Urine Analysis PDF

Urine Analysis (Complete urine analysis) Fatima Yousuf Mohamed MSc Clinical Chemistry Objectives To know clinical significance of CUA Identify different types of urine specimens Understand macroscopic urine analysis (physical &chemical ) How to perform microscopic urine a...

Urine Analysis (Complete urine analysis) Fatima Yousuf Mohamed MSc Clinical Chemistry Objectives To know clinical significance of CUA Identify different types of urine specimens Understand macroscopic urine analysis (physical &chemical ) How to perform microscopic urine analysis  The Clinical and Laboratory Standards Institute (CLSI) defines urinalysis as the testing of urine with procedures commonly performed in a fast, reliable, accurate, safe, and cost-effective manner. Clinical significance of CUA Aids in the diagnosis of diseases or disorders of the kidney or urinary tract. Screening asymptomatic populations for undetected disorders. Monitoring the progress of disease and the effectiveness of therapy Screening of drug abuse.  A urine specimen is the most popular sample to be investigated due to the following : Is a readily available and easily collected specimen.  It contains information, which can be obtained by inexpensive laboratory tests, about many of the body’s major metabolic functions.  Urine Composition In general, urine is normally 95% water and 5% solutes.  Solutes consists of urea and other organic and inorganic chemicals dissolved in water. Urea, a metabolic waste product produced in the liver from the breakdown of protein and amino acids, accounts for nearly half of the total dissolved solids in urine.  Urine Composition Cont... Other organic substances include primarily creatinine and uric acid. The major inorganic solid dissolved in urine is chloride, followed by sodium and potassium. Trace amounts of additional inorganic chemicals such as: sulfate, phosphate, ammonium, calcium, and magnesium.  Urine specimen Collection Specimens must be collected in clean, dry, leak-proof, with a tight-fitting cover containers, disposable containers are recommended. Disposable containers are available in a variety of sizes and shapes, including bags with adhesive for the collection of pediatric specimens, and large containers for 24-hour specimens. Sterile containers should be used for microbiology.  Specimen Collection Cont… All specimens must be labeled properly (on cup not led) with the patient’s name, age, sex, identification number, Physician’s name date and time of collection. A requisition form (manual or computerized) must accompany specimens delivered to the laboratory. Following collection, specimens should be delivered to the laboratory promptly and tested within 1-2 hrs. A specimen that cannot be delivered and tested within specific time should be refrigerated (2-8 C for not more than 8 hours before analysis.) or have an appropriate chemical preservative ( eg: thymol, boric acid, formaldehyde). Types of Urine Specimens Random (spot), first Morning, fasting Specimen (Second Morning), 2-hrs Postprandial, glucose tolerance specimens, catheterized, 24-Hour (or Timed), midstream clean-catch, suprapubic aspiration, and pediatric specimens. Routine Urinalysis Examination  Urine Examination Physical Examination The physical examination of urine includes the determination of the urine color, volume, clarity (Appearance),specific gravity, and odor. Color:  Normal urine color varies from pale yellow, yellow, to dark yellow, and amber. The yellow color of urine is caused by the presence of a pigment, named urochrome.  Examples of abnormal Urine Color Pink or red : due to the presence of RBCs or Hb in urine, as result of infections, intravascular hemolysis, bleeding, renal stones, and menstrual cycle.  Green: due to Pseudomonas infection. Blue-green: due to certain drugs such as methocarbamol. Brown black: caused by methemoglobin, melanin or melanogen. Dark Yellow/Amber/Orange: may not always signify a normal concentrated urine but can be caused by the presence of the abnormal pigment bilirubin.  Urine volume The volume of urine excreted indicates the balance between fluid ingestion and water lost from the lungs, sweat, and intestine. Most adults produce from 750 to 2,000 mL every 24 hours (average 1.5 L). Oligouria: decreased urine out put < 400 ml, due to dehydration, shock, acute glomerulonephritis, acute renal failure. Polyuria: increased urine out put >2.5 L, observed in diabetes mellitus and insipidus (in insipidus, as a result of lack of ADH), as well as in chronic renal disease. Urine volume Cont… Anuria: No urine out put or