Synonym/Acronym
UA.
Rationale
To screen urine for multiple markers to assist in diagnosing disorders such as urintary tract infections (UTIs), kidney and liver disease, as well as to assess hydration status.
A small group of studies in this manual have been identified as Core Lab Studies. The designation is meant to assist the reader in sorting the basic “always need to know” laboratory studies from the hundreds of other valuable studies found in the manual—a way to begin putting it all together.
Normal, abnormal, or various combinations of core lab study results can indicate that all is well, reveal a problem that requires further investigation with additional testing, signal a positive response to treatment, or suggest that the health status is as expected for the associated situation and time frame.
Urinalysis is another of the most commonly ordered laboratory studies. Its popularity is based on the wide range of clinical information it can provide, ease of collection (noninvasive), low cost, and availability in most settings.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction. As appropriate, provide the required urine collection container and specimen collection instructions.
Normal Findings
Method: Macroscopic evaluation by dipstick and microscopic examination. Urinalysis comprises a battery of tests including a description of the color and appearance of urine; measurement of specific gravity and pH; and semiquantitative measurement of protein, glucose, ketones, urobilinogen, bilirubin, hemoglobin (Hgb), nitrites, and leukocyte esterase. Urine sediment may also be examined for the presence of crystals, casts, renal epithelial cells, transitional epithelial cells, squamous epithelial cells, white blood cells (WBCs), red blood cells (RBCs), bacteria, yeast, sperm, and any other substances excreted in the urine that may have clinical significance. Examination of urine sediment is performed microscopically under high power, and results are reported as the number seen per high-power field (hpf).
Normal Physical Characteristics of Urine- Color: ranges from light yellow to deep amber and depends on:
- the patient’s state of hydration (more concentrated samples are darker)
- diet
- medication regimen
- exposure to other substances or foods may contribute to unusual color.
- Appearance: Clear Cloudiness is sometimes attributable to the presence of amorphous phosphates or urates as well as blood, WBCs, fat, or bacteria.
- Odor: Varies by individual, but generally urine does not have a strong odor. In the case of dehydration, the urine is more concentrated and may have a stronger, almost ammonia-type odor; exposure to other substances or foods may also contribute to unusual odor (e.g., asparagus)
Dipstick
| pH | 4.5–8 | | Protein | Negative | | Glucose | Negative | | Ketones | Negative | | Hemoglobin | Negative | | Bilirubin | Negative | | Urobilinogen | Up to 1 mg/dL | | Nitrite | Negative | | Leukocyte esterase | Negative | | Specific gravity | 1.005–1.03 |
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Microscopic Examination
| RBCs | Less than 5/hpf | | WBCs | Less than 5/hpf | | Renal cells | None seen | | Transitional cells | None seen | | Squamous cells | Rare; usually no clinical significance | | Casts | Rare hyaline; otherwise, none seen | | Crystals in acid urine | Uric acid, calcium oxalate, amorphous urates | | Crystals in alkaline urine | Triple phosphate, calcium phosphate, ammonium biurate, calcium carbonate, amorphous phosphates | | Bacteria, yeast, parasites | None seen |
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Possible critical findings are the presence of uric acid, cystine, leucine, or tyrosine crystals.
The combination of grossly elevated urine glucose and ketones is also considered significant.
Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.
Study type: Urine, from an unpreserved, random specimen collected in a clean plastic collection container; related body system: Urinary system.
Routine urinalysis, one of the most widely ordered laboratory procedures, is used for basic screening purposes. It is a group of tests that evaluate the kidneys’ ability to selectively excrete and reabsorb substances while maintaining proper water balance. The results can provide valuable information regarding the overall health of the patient and the patient’s response to disease and treatment. The urine dipstick has a number of pads on it to indicate various biochemical markers. Urine pH is an indication of the kidneys’ ability to help maintain balanced hydrogen ion concentration in the blood. Specific gravity is a reflection of the concentration ability of the kidneys. Urine protein is the most common indicator of kidney disease, although there are conditions that can cause benign proteinuria. Glucose is used as an indicator of diabetes. The presence of ketones indicates impaired carbohydrate metabolism. Hemoglobin indicates the presence of blood, which is associated with kidney disease. Bilirubin is used to assist in the detection of liver disorders. Urobilinogen indicates hepatic or hematopoietic conditions. Nitrites and leukocytes are used to test for bacteriuria and other sources of urinary tract infections (UTIs). Most laboratories have established criteria for the microscopic examination of urine based on patient population (e.g., pediatric, oncology, urology), unusual appearance, and biochemical reactions.
