If the casualty is not experiencing persistent massive external hemorrhage, the potential for massive internal hemorrhage from a pelvic injury should be assessed. Most pelvic fractures are associated with dismounted improvised explosive device (IED) attacks accompanied by amputations, but they also occur in severe blunt trauma (such as motor vehicle crashes, aircraft mishaps, hard parachute landings, and falls). 26% of service members who died in OEF/OIF had a pelvic fracture, and bleeding pelvic fractures with hemodynamic instability have up to a 40% mortality. 

Several major vessels run alongside the pelvic bones that can be disrupted by the sharp edges of a fracture and are in anatomic locations that do not allow for effective direct or indirect pressure to be applied.

Pelvic fracture should be suspected in any casualty who suffers severe blunt force or blast injury and has one or more of the following indications:

Additional signs include scrotal, perineal, or perianal bruising, blood at the urethral meatus or massive hematuria, blood in the rectum or vagina, or neurologic deficits in lower extremities.

Many prior courses have taught combat medics (and others) to check for pelvic instability by applying downward pressure on the anterior ilia (also called “opening the book”), but this causes further damage if a pelvic fracture is present and should NOT be done.