What abdominal organ is likely damaged in a patient with upper abdominal pain and tenderness after a handlebar injury, with an inconclusive Focused Assessment with Sonography for Trauma (FAST) and tachycardia?

Pancreas is the Most Likely Injured Organ (Answer: C)

In a patient with handlebar injury presenting with upper abdominal pain, inconclusive FAST, and tachycardia, the pancreas is the most likely damaged organ because FAST routinely misses pancreatic injuries while effectively detecting the free fluid that would be present with significant spleen or liver injuries. 1

Why Pancreas is Most Likely

FAST Performance Characteristics

• FAST has poor sensitivity (68-91%) for detecting all intra-abdominal injuries and frequently misses bowel and pancreatic injuries 2, 1
• The World Journal of Emergency Surgery explicitly states that E-FAST is not recommended to routinely diagnose pancreatic trauma 1
• Among 30 patients with false negative FAST examinations, 16 had either bowel or mesenteric injuries 2

Handlebar Injury Mechanism

• Handlebar injuries classically cause pancreatic trauma due to direct compression of the pancreas against the spine 3
• Pancreatic injury is characterized by discordance between the severity of injury and its initial clinical expression 3
• The pancreas is more deeply placed and injuries may not produce immediate free fluid detectable by FAST 3

Why Not Spleen or Liver

Both spleen and liver injuries would likely show positive FAST findings:

• E-FAST has high sensitivity (approaching 96-100%) for detecting significant liver and spleen injuries when they produce hemoperitoneum 1
• Both spleen and liver injuries typically present with free intraperitoneal fluid that E-FAST readily detects 1
• 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 1
• The spleen is the most commonly injured organ in blunt abdominal trauma and typically manifests with acute intraperitoneal hemorrhage 4, 5
• Liver injuries typically present with right upper quadrant pain and would likely show free fluid on FAST if significant 1

Why Not Bladder

• The bladder is located in the pelvis, not the upper abdomen, making this anatomically inconsistent with the clinical presentation 1
• The patient specifically has upper abdominal pain and tenderness 1

Critical Next Steps

Immediate Diagnostic Workup

• CT scan with intravenous contrast is essential for diagnosing pancreatic injuries in hemodynamically stable patients (sensitivity 97%, specificity 95%) 1
• CT is specifically superior for detecting pancreatic injuries, which FAST routinely misses 1
• The American College of Emergency Physicians emphasizes that negative or inconclusive FAST does not exclude significant intra-abdominal injury and should never be the sole diagnostic test 1

Time-Dependent Evaluation

• 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 1
• Elevated or rising enzyme levels mandate further investigation with CT scan, even if initial imaging is negative 1
• Repeat CT scan within 12-24 hours should be considered in patients with high clinical suspicion for pancreatic injury despite negative initial imaging 1

Common Pitfalls to Avoid

• Never rely on FAST alone when mechanism suggests solid organ injury or when peritoneal signs are present 1
• Do not assume an inconclusive FAST rules out significant injury—it has limited sensitivity for pancreatic trauma 2, 1
• Do not delay CT imaging in hemodynamically stable patients with handlebar mechanism and upper abdominal pain 1
• Remember that pancreatic injuries may have minimal initial clinical findings despite significant underlying damage 3