Factors That May Alter the Results of the Study
- Certain foods, such as onion, garlic, and asparagus, contain substances that may give urine an unusual odor. An ammonia-like odor may be produced by the presence of bacteria. Urine with a maple syrup–like odor may indicate a hereditary metabolic defect (maple syrup urine disease).
- The various biochemical strips are subject to interference that may produce false-positive or false-negative results. Consult the laboratory for specific information regarding limitations of the method in use and a listing of interfering drugs.
- The dipstick method for protein detection is mostly sensitive to the presence of albumin; light-chain or Bence Jones proteins may not be detected by this method. Alkaline pH may produce false-positive protein results.
- Large amounts of ketones or ascorbic acid may produce false-negative or decreased color development on the glucose pad. Contamination of the collection container or specimen with chlorine, sodium hypochlorite, or peroxide may cause false-positive glucose results.
- False-positive ketone results may be produced in the presence of ascorbic acid, levodopa metabolites, valproic acid, phenazopyridine, phenylketones, or phthaleins.
- The Hgb pad may detect myoglobin, intact RBCs, and free Hgb. Contamination of the collection container or specimen with sodium hypochlorite or iodine may cause false-positive Hgb results. Negative or decreased Hgb results may occur in the presence of formalin, elevated protein, nitrite, ascorbic acid, or high specific gravity.
- False-negative nitrite results are common. Negative or decreased results may be seen in the presence of ascorbic acid and high specific gravity. Other causes of false-negative values relate to the amount of time the urine was in the bladder before voiding or the presence of pathogenic organisms that do not reduce nitrates to nitrites.
- False-positive leukocyte esterase reactions result from specimens contaminated by vaginal secretions. The presence of high glucose, protein, or ascorbic acid concentrations may cause false-negative results. Specimens with high specific gravity may also produce false-negative results. Patients with neutropenia (e.g., oncology patients) may also have false-negative results because they do not produce enough WBCs to exceed the sensitivity of the biochemical reaction.
- Specimens that cannot be delivered to the laboratory or tested within 1 hr should be refrigerated or should have a preservative added that is recommended by the laboratory. Specimens collected more than 2 hr before submission may be rejected for analysis.
- Because changes in the urine specimen occur over time, prompt and proper specimen processing, storage, and analysis are important to achieve accurate results. Changes that may occur over time include:
- Production of a stronger odor and an increase in pH (bacteria in the urine break urea down to ammonia)
- A decrease in clarity (as bacterial growth proceeds or precipitates form)
- A decrease in bilirubin and urobilinogen (oxidation to biliverdin and urobilin)
- A decrease in ketones (lost through volatilization)
- Decreased glucose (consumed by bacteria)
- An increase in bacteria (growth over time)
- Disintegration of casts, WBCs, and RBCs
- An increase in nitrite (overgrowth of bacteria)
Unusual Color
| Color | Presence Of |
|---|
| Deep yellow | Riboflavin (vitamin B2) | | Orange | Bilirubin, chrysophanic acid (e.g., rhubarb), phenazopyridine, rifampin | | Pink | Beet pigment, docusates, Hgb, myoglobin, phenytoin, porphyrin, rhubarb | | Red | Beet pigment, cascara, docusates, Hgb, myoglobin, phenolphthalein, phenytoin, porphyrin, rifampin, uroerythrin | | Green | Oxidized bilirubin, Clorets (breath mint) | | Blue | Diagnex, indican, methylene blue, triamterene | | Brown | Bilirubin, cascara, chloroquine, docusates, hematin, methemoglobin, metronidazole, nitrofurantoin, metabolites of rhubarb, senna | | Black | Homogentisic acid, melanin | | Smoky | RBCs |
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| Test | Increased In | Decreased In |
|---|
| pH | Ingestion of citrus fruits
Vegetarian diets
Metabolic and respiratory alkalosis | Ingestion of cranberries
High-protein diets
Metabolic or respiratory acidosis | | Protein | Benign proteinuria owing to stress, physical exercise, exposure to cold, or standing
Diabetic nephropathy
Glomerulonephritis
Nephrosis
