CLINMIC LEC CHEMICAL EXAMINATION OF URINE

Confirmatory

Confirmatory

Benedict’s is not ___________ since not all tube methods are considered ___________

Reagent strip

Consist of chemical-impregnated absorbent pads attached to a plastic strip

A color reaction takes place when the pad comes in contact with urine

Reactions are interpreted by comparing the color pads with a chart provided by the manufacturer

Results are described as trace 1+, 2+, 3+, 4+

SEMIQUANTITATIVE

pH

Specific gravity

Glucose

Protein

4 parameter consists of what parameters? (PSGP)

pH

Specific gravity

Glucose

Ketones

Proteins

Blood

Bilirubin

Urobilinogen

Nitrite

Leukocyte esterase

10 parameter strip consists of what parameters? (PSG-KPB-BUNL)

Vitamin C

The 11th parameter?

Creatinine

The 12th parameter?

Microalbumin

The 13th parameter?

Siemens

Multistix manufacturer

Roche

Chemstrip manufacturer

Tetramethylbenzidine

Chemstrip chromogen for glucose

Urobilinogen

Only parameter we don’t report as negative

Unmixed

Formed elements, such as red and white blood cells, sink to the bottom of the specimen and will be undetected in an _________ specimen.

leaching of reagents from the pads.

Allowing the strip to remain in the urine for an extended period may cause:

Horizontally

When comparing the strip with the color chart, how is the strip held?

Reflectance photometry

Automated reagent strip reader principle?

Room temperature

Specimens that have been refrigerated must be allowed to return to what temp before reagent strip testing, as the enzymatic reactions on the strips are temperature dependent?

1. Store with desiccant in an opaque, tightly closed container.

2. Store below 30°C; do not freeze.

3. Do not expose to volatile fumes.

4. Do not use past the expiration date.

5. Do not use if chemical pads become discolored.

6. Remove strips immediately before use.

Care of reagent strips (6)

1. Test open bottles of reagent strips with known positive and negative controls every 24 hrs

2. Resolve control results that are out of range by further testing.

3. Test the reagents used in confirmatory tests with positive and negative controls.

4. Perform positive and negative controls on new reagents and newly opened bottles of reagent strips.

5. Record all control results and reagent lot numbers.

Quality control (5)

Daily

When do you perform QC in urinalysis lab?

60-120 seconds

If precise timing cannot be achieved, what is the recommended range of time that reactions are read?

Glucose and bilirubin

30 secs

Ketones

40 secs

Sp gravity

45 secs

pH

Protein

Blood

Urobilinogen

Nitrite

60 secs (PPBUN for 60 seconds)

Leukocyte esterase

Parameter read after 120 seconds

pH

Parameter that is first to be read because it is most vulnerable

60 seconds

pH cannot be read after how many secs?

Tubular secretion

pH, what tubular function?

Crystal identification

pH is the parameter that can differentiate what?

Ammonium ions and hydrogen phosphate

Hydrogens ions are excreted in the form of?

Bicarbonate

Hydrogen ions are retained in the form of?

pH 4.5-8.0

Physiologic pH

pH 5-6

pH range in first morning specimen

Alkaline tide

pH after meal turns alkaline which is termed:

pCO2

Reflects carbon dioxide dissolved in water

CHON

Cranberry

DM

Dehydration

Diarrhea

E. coli

Emphysema

Starvation

UTI medication

Causes of acidic urine (CCDDDEESU)

High fruit and vegetables

Hyperventilation

Vomiting

Renal tubular acidosis

Old specimen

Post-prandial specimen

Presence of urease producing-bacteria (Enterobacteriaceae)

Causes of alkaline pH (HHVROPP)

Bicarbonate

Fruits are rich in what that’s why it leads to alkaline urine when eaten?

Respiratory acidosis

Emphysema leads to this condition

Urine protein

Most indicative of renal disease

<10 mg/dL or <100mg/day (Henry’s: <150 mg/day)

Normal urine protein levels

Proteins from prostatic, seminal, and vaginal secretion

Albumin

Serum and tubular microglobulins

Tamm-Horsefall protein

4 proteins normally found in urine (PAST)

Albumin

Major serum protein found in urine

Tamm-Horsefall protein

A mucoprotein produced by the renal tubules

Matrix of cast formation

Uromodulin

other name for Tamm-Horsefall protein

<10 mg/dL

What is the sensitivity of urine strip for protein?

>30 mg/dL

Clinical proteinuria levels?

Prerenal proteinuria

OVERFLOW of plasma proteins with low molecular weight

True

(T/F) Prerenal proteinuria is not indicative of actual renal disease

False, prerenal proteinuria is not detected by reagent strip

(T/F) Prerenal proteinuria is detected by reagent strip

Severe infection or inflammation (↑ APRs)

Hemoglobinuria

Myoglobinuria

Multiple myeloma (BJP)

4 causes of prerenal proteinuria (SHMM)

Coagulates at 40-60 degrees Celsius, dissolves at 100 degrees Celsius

BJP coagulates at what temp and dissolves at what temp?

