. He also became nauseated and vomited once. He eventually called EMS and was brought to the ER. On arrival, his vitals are as follows. 

Vitals: T: 90.7, HR: 108, BP: 74/48, RR: 28, SpO2 98 on 4L

He is alert, oriented and his only complaint is abdominal pain. A FAST exam was done. What do you see? What are your next steps?

 

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Answer and Learning Points

Answer

Although the quality of images is lacking due to the urgency of the situation and the patient's body habitus, the first image (RUQ) does not show obvious free fluid. The following images (suprapubic and LUQ) clearly show free fluid in the abdomen. 

An emergent evacuation of the patient to a level 1 Trauma service was requested. Patient was transfused with two units of O blood. Due to his history of hemophilia A, the patient was also given factor VIII to 100% repletion. The patient was taken to the OR at the level 1 trauma center where he was found to have a greater omental bleed and was successfully treated with clot evacuation and laceration repair. He was placed on a factor VIII drip postop. 

Learning Points

    • Per ATLS guidelines, a hypotensive patient with a + FAST and no other signs of bleeding warrants immediate surgical exploration. 
    • In a 2018 meta-analysis, a positive FAST has a sensitivity of 68% and a specificity of 95%. Therefore a negative FAST does not rule out the disease, but a positive fast in the correct clinical sitting (such as this) does rule in hemoperitoneum(1). 
    • Hemophiliac patients require factor VIII replacement to 100% in the setting of major trauma, which is typically 50 IU/kg(2). 
 

Author

Feigenbaum, Adam, PA-C. Emergency Medicine Fellow, Naval Medical Center San Diego.

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

  1. Stengel D et al. Point-of-care ultrasonography for diagnosing thoracoabdominal injuries in patients with blunt trauma. Cochrane Database Syst Rev. 2018. Dec 12;12
  2. Guidelines for Emergency Department Management of Individuals with Hemophilia and Other Bleeding Disorders. https://www.hemophilia.org/Researchers-Healthcare-Providers/Medical-and-Scientific-Advisory-Council-MASAC/MASAC-Recommendations/Guidelines-for-Emergency-Department-Management-of-Individuals-with-Hemophilia-and-Other-Bleeding-Disorders. December 5, 2019

 

Does This Adult Patient Have a Blunt Intra-abdominal Injury?

Background

Trauma is the leading cause of death in those younger than 45 years in the United States. Around 80% of injuries are due to blunt trauma with 20% involving penetrating trauma. It is blunt trauma, however, that carries substantial diagnostic challenges due to complex injury patterns and difficult management strategies. This paper sets out to review and summarize the comparisons of different techniques in diagnosis of intra-abdominal injury via physical exam findings, laboratory values, and imaging including bedside ultrasound. 

Does This Adult Patient Have a Blunt Intra-abdominal Injury? 

Clinical Question

How accurate and reliable are existing symptoms, signs, laboratory tests and bedside imaging studies at diagnosing intra-abdominal injury following blunt abdominal trauma?

Methods & Study Design

  • Population
    • The study analyzed 12 papers that assessed clinical examination and 22 papers to assess role of FAST in identifying intra-abdominal injury. Sample sizes ranged from 117 to 3435 patients. All studies defined inclusion criteria as adult patients with any blunt abdominal trauma except for 2 studies that included only adult patients in motor vehicle collisions.
  • Intervention
    • This particular paper focused on the likelihood ratios of various approaches in predicting intra-abdominal injury including: physical exam findings (i.e rebound tenderness, abdominal distention, guarding, seat belt sign, and hypotension), laboratory tests (i.e.  base deficit, hematuria, elevated transaminases and anemia), and FAST examination.
  • Outcomes
    • Researchers measured specificity, sensitivity, positive likelihood and negative likelihood of the various physical exam, laboratory, and imaging findings associated with blunt trauma.
  • Design
    • This is a meta-analysis of numerous prospective studies looking at blunt abdominal trauma.
  • Excluded
    • The publishers chose to include studies that were prospective, with consecutive enrollment and blinding, and included a reference standard (i.e.  abdominal CT, DPL, laparotomy, autopsy, or clinical course to detect intra-abdominal injury or hemoperitoneum).

Results

Strengths & Limitations

  • Strengths
    • Analyzed the biggest publications from top-trauma centers focusing on strength of statistical analysis.
    • Created subcategories of studies that focused on FAST in order to ascertain if any of the information was skewed.
  • Limitations
    • This is a 2012 study that only focused on papers older than 2007, excluding any new techniques and standards as well as imaging advancements of the last decade.
    • They did not review studies for clinical outcome, so cannot draw conclusions regarding how change in bedside exam and procedures impact patient care post diagnosis.
    • As with all large meta-analysis studies there is always risk of significant heterogeneity from varying study inclusion/exclusion criteria making generalizability complex.

Author's Conclusions

“Bedside ultrasonography has the highest accuracy of all individual findings, but a normal result does not rule out an intra-abdominal injury. Combinations of clinical findings may be most useful to determine which patients do not require further evaluation, but the ideal combination of variables for identifying patients without intra-abdominal injury requires further study.”

Our Conclusions

Overall, this paper reinforces the strength of bedside ultrasonography (adjusted positive LR of 30) as a diagnostic tool of intra-abdominal injury following blunt trauma compared to physical exam and laboratory findings. This reinforces ultrasounds role as the best tool to "rule-in" an intra-abdominal injury. However, it also elucidates a relatively poor sensitivity of the FAST exam, making it a poor tool to "rule-out." This is important as it urges physicians to not rely solely on a negative FAST exam when ruling out intra-abdominal injury but consider other factors including clinical gestalt, mechanism of injury, physical exam and laboratory work up.

Additionally, to better understand the magnitude of this paper's findings it is important to known what a likelihood ratio really tells us. The following image is a quick way to think about likelihood ratios. A positive likelihood ratio of 2 should increase your probability of disease ( resulting in your post test probability) by 15%, 5 by 30% and 10 by 45%. Likewise a negative likelihood ratio of 0.5 should decrease your probability of disease by 15%, 0.2 by 30% and 0.1 by 45%.

The Bottom Line

Bedside ultrasonography is a highly specific diagnostic tool to rule in  intra-abdominal injury following blunt trauma but should be used in conjunction with clinical gestalt, physical exam findings and laboratory values when ruling out injury.

Authors

This post was written by Olga Miakicheve, MS4 at UCSD. It was edited by Michael Macias, MD.

References

    1. Simel, D. (2012). Does This Adult Patient Have a Blunt Intra-abdominal Injury?. JAMA, 307(14), 1517. doi:10.1001/jama.2012.422
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