1. Clinical Indications

a. Persistent hypotension (SBP <90) despite resuscitation and stabilization of unstable pelvic fracture.

2. Key Anatomy

a. Pre-peritoneal space: Space of Retzius

b. Peritoneal space: abdominal cavity

c. Retroperitoneal space: space posterior to peritoneum

d. Venus plexus along anterior sacrum

e. Large potential space for hemorrhage in the pre and retroperitoneal space