Free intraperitoneal fluid in the trauma setting

Case contributed by Dr Heather Pascoe


Car vs tree. Lower abdominal pain.

Patient Data

Age: 42
Gender: Female

Brain and Cervical spine

Brain, Face and Skull 

  • No intracranial injury.
  • Left lateral maxillary sinus wall fracture with associated haemoantrum. Soft tissue gas and swelling of the left cheek.
  • Tiny locule of intraorbital gas on the left is suspicious for an undisplaced orbital floor/medial wall fracture.
  • Non-displaced fracture through the posterior aspect of the left zygomatic arch.
  • Previous fixation of bilateral mandibular fractures.
  • Dental braces.


  • No fracture
  • Right lower neck soft tissue swelling and edema.

Chest, Abdomen and Pelvis


  • Undisplaced sternal fracture.
  • Dependent lung changes.


  • Seatbelt sign.
  • Perihepatic, right paracolic gutter, Morrison's pouch, and pelvic free fluid.
  • Possible bladder injury - non dependent high density material within the bladder, and some thickening of the anterosuperior bladder wall.  Bladder injury may be the cause of the free fluid.
  • Right L2 transverse process fracture

Incidental findings

  • Left ovarian dermoid containing fat and tooth.
  • Appendicoliths.

CT Cystogram subsequently demonstrated evidence of anterior bladder dome rupture, with intraperitoneal leakage of contrast.

Case Discussion

Free intraperitoneal fluid is a common finding in trauma and sometimes no cause is identified. Isolated free fluid is present in approximately 3% of all trauma CTs 1. The causes for free intraperitoneal fluid (not of blood density) include injury to bowel, mesentery, gallbladder and bladder. If CT does not conclusively confirm the presence of bowel, mesentery or gallbladder injury, then bladder injury needs to be ruled out. It must be noted that a small volume isolated pelvic free fluid in females is often not significant. Small amounts of free fluid in males may also be a benign finding.

In this case the bladder rupture was intraperitoneal which is less common than extraperitoneal rupture (80-90% of cases) 2. Intraperitoenal rupture generally results from a direct blow to a distended bladder and is typically seen in people who have been drinking alcohol and are then involved in an accident. These injuries require surgical repair. Simultaneous intra and extraperitoenal rupture can also occur.


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Case information

rID: 32894
Published: 11th Jul 2015
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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