Tintinalli's Emergency Medicine - Just the Facts, 3ed.

169. GENITOURINARY TRAUMA

Matthew C. Gratton

EPIDEMIOLOGY

images Falls, assaults, motor vehicle crashes, and sports injuries are the most common causes of blunt genitourinary (GU) injury while gunshot and stab wounds are the most common causes of penetrating injury.

images GU injuries frequently occur in the setting of multiple trauma, and so a thorough evaluation is necessary to avoid missing significant injuries.

CLINICAL FEATURES

images Patients with any abdominal trauma, including penetrating trauma in the vicinity of GU structures, are at risk.

images High-velocity deceleration predisposes to renal pedicle injuries, including lacerations and thromboses of the renal artery and vein.

images Fractures of the lower ribs or lower thoracic or lumbar vertebrae are often associated with renal injuries, while pelvic fractures and straddle injuries are associated with bladder or urethral injuries.

images Flank ecchymoses, tenderness, mass, or penetrating injury raises concern for renal injury.

images The perineum should be inspected for blood or lacerations, which may denote an open pelvic fracture.

images The presence of a penile, scrotal, or perineal hematoma or blood at the penile meatus suggests urethral injury.

images If blood at the meatus is present, then do not attempt to insert a urethral catheter due to the concern for converting a partial urethral laceration into a complete transection.

images Perform a rectal examination, assessing sphincter tone, checking for blood, and determining the position of the prostate.

images A high-riding prostate or one that feels boggy suggests injury to the membranous urethra.

images Examine the scrotum in male patients for ecchymoses, lacerations, or testicular disruption.

images Inspect the vaginal introitus in female patients for lacerations and hematomas, which may be associated with pelvic fractures. If there is evidence of injury in this area, or if injury is suspected, a bimanual examination should be performed. If blood is present, a speculum examination is warranted to check for vaginal lacerations.

DIAGNOSIS AND DIFFERENTIAL

images Urinalysis is important, but there is no direct relationship between the degree of hematuria and the severity of renal injury.

images There is some evidence that gross hematuria or microscopic hematuria in patients with a systolic blood pressure <90 mm Hg are associated with more significant injury.

images In hemodynamically stable patients, isolated microscopic hematuria rarely represents significant injury. However, a renal pedicle or vascular injury from rapid deceleration may be an exception.

images In stable children, renal injury is unlikely if the urine contains <50 RBCs/hpf.

images Analysis of the first-voided urine may help localize the injury. Initial hematuria suggests injury to the urethra or prostate, while terminal hematuria is associated with bladder neck trauma. Continuous hematuria may be due to injury to the bladder, ureter, or kidney.

images An IV contrast-enhanced abdominopelvic CT is the imaging “gold standard” for the stable trauma patient with suspected kidney injury.

images A “one shot” intraoperative IV urogram is recommended by some for the unstable patient, although this is controversial.

images A retrograde cystogram (plain radiograph or CT) is the “gold standard” for demonstrating bladder injury, as is a retrograde urethrogram for demonstrating urethral injury.

images Indications for imaging in suspected renal trauma patients are listed in Table 169-1.

TABLE 169-1 Indications for Imaging in Patients with Suspected Renal Trauma

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EMERGENCY DEPARTMENT CARE AND DISPOSITION

images Take a standardized approach to all multiple trauma patients to identify and treat life-threatening injuries (primary survey) and then perform a thorough secondary survey, including a GU examination to avoid missing subtle injuries.

images Patients with isolated microscopic hematuria and no other injuries may be discharged with repeat urinalysis in 1 to 2 weeks.

