Hematuria, Proteinuria and Urinalysis Flashcards
What is the normal range for urine pH?
5-5.6
Looking at urine pH in a urinalysis is useful for…
- diagnosing renal tubular acidosis
- following patients with kidney stones
Specific gravity of the urine sample indicates..
Concentration of urine (high specific gravity = highly concentrated urine)
Normally, urine glucose is…
NEGATIVE
When would glucose in urine be positive, i.e. glucosuria (urinalysis)? (3)
In uncontrolled diabetics
In patients on SGLT2 inhibitors
In patients with proximal RTA (Fanconi syndrome)
What type of protein does a dipstick detect?
Albumin only
Normal protein (albumin) levels in urine
Normally NEGATIVE (>0.3 g/L)
What is the normal level of RBCs in urine?
0-2 RBC?HPF
Why would a person have positive dipstick for blood without presence of RBC in urine?
They have …?
Normal WBC levels in urine
0-2 WBC/HPF
If more than 3 WBC/HPF in urine, the patient may have…
infection
interstitial nephritis
contamination
Nitrites in urine are normally…
negative
Positive nitrites in urine indicates…
infection with bacteria that can convert nitrate to nitrite
Ketones in urine are normally…
negative
Describe the difference between gross and miscroscopic hematuria
How is clinically significant hematuria defined?
It is defined at >= 3 RBC/HPF in a spun urine sediment.
Dysmorphic RBCs in the urine suggest…
Renal (glomerular) source of the hematuria
Glomerulonephritis is characterized by … (2) on microscopic examination
Dysmorphic RBCs or cellular casts (caused by glomerular inflammation)
5 causes of non-glomerular hematuria
- Malignancy
- Stones
- Infection
- Polycystic kidney disease (PKCD)
- Sample from Foley catheter
The normal total daily protein excretion
VERY low (<0.15g of which 4-7mg is albumin)
What are the 4 mechanisms of proteinuria?
- Functional
- Overflow
- Tubular protein loss
- Glomerular protein loss
What is functional proteinuria?
What is overflow proteinuria?
Capacity of …?
What is tubular proteinuria?
Impaired reabsorption of low molecular weight proteins along the renal tubules.
What is glomerular proteinuria?
Loss of integrity of glomerular filtration barrier (basement membrane).
What is nephrotic syndrome?
- At least 3.5 grams of proteinuria (albuminuria)
- Hypoalbumineia (low serum albumin)
- Edema (due to decreased oncotic pressure)
- Hyperlipidemia
Characteristic microscopic findings in nephrotic syndrome.
How do we approach proteinuria (summary)
- Urinalysis
- Urine albumin/Cr ratio and urine protein/Cr ratio (more quantitative than dipstick)
- 24-hour urine collection (if Cr is not in a steady state)
What is the purpose of an albumin/Cr ratio?
What is a normal urine albumin/Cr ratio?
1.9 mg/mmol (man)
2.7 mg/mmol (woman)
What is the difference between overt albuminuria and microalbuminuria? How is each defined?
Overt: >300 mg/d
Micro: 30-300 mg/d
?
What are the 4 ranges of albuminuria?
Normal
Micro
Macro
Nephrotic range
When is spot urine assessment NOT reliable?
If patient is not in a steady state (e.g. AKI)
Why is quantitating proteinuria important in CKD?
Increasing proteinuria in CKD is associate with rapid renal deterioration (worse prognosis).
