Hematuria, Proteinuria and Urinalysis

Question 1

What is the normal range for urine pH?

Answer 1

5-5.6

Question 2

Looking at urine pH in a urinalysis is useful for…

Answer 2

• diagnosing renal tubular acidosis
• following patients with kidney stones

Question 3

Specific gravity of the urine sample indicates..

Answer 3

Concentration of urine (high specific gravity = highly concentrated urine)

Question 4

Normally, urine glucose is…

Answer 4

NEGATIVE

Question 5

When would glucose in urine be positive, i.e. glucosuria (urinalysis)? (3)

Answer 5

In uncontrolled diabetics
In patients on SGLT2 inhibitors
In patients with proximal RTA (Fanconi syndrome)

Question 6

What type of protein does a dipstick detect?

Answer 6

Albumin only

Question 7

Normal protein (albumin) levels in urine

Answer 7

Normally NEGATIVE (>0.3 g/L)

Question 8

What is the normal level of RBCs in urine?

Answer 8

0-2 RBC?HPF

Question 9

Why would a person have positive dipstick for blood without presence of RBC in urine?

Answer 9

They have …?

Question 10

Normal WBC levels in urine

Answer 10

0-2 WBC/HPF

Question 11

If more than 3 WBC/HPF in urine, the patient may have…

Answer 11

infection
interstitial nephritis
contamination

Question 12

Nitrites in urine are normally…

Answer 12

negative

Question 13

Positive nitrites in urine indicates…

Answer 13

infection with bacteria that can convert nitrate to nitrite

Question 14

Ketones in urine are normally…

Answer 14

negative

Question 15

Describe the difference between gross and miscroscopic hematuria

Question 16

How is clinically significant hematuria defined?

Answer 16

It is defined at >= 3 RBC/HPF in a spun urine sediment.

Question 17

Dysmorphic RBCs in the urine suggest…

Answer 17

Renal (glomerular) source of the hematuria

Question 18

Glomerulonephritis is characterized by … (2) on microscopic examination

Answer 18

Dysmorphic RBCs or cellular casts (caused by glomerular inflammation)

Question 19

5 causes of non-glomerular hematuria

Answer 19

1. Malignancy
2. Stones
3. Infection
4. Polycystic kidney disease (PKCD)
5. Sample from Foley catheter

Question 20

The normal total daily protein excretion

Answer 20

VERY low (<0.15g of which 4-7mg is albumin)

Question 21

What are the 4 mechanisms of proteinuria?

Answer 21

1. Functional
2. Overflow
3. Tubular protein loss
4. Glomerular protein loss

Question 22

What is functional proteinuria?

Question 23

What is overflow proteinuria?

Answer 23

Capacity of …?

Question 24

What is tubular proteinuria?

Answer 24

Impaired reabsorption of low molecular weight proteins along the renal tubules.

Question 25

What is glomerular proteinuria?

Answer 25

Loss of integrity of glomerular filtration barrier (basement membrane).

Question 26

What is nephrotic syndrome?

Answer 26

- At least 3.5 grams of proteinuria (albuminuria) - Hypoalbumineia (low serum albumin) - Edema (due to decreased oncotic pressure) - Hyperlipidemia

Question 27

Characteristic microscopic findings in nephrotic syndrome.

Question 28

How do we approach proteinuria (summary)

Answer 28

1. Urinalysis 2. Urine albumin/Cr ratio and urine protein/Cr ratio (more quantitative than dipstick) 3. 24-hour urine collection (if Cr is not in a steady state)

Question 29

What is the purpose of an albumin/Cr ratio?

Question 30

What is a normal urine albumin/Cr ratio?

Answer 30

1.9 mg/mmol (man) 2.7 mg/mmol (woman)

Question 31

What is the difference between overt albuminuria and microalbuminuria? How is each defined?

Answer 31

Overt: >300 mg/d Micro: 30-300 mg/d ?

Question 32

What are the 4 ranges of albuminuria?

Answer 32

Normal Micro Macro Nephrotic range

Question 33

When is spot urine assessment NOT reliable?

Answer 33

If patient is not in a steady state (e.g. AKI)

Question 34

Why is quantitating proteinuria important in CKD?

Answer 34

Increasing proteinuria in CKD is associate with rapid renal deterioration (worse prognosis).