intro to labs Flashcards
what is a urinalysis comprised of?
macroscopic/microscopic, examination, dipstick and specialty testing
what must every label collection container have?
at least 2 patient identifiers with a sterile container
what is the preferred method for collecting a urine sample?
clean catch technique (necessary for UTI) , mid stream preferable
when is the best time to collect urine?
in the morning because its when it is most concentrated, preferred particularly for protein and specific gravity
A urine sample should be tested with in how many hours?
2 hour otherwise results will not be accurate
up to 4 hours if refrigerated
when do you send a urine for culture
Only send if patient has signs and symptoms of infection or an abnormal U/A
A urinary infection is classified as a bacterial count of?
> 100,00 colonies
or
10,000 colonies if symptomatic, immunosuppressed or antibiotic treated
what happens if you get back a mixed bacterial count <10,000
would be contaminated
when would it be normal to see RBC on microscopic U/A?
after exertion, trauma, fever, menstruation
when would RBC be abnormal on microscopic U/A?
UTI, glomerulonephritis, necrosis, tumors, stones, coagulopathies
when would you see WBC on a U/A
UTI or inflammation
when would you see squamous cells on U/A?
contamination
when would you see renal tubular cells?
acute tubular necrosis, nephrotic syndrome
When would you see bacteria in a U/A
UTI
what do fat bodies on a U/A tell you?
Nephrotic syndrome, you will see maltese cross appearance
what are casts?
- Unique to kidneys – formed in lumen of DCT and collecting duct
- The shape represents molds of the renal tubule from which they arise
what are hyaline casts?
- Tamm-Horsfall protein (small amt is normal)
* Multiple casts-assoc w/ all renal dz, essential HTN, nephrotic syndrome
WBC casts
renal parenchymal infx, MC pyelonephritis
RBC casts
Hydronephrosis, infections
granular casts
- Formed by breakdown products of cellular casts and immunoglobulins
- Deeply pigmented (muddy brown) = acute tubular necrosis
Fatty casts
•Leakage of lipoproteins through glomerular filter (nephrotic syndrome)
When there is protein in the urine what is that indicative of?
renal disease
proteins can be either albumin or globulins (bence-jones are associated with multiple myeloma)
small amounts in DM and HTN may be first sign of CKD
what does the presence of bilirubin in the urine tell you?
early sign of biliary obstruction
Urobilinogen?
formed by bacterial conversion of conjugated bilirubin in intestine
Most sensitive test to determine impaired liver function
One of the earliest signs of liver disease and hemolytic disorders
what causes hemoglobinuria?
burns, transfusions rxns, chemical agents, malaria, post-op hemolysis