MANAGEMENT OF SPECIFIC INJURIES

KIDNEY

images Renal injuries are present in 8% to 10% of patients with abdominal trauma, and 80% of those with renal injury have additional visceral or skeletal injuries.

images Most renal injuries are handled nonoperatively, but indications for exploration and intervention include life-threatening bleeding from the kidney; expanding, pulsatile, or noncontained hematoma (thought to be from a renal avulsion); renal avulsion injury; and renal pelvis or ureteral injuries.

images Renal contusions and lacerations not involving the collecting system are managed nonoperatively. In the absence of other injuries, patients with renal contusions may be discharged with repeat urinalysis in 1 to 2 weeks.

images Admit patients with renal lacerations, pedicle injuries, or lacerations involving the collecting system. Many of these patients have associated injuries requiring surgical repair.

images Urinary extravasation alone is not an indication for operative repair as it resolves spontaneously in the majority of cases. Extravasation from a renal pelvis or ureteral injury does require repair.

images In the case of isolated renal injury with no indication for operative repair, patients need frequent reassessment and should be put on bed rest, kept well hydrated, and have frequent hematocrit determinations and urinalyses until hematuria clears.

images Some gunshot and stab wounds to the kidney can be treated nonoperatively with the absolute indications for exploration mentioned above. Many with renal injuries will have other injuries that mandate exploration.

URETER

images Ureteral injuries are the rarest of the GU injuries and usually result from penetrating trauma or are complications due to instrumentation.

images The absence of hematuria does not rule out injury.

images Ureteral injuries are managed operatively, including simple stenting in some cases.

BLADDER

images Bladder injury occurs in about 2% of blunt abdominal trauma and 80% are associated with pelvic fractures.

images Gross hematuria is present in about 95% of patients with significant injury.

images Intraperitoneal rupture usually results from a burst injury of a full bladder and always requires surgical exploration and repair.

images Extraperitoneal rupture is more common, is often associated with a pelvic ring fracture, and can usually be managed by bladder catheter drainage alone.

images Symptoms and signs of bladder rupture include lower abdominal pain and tenderness, gross hematuria, lower abdominal bruising, abdominal swelling from urinary ascites, perineal or scrotal edema from urinary extravasation, and inability to void.

images Penetrating bladder injuries are managed operatively.

URETHRA

images Urethral injuries in males can involve the posterior (prostatic and membranous) urethra and/or the anterior (bulbous and penile) urethra.

images Posterior injuries are typically related to major blunt force trauma and are associated with pelvic fractures. Treatment is via suprapubic bladder drainage followed in several weeks by surgical repair.

images A urinary catheter should not be placed if there is suspicion of a posterior urethral injury without first obtaining a retrograde urethrogram since the catheter could convert a partial to a complete disruption.

images Anterior injuries result from direct trauma or instrumentation and are usually managed conservatively, with or without a urethral catheter.

images Penetrating injuries to the anterior urethra usually require operative repair.

images In females, urethral injuries are often associated with pelvic fractures and commonly present with vaginal bleeding.

TESTICLES AND SCROTUM

images Blunt testicular injuries should be evaluated with color Doppler ultrasonography to determine the extent of injury and determine if a rupture is present.

images Contusions may be managed conservatively with nonsteroidal anti-inflammatory drugs, ice, elevation, scrotal support, and urologic follow-up.

images Testicular rupture or penetrating trauma requires operative repair to improve outcome.

images Scrotal skin avulsion is managed by housing the testicle in the remaining scrotal skin, which will usually return to normal size in several months.

PENIS

images Injuries range from small contusions to degloving injuries or amputations.

images Simple skin lacerations can be directly repaired but deeper lacerations and/or penetrating injuries require operative exploration and repair.

images Amputations require microvascular reimplantation if the amputated segment is viable.

images A fractured penis, due to traumatic rupture of the corpus cavernosum, is managed by immediate surgical drainage of blood clot and repair of the torn tunica albuginea and any associated urethral injuries.

images Penile skin avulsion is managed with split-thickness skin grafting after debridement.

images Zipper injury to the penis results when the penile skin is trapped in the trouser zipper. Mineral oil and lidocaine infiltration are useful in freeing the penile skin from the zipper. Wire-cutting or bone-cutting pliers are used to cut the median bar (diamond) of the zipper, causing the zipper to fall apart.

images Contusions to the perineum or penis are treated conservatively with cold packs, rest, and elevation.

images If the patient is unable to void, catheter drainage may be required.


For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 262, “Genitourinary Trauma,” by John McManus, Matthew C. Gratton, and Peter J. Cuenca.



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