Hematuria Flashcards
Hematuria
The presence of five or more RBCs per high-power (40X) field in three consecutive fresh, centrifuged specimens obtained over the span of several weeks
Confirmation of hematuria is critical
A positive urine dipstick test may result from myoglobinuriaor hemoglobinuria, in which the urine often is discolored, but no RBCs are noted on microscopic evaluation.
In addition, certain drugs (sulfonamides, nitrofurantoin, salicylates, phenazopyridine, phenolphthalein), toxins (lead, benzene), and foods (food coloring, beets, blackberries, rhubarb, paprika) may falsely discolor urine, in which case the urine dipstick test is negative for heme.
In newborns, a red or pink discoloration in the diaper can be seen when urate crystals precipitate in the urine.
Glomerular blood
Color - Smoky, tea-or cola-colored, red
RBC Morphology - Dysmorphic
Casts - RBC, WBC
Clots - absent
Proteinuria - >2+
Extrglomerular blood
Color - Red or pink
RBC morphology - normal
Casts - None
Clots - Present
Proteinuria -
Asymptomatic Microscopic Hematuria
Asymptomatic microscopic hematuria has a prevalence of 3-6% in school aged children. With repeat evaluations this drops to 0.5%-1%.
Of these pathology is exquisitely rare.
Routine urinalysis screening is discouraged by current recommendations.
Hematuria comes to the attention of the practitioner either incidentally or when evaluating a child who has urinary tract symptoms or gross hematuria.
Hematuria may be either microscopic or macroscopic (gross hematuria).
Microscopic hematuria may be either persistent or transient. The diagnostic evaluation of hematuria depends on the category: gross hematuria, symptomatic microscopic hematuria, asymptomatic microscopic hematuria with proteinuria, or isolated asymptomatic microscopic hematuria .
Gross Hematuria
Gross hematuria is suspected when urine is discolored, usually red or tea-colored.
In contrast to microscopic hematuria, underlying causes of gross hematuria are identified in 56% of cases
In evaluating gross hematuria, it is important to confirm the presence of RBCs by microscopy.
Following centrifugation of the urine, the finding of red urinary sediment with a positive dipstick test for hemoglobin is indicative of hematuria, whereas red supernatant with negative dipstick testing for hemoglobin is indicative of myoglobinuria, hemoglobinuria, or other causes of discolored urine.
Aside from renal disease, common causes of gross hematuria include urinary tract infection, trauma, coagulopathy, crystalluria, and nephrolithiasis.
Lower tract symptoms (dysuria, urgency, frequency, suprapubic pain)
UTI
Lower tract symptoms (dysuria, urgency, frequency, suprapubic pain)
Postinfectious glomerulonephritiis
abdominal pain
UTI, HSP, crystalluria/stone
Concurrent Illness
Iganephropathy
Extreme exertion, influenza
rhabdpmyolysis
arthralgias
hsp, sle
diarrhea (+/- bloody)
hus
Cough, hemoptysis
Vasculitis
Hearing loss
alport disease
