Acknowledgements•Addisa Ababa University•Jimma University•Hawassa University•Haramaya University•University of Gondar•American Society for Clinical Pathology •Center for Disease Control and Prevention-Ethiopia2
Chapter Objective At the end of this chapter the students will be able to describe Microscopic examination for urine sedimentNormal and abnormal organized urine sediments with their diagnostic features.Formation and significance of castsNormal and abnormal crystals encounter in urine sedimentsRelationship between sediments, chemical, physical findings in urineReporting of urinary sedimentsQuality control in urinalysis.3
Chapter Outline Microscopic Examination Of UrineProcedure for microscopic examinationSource of errors in the microscopic examination of urineUrinary Sediments Organized Urinary SedimentsParasite, fungus and bacteria in urineNon-Organized Urinary Sediments Urine CrystalsBody cells, crystals, casts, yeasts, bacteria, spermMethods of reporting formed elementsQuality control in urinalysis.4
Introduction•In examining urinary sediment it is necessary to learn the distinguishing characteristics of elements which have clinical significance .•If the urine sample is properly collected, the test is carefully performed, and the person performing the test is knowledgeable, skillful valuable information can be obtained from microscopic examination of urine specimen.•Normally small amount of solid substances is found in the urine. But when their concentration become high, may indicate the existence of abnormal physiological function of our body.5
Standardization •Aspects of microscopic examination that should be standardizes:1. Volume of urine analyzed 2. Length and force of centrifugal 3. Re-suspending volume and concentration of sediment 4. Volume and amount of sediment examined 5. Terminology and reporting format6
Principles of methodCentrifuge 10-12 ml urine specimen at 1500 – 2000 rpm for 3-5 minutes then discard the supernatant by quick inversion of the tube, resuspend and take the sediment by Pasteur pipette from the tube, transfer a drop into the clean and dry slide finaly examin on the microscope •Repeated evaluation of urine sediment is frequently valuable in following the course and management of urinary tract disorders, because the appearance of cellular elements, and casts in the urine is a reflection of changes that take place in the kidney.7
Reagents and equipment •Assemble all necessary materials used for the collection, centrifugation and examination. –centrifuge.–Conical centrifuge tubes, or regular test tubes. –Pasture pipette with rubber fit or automatic pipettes if possible.