Week 3: Clinical evaluation of hematuria Flashcards
Definition of hematuria.
Normally 3 RBC/HPF is considered abnormal
-occasionally 3-10 RBCs can be found in normal individuals
Describe the patterns of hematuria.
- Macroscopic: brownish-red urine, coffee or tea colored. May be bright read when bleeding is active or in alkaline urine
- Microscopic: abnormal amounts of RBCs detected only microscopic examination of urinary sediment.
- persistent or transient: transient is common in young adults with no obvious cause. In older patients, transit hematuria has risk of malignancy. Persistent hematuria in patients>40 requires full evaluation
- symptomatic or asymptomatic
- Time-based on 3 cup urine test
- initial -urethra
- terminal-bladder
- total: kidney/ureter
What may be the causes of red urine? How to differentiate using dipstick test or presence of RBCs?
If dipstick is negative, consider
-beets, bilirubin, rifampin, carrots, rhubarb, laxatives, porphyria
If dipstick is positive, and RBCs are present after centrifugation
-consider renal causes
If dipstick is positive, and RBCs are absent
-myoglobin from crush injury
-hemoglobin
What are non-renal causes of hematuria?
- after physical activity: diagnosis of exclusion and must be temporarily related to exercise. Must be differentiated from myoglobinuria due to rhabdomyolysis
- contamination by mentrual blood
- over-anticoagulation. High INR. Likelihood of GU malignancy
What are urinary tract causes of hematuria?
- neoplasms
- stones -will have pain
- UTI
- prostatitis
- benign prostatic hypertrophy
- hemorrhagic cystitis (cyclophosphamide)
- radiation cystitis
- catheter
- over anti coagulation
What are non-glomerular renal causes of hematuria?
- tumors (renal cell carcinoma)
- vascular disorders
- metabolic disorder (hypercalcicuria)
- renal malformation
- infection
- drugs
- trauma
What are glomerular causes of hematuria?
- Isolated hematuria
- IgA
- Familial causes:
a. Benign familial hematuria-thin basement membrane, mutations of Type IV collagen a4 gene
b. Alport’s syndrome: X linked disease of type IV collagen a-3,4,5 gene. Associated with renal failure, deafness, and lens abnormalities of the eye - Nephritic syndrome
- hematuria, proteinuria, reduced renal function, HTN
- can be caused by:
a. low serum complement: lupus nephritis, post infectious GN, IgA, membranoproliferative GN, cryoglomulinemia
b. normal serum complement: anti-glomerular basement membrane, IgA
How do you distinguish between glomerular vs. extraglomerular hematuria on urinalysis?
- Glomerular:
- red, smoky brown or coca cola color
- clots absent
- proteinuria may be >500 mg/day
- Dysmorphic RBC
- RBC casts present - Extraglomerular
- red or pink color
- clots may be present
- proteinuria <500 mg/day
- RBC morphology is normal
- RBC cast absent
What symptoms are connected to which renal diseases? (Things to look for in evaluating hematuria)
- Dysuria, frequency, pyuria: UTI
- flank pain, fever: pyelonephritis
- uteric colic: stones
- edema, oliguria: Acute GN
- URI 1-3 days: IgA nephropathy
- URI, 1-2 weeks: Post infectious GN
- weight loss: neoplasm
- Hesitancy, dribbling in men: benign prostatic hypertrophy
- bleeding from multiple sites: uncontrolled anticoagulation
What are risk factors for significant disease with findings of hematuria?
Smoking history
Occupational exposure to chemicals or dyes
History of gross hematuria
Age > 40 years
Analgesic abuse
History of pelvic radiation
History of cyclophosphamide use (hemorrhagic cystitis)
Describe workup for hematuria.
- hx and PE
- urinalysis for protein
- urine sediment for dysmorphic RBC, RBC casts
- cystoscopy
- cytology
- imaging: ultrasound, IVP, CT, MRI
What are the major causes of acute nephritis, gripped by complement level?
- Low serum complement
- post streptococcal GN
- SLE
- mixed cryoglobulinemia
- membranoproliferative GN - Normal Serum Complement
- goodpasture syndrome
- IgA nephropathy
- Anti-GBM disease/ Goodpastures
