Haematuria in trauma

OVERVIEW

• Haematuria in trauma may be microscopic (with or without symptoms) or macroscopic
• In general, the greater the degree of hematuria the greater the risk of significant intra-abdominal injury (including non-urinary tract structures)
• About 5% of renal injuries and up to 20% of renovascular injuries lack hematuria — even severe injuries such as renal artery injury or ureteropelvic disruption may present without hematuria

GOALS

• find source of bleeding along urological tract
• treat cause
• support blood volume
• identify associated injuries

ASSESSMENT

Clinical interpretation of haematuria is not diagnostic, however:

• Faint haematuria, primarily shades of pink, is usually associated with renal injury or a bladder contusion
• A moderate amount of darkly bloody urine is frequently associated with extraperitoneal bladder injury
• A small amount of very dark, bloody urine may mean an intraperitoneal bladder injury
• Scant and very dark blood in the catheter suggests a urethral injury or a catheter balloon inflated in the urethra

Microscopic haematuria in blunt trauma

• If the patient is asymptomatic the yield of injuries requiring intervention in this setting is extremely low:
  — no further imaging is needed
  — arrange repeat urinalysis (e.g. in a week’s time) and close follow up by a GP
  — Some experts advocate imaging in pediatric patients with asymptomatic haematuria following blunt abdominal trauma as they are more vulnerable to significant renal injury; cut off values vary, with values from 5 to 50 RBCs/hpf being suggested.
• Haematuria with <5 RBCs/hpf can be caused by urinary catheter insertion
• If the patient is significantly symptomatic, they may have associated non-urinary intrabdominal or retroperitoneal injury:
  — CT abdomen with IV contrast

Macroscopic haematuria in blunt trauma

• 50% of such patients have renal injuries, and a further 15% have injuries to other intra-abdominal organs:
  — CT abdomen with IV contrast and CT cystogram

Haematuria in penetrating trauma

• surgical exploration +/- CT if stable

Perform urethrogram if suspected urethral injury

• displaced fractures of the pelvic ring, particularly ‘butterfly fractures’
• Gross haematuria, difficulty placing a urinary catheter
• Classic clinical features are uncommon:
  — blood at the meatus
  — perineal / scrotal haematoma
  — high riding prostate on examination

Skeletal injuries associated with genitourinary injury:

• Pelvic fractures
  — posterior urethrethal injury (above the urogenital diaphragm) and bladder injury
• Perineal straddle injury
  — anterior urethral injury
• Fracture of the lower posterior ribs, lower thoracic or lumbar vertebrae
  — renal or ureteral injuries

MANAGEMENT

• ATLS approach
• Urology referral if significant identifiable injury
• Renal injury
  — Most renal injuries (Grades I to III, and most Grade IV injuries) can be managed conservatively, as they tend to heal spontaneously
  — Surgical repair is needed for urinary extravasation or if ongoing bleeding or hemodynamic instability due to renal injury
  — Alternatives to operative repair are interventional radiology to embolise bleeding vessels or to stent dissected renal arteries, and urinary extravasation may be amenable to stenting
  — Grade V injuries (avulsed kidneys) need operative intervention and often require nephrectomy
• Ureteral injury
  — contusions may be conservatively managed
  — more significant injuries require operative repair, urinary diversion, or (rarely) nephrectomy
• Bladder injury
  — Bladder contusion and hematomas can be observed
  — Intraperitoneal rupture requires laparotomy and surgical repair
  — Extraperitoneal rupture can often be managed with simple catheterisation (usually about 10 days)
• Urethral injury
  — Suprapubic catheterization may be required initially, followed by operative repair

Reference and Links

LITFL

• Trauma! Genitourinary Injuries
• CCC — Kidney trauma

FOAM and web resources

• The Trauma Professional’s Blog — AAST Revises Renal Injury Grading
• The Trauma Professional’s Blog — Evaluation of Hematuria in Blunt Trauma

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