A diagnostic negative ultrasound finding in blunt abdominal trauma.

Introduction: Ultrasound is an extension of the clinical examination and its findings should be correlated with the clinical picture as a whole to be useful. Hereby, we report a unique negative diagnostic ultrasound finding in blunt abdominal trauma which was not reported before.

Clinical presentation: A 50-year-old obese man presented complaining of severe generalized abdominal pain and inability to pass urine of three days duration after he slipped on his abdomen. The abdomen was distended and tender all over. There was no blood on the urethral meatus. FAST scan showed significant intra-peritoneal fluid. The urinary bladder could not be seen. A Foley catheter was inserted which drained 3 L of clear urine. The abdominal distention became less. Repeated FAST scan was completely negative. A clinical diagnosis of major intra-peritoneal rupture of the urinary bladder was made. Trauma CT scan and laparotomy confirmed the diagnosis.

Conclusions: The change of a positive FAST to a negative FAST was diagnostic of a major intra-peritoneal urinary bladder rupture even before performing a trauma CT scan. When performing FAST in blunt abdominal trauma, it is more useful to perform FAST before inserting a urinary catheter and it is advised to repeat it.