Pediatric emergency medicine trisk 187

catheterized urinary specimens must take into account that the catheterization
itself might produce a small amount of trauma and cause a small number of
RBCs (<10 RBCs/HPF).
Other blood studies may be useful in selected cases and include a complete
blood cell (CBC) count, prothrombin time (PT), partial thromboplastin time
(PTT), erythrocyte sedimentation rate (ESR), blood urea nitrogen (BUN), serum
creatinine, complement levels (C3 and C4), and streptococcal serologies
(antistreptolysin O, anti-DNase B, and antihyaluronidase titers). The history and
physical examination should direct the emergency physician to those additional
tests that are needed, if any.
A clinical algorithm for evaluating hematuria in the ED is shown in Figure
36.1 . The first step is to confirm the presence of true hematuria. If a traumatic
cause for the hematuria is suspected on the basis of history or physical findings,
emergent evaluation for serious anatomic lesions must be initiated.
Parenchymal contusions, lacerations, renal transections, and pedicle disruptions
are possible injuries. Hematuria is the cardinal marker of renal injury, with the
magnitude of hematuria paralleling the severity of injury (except for renal
pedicle injuries, which may have no associated hematuria). Hematuria may also
signal traumatic injury to adjacent organs such as the spleen. Patients presenting
with blunt trauma associated with microscopic hematuria and no other
associated injuries and who are hemodynamically stable do not require
radiologic evaluation because significant renal injuries are unlikely. The
presence of gross hematuria or significant microscopic hematuria (more than 50
RBCs/HPF) in the context of significant mechanisms of injury necessitates
emergent imaging (see Chapter 103 Abdominal Trauma ). Hematuria
disproportionate to the injury may indicate a congenital renal anomaly or tumor.
If there is no history of trauma, then coagulopathies should be considered as
the cause. However, the medical history alone usually will point to this cause
because the sudden occurrence of isolated hematuria in a previously healthy
child is unlikely with either a congenital or an acquired bleeding disorder.
Hematuria in a child known to have hemophilia or a related disorder often

requires minimal investigation and is managed in accordance with standard
protocols. If an acquired coagulopathy is suspected, a CBC count, PT, and PTT
are warranted.
If trauma and coagulopathies are considered unlikely, identifying the site of
bleeding as either glomerular or nonglomerular (based on urinalysis and other
signs or symptoms) can direct further evaluation and diagnosis. Acute


glomerulonephritis characterized by hypertension, edema, RBC casts,
proteinuria, and tea-colored urine most often follows a streptococcal infection
and merits serious consideration in the ED because it may cause significant
hypertension and pulmonary edema requiring immediate intervention. HUS is a
serious disorder that may present with glomerular-induced hematuria and
proteinuria as well as a characteristic microangiopathic hemolytic anemia,
thrombocytopenia, and renal failure. Laboratory studies useful in children
suspected of having nephritis include a CBC, ESR, BUN, serum creatinine,
complement levels, and antistreptococcal antibodies. Other nephritides
associated with vasculitis may require further diagnostic evaluation before a
specific diagnosis is made (see Chapter 101 Rheumatologic Emergencies ).
Most children without a history of trauma who are evaluated for gross and/or
microscopic hematuria in the ED have a UTI. The infection may be either in the
upper tract (e.g., pyelonephritis, characterized by fever, chills, flank pain,
vomiting, and dysuria) or in the lower tract (e.g., cystitis, characterized by
dysuria, frequency, and occasionally, abdominal pain and fever). The cause of a
UTI is either bacterial or viral. Acute hemorrhagic cystitis is often associated
with adenovirus. The findings of pyuria and bacteriuria on urinalysis suggest an
infectious cause, although their absence does not exclude either pyelonephritis
or cystitis; thus, a urine culture is essential if no other cause has been
uncovered. If the clinical suspicion is high for a bacterial UTI, presumptive
antimicrobial treatment should be initiated (see Chapter 94 Infectious Disease

Emergencies ).


FIGURE 36.1 Approach to hematuria in the emergency department.


Severe flank pain radiating to the groin is characteristic of renal colic from
calculi, which may present with either gross or microscopic hematuria. Crystals
may be seen on urinalysis. Stones may occur in children with metabolic
abnormalities or stasis secondary to obstruction, in premature infants taking
furosemide, and children taking topiramate. While stones may be visualized by
plain radiographs, ultrasound is the preferred method for detection in children
due to its ability to detect both radiopaque and radiolucent stones and concerns
for radiation expose with CT. CT is more sensitive for detecting small ureteral
stones. Hypercalciuria is an important cause of hematuria in children and may
be idiopathic or secondary to another disease and can lead to nephrocalcinosis
(see Chapter 100 Renal and Electrolyte Emergencies ).
Hematuria that persists after the previously mentioned causes have been ruled
out or deemed unlikely on the basis of history and physical examination usually
does not require further evaluation in the ED and should be pursued by the
primary health care provider, possibly in collaboration with a pediatric
nephrologist. These additional causes are listed in Figure 36.1 and Table 36.1
and may require more extensive imaging and interventions such as renal biopsy,
metabolic studies, or serial urinalyses (benign hematuria, exercise-induced
hematuria).
Suggested Readings and Key References
Bignall ONR 2nd, Dixon BP. Management of hematuria in children. Curr Treat
Options Pediatr 2018;4:333–349.
Colleran GC, Callahan MJ, Paltiel HJ, et al. Imaging in the diagnosis of
pediatric urolithiasis. Pediatr Radiol 2017;47:5–16.

Cyriac J, Holden K, Tullus K. How to use… urine dipsticks. Arch Dis Child
Educ Pract Ed 2017;102:148–154.
Davis TK, Hmiel P. Pediatric hematuria remains a clinical dilemma. Clin
Pediatr 2015;54:817–830.
Hynick NH, Brennan M, Schmit P, et al. Identification of blunt abdominal
injuries in children. J Trauma Acute Care Surg 2014;76:95–100.