Urinalysis
Urinalysis
Urinalysis
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Dipstick Indicators of Infection
pH
– Normal: 4.5 – 8
– Alkaline urine in a patient with UTI suggests the presence of a
urea-splitting organism (ex. Proteus)
• Some exceptions exist, such as Staphylococcus, Enterococcus, and
Pseudomonas
Leukocyte esterase
– Normal: negative
– Esterase released by White Blood Cells (WBCs)
Nitrite
– Normal: negative
– Bacteria reduce dietary nitrates to nitrites
Hemoglobin
– Normal: negative
– RBCs can enter urinary tract due to disease or trauma
Non-infectious Dipstick Tests
Specific gravity
– Normal: 1.003 – 1.030
– Indication of hydration status
Protein
– Normal: negative
– Positive result could indicate infection, diabetes,
trauma
Glucose
– Normal: negative
– Most glucose filtered by kidneys is reabsorbed
– Glucose may spill into urine if amount of glucose
present exceeds kidney’s capacity to reabsorb
(uncontrolled diabetes)
Non-infectious Dipstick Tests
(cont.)
Ketones
– Normal: negative
– Product of body fat metabolism commonly associated
with uncontrolled diabetes
Urobilinogen
– Normal: 0.1 – 1.0 mg/dL
– Excess concentrations can indicate liver damage (e.g
hepatitis, cirrhosis) or hemolytic anemia
Bilirubin
– Normal: negative
– Can indicate liver disease or biliary obstruction
Microscopic Urinalysis
Used to confirm and further define a positive
dipstick urinalysis
Will provide quantity of bacteria
Allows for eventual speciation and sensitivity
testing to be completed, in order to guide
therapy
Often used in patients with:
– Recurrent infection
– Prior infection unresolved with antibiotics
– Signs/symptoms of an upper urinary tract infection
– Complicated UTIs
Microscopic Urinalysis (cont.)
WBC
– Normal: 0 – 5 per hpf
• Men usually have < 2/hpf; women usually have < 5/hpf
– Presence of elevated WBCs indicates the body may
be fighting infection in the urinary tract
RBC
– Normal: 0 – 1 per hpf
– Presence indicates damage to urinary tract (e.g.,
infection, physical trauma, etc.)
Bacteria
– Normal: negative
– Presence of bacteria is not always predictive of a UTI
(ex. asymptomatic bacteriuria, catheter colonization)
– Must use in conjunction with other factors
Microscopic Urinalysis (cont.)
Epithelial cells
– Squamous epithelial cells
• Normal: 0 – 2 per hpf
• Large numbers may indicate a poor sample
(contamination)
– Renal epithelial cells
• Normal: 0 – 1 per hpf
• Large numbers may indicate renal tubular injury