Hematuria Flashcards
Urine dipstick testing
- -Most common test for blood and protein in urine.
- -Utilizes hydrogen peroxide which catalyzes chemical reaction.
- -Roughly corresponds to 2-5 RBCs per high power field
False negative and positive results on urine dipstick testing
- Negative: formalin and high urinary concen. of ascorbic acid can cause
- Positive: alkaline urine (>9) or contamination with oxidizing agents used to clean perineum
Hematuria (microscopic exam findings)
2 RBCs/high power field in adults
5 RBCs/high power field in children
Common causes of hematuria
- -Transient, unexplained
- -UTI
- -Stones
- -Cancer: bladder, kidney, prostate
Other causes of hematuria
Exercise, trauma, endometriosis, sickle cell, polycystic kidney disease, glomerular disease
Risk factors for urinary tract malignancy
- -Older than 35
- -Smoking history
- -Occupational exposure
- -Hx of gross hematuria, chronic cystitis, pelvic irradiation, exposure to cyclophosphamide, chronic indwelling of foreign body, obesity, analgesic abuse, HTN
- -Alcohol use may be protective
What if urine sediment is red when sample spun?
Hematuria
What if the supernatant is red when sample spun?
Not hematuria. Check for heme
What if dipstick with red supernatant is negative for heme as well?
Think about porphyria, phenazopyridine, BEETS (from betalaine pigment)
What if the red supernatant is + for heme?
Myoglobinuria (plasma clear) or hemoglobinuria (plasma red)
Clues to diagnosis of hematuria
- -Concurrent pyuria and dysuria
- -Recent URI
- -FHx of renal failure
- -Unilateral flank pain w/radiation to groin
- -Symptoms of hesitancy and dribbling
- -Vigorous exercise/trauma
- -Cyclic hematuria in women
What signs indicate glomerular bleeding?
- -Red cell casts
- -Proteinuria (if large amounts)
- -Dysmorphic appearing red cells
- -Smokey brown or “coca cola” color
What signs indicate extraglomerular bleeding?
Clots
Tests for hematuria
- -CT scan of abdomen and pelvis
- Cystpscpy
- -US
- -Retrograde pyelography
- -Urinary cytology
- -Angiography (usually for therapeutic reasons)
What percentage of cases of unexplained hematuria are due to underlying glomerular disease?
50%
Microscopic hematuria in children (pop. studies)
3-4% have + dipstick for blood, 1% after 2nd UA
Most common causes of microscopic hematuria in children that is persistent
- -Glomerulopathies (IgA nephropathy, Alport’s syndrome, thin basement membrane disease, post-infectious glomerulonephritis
- -Hypercalciuria
- -Nutcracker syndrome
Nutcracker syndrome
L renal vein comprssion by the aorta and superior mesenteric artery. Increased venous pressure and hematuria based on this.
Eval of asymptomatic microscopic hematuria in children
- -Asymptomatic w/o protein: benign/observe
- -Asymptomatic w/proteinuria: 1st void morning speciment to quantitate total protein/creatinine ratio and measure serum creatinine, consider nephrology referral if either abnormal
Causes of symptomatic hematuria in children
- -Glomerular diseases
- -Interstitial/tubular disease
- -Lower UT cause
- -Nephrolithiasis
- -Tumor
- -Vascular disease
- -Gross hematuria: UTI, trauma
Urolithiasis Epidemiology
12% men and 5% women will develop symptomatic stone by age 70. Rate of occurrence increases with age. Whites > blacks, 7-10/1000 hospital admissions
Urolithiasis etiology
- -80% calcium
- -Oxalate > phosphate
- -Remainder uric acid, struvite, or cysteine stones
Urolithiasis symptoms
- Flank pain
- Abdominal pain
- Testicle/labial pain
- Pain tends to wax/wane
- Gross/microscopic hematuria
- Possible N & V, dysuria, urgency
Diagnosis of urolithiasis
- X ray (more so to follow up)
- US (if recurrent stones)
- CT (most common, esp. in ER setting)
Treatment of urolithiasis
- Pain meds
- Hydration
- Ureteroscopy
- Lithotripsy
- Pyelolithotomy
- Percutaneous nephrolithotomy
Calcium oxalate/calcium phosphate stones risk factors
- -Increased Ca++ excretion
- -Increased uric acid excretion
- -Reduced citrate excretion
- -Low urine vol.
- -Increased oxalate excretion
Medical problems associated with Ca++ stone formation
- -Primary hyperparathyroidism
- -Medullary sponge kidney
- -Distal renal tubular acidosis
Causes of Idiopathic hypercalciuria
- -Absorptive hypercalciuria
- -Fasting hypercalciuria (bone loss)
- -Renal hypercalciuria (renal leak)
Hypocitraturia causes
- -Chronic diarrhea
- -Renal tubular acidosis
- -Ureteral diversion
- -High protein diet
- -Topiramate
Hyperoxaluria causes
- -Diet 10%, Glycine metabolism 40%, ascorbic acid metabolism 40%.
- -Increased oxalate absorption (low Ca++ diet, absorptive hypercalciuria, enteric hyperoxaluria)
- -Overproduction of oxalate
Metabolic work-up for Ca++ stone formation
- -Measure plasma Ca++ concen.
- -Parathyroid hormone
- -Electrolytes
- -Serum uric acid
- -24 hr urine collection (for vol, Ca++, uric acid, citrate, oxalate, creatinine, pH, Na+, PO4-
