Lab Procedures Chapter 46:Urinalysis Professor Fowler

introduction Urinalysis: the testing of urine for the presence of infection or disease One of the most commonly performed tests Readily available, easily collected, and often provides the first clues to illness Void: urinate Micturate: urinate

asepsis Very important in urinalysis!!!!

Collecting the specimen Urine samples provide valuable indicators of the overall health of the pt Generally at least 10mL is needed for testing

Collecting the specimen Routine (random) sample Most commonly collected type Collected in non-sterile container Used for routine screenings Morning specimen: first void Most concentrated Used for pregnancy tests, urine cultures, and microscopic exams Should be brought to office within 30 minutes to 1 hour

Collecting the specimen Timed specimen Necessary for quantitative analysis of substances (protein, creatinine, glucose) 24 hour specimen Used to determine the glomerular filtration rate of kidneys, check hormone levels, and to check for other metabolic abnormalities Procedure 46-1 2-hour postprandial: two hours after a meal Used as a screen for glucose that may be spilled into urine once blood levels exceed renal threshold (concentration at which a substance excreted by kidneys begins to appear in urine)

Collecting the specimen Catheterization specimen: used to collect a sterile urine specimen – catheter inserted into urethra into bladder to obtain sample – figures 46-3A, B and figures 46-4 A, B Clean-catch midstream specimen – Procedure 46-2 Pediatric specimen: attach a pediatric urine specimen bag Suprapubic specimen: puncture performed using a sterile needle and syringe so the resulting urine specimen is sterile

Routine urinalysis Physical Characteristics – normal values table 46-2 Begins with an exam of appearance, color, odor, quantity and specific gravity Procedure 46-3 Appearance Clear: can see through it – nothing seen floating Cloudy: can not see through it – many things seen floating Terms Slightly cloudy, cloudy with sediment or turbid (cloudiness) Turbid caused by bacterial infection, white blood cells, red blood cells, or epithelial cells Always look before it cools as crystals form as it cools Color Normal color is straw (pale yellow) Medications, vitamins, some foods can change color Brown or black indicates serious condition Reddish-brown may indicate bleeding Orange may be result of Pyridium (used for bladder spasms) Bright yellow may be from large quantities of B vitamins

Routine urinalysis Physical Characteristics Odor Quantity Normally no odor Fruity: possible ketones in urine Putrid or foul odors might indicate infections Ammonia odors usually result from breaking down over time Quantity Usually only measured with 24 hour urine samples Polyuria: excessive amounts of urine production – DM or kidney disease Oliguria: decreased amounts of urine production – dehydration, bleeding, decreased fluid intake or kidney disease Anuria: no urine production – renal failure or obstruction Specific Gravity: weight of a substance in relation to the weight of the same amount of distilled water – concentration changes throughout the day with fluid intake Rough estimate of amount of substances dissolved in urine Indicates how well kidneys can concentrate or dilute urine Dipstick or reagent strip method Refractometer method - Procedure 46-4 video

Routine urinalysis Chemical Characteristics – Procedure 46-5 Most common method is dipstick method Chemicals on the strip react with specific chemicals in the urine to allow for measurement (color changes) Dipstick tests are available for pH, protein, glucose, ketones, blood, bilirubin, urogilinogen, nitrite, leukocytes, and specific gravity Tests provide info about the functioning of the kidneys, liver and other organs Figure 46-11 Each test has a specific time before reading the results DO NOT TOUCH TO OUTSIDE OF THE BOTTLE WHILE READING RESULTS!

Routine analysis Chemical Characteristics pH: indicates acidity and alkalinity Protein: normally not found in urine but may be found in urine after exposure to cold, strenuous exercise, or after eating large amounts of protein Proteinuria (presence of protein in urine): can indicate renal dysfunction, preeclampsia, CHF, and glomerulonephritis Glucose: normal urine has no glucose (sugar) Glycosuria (sugar in the urine): may indicate DM, gestational diabetes, stress, infection, or Cushing’s syndrome, or medications Sugar spills into the urine at about 160-180 mg/dL Blood: normal urine has no blood Hematuria (blood in the urine): may indicate anemia, UTI, kidney stones or trauma unless it is from menses

Routine analysis Chemical Characteristics Ketones: by products of fat metabolism Acidosis may occur if prolonged fat burning for source of energy instead of glucose Elevated ketones are common in conditions like poorly controlled DM, dehydration, starvation, ingestion of large quantities of aspirin and occasionally after general anesthesia Bilirubin: product of breakdown of hemoglobin Presence of bilirubin may be one of the first signs of liver disease, obstructive biliary disease, or mononucleosis Large amounts will turn urine to yellow-brown to dark orange Stored in dark as light breaks down bilirubin Urobilinogen: result of RBCs destruction Elevated in any condition causing an increase in bilirubin Nitrates: by-product of chemical breakdown by certain bacteria measurement is a method for detection of bacteria If present, usually UTI Leukocytes: white blood cells When present, usually indicative of UTI

Routine analysis Reagent Tablet Testing Some institutions routinely perform tablet testing when a reagent strip test for glucose is positive Chemically created tablets are added to urine specimen and the resulting color is compared to a reaction chart to determine the presence of certain sugars Procedure 46-6 Automated Urine Chemical Analyzers Widely used in many types of facilities Use light photometry to test the strips, which eliminates human error Figure 46-17 Microscopic Examination Identifies the type and approximate numbers of organisms present in a urine specimen Helps physicians determine a disease process MAs must be able to properly prepare a urine specimen for microscopic exam and understand the meaning and importance of the results of the microscopic exam Procedure 46-7 (video) Procedure 45-6 (video and demo?)

others Urine Pregnancy Test – Procedure 46-8 Two types of pregnancy testing: urine and blood Both tests are based on the detection of hCG which is produced by the placenta and is present is the urine and blood of pregnant woman First morning sample is preferred for urine testing because the concentration of the hormone is greatest at that time Urine tests can be preformed at home and/or the office   Quality Control System of ensuring that patients test results are accurate and reported in a timely manner Should be done on regular basis, following protocol, and documented in quality control log New employees should be trained to perform urine tests and the training documented All instruments associated with urine testing should be cleaned and maintained on a regular basis and documented accordingly