a whack to the flank….

the case.

an 84 year old man is bought to your emergency department following a 3 metre fall from a ladder. He has landed on his right-hand side & is complaining of severe bilateral chest & flank pain.

His systolic blood pressure with the paramedics has been 100-105 mmHg, except for a transient episode of hypotension [72mmHg systolic] which resolved after a 300mL  bolus of crystalloid. On arrival to ED he has a GCS of 15,  full recollections of events & no focal neurological deficit but is in excruciating pain.

Pulse 66/min. BP 106/72. SaO2 94%. RR 26.

He is on warfarin for atrial fibrillation, but does not recall his last INR measurement.

[DDET What are your principles of management in this case ?]

• Rapid assessment [Primary survey] & concomitant treatment of life threatening injuries.
  • Multidisciplinary approach. Trauma call. Resuscitation bay.
  • Includes empiric C-spine immobilisation [mechanism, age, distracting injuries]
• Rapid detection of early evidence of haemorrhage.
  • E-FAST.
  • Pelvic x-ray.
  • Early CT-scan including arterial-phase if remains ‘stable’.
• Preparation for massive transfusion.
  • Multiple possible injuries each with potential for massive blood loss.
  • Minimum of 2x large-bore cannula.
  • Cross-matched blood.
• Analgesia.
  • Titrated intravenous opiates.
  • Likely to require PCA.
• Preparation/expectation for warfarin reversal.
  • Prothrombinex.
  • Vitamin K.
  • Fresh frozen plasma.
  • Consideration of tranexamic acid if requiring massive transfusion.
• Assess for potential medical reasons for ‘fall’.
  • ie. was this syncope ?
  • ECG
• Seek and treat less significant traumatic injuries.
  • Secondary survey.
  • CT-Brain + C-spine.
  • X-rays dictated by physical exam.
• Others:
  • Family notification.
  • Consider tetanus booster + prophylactic antibiotics.

[/DDET]

[DDET What happens next ??]

Whilst the team are seeing to the primary survey & getting IV access, you obtain the following images on your bedside FAST exam…

httpv://youtu.be/MyD8ctITRfQ

httpv://youtu.be/GY2WqvbhZvc

Moderate amount of hypoechoic material in the RUQ ?blood+clot. This appears to be more in the perinephric space than ‘Morrison’s pouch’.

The remainder of the E-FAST is unremarkable.

The patient remains haemodynamically stable, however receives empiric reversal of his anticoagulation with 50IU/kg of prothrombin complex concentrates [Prothrombinex®], plus 10mg IV vitamin K. He is then taken rapidly to CT for further assessment….

[/DDET]

[DDET Here is his CT scan…]

httpv://youtu.be/P6OVxUYIdqE

Other positive findings included:

• Multiple rib fractures including left sided flail segment.
• Associated left pulmonary contusion.
• Fractures of T4 & T8.
• Comminuted fracture of right ilium plus left superior & inferior pubic rami.
• Right sacroiliac joint subluxation.

[/DDET]

[DDET The diagnosis ??]

RENAL TRAUMA.

• Present in 8-10% abdominal trauma.
  • Penetrating vs Blunt mechanisms
• Accounts for < 0.1% of trauma deaths.
• Rarely occurs in isolation.
  • > 80% have additional visceral/skeletal injuries.
  • Often non-urological injuries result in haemodynamic instability.
• Recall: the kidneys receive 20-25% of cardiac output [~1200mL per minute], therefore have potential for massive blood loss.

INVESTIGATIONS.

Urinalysis.

• No correlation between presence & absence of haematuria with severity of injury.
  • ~14% of major injuries [& ~10% of minor injuries] have no haematuria.
• No correlation between degree of microscopic haematuria and severity of injury.
• Gross haematuria MAY correlate with severe renal injury.
  • Can miss up to two-thirds of renal injuries if used in isolation.

Ultrasound [FAST].

• High sensitivity & specificity for free-fluid.
• Misses up to 78% of known renal injuries.
• Will not identify renal vascular injury.

Advanced imaging.
Goals of imaging are to stage the injury, assess for preexisting renal pathology, functionality/disease-state of contralateral kidney & assess for concomitant traumatic injuries.

• CT with IV contrast.
  • GOLD STANDARD.
  • Delineates grade of injury [contusion, laceration, haematoma] + perfusion abnormalities.
  • Contrast extravasation = active haemorrhage.
  • Use of delayed scan [~10min post contrast administration] = ?urinary extravasation.
• IV urography.
  • KUB-xray is taken ~10 minutes after an IV contrast bolus is administered.
  • ↓ Sn in hypotensive/shocked patients.
  • Does not aid in grading.
  • Does have a role in on-table imaging if patient is taken straight to laparotomy for other reasons.
• Formal angiography.
  • Allows for embolisation or stenting at initial assessment.
  • Has role for further assessment for delayed injuries/pathology [ie. thrombosis, aneurysm formation].

GRADING OF RENAL INJURIES.

For further examples of renal injuries check out Radiopaedia.org

TREATMENT.

• Standard ‘Trauma-rules’ apply.
  • Haemodynamic compromise → exploratory laparotomy.
• Majority of renal injuries [Grades I, II & III] can/will be managed conservatively.
  • Some Grade IV injuries will too.
  • Only ~9% of renal injuries require surgical exploration. Of these ~11% require nephrectomy.
• Indications for surgical intervention.
  • Life-threatening haemorrhage.
  • Expanding, pulsatile or non-contained retroperitoneal haematoma.
  • Renal avulsion injury [Grade V]
  • Renal pelvis or ureteric injuries DO require repair. Urinary extravasation is NOT a sole reason for exploration. These usually resolve spontaneously.
• Some injuries are amenable to stenting or angio-embolisation.

COMPLICATIONS.

• Delayed bleeding
  • usually secondary to AV-fistula formation [~25% of Grade III or IV injuries]
• Urinary extravasation
• Urinoma
• Perinephric abscess
• HTN

DISPOSITION.

• The majority of patients will require admission for concomitant injuries.
• Patients with gross haematuria should be admitted & observed until it clears.
• Who can be discharged ?
  • Patients with microscopic haematuria & no indications for imaging.
  • Light duties only & close follow-up.

[/DDET]

[DDET References.]

1. Rosenʼs Emergency Medicine. Concepts and Clinical Approach. 7th Edition
2. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th Edition.
3. Renal Trauma – Trauma.org
4. Renal Trauma Grading – Radiopaedia.org

[/DDET]