Renal, Fluids, Electrolytes & Acid-Base · Topic 8 of 22
Renal & Genitourinary Trauma
Renal & GU · trauma
Renal & Genitourinary Trauma
After trauma, gross hematuria or hematuria with shock means contrast CT; blood at the meatus means a urethrogram before any Foley.
Key numbers
Contrast CT for gross hematuria or shockSBP < 90 mmHg
01 · The ruleBlood at meatus: urethrogram before Foley
Blood at the urethral meatus is the key sign of urethral injury: in men, obtain a retrograde urethrogram before any urethral catheter, because catheterization can convert a partial disruption into a complete one.
02 · Defined byContrast CT for gross hematuria or shock
After blunt trauma, order contrast-enhanced CT with delayed (10–15 min) images for gross hematuria, microscopic hematuria with SBP < 90 mmHg, or a high-risk mechanism (major deceleration, flank blow, lower rib fractures).
03 · DoStable renal injury: nonoperative, any grade
Nonoperative management is the treatment of choice for hemodynamically stable or stabilized renal injuries of any grade (AAST I–V); unstable patients who do not respond to resuscitation go to the operating room.
01
Causes & risk factors
Why it happensPosterior urethra: pelvic fracture; anterior: straddlePosterior urethral injuries occur almost exclusively with pelvic fractures; anterior (bulbar, penile) injuries follow a perineal blow or straddle fall.
02
Presentation
What you'll seeBladder rupture: pelvic fracture plus gross hematuriaMore than 95% of blunt bladder ruptures occur with a pelvic fracture, and almost all present with gross hematuria; most ruptures are extraperitoneal.
03
Diagnosis & monitoring
Work-upAAST renal grades I–VAAST renal grades: I contusion or subcapsular hematoma; II laceration ≤ 1 cm; III laceration > 1 cm without extravasation; IV collecting-system or segmental vascular injury; V shattered or devascularized kidney, hilar avulsion.
Bed rest and serial hematocrit until urine clearsNonoperative renal injury: strict bed rest until gross hematuria clears, with serial vital signs and hematocrit; most grade I–II injuries can be discharged.
04
Do right now
In this orderFirst moves
1
→Blood at meatus: urethrogram before Foley
2
→Contrast CT for gross hematuria or shockSBP < 90 mmHg
3
→Diagnose bladder rupture with retrograde cystography
4
Stable renal injury: nonoperative, any grade
Why each step
Blood at meatus: urethrogram before FoleyBlood at the urethral meatus is the key sign of urethral injury: in men, obtain a retrograde urethrogram before any urethral catheter, because catheterization can convert a partial disruption into a complete one.
Contrast CT for gross hematuria or shockAfter blunt trauma, order contrast-enhanced CT with delayed (10–15 min) images for gross hematuria, microscopic hematuria with SBP < 90 mmHg, or a high-risk mechanism (major deceleration, flank blow, lower rib fractures).
Diagnose bladder rupture with retrograde cystographyConfirm bladder injury with retrograde cystography (plain film or CT), filling the bladder with at least 300 mL of dilute contrast; a routine contrast CT with delayed phase is less sensitive.
Stable renal injury: nonoperative, any gradeNonoperative management is the treatment of choice for hemodynamically stable or stabilized renal injuries of any grade (AAST I–V); unstable patients who do not respond to resuscitation go to the operating room.
05
Management
OrdersIntraperitoneal bladder rupture needs surgical repair must knowIntraperitoneal bladder rupture (peritoneal signs, urinary ascites) and all penetrating bladder injuries need surgical repair; uncomplicated extraperitoneal rupture is managed with urethral catheter drainage alone.
Angioembolization for active extravasation if stableSelective angioembolization is indicated in stable or stabilized patients with arterial contrast extravasation, pseudoaneurysm, arteriovenous fistula or persistent gross hematuria.
Intervene for ongoing bleeding or expanding hematomaPrompt surgery, stenting or embolization is needed for bleeding requiring repeated transfusion, an expanding perinephric hematoma, renal pedicle avulsion or other major renovascular injury, or ureteropelvic junction disruption.
Urethral disruption: suprapubic tube, repair laterA pelvic-fracture urethral disruption is drained with a suprapubic cystostomy and reconstructed after about 8–12 weeks; a urethral contusion needs only a Foley for about 5–7 days.
Extraperitoneal rupture with bladder-neck injury: repairAn extraperitoneal bladder rupture still needs surgical repair if it involves the bladder neck, rectum or vagina, or causes persistent gross hematuria or clot retention.
06
The rules
Know theseStable, microscopic hematuria only: no imagingA hemodynamically stable patient with blunt trauma and only microscopic hematuria has at most a minor renal injury and does not need renal imaging; penetrating trauma with any hematuria gets CT.
07
Intraperitoneal or extraperitoneal bladder rupture?
Commonly confused| Frequency | Less common |
|---|---|
| Findings | Peritoneal signs, urinary ascites |
| Diagnosis | Retrograde (CT) cystography |
| Treatment | Surgical exploration and repair |
| Needs surgery when | Always |
08
More detail
ReferenceShow 8 reference facts
A high-riding prostate on rectal examination is an unreliable sign of urethral injury; perineal, scrotal or penile ecchymosis and inability to void are supportive.
The kidney is the most commonly injured genitourinary organ; 85–90% of renal injuries are blunt and most are low grade.
Anticoagulated patients and those with congenital renal anomalies can develop gross hematuria after relatively minor trauma.
Ureteral injury is easily missed: hematuria is absent in up to 25%; it is found on CT with delayed excretory images.
Persistent urinary extravasation from a renal injury is treated with a ureteral stent.
Mortality from traumatic bladder rupture approaches 20%, driven by associated injuries rather than the bladder itself.
Female urethral injuries are rare; evaluate with cystoscopy and a thorough vaginal examination, and repair immediately.
When pelvic bleeding needs angioembolization and bladder injury is suspected, perform cystography after angiography so contrast does not obscure the angiogram.
Blood at the meatus: no Foley until the retrograde urethrogram is done.
Sources · Merck Manual Professional — Renal Trauma (2025) · Merck Manual Professional — Bladder Trauma (2025) · Merck Manual Professional — Urethral Trauma (2025) · Coccolini F et al. Kidney and uro-trauma: WSES-AAST guidelines. World J Emerg Surg 2019;14:54 · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).