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

ASSESSMENT

Clinical interpretation of haematuria is not diagnostic, however:

Faint hematuria, 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 hematuria 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.
Hematuria 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

Perform urethrogram if suspected urethral injury

displaced fractures of the pelvic ring, particularly ‘butterfly fractures’
Gross hematuria, 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

LITFL

Trauma! Genitourinary Injuries

CCC — Kidney trauma

Journal articles and textbooks

Legome E, Shockley LW. Trauma: A Comprehensive Emergency Medicine Approach, Cambridge University Press, 2011.

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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