Renal 1

Question 1

Functions of the kidney (8)

Answer 1

1. Water and electrolyte balance (Na, K, Ca, P, etc.)
2. Metabolic waste excretion
3. Blood pressure control
4. Erythropoietin
5. Acid- base balance
6. Excretion of drugs and hormones
7. Activation of vitamin D
8. Gluconeogenesis

Question 2

Alkaline pH (5)

Answer 2

> 7.0

a. Bacteriuria
b. Renal failure
c. Presence of antibiotics, sodium bicarbonate
d. Diet high in vegetables, citrus fruits and dairy products

Question 3

Acidic pH (8)

Answer 3

1. Acidic (<7.0)
2. Acidosis – Renal tubular acidosis
3. Presence of certain drugs
4. Out of control DM
5. Starvation
6. High-protein diet
7. Ketones make urine acidic

Question 4

Urine dipstick: blood

Answer 4

Extremely sensitive and so will detect clinically insignificantly amounts of hemoglobin or myoglobin

Question 5

Color of urine: upper renal hematuria (4)

Answer 5

1. Brown cola colored urine
2. RBS, WBC casts
   * Significant casts if RBC and WBC
3. > /= +2 proteinuria
4. Deformed RBC

Question 6

Color of urine: lower bladder disease (4)

Answer 6

a. Terminal hematuria
b. Passage of blood clots
c. = 2+ proteinuria
d. Normal RBC

Question 7

Protein count (5)

Answer 7

1. Trace (about 15 mg/dL)
2. 1+ (about 30 mg/dL)
3. 2+ (about 100 mg/dL)
4. 3+ (about 300 mg/dL)
5. 4+ (2,000 mg/dL or greater)
   * Vast difference between amount of protein from 3 and 4

Question 8

urine dipstick

Answer 8

measures albumin

*does not measure low molecular weight protein

Question 9

Dipstick interpretation (4)

Answer 9

1. Urinary dipstick method measures the concentration of urine protein,
2. False-negative results-very dilute urine specimen.
3. If the urine sample has specific gravity of ≤ to 1.015, then 1+ is considered positive
4. If the urine sample has a specific gravity of ≥ to 1.015 then >/= to 2+ is positive

Question 10

False positive dipstick results (8)

Answer 10

a. Very alkaline or concentrated specimens
b. Gross hematuria
c. Pyuria
d. Bacteriuria
e. Presence of contaminating antiseptics
f. Radiographic contrast
g. Presence of heavy mucus, blood, pus, semen or vaginal secretion
h. Trace positive proteinuria by dipstick does not imply pathologic proteinuria

Question 11

Urine Dipstick: Nitrite and Leukocyte esterase (3)

Answer 11

1. Negative nitrite result
   a. Does not rule out UTI (poor sensitivity)
2. Positive result is likely true-positive
   a. High specificity—whatever the collection method.
3. Leukocyte esterase
   a. More sensitive (positive in disease) indicator of infection than nitrites are
   b. Better when tested using a catheterized, rather than a bagged, specimen

Question 12

Urine dipstick: Glucose/bilirubin (3)

Answer 12

1. Urine should not contain glucose
2. False positive can occur with ascorbic acid
3. Most common reason for positive bilirubin is old or poorly sealed dipsticks.

Question 13

Pigmenturia (3)

Answer 13

1. Urine can get discolored from free hemoglobin, myoglobin, endogenous pigments (bili and prophyrins), food dyes, and certain drugs
2. Foods: Rhubarb, beets, blackberries, blueberries, paprika, fava beans, and food dyes
3. Drugs: Rifampin, nitrofurantoin, sulfonamides, metronidazole, phenytoin, quinine, chloroquine, levedopa, methyldopa, deforoxamine

Question 14

Quantitative Urine Tests: Urine protein/creatinine ratio (3)

Answer 14

a. Random urine specimen
b. More accurate quantification
c. Normal ratio is < .2 mg of protein per milligram of creatinine in most children. <0.5 first few months of life

Question 15

Quantitative Urine Tests: urine albumin/creatinine ratio (3)

Answer 15

a. Normal albumin secretion is less than 20 mg/d
b. 30-300 mg/d is abnormal and not detected by dipstick = microalbuminuria
c. Ratio of > .03 mg of albumin per milligram of albumin is abnormal

Question 16

Other Lab to do with Abnormal Urianalysis (6)

Answer 16

1. CBC with diff
2. Complete Metabolic Profile
   a. Creatinine better reflects renal function
   i. BUN better reflects hydration level
3. SCP
4. C3 and C4
5. ANA
   a. Checks for lupus nephritis
6. ASO (antistreptolysin titer), DNAse B test
   a. ASO titers remain elevated for up to a year

Question 17

Hematuria definition (5)

Answer 17

1. 1+ or higher reaction on urine dipstick for blood
2. Greater than 5 RBCs/HPE (40X) in three consecutive fresh centrifuged urine specimens over a 2-3 week period
3. Dip stick is reacting to hemoglobin in urine
4. Is this hematuria or hemoglobinuria
5. High glucose can cause a false positive

Question 18

How is hematuria discovered? (3)

Answer 18

1. Onset of gross hematuria
2. Onset of urinary or other symptoms with incidental finding of microscopic hematuria
3. Inadvertent discovery of microscopic hematuria during a visit where a urinalysis is required (camp or sports physical)

Question 19

Hematuria Urinalysis (2)

Answer 19

Check if it is this true hematuria

1. Urine dipstick utilizes a peroxidase like reaction to detect hemoglobin and myoglobin
   100% sensitivity
   99.3% specificity
2. For familial hematuria, you need a urine sample from both parents

Question 20

what causes false negatives with urinalysis (2)

Answer 20

1. Formalin (urine preservative)

2. High urine concentration of ascorbic acid

Question 21

what causes positive negatives with urinalysis (2)

Answer 21

1. Peroxidase (skin Cleaner)
2. Alkaline urine with pH >9
3. Menses, fever, exercise

Question 22

Four Categories of Hematuria

Answer 22

1. Gross hematuria
2. Microscopic hematuria with clinical symptoms
3. Asymptomatic microscopic (isolated) hematuria
   * Significant renal disease is very rare if there is only microscopic hematuria
4. Asymptomatic microscopic hematuria with proteinuria
   * Most of these are isolated, asymptomatic hematurias