Flashcards in Urinalysis Deck (62):
What does the urinalysis important for?
-Discovering disease in the urinary tract
-Estimate renal function
-Clues as to what causes renal dysfunction
-Some systemic diseases cause alterations in urine constituents
What is included in a standard urine panel?
When is appearance of urine reported? What is normal appearance?
When it is abnormal
-Should be pale, dark yellow, and clear
What does urine have in it if it is turbid
-Excessive cellular material or protein
-or from crystallization or precipitation of salts
When do salts precipitate?
When urine is basic (should be acidic)
If the specimen clears with the addition of small amounts of acid, what is the cause?
-Precipitation of salts
What can cause red or brown urine?
-Pyridium (causes dark orange urine)
What acidifies glomerular filtrate of plasma
Renal tubules and collecting ducts from a pH of 7.4 to 5-6
When will you see a pH of 6 or more
-If the acidifying mechanism of the kidney fails
What happens to urine if it is left standing
-Become alkaline due to bacterial growth
What is directly proportional to urine osmolarity
What does specific gravity measure
The ability of the kidney to dilute or concentrate the urine
What diseases cause the inability to concentrate the urine?
What prevents the majority amount of large materials to escape from the blood into the urine
What is normal protein excretion
What defines proteinuria
Protein excretion more than 150mg per day
What classifies severe proteinuria
more than 3.5mg/24 hours
What causes severe proteinuria
200-500 mg/24 hours
500-1500 mg/24 hours
1.5-5 g/24 hours
greater than 5g/24
What is the dominant constituent in proteinuria and why?
-Because it is the smallest
What abnormal protein usually appears in the urine in patients with multiple myeloma
Bence jones proteins
What are the 2 types of proteinuria
-not associated with systemic or renal disease
-associated with systemic disease or renal pathology
What are examples of functional proteinuria
-Severe muscular exertion
What are examples of organic proteinuria
Describe pre-renal organic proteinuria
-Not due to renal disease
-Problem occurs before reaching the kidney
-Bence Jones proteins
Describe renal organic proteinuria
-Primary kidney disease
Describe post-renal organic proteinuria
-Protein is added to the urine farther down the urinary tract
-Infection of the ureter
-Contamination with vaginal secretions
What is commonly seen in urine contamination with vaginal secretions
High number of squamous epithelial cells
What is the most common cause of glucosuria
What is the normal renal threshold for glucose before it starts spilling over into the urine
T/F- Individuals can vary in their tubular transfer reabsorptive capacities
If reabsorptive capacity is low, the patient will spill glucose at (higher/lower) levels
-what causes this
-Pregnancy and the exposure to carbon monoxide and lead cause it
What are examples of ketones
-Beta-hydroxyl butyric acid
What is the major cause of increased ketones
-impaired carbohydrate metabolism
What muscle types can utilize a limited amount of ketones as an energy source when glucose is insufficient
T/F- After a certain point, metabolic capacity is exceeded and excess ketone bodies are excreted by the kidney
When ketones accumulate in the plasma
Many bacteria produce an enzyme called...
What does reductase do?
Converts nitrates to nitrites
A positive nitrite test indicates that...
bacteria may be present in the urine
What is the sensitivity of the nitrite test
What is the gold standard test for urine
T/F-The nitrite test can enhance the sensitivity of the leukocyte esterase test to detect urinary tract infections
This is an enzyme found in the cytoplasm of neutrophils
When is a positive leukocyte esterase test seen?
-When there are WBC as whole or lysed cells in the urine
What does positive leukocyte esterase indicate?
How sensitive is leukocyte esterase test in detecting urinary tract infections
Can leukocyte esterase differentiate between WBC from the urinary tract or vaginal secretions?
What is produced from the conjugated bilirubin by metabolic activity of bacteria in the intestine followed by reabsorption into the blood steam
When can conjugated bilirubin be seen?
Secondary to biliary tract obstructions
Common bile duct obstruction
Liver cell injury (cirrhosis or hepatitis)
When is a microscopic analysis of urine completed
After the urine has been centrifuged
What is the presence of RBC in the urine called
What are causes of hematuria
-Urinary tract infections
When can contamination with RBC occur
During menses or catheriziation (especially if you have prostate problems)
How can RBC look
-Swollen (dilute urine)
-Crenated (concentrated urine)
When are squamous epithelial cells typically seen
Contamination with normal skin flora