LAB 3 - Urinalysis Flashcards
Urine Colour
-normal is pale yellow
-red indicates blood (hematuria) or hemoglobin (hemoglobinuria)
Urine Transparency
-should be clear
-cloudiness siggests mucus, bacteria or various cell types
Urine Specific Gravity
-specific gravity = weight of solution compared to an equal amount of water
-normal specific gravity in urine is 1.015-1.020 so urine is denser than water
-solutes increase urine density
Urine pH
-between 5-9 usually around 6
-persistent low pH/acidic indicates renal compensation for high H+ in blood
Protein in urine
-protein concentration is normally below detection limit on multistix
-proteinuria is protein in urine, indicating a UTI, kidney pathologies, or high blood pressure like pregnancy induced hypertension
Glucose in urine
-glucose not normally in urine
-when kidneys can not reabsorb anymore, it can remain in kidney tubules and enter urine - glycosuria (diabetes mellitus - insulin dependent), liver or kidney disease
-low glycosuria in pregnancy is common but higher levels indicate gestational diabetes
Ketones in urine
-ketones are products of lipid metabolism
-ketones arent normally in urine though
-diabetes mellitus will have ketonuria
-ketone bodies are actually acetone, acetoacetic acid and β-hydroxybutyric acid,
-ketone test reacts with acetoacetic acid
Urobilinogen in urine
-bilirubin that was converted into urobilinogen by the bacteria in the intestines
-then absorbed back into the blood and filtered out in the kidneys
-then broken down into urochrome which gives urine its yellow colour
-too much = liver disease
Blood in urine
-Multistix detect urine hemoglobin (hemoglobinuria) and
red blood cells (hematuria).
-blood is abnormal in urine - kidney or urinary tract disease
-normal = cycle or UTI
-Spotting on the strip indicates whole red blood cells. Solid colour
indicates hemolysis.
wBCs in urine
-large quantity of WBCs in urine = UTI or kidney infection
Nitrites in urine
nitrite is gram-negative bacteria (like E. coli, the commonest cause of urinary tract infection). If urine has not remained in the bladder for sufficient time
for nitrite production, the test will always be negative. This is one of the urine tests that should be done with the first voided sample in the morning
reasons for false positives/negatives in urine
glucose (-ve) –> refrigerated can decrease glucose falsely
ketones (-ve) –> (ketoacidosis), false postive if urine is isnt refrigerated after 2 hours
bilirubin (-ve) gallstones in biliary tract can cause bilirubin in urine. false positive = etodolac mediaction for mild pain
nitrate (-ve) indicates UTI –> false postive if urine stick is left in open air for longer than 10 min before being read
What sort of urinalysis results would you expect to see in a woman with
pregnancy induced hypertension?
-pregnancy induced hypertension = protein in urine (proteinuria)
-proteinuria due to endothelial cell swelling and disruption of fenestrae
Bilrubin in blood
-bilirubin is transported in the blood in its unconjugated form
-unconjugated bilirubin is bound to the albumin protein in the blood
-the liver changes unconjugated bilirubin to conjugated bilirubin so the body can dispose of it
-urobilinogen and urobilin are broken down components of bilirubin that are found in the urine
-bilirubin found in urine can indicate a liver condition of gallstones in the biliary tract
What are some of the solutes that give normal urine its specific gravity of > 1.0?
-an ideal specific gravity is urine is 1.005 to 1.030
-Na, Cl, K, urea contributing to its specific gravity of > 1.0.