Toxemia of pregnancy | N/A | | Glucose | Diabetes | N/A | | Ketones | Diabetes
Fasting
Fever
High-protein diets
Isopropanol intoxication
Postanesthesia period
Starvation
Vomiting | N/A | | Hgb | Diseases of the bladder
Exercise (march hemoglobinuria)
Glomerulonephritis
Hemolytic anemia or other causes of hemolysis (e.g., drugs, parasites, transfusion reaction)
Malignancy
Menstruation
Paroxysmal cold hemoglobinuria
Paroxysmal nocturnal hemoglobinuria
Pyelonephritis
Snake or spider bites
Trauma
Tuberculosis
Urinary tract infections
Urolithiasis | N/A | | Urobilinogen | Cirrhosis
Heart failure
Hemolytic anemia
Hepatitis
Infectious mononucleosis
Malaria
Pernicious anemia | Antibiotic therapy (suppresses normal intestinal flora)
Obstruction of the bile duct | | Bilirubin | Cirrhosis
Hepatic tumor
Hepatitis | N/A | | Nitrites | Presence of nitrite-forming bacteria (e.g., Citrobacter, Enterobacter, Escherichia coli, Klebsiella, Proteus, Pseudomonas, Salmonella, and some species of Staphylococcus) | N/A | | Leukocyte esterase | Bacterial infection
Calculus formation
Fungal or parasitic infection
Glomerulonephritis
Interstitial nephritis
Tumor | N/A | | Specific gravity | Adrenal insufficiency
Dehydration
Diabetes
Diarrhea
Fever
Heart failure
Proteinuria
Sweating
Vomiting
Water restriction
X-ray dyes | Diuresis
Excess IV fluids
Excess hydration
Hypothermia
Impaired renal concentrating ability |
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Formed Elements in Urine Sediment
Cellular elements
- Clue cells (cell wall of the bacteria causes adhesion to epithelial cells) are present in nonspecific vaginitis caused by Gardnerella vaginitis, Mobiluncus curtisii, and M. mulieris.
- RBCs are present in glomerulonephritis, lupus nephritis, focal glomerulonephritis, calculus, malignancy, infection, tuberculosis, infarction, renal vein thrombosis, trauma, hydronephrosis, polycystic kidney, urinary tract disease, prostatitis, pyelonephritis, appendicitis, salpingitis, diverticulitis, gout, scurvy, subacute bacterial endocarditis, infectious mononucleosis, hemoglobinopathies, coagulation disorders, heart failure, and malaria.
- Renal cells that have absorbed cholesterol and triglycerides are also known as oval fat bodies.
- Renal cells come from the lining of the collecting ducts, and increased numbers indicate acute tubular damage, as seen in acute tubular necrosis, pyelonephritis, malignant nephrosclerosis, acute glomerulonephritis, acute drug or substance (salicylate, lead, or ethylene glycol) intoxication, or chemotherapy, resulting in desquamation, urolithiasis, and kidney transplant rejection.
- Squamous cells line the vagina and distal portion of the urethra. The presence of normal squamous epithelial cells in female urine is generally of no clinical significance. Abnormal cells with enlarged nuclei indicate the need for cytological studies to rule out malignancy.
- Transitional cells line the renal pelvis, ureter, bladder, and proximal portion of the urethra. Increased numbers are seen with infection, trauma, and malignancy.
- WBCs are present in acute UTI, tubulointerstitial nephritis, lupus nephritis, pyelonephritis, kidney transplant rejection, fever, and strenuous exercise.
Casts
- Granular casts are formed from protein or by the decomposition of cellular elements. They may be seen in kidney disease, viral infections, or lead intoxication.
- Large numbers of hyaline casts may be seen in kidney diseases, hypertension, heart failure, or nephrotic syndrome and in more benign conditions such as fever, exposure to cold temperatures, exercise, or diuretic use.
- RBC casts may be found in acute glomerulonephritis, lupus nephritis, and subacute bacterial endocarditis.
- Waxy casts are seen in chronic kidney disease or conditions such as kidney transplant rejection, in which there is renal stasis.
- WBC casts may be seen in lupus nephritis, acute glomerulonephritis, interstitial nephritis, and acute pyelonephritis.
Crystals
- Crystals found in freshly voided urine have more clinical significance than crystals seen in a urine sample that has been standing for more than 2 to 4 hr.
- Calcium oxalate crystals are found in ethylene glycol poisoning, urolithiasis, high dietary intake of oxalates, and Crohn disease.
- Cystine crystals are seen in patients with cystinosis or cystinuria.
- Leucine or tyrosine crystals may be seen in patients with severe liver disease.