Renal proteinuria

Proteinuria associated with true renal disease

Glomerular proteinuria

Tubular proteinuria

Microalbuminuria

3 causes of renal proteinuria

Glomerular proteinuria

Most common and most clinically significant cause renal proteinuria

Orthostatic proteinuria

Orthostatic proteinuria

Glomerular proteinuria is associated with what condition?

Tubular proteinuria

A cause of renal proteinuria that occurs when normal tubular reabsorptive function is impaired

Fanconi’s syndrome

Tubular proteinuria is associated with what syndrome?

Microalbuminuria

Proteinuria not detected by the routine reagent strip

Diabetic nephropathy

Microalbuminuria is associated with what condition?

Post renal proteinuria

Proteinuria caused by proteins produced by the urinary tract

Contamination by proteins during excretion

Lower UTI

Vaginal secretions

Menstrual contamination

Semen

Hemorrhoidal blood

5 causes of post renal proteinuria (LVMSH)

Microalbuminuria

Signifies onset of renal complications due to DM

Associated with increased risk of CVD

Protein excretion of 30-300 mg/24 hours

AER of 20-200 micrograms/min

>3.4 mg/mmol

Albumin:Creatinine ratio indicating microalbuminuria?

Micral test

Enzyme immunoassay for microalbuminuria

Read after 60 seconds

White (negative) to red (represents amount of protein in specimen)

Color range for Micral test?

Immunodip test

Immunochromographic technique for microalbuminuria testing

3 minutes

Immunodip strips are placed in specimen for how long?

<1.2 mg/dL (negative)

Immunodip: darker bottom band, interpretation?

1.2-1.8 mg/dL (borderline)

Immunodip: equally dark bands, interpretation?

2-8 mg/dL (positive)

Immunodip: darker top band, interpretation?

Heat and acetic acid test

Sulfosalicylic acid test

What are the 2 tests for urine albumin?

Heat and acetic acid test

What is the reference method in testing for albumin in the urine?

5-10% acetic acid

Concentration of acetic acid used in heat and acetic acid test?

Diffuse cloud

HAc test: 1+

Granular cloud

HAc test: 2+

Distinct floccule

HAc test: 3+

Large floccule, dense, something solid

HAc test: 4+

Sulfosalicyclic acid test

Urine supernatant + SSA

Incubate at room temperature for 10 minutes

Most proteins are precipitated by dilute (3%) SSA

<6 mg/dL

SSA

Grade: NEG

Description: No increase in turbidity

What is the protein range?

<6-30 mg/dL

SSA

Grade: TRACE

Description: Noticeable turbidity

What is the protein range?

30-100 mg/dL

SSA

Grade: 1+

Description: Distinct turbidity with no granulation

What is the protein range?

100-200 mg/dL

SSA

Grade: 2+

Description: Turbidity with granulation, no flocculation

What is the protein range?

200-400 mg/dL

SSA

Grade: 3+

Description: Turbidity with granulation and flocculation

What is the protein range?

>400 mg/dL

SSA

Grade: 4+

Description: Clumps of protein

What is the protein range?

Radiographic contrast media

Drugs

Salicylates

Causes false (+) in SSA (RDS)

Highly alkaline urine

QUATS

Causes false (-) in SSA (RDS) (HQ)

5-10 mg/dL to any protein

What is the sensitivity of SSA?

Albumin

SSA: (+)

Reagent strip: (+)

What proteins are present in the urine?

Proteins other than albumin

SSA: (+)

Reagent strip: (-)

What proteins are present in the urine?

Glucose

What is the most frequent chemical test performed on urine?

<15 mg/dL

What is the normal urine glucose level?

Diabetes mellitus

Urine glucose test is used to diagnose what disease?

DM

Pheochromocytoma

Hyperthyroidism

Acromegaly

Cushing’s syndrome

5 conditions associated with hyperglycemia? (DPHAC - da fak?)

Increased plasma glucose, exceeding renal threshold

Acromegaly

high growth hormones

Cushing’s syndrome

high cortisol

Hyperthyroidism

High thyroxine

Pheochromocytoma

High catecholamines

Pregnancy

Osteomalacia

Nephrotic syndrome

Fanconi’s syndrome

Advanced renal disease

5 Renal-associated conditions in glucose test (PONFA)

Normal plasma glucose, but glucose still appears in the urine

Benedict’s test

General test for glucose and other reducing sugars, NOT SPECIFIC TO GLUCOSE

Principle is based on the ability of glucose and other reducing substances to reduce copper sulfate to cuprous oxide in the presence of alkali