Haematuria following Blunt Flank Trauma in Children


Haematuria following Blunt Flank Trauma: Can Children who Walk in Safely Walk out?

By Dr. Cara Jennings, Consultant EM and Major Trauma.


Blunt flank trauma is a common problem in children which can result in renal injury.
Renal injury varies from simple haematoma to large laceration or avulsion of the kidney.
Children with renal injury often have normal observations, laboratory tests are unhelpful, FAST isn’t sensitive in children and CT requires large doses radiation.
Urinalysis offers a cheap, non-invasive method of risk stratifying patients with blunt flank trauma.


To determine whether children that walk into the ED with microscopic haematuria following blunt flank trauma can be safely discharged without imaging.

Methods and Material:

A search was performed on Medline, CINAHL and EMBASE for articles relating to blunt flank /abdominal trauma (BAT) with haematuria/microscopic haematuria in children.
27 articles were identified from the search. 14 articles were found to be relevant and were systematically reviewed.
All paediatric patients with blunt flank or abdominal trauma presenting to King’s College Hospital (KCH) from August 2013-14 had a retrospective notes review. 54 patients were identified, 13 of which had microscopic haematuria.


All 14 articles were case series.
Some authors’ only discussed major trauma patients, or those who had required CT or laparotomy.
Summary of authors’ conclusions:
Decision to image should be based on clinical findings and mechanism of injury rather than urinalysis(1,2,3).
Children with BAT, microscopic haematuria and no other injuries unlikely to have significant renal injury(4).
Higher degree suspicion of significant renal injury for patients >50rbc/hpf or 3+ on urinalysis(5,6).

In the case series from KCH no walk in patient with microscopic haematuria had significant injury.
The patients identified with significant injury were major trauma patients who did not walk into the department:

The findings from the literature review and the case series were used to develop the guideline below.


The presence of microscopic haematuria is not a sensitive marker for renal injury and should be interpreted as part of the wider clinical picture.
Haemodynamically stable patients who walk into the department following blunt flank trauma and microscopic haematuria <50rbc/hpf are highly unlikely to have clinically significant injury and can be safely discharged. Patients with >50rbc/hpf have a very small risk of clinically significant injury. It would be prudent to perform renal ultrasound on these patients within 24 hours.


1. Nguyen MM et al Pediatric renal trauma. Urology. 2002May;59(5):762-6.
2. Abou-Jaoude W et al. Indicators of genitourinary tract injury or anomaly in cases of pediatric blunt trauma. J Pediatr Surg. 1996 Jan;31(1):86-9;
3. Taylor G et al. Hematuria. A marker of abdominal injury in children after blunt trauma. Ann Surg. 1988 Dec;208(6):688-93
4. Brown SL et al.Radiologic evaluation of pediatric blunt renal trauma in patients with microscopic hematuria. World J Surg. 2001 Dec;25(12):1557-60.
5. Stein J et al. Blunt renal trauma in the pediatric population: indications for radiographic evaluation. Urology. 1994 Sep;44(3):406-10
6. Morey AF et al Efficacy of radiographic imaging in pediatric blunt renal trauma. J Urol. 1996 Dec;156(6):2014-8