Pancreas (B) is the Most Likely Injured Organ
In a trauma patient with an unremarkable E-FAST, pancreatic injury is the most likely among the options provided because E-FAST has poor sensitivity for detecting pancreatic injuries, which are routinely missed by this modality. 1
Why E-FAST Misses Pancreatic Injuries
E-FAST is effective for detecting free fluid and solid organ injuries like spleen and liver (sensitivity 96-100% for these organs when significant free fluid is present), but it is not recommended to routinely diagnose pancreatic trauma. 2
Pancreatic injuries are frequently missed by FAST/E-FAST because they often do not produce immediate free fluid, and the retroperitoneal location of the pancreas makes visualization difficult. 1, 3
The sensitivity of E-FAST for pancreatic injuries is only 68-91%, with the modality routinely missing bowel and pancreatic injuries compared to its high sensitivity for liver and spleen injuries. 1
Why Other Options Are Less Likely
Spleen and Liver (A and D)
Both spleen and liver injuries typically present with free intraperitoneal fluid that E-FAST readily detects. 2
E-FAST has high sensitivity (approaching 96-100%) for detecting significant liver and spleen injuries when they produce hemoperitoneum. 2
If E-FAST is unremarkable, significant spleen or liver injury is unlikely because these highly vascular organs bleed into the peritoneal cavity, which E-FAST detects effectively. 2
Urinary Bladder (C)
Bladder injuries typically present with pelvic free fluid or extraperitoneal fluid collections that can be detected on E-FAST pelvic views. 1
The bladder is anatomically located in the pelvis, not the upper abdomen, making it inconsistent with typical blunt abdominal trauma mechanisms that would be missed by E-FAST. 1
Critical Next Steps When E-FAST Is Unremarkable
CT scan with intravenous contrast is essential for diagnosing pancreatic injuries in hemodynamically stable patients (sensitivity 97%, specificity 95%). 2, 4
Serial measurement of serum amylase and lipase starting 3-6 hours after injury is crucial because pancreatic injury findings are time-dependent and may not be evident immediately. 2, 4
Elevated or rising enzyme levels mandate further investigation with CT scan, even if initial imaging is negative. 2, 4
Repeat CT scan within 12-24 hours should be considered in patients with high clinical suspicion for pancreatic injury despite negative initial imaging. 2
Common Pitfalls to Avoid
Never rely on E-FAST alone to exclude significant intra-abdominal injury when mechanism suggests solid organ injury or when clinical suspicion remains high. 1
Do not assume a negative E-FAST rules out pancreatic injury – the American College of Emergency Physicians emphasizes that negative or inconclusive FAST should never be the sole diagnostic test. 1
Pancreatic injuries are often overlooked in multiorgan trauma because alterations may not be visualized for several hours following trauma. 3
Delayed diagnosis of pancreatic injuries is associated with high morbidity and mortality, making early recognition of main pancreatic duct disruption critical. 3, 5