Hematuria From Kidneys That Is Not Glomerular
1. Interstitial disease (usually with proteinuria). Analgesic nephropathy, toxins (heavy metal, drugs); eosinophils may be present in urine.
2. Infections (pyelonephritis, tuberculosis). Always associated with pyuria.
3. Malformations. Cystic disease (family history); obstructive disease (can occur with minimal trauma); vascular problem (hemangioma, arteriovenous fistula).
4. Tumors. Rare in children.
5. Ischemia related; emboli (post-cardiac catheterization or surgery); thrombosis (coagulation disorder, nephrotic syndrome).
Hematuria From Lower Urinary Tract (Ureter, Bladder, Urethra)
1. Mechanical (stones, usually associated with pain).
2. Obstruction (posterior urethral values).
3. Infection or inflammation a. Cystitis. Bacterial, viral (adenovirus), or chemical (cyclophosphamide).
b. Urethritis. Sexually transmitted.
4. Hypercalciuria. In children, commonly presents without stones but often with dysuria; few WBCs in urine; urine calcium-to-creatinine ratio is > 0.2.
1. Exercise-related hematuria or myoglobinuria.
2. Benign recurrent hematuria. Diagnosis of exclusion; patient may have positive family history.
IV. Database. The effort involved in the search for a cause of hematuria is expensive and time-consuming. Remember that isolated hematuria without or with minimal proteinuria is almost always a benign condition and workup can be deferred. On the other hand, gross hematuria, symptomatic hematuria, and hematuria with heavy proteinuria need an aggressive and early evaluation. A. Physical Exam Key Points
1. BP. Often elevated with nephritis.
2. Abdomen. Examine for mass effect (tumor, obstruction, cystic disease), pain, and tenderness (infection, infarction, obstruction, stone).
3. Genitalia. Examine urethral meatus (discharge, blood), vagina (discharge, blood), and rectum (blood, fissure, hemorrhoids).
4. Skin and joints. Observe for rashes, petechiae, purpura, ecchymosis, and swelling suggestive of vasculitis or systemic disease.
B. Laboratory Data
1. Urinalysis a. RBC casts (sometimes), proteinuria (usually). Think nephritis.
b. WBCs (> 10/HPF), bacteria (unspun urine). Think infection.
c. Crystals with pain. Think stones or hypercalciuria.
d. Positive urine dipstick for blood with few or no RBCs.
Think myoglobin or hemoglobinuria (check LDH, CPK, blood smear).
2. Urine for calcium and creatinine. Think hypercalciuria if ratio is > 0.2.
a. Increased WBC count with left shift. Think infection and inflammation.
b. Elevated ESR (C-reactive protein). Think infection (pyelonephritis).
c. Abnormal smear (low platelets, abnormal RBCs). Think HUS.
d. Anemia. Hemoglobinopathies, HUS.
4. Sickle cell screen. Obtain, if not known, in African-American children.
5. Metabolic panel a. Elevated BUN and creatinine, abnormal electrolytes. Think primary renal disease.
b. Low total protein and albumin. Think nephritis and nephrotic syndrome.
6. Immunologic screening tests. If significant proteinuria accompanies hematuria, obtain C3, C4, ANA, antistreptolysin O, ANCA, IgA, hepatitis panel, HIV.
7. Cultures a. Urine. For bacterial, viral (in special cases; many RBCs and few WBCs); acid-fast bacilli.
b. Blood. When patient has significant fever or systemic symptoms.
c. Stool. Bloody diarrhea fits picture of HUS.
8. Coagulation studies. When CBC is abnormal or other sites of bleeding are present.
1. Ultrasound. Simple, noninvasive, and useful in patients with microscopic hematuria; will show anatomy (cysts, obstruction), possible stone, evidence of renal parenchymal disease if tissue is echodense, and loss of cortical-medullary junction.
2. CT scan. First choice in patients with gross, painful hematuria; post-traumatic hematuria; or possible stone. Before contrast is given, renal function (serum creatinine) must be evaluated.
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