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