16 year old female presents to your Emergency Department after falling from her mountain bike on a nearby track. As she fell to the ground, she reports landing on the handlebars which struck her upper abdomen.
She describes navigating a difficult section of a familiar track when her front wheel impacted a large tree root causing a loss of balance and the subsequent accident. A handlebar from her bike impacted her upper abdomen causing immediate pain and a moderate sized contusion. She has vomited once since the injury.
She otherwise appears to be ok.
– Was wearing a helmet at the time, did not lose consciousness and recalls all events.
– Has no dyspnoea, painful breathing or chest pain.
– Has no extremity pain, swelling or deformity.
She has no significant past medical history, takes no regular medications and has no known allergies.
On examination, she looks well but is in moderate pain.
- A. patent & protected.
- B. No chest wall crepitus, tenderness or emphysema. Respiratory rate 18/min. SaO2 98% (room air) Clear lung fields.
- C. Warm and well perfused. Pulse rate 92 per minute. Blood pressure 110/68. No active external haemorrhage or long bone fractures.
- D. GCS 15. Moving all 4 limbs. Pupils 5mm and reactive to light.
- E. Well circumscribed abdominal wall contusion (~3 cm diameter) in the epigastrium, just left of the midline. She has moderate tenderness on deep palpation with voluntary guarding, but no rebound or percussion tenderness.
Your colleagues place a cannula and administer some analgesia.
During that time you grab your ultrasound …
The remainder of her images are normal.
Free fluid at the caudal liver edge & the splenorenal interface.
In the unstable patient with blunt abdominal trauma, the test characteristics of the FAST scan are impressive (Sn 73-88%, Sp 98-100%). However, in patients with penetrating trauma & in those with stable haemodynamics, this sensitivity falls away to 50% or less. This brings into question whether or not the FAST scan still has a role in the bedside assessment of these patients, where advanced imaging with contrast CT provides a greater level of diagnostic accuracy.
Here is a talk that I gave at the 2017 SWAN Trauma Conference on the role of the FAST scan in stable blunt trauma patients…
& here are the accompanying slides…
Despite her normal haemodynamics, this positive FAST scan signifies that she is carrying a significant intraabdominal injury & a high likelihood of clinical deterioration.
You notify your surgical colleagues & arrange an urgent abdominal CT…
- Grade III splenic laceration (predominant grade II anterior laceration with other small subcapsular lacerations).
- Intra parenchymal vascular injury is noted.
- Small volume of free fluid.
Whilst your patient remains stable, with normal vital signs, the decision is made to proceed to interventional radiology. Here she undergoes selective angio-embolisation of a branch of the splenic artery.
She is admitted to the High Dependency Unit for overnight observation, where her haemodynamics and haemoglobin remain stable. Her recovery is uneventful and is discharged well 5 days later.
- Natarajan B, Gupta PK, Cemaj S, Sorensen M, Hatzoudis GI, Forse RA. FAST scan: is it worth doing in hemodynamically stable blunt trauma patients? Surgery. 2010; 148(4):695-700; discussion 700-1. [pubmed]
- Dammers D, El Moumni M, Hoogland I, Veeger N, ter Avest E. Should we perform a FAST exam in haemodynamically stable patients presenting after blunt abdominal injury: a retrospective cohort study Scand J Trauma Resusc Emerg Med. 2017; 25(1). [pubmed]
- Lee BC, Ormsby EL, McGahan JP, Melendres GM, Richards JR. The utility of sonography for the triage of blunt abdominal trauma patients to exploratory laparotomy. AJR. American journal of roentgenology. 2007; 188(2):415-21. [pubmed]
- Liu K. FAST Scan: Is it Worth Doing in Hemodynamically Stable Blunt Trauma Patients? The Journal of Emergency Medicine. 2011; 40(5):607-608. [link]
- Cho Y, Judson R, Gumm K, Cho Y, Santos R, Walsh M, et al. Blunt Abdominal Trauma. Trauma Service Guidelines: The Royal Melbourne Hospital; 2012. [link]
- Fleming S, Bird R, Ratnasingham K, Sarker S, Walsh M, Patel B. Accuracy of FAST scan in blunt abdominal trauma in a major London trauma centre International Journal of Surgery. 2012; 10(9):470-474. [link]
- Hsu JM, Joseph AP, Tarlinton LJ, Macken L, Blome S. The accuracy of focused assessment with sonography in trauma (FAST) in blunt trauma patients: Experience of an Australian major trauma service Injury. 2007; 38(1):71-75. [link]
- Bowra J, Forrest-Horder S, Caldwell E, Cox M, D’Amours SK. Validation of nurse-performed FAST ultrasound. Injury. 2010; 41(5):484-7. [pubmed]
- Behboodi F, Mohtasham-Amiri Z, Masjedi N, Shojaie R, Sadri P. Outcome of Blunt Abdominal Traumas with Stable Hemodynamic and Positive FAST Findings. Emergency (Tehran, Iran). 2016; 4(3):136-9. [pubmed]
- Matsushima K, Frankel HL. Beyond focused assessment with sonography for trauma: ultrasound creep in the trauma resuscitation area and beyond. Current opinion in critical care. 2011; 17(6):606-12. [pubmed]
- Richards JR, McGahan JP. Focused Assessment with Sonography in Trauma (FAST) in 2017: What Radiologists Can Learn Radiology. 2017; 283(1):30-48. [link]
- The Use of FAST Scan by Paramedics in Mass-casualty Incidents: A Simulation Study Prehosp. Disaster med.. 2014; 29(06):576-579. [link]