- Large numbers of uric acid crystals are seen in patients with urolithiasis, gout, high dietary intake of foods rich in purines, or who are receiving chemotherapy (see study titled “Uric Acid, Urine”).
Yeast
- Yeast cells, usually Candida albicans, may be seen in diabetes and vaginal moniliasis.
Potential Nursing Problems: Assessment & Nursing Diagnosis
| Problems | Signs and Symptoms |
|---|
| Confusion (related to an alteration in fluid and electrolytes secondary to hepatic disease and encephalopathy, acute alcohol consumption, hepatic metabolic insufficiency) | Disorganized thinking; restlessness; irritability; altered concentration and attention span; changeable mental function over the day; hallucinations; inability to follow directions; disoriented to person, place, time, and purpose; inappropriate affect | | Fluid volume (deficit—related to hypovolemia associated with body fluid shifts to third space, body fluid loss, reduced oral intake; increased perspiration; diaphoresis; gastrointestinal [GI] tract loss from vomiting, diarrhea; overly aggressive diuresis) | Decreased urinary output, fatigue, sunken eyes, dark urine, decreased blood pressure, increased heart rate, altered mental status | | Kidney function (altered kidney function related to renal ischemia associated with shock, sepsis, hypovolemia; postoperative injury; trauma; nephrotoxic drugs [aminoglycoside, heavy metals, radiographic contrast]; renal vascular occlusion; hemolytic transfusion reaction; decreased cardiac output; tubular necrosis; obstruction; tumor; medications [NSAIDs, angiotensin-converting enzyme, immunosuppressants, antineoplastics, antifungals]) | Increased BUN; increased Cr; decreased Cr clearance; increased urine specific gravity (greater than 1.029); hematuria; proteinuria; metabolic acidosis; decreased urine output less than 400 mL/day (with adequate intake and no fluid loss); weight gain; elevated K+; elevated phosphate; decreased Ca, decreased Na+; increased magnesium; decreased Hgb/Hct |
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Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how this test can assist in assessing for disease, infection, and inflammation and evaluate for dehydration.
- Explain that a urine sample is needed for the test. If a catheterized specimen is to be collected, explain this procedure to the patient, and obtain a catheterization tray.
- Information regarding urine specimen collection is presented with other general guidelines in Appendix A: Patient Preparation and Specimen CollectionPatient Preparation and Specimen Collection.
Potential Nursing Actions
- Include on the collection container’s label the specimen collection type (e.g., clean catch, catheter), date and time of collection, and any medications that may interfere with test results.
- Promptly transport the specimen to the laboratory for processing and analysis.
After the Study: Implementation & Evaluation Potential Nursing Actions
Avoiding Complications
- Instruct the patient to report symptoms such as pain related to tissue inflammation, pain or irritation during void, bladder spasms, or alterations in urinary elimination.
- Observe/assess for signs of inflammation if the specimen is obtained by suprapubic aspiration.
Treatment Considerations
Fluid Volume
- Establish baseline assessment data.
- Manage underlying cause of fluid alteration.
- Record accurate intake and output.
- Monitor urine characteristics and respiratory status.
- Collaborate to adjust oral and IV fluids to provide optimal hydration status.
- Monitor laboratory values that reflect alterations in fluid status; potassium, BUN, Cr, Ca, Hgb, and Hct.
Kidney Function
- When kidney function is altered, it is important to monitor, record, and trend intake and output, daily weight, urine specific gravity, BUN, Cr, Na+, K+, magnesium, pH, urinalysis, and Hgb/Hct.
- Assess and monitor for edema, jugular vein distention, hypertension, adventitious breath sounds, and impaired gas exchange.
- Administer prescribed oxygen, fluids, diuretics; consider renal function with antibiotic administration.
- Facilitate ordered hemodialysis.
Safety Considerations
Confusion
- Confusion can occur due to altered fluid and electrolytes, acute alcohol consumption, as well as renal or hepatic disease.
- Correlate confusion with the need to reverse altered electrolytes and evaluate medications.
- Prevent falls and injury through appropriate use of postural support, bed alarm, or restraints.
- Consider pharmacological interventions.
Clinical Judgement
- Consider the best method of instruction to ensure the urine sample is adequate and free of contamination.
Follow-Up and Desired Outcomes
- Understands the importance of completing prescribed medications such as antibiotic therapy even if symptoms are no longer present.
- Understands the implications of compromised renal status and the necessary therapeutic interventions to maintain overall health.