Urinalysis Flashcards
Red colored urine suggests the presence of?
hemoglobin, myoglobin, or red blood cells
Cloudy or turbid urine suggests the presence of?
crystals, cells or casts
hematuria from hemolysis
hemoglobinuria
hematuria from skeletal muscle injury or rhabdomyolysis
myoglobinuria
How do you determine whether red colored urine contains hemoglobin, myoglobin or RBCs?
Look for cloudiness. This would indicate the presence of red blood cells, which would only be present in hematuria. Alternatively, one can centrifuge the urine and see if the red color moves into the heavier pellet (red blood cells), or stays in the supernatant (hemoglobin or myoglobin).
higher specific gravity of urine indicates?
more concentrated urine
Urine protein by dipstick uses the free amino groups on proteins to bind to pH indicators on the strip. This is not really measuring protein directly and tends to better detect (1) more than (2)
- charged proteins like albumin 2. globulins
Patients can have quite a bit of proteinuria from (3) like the (1) proteins found in (2) and have dipstick negative urine
- globulins 1. Bence-Jones 2. multiple myeloma
Interpreting the dipstick for blood requires comparison with the microscopic exam and generally there should be (1) on microscopic exam when there is positive blood on dipstick
red cells (erythrocytes)
If the dipstick shows blood without red cells present, then this could be (1), indicating that hemolysis has occurred (for (2) or muscle injury (for (3).
- hemoglobulinuria or myoglobinuria 2. hemoglobulinuria 3. myoglobin
If nitrite is present in urine by dipstick, it may be an indication that (1) are present
- nitrite producing bacteria
Another dipstick test for urinary tract infection is the detection of (1) which is not normally found in urine unless the white cells which express (1) are present
- leukocyte esterase
pyuria
white cells in urine; pus
Microscopic examination of urine is performed on centrifuged sediment which means it is a (1) sample
concentrated
The most important concept in urinalysis is that casts indicate (1) and cells indicate (2)
- renal location of disease 2. disease anywhere else
form when cells or protein are trapped in tubules and form molds of their surroundings
casts
In stained samples or by light microscopy, red blood cells are (1), whereas by phase contrast, (2)
- red 2. one notices a lack of nuclei without the aid of color
Red cells, either alone or within casts, lack nuclei so can generally be readily distinguished from (1) casts
white cell or epithelial cell
White cells are usually?
neutrophils
Red cells are found in conditions of bleeding (1) is always a concern) and white cells are found in (2)
- cancer 2. infection
Red blood cell casts generally indicate (1) and white blood cell casts indicate (2)
- glomerular inflammation/type of glomerulonephritis 2. infection within the kidney which is called pyelonephritis
Epithelioid cell casts are found in (1) but often degenerate into (2)
- acute kidney injury (previously called acute tubular necrosis or ATN) 2. granular casts
Protein can form casts in the renal tubules in patients with (1) which is also useful for diagnosis
- nephrotic syndrome
found frequently in urine even in asymptomatic patients and are often not very diagnostically useful other than as another measure of urine pH
crystals
(1) crystals tend to form in acidic urine while (2) crystals tend to form in alkaline urine
- Uric acid and cystine 2. triple phosphate
one strategy to try and prevent crystal formation is?
making urine pH more or less alkaline in order to decrease crystal formation
There is one time when the microscopic exam can be wrong, and that is when the urine is so (1) it lyses the red cells, because red cells can’t survive in a (2) fluid
- dilute 2. hypotonic
Urinalysis can be ___, ____, and ____
Macroscopic; chemical; or microscopic`
Gross examination of the urine to determine whether there is serious renal disease
macroscopic urinalysis
what is clarity of urine
Measure of transparency; NOT color;
Red urine: centrifuge it to differentiate RBCs from Hbemia/myoglobinemia
centrifuge the urine to see if the red color moves into the heavier pellet (indicates RBCs, i.e. hematuria) or stays in the supernatant (Hbemia or myoglobinemia)
Note: these are SCREENING tests
Chemical urinalysis
______ detects esterase enzyme present in certain WBCs (neutrophils and monocytes) –> indicates urinary tract infection, since seeing host response
Leukocyte esterase
If there is bacteria present w/o a host rxn (WBCs) then it is likely a _____ (since bacterial diseases usually produce neutrophilic response)
contaminan
Microscopic exam: ___ urine to get concentrated sediment (for better determination). Examination can be viewed either 1) 2)
Centrifuged; 1. with a stain or unstained by phase contrast 2. light microscopy.
____ can be present anyplace between kidney and the collection system—i.e. indicates disease anywhere
Cells
RBCs–> indicates ____, thus worry about ___
bleeding, cancer
- Result of bleeding at any point in the urinary system.
- No nuclei
) RBCs
- (b) WBCs –> Indicates ___
- Usually ____ (type of cell)
- Presence of a few is normal
- High numbers indicate inflammation or infection.
See nuclei and cytoplasm—so more internal structure
infection;
neutrophils (poly-lobed nuclei)
RBCs vs. WBCs on histo
RBCs have NO nuclei; WBCs have nuclei and are multi-lobed
____ are much smaller than the cells;
small numbers–> ____; high numbers–> more likely to be contamination
bacteria;
infection;
____ –> indicate glomerulonephritis (both acute and chronic; this is a more severe disorder than pyelonephritis)
RBC Casts;
__->indicate pyelonephritis; suggests acute inflammation (if ____) or chronic (if ___); can be treated w/ antibiotics and less severe than _____
WBC Casts; neutrophils; lymphocytes; glomerulonephritis
- Cells are large and flat.
- Normal cells that line the urinary and genital tract or renal tubules + transitional cells (bladder)
Epithelial cells
epithelial cells vs. epithelioid casts
Normal cells that line the urinary and genital tract or renal tubules + transitional cells (bladder
Epithelioid Casts –> indicate Acute Renal Injury (AKI)
- ) ____ –> indicate Acute Renal Injury (AKI) (pts will have low urine output/oligouria).
- Often degenerate into granular casts go from coarse granular cast -> fine granular cast -> waxy cast (not much internal structure) as gets older.
Form in the loops of Henle, distal tubules, and collecting ducts
Epithelioid Casts
indicate nephrotic syndrome, can be normally present, or in those w/ dehydration
Hyaline Casts
Hyaline casts
- ___ and fatter than mucus.
- A few are normal; a lot indicates ___.
- May be increased after ____.
From when ___ solidifies in the nephron
Colorless; nephrotic syndrome; strenuous exercise;protein
Found frequently in urine, even in asymptomatic pts; more distraction than useful—clinical correlation required
Crystals
•colorless; octahedron; found in acidic urine
Calcium oxalate crystals
•in cystinuria in small children; hexagon (6 sides); acidic urine
Cystine Crystals
•in MSUD (important to diagnoses, especially in children); round shape w/ clear border and a darker center.
Leucine Crystals
•colorless; coffin-lid prism; common finding and not usually significant (pH info).; alkaline urine
Triple Phosphate Crystals
Acidic urine
(1) ___: colorless; octahedron.
(2) ___: sharper borders
- (3) Other urates: sodium urate, amorphous urates (all sharp borders)
- (4) Cystine Crystals: in cystinuria in small children; hexagon (6 sides)
- (5) Leucine Crystals: in MSUD (important to diagnoses, especially in children); round shape w/ clear border and a darker center.
Calcium Oxalate Crystals; Uric Acid Crystals;
(1) Triple Phosphate Crystals: colorless; coffin-lid prism; common finding and not usually significant (pH info).
(2) Calcium phosphate (spear-head) and amorphous phosphates
Found in ___
alkaline urine
