C4 Physical Examination of Urine Flashcards
physical examination of urine includes:
color, clarity, & specific gravity
what is urochrome?
pigment causing yellow color
what is uroerythrin?
pink pigment, attaches to amorphous urates formed in refrigerated specimens
what is urobilin?
oxidation of normal constituent, urobilinogen, orange-brown color in older specimens
dark yellow and amber urine that is normal is?
concentrated urine
dark yellow and amber urine that is abnormal is?
bilirubin
bilirubin may indicate possible?
hepatitis virus present
Foam in urine indicates?
bilirubin produces yellow foam when shaken, normal urine produces small amounts of white foam caused by protein
Photooxidation of large amounts of urobilinogen produces what color urine?
yellow-orange
photooxidation of bilirubin to biliverdin produces what color urine?
yellow-green
Phenazopyridine (pyridium) or Azo-Gantrisin for UTIs produces?
thick orange pigment & yellow foam (no bilirubin)
What is a common cause of red urine?
Blood
Methemoglobin
RBCs remain in acid urine, fresh brown specimens can indicate glomerular bleeding
cloudy red urine?
RBCs
clear red urine?
hemoglobin/myoglobin
hemoglobin?
in vivo lysis of RBCs, pt plasma will also be red, consider in vitro lysis/specimen handling
Myoglobin
breakdown of skeletal muscle, fresh urine is often more reddish brown, patients plasma is clear
Port-wine colored urine?
oxidation of porphobilinogen to phorphyrias
Melanin
excess in malignant melanoma, oxidation of melanogen to melanin
Homogentisic acid
black color in alkaline urine, alkaptonuria
What causes blue-green urine?
urinary and intestinal bacterial infections, IV phenol medications: Clorets (green), Robaxin, methylene blue, Elavil (blue)
clarity
refers to the transparency or turbidity of a specimen
Normal reporting of clarity
clear, hazy, cloudy, turbid, milky
clear:
no visible particulates, transparent
hazy:
few particulates, print easily seen through urine
cloudy:
many particulates, print blurred through urine
turbid:
print cannot be seen through the urine
milky:
may precipitate or be clotted
causes of nonpathogenic turbidity:
squamous epithelial cells and mucus, bacterial growth in nonpreserved specimens, refrigerated specimens with precipitated amorphous phosphates (white) and urates (pink), contamination
causes of pathologic turbidity:
RBCs, WBCs, bacteria, nonsquamous epithelial cells, yeast, abnormal crystals, lymph fluid, lipids
Specific gravity
evaluation of urine concentration, determines if urine is concentrated enough to provide reliable screening results, the density of a solution compared with the density of an equal volume of distilled water at the same temp
Isothenuric:
SG of 1.010
Hyposthenuric
SG lower than 1.010
Hypersthenuric
SG higher than 1.010
Refractometer
measures velocity of light in air versus velocity of light in a solution
advantages of the refractometer
temperature compenstation not needed, small specimen size: 1 or 2 drops
osmole
1 g molecular weight of a substance divided by the number of particles into which it dissociates (= to MW of substance)
unit of measure used in the clincial lab is?
milliosmole (mOsm)
Reagent Strip SG
based on the change in pka (dissociation constant) of a polyelectrolyte in an alkaline medium
aromatic odor
normal
foul, ammonia-like odor
bacterial decomposition, UTI
fruity, sweet odor
ketones (DM, starvation, vomiting)
maple syrup odor
maple syrup urine disease
mousy odor
phenylketonuria
rancid odor
tyrosinemia
sweaty feet odor
isovaleric acidemia
cabbage odor
methionine malabsorption
bleach odor
contamination