Chapter 47 provides knowledge of collecting, processing, and testing urine specimens. This chapter reviews the function of the urinary system and the formation of urine. You will learn about various types of urine specimens and howto properly instruct or assist patients with the collection of these specimens.
CHAPTER 47 Collecting, Processing, and Testing Urine Specimens © 2011 The McGraw-Hill Companies, Inc All rights reserved 472 Learning Outcomes 47.1 Describe the characteristics of urine, including its formation, physical composition, and chemical properties 47.2 Explain how to instruct patients in specimen collection 47.3 Identify guidelines to follow when collecting urine specimens 47.4 Describe proper procedures for collecting various urine specimens © 2011 The McGraw-Hill Companies, Inc All rights reserved 473 Learning Outcomes (cont.) 47.5 Explain the process of urinary catheterization 47.6 List special considerations that may require you to alter guidelines when collecting urine specimens 47.7 Explain how to maintain the chain of custody when processing urine specimens 47.8 Explain how to preserve and store urine specimens © 2011 The McGraw-Hill Companies, Inc All rights reserved 474 Learning Outcomes (cont.) 47.9 Describe the process of urinalysis and its purpose 47.10Identify the physical characteristics present in normal urine specimens 47.11Identify the chemicals that may be found in urine specimens 47.12Identify the elements categorized and counted as a result of microscopic examination of urine specimens © 2011 The McGraw-Hill Companies, Inc All rights reserved 475 Introduction • Routine analysis of a urine specimen – Noninvasive – Used to diagnose significant conditions • Medical assistant – Learn about types of urine specimens – Instruct or assist patient in collection of a sample – Learn to process urine specimens – Learn about normal/abnormal components of urine © 2011 The McGraw-Hill Companies, Inc All rights reserved 476 Role of the Medical Assistant • Collect, process, and test urine samples • Knowledge necessary – Anatomy and physiology of kidneys – How urine is formed – Normal components of urine © 2011 The McGraw-Hill Companies, Inc All rights reserved 477 Role of the Medical Assistant • Safety – Standard Precautions – PPE as needed – Handle and dispose of specimens properly – Dispose of used supplies and equipment properly – Sanitize, disinfect, and/or sterilize reusable equipment © 2011 The McGraw-Hill Companies, Inc All rights reserved 478 Anatomy and Physiology of the Urinary System • Organs – Kidneys – remove excess water and waste products – Ureters – drain urine into bladder – Bladder – stores urine – Urethra – drains urine to outside of the body © 2011 The McGraw-Hill Companies, Inc All rights reserved 479 Formation of Urine • Nephron – Functional unit of the kidney – Removes end products of metabolism – Allows for reabsorption of water and electrolytes • Processes in urine formation – Glomerular filtration – Tubular reabsorption – Tubular secretion – Maintains normal fluid balance © 2011 The McGraw-Hill Companies, Inc All rights reserved 4710 Physical Composition and Chemical Properties of Urine • 95% water • 5% waste products • Other dissolved chemicals – – – – – Urea Uric acid Ammonia Calcium Creatinine – – – – – Sodium Chloride Potassium Sulfates Phosphates Hydrogen ions Urochrome Urobilinogen A few RBCs A few WBCs © 2011 The McGraw-Hill Companies, Inc All rights reserved Chemical Testing of Urine Specimens 4737 (cont.) • Presence of STDs – Screening for chlamydia – 15- to 25-year-old sexually active females – Nucleic acid amplification tests (NAATs) • • • • Detect nucleic acid in urine Chlamydia and gonorrhea Advantage – highly specific, non-invasive Disadvantage – expensive, no organism remains for culture © 2011 The McGraw-Hill Companies, Inc All rights reserved Microscopic Examination of Urine Specimens 4738 • View elements only visible with microscope • Centrifuge – Obtain sediment – Spins fluid – heavier substances settle to the bottom of the tubes © 2011 The McGraw-Hill Companies, Inc All rights reserved Microscopic Examination of Urine Specimens (cont.) • Casts • Cells – Epithelial cells – White blood cells – Red blood cells 4739 – Cylindrical elements – Types • • • • • • Hyaline Granular RBC casts WBC casts Epithelial cell casts Waxy © 2011 The McGraw-Hill Companies, Inc All rights reserved Microscopic Examination of Urine Specimens (cont.) • Crystals • Yeast cells – Naturally produced solids of definite form – May be confused with RBCs – Common in urine – Associated with genitourinary tract infection, diabetes – Determine pH before testing 4740 © 2011 The McGraw-Hill Companies, Inc All rights reserved Microscopic Examination of Urine Specimens (cont.) • Bacteria – A few are normal – Infection if urine also has • Putrid odor • WBCs 4741 • Parasites – Infection or contamination – Trichomonas vaginalis – most common © 2011 The McGraw-Hill Companies, Inc All rights reserved 4742 Apply Your Knowledge What is the specific gravity shown on this refractometer screen? ANSWER: The specific gravity shown here is 1.030 © 2011 The McGraw-Hill Companies, Inc All rights reserved 4743 Apply Your Knowledge A urinalysis has detected that a patient has protein in his urine Why is this important? ANSWER: Protein in the urine usually indicates renal disease © 2011 The McGraw-Hill Companies, Inc All rights reserved 4744 In Summary 47.1 Urine is formed during a filtration process that occurs in the nephron It is made up of 95% water and 5% waste products and other dissolved chemicals, including urea, uric acid, ammonia, calcium, creatinine, sodium, chloride, potassium, sulfates, phosphates, bicarbonates, hydrogen ions, urochrome, urobilinogen, a few red blood cells, and a few white blood cells © 2011 The McGraw-