Chapter 5: Chemical Examination of Urine
nitrite
Greiss reaction; UTI
stercobilin & urobilin
brown pigment of feces
galactosemia
clinitest is used to screen newborns for IEM
Renal proteinuria
protein in urine associated with true renal disease and may the the result of either glomerular or tubular damage
uromodulin
protein produced by the renal tubules
blood
pseudoperoxidase activity of Hgb
Enterics
reductase is found in gram-neg bacteria that most frequently cause UTIs
urobilinogenuria
seen in liver disase and hemolytic disorders
ketones
sodium nitroprusside reaction; increased fat metabolism, DM, vomiting, starvation, low carb diet
clinitest
test for reducing sugars, especially galactose, not specific for glucose; copper reduction method
urobilinogen
In the intestines, conjugated bilirubin is converted by bacteria
microalbuminuria
Low levels of urine protein not detected by routine reagent strips; common in pt with Type I or II diabetes mellitus
bilirubin
diazo reaction; early indication of liver disease
conjugated bilirubin
does not appear in urine it is passed directly from the liver into the bile duct and on to the intestine
pH
double buffer system; useful in management of UTI and renal calculi
protein
error of indicator; significant in diagnosing or monitoring renal disease
glucose
glucose oxidase/peroxidase; diabetes mellitus
160-180mg/dL
glucose renal threshold
leukocyte esterase
granulocytic esterase reaction; UTI
prerenal proteinuria
increased protein in the urine caused by factors affecting the plasma before it reaches the kidney
hematuria
major causes include renal calculi, glomerular disease, tumors, trauma, pyelonephritis, toxic chemicals and anti-coag therapy
albumin
major serum protein found in normal urine
hemoglobinuria
may result from lysis of RBCs produced in the urinary tract in dilute, alkaline urine; short term condition can be caused by strenuous exercise
hemolytic disease
negative bilirubin and positive urobilinogen; increased destruction of RBCs does not produce bilirubinuria
gram-positive bacteria and yeast
non-nitrate reducing bacteria, therefore not detected on reagant strip test
4.5-8.0
normal pH of urine
1.002-1.035
normal range of SG for random specimen
0.2-1 mg/dL
normal range of urobilinogen
SG
pKa change of polyelectrolyte; indication of kidneys concentration ability and state of body hydration
glomerulonephritis
positive for blood
pyelonephritis
positive for blood and nitrite
diabetes
positive for glucose, ketones, and SG
starvation
positive for ketones
bile duct obstruction
positive for urine bilirubin and normal urobilinogen; only conjugated bilirubin appears in urine bc the normal degradation cycle is disrupted
cystitis
positive nitrite
liver damage
positive or negative for bilirubin and positive urobilinogen; allowing leakage of conjugated bilirubin into circulation
myoglobinuria
presence of myoglobin in urine; conditions associated with muscle destruction
3 major ketones
acetone, acetoacetic acid, beta-hydroxybutyrate
ictotest
Confirmatory test for bilirubin; diazo reaction
acetest
Confirmatory test for ketones; sodium nitroprusside reaction
SSA
Confirmatory test for urinary protein; acid precipitation reaction
urobilinogen
Ehrlich reaction; liver disease and hemolysis
Postrenal proteinuria
Increased protein in the urine caused by infections/inflammation that add protein to the urine after its formation