Which of the following statement(s) is/are true concerning the diagnosis and management of pelvic fractures secondary to blunt trauma?

b. An infra-umbilical approach to peritoneal lavage in a patient with a major pelvic fracture may yield a falsepositive rate approaching 50%

d. The application of pelvic external fixation may be used as the initial step in control of hemorrhage from pelvic fractures

The spectrum of pelvic fracture injuries range from minor isolated non-displaced fractures of the pubic rami to severe injuries with multiple fractures that can be rapidly lethal. Unlike most long bone fractures, only 25% of pelvic fractures are apparent on physical examination. Hemorrhage caused by laceration of the sacral venous plexus, multiple arterial branches of the hypogastric vessels, or bleeding from fractured cancellous bone presents a formidable challenge to the trauma surgeon. Massive hemorrhage is the principle cause of early death in patients with pelvic fracture, and survival depends principally on rapid identification and control. The presence of hemorrhage from associated intraperitoneal injuries should be considered first, therefore diagnostic peritoneal lavage is indicated for most patients with pelvic fractures. A supraumbilical lavage is preferable under these circumstances because the possibility of catheter penetration of a large retroperitoneal hematoma dissecting into the preperitoneal space. Peritoneal lavage performed incorrectly in the infraumbilical site with a major pelvic fracture may yield an incidence of false-positive results as high as 45%. When performed properly in the supraumbilical position, false-positive lavage rates have been reported to be as low as 1%. If laparotomy is indicated once a thorough abdominal exploration is performed and injury is repaired, the size of the pelvic hematoma may be assessed. If a rapidly expanding pelvic hematoma is seen, rapid closure of the abdominal wound is indicated followed immediately by pelvic angiography and embolization of active arterial bleeding. In selected patients with unstable fractures involving the sacrum or pubic diastasis injuries, the application of pelvic external fixation may reduce hemorrhage from cancellous bone and sacral venous plexus. In many centers, pelvic fixation is preferred to arteriography and embolization for the initial control of bleeding.

 A urethral tear should be suspected in any male with a pelvic fracture. These patients should be examined carefully for signs of urethral injury including scrotal or perineal hematoma, blood at the urethral meatus, or anterior displacement of the prostate gland on rectal examination. The presence of any of these clinical findings constitutes a contraindication to immediate placement of a urethral catheter. A retrograde urethrogram should be obtained in these cases by the placement of a small balloon catheter in the fossa navicularis and gravity infusion of 10–15 ml of contrast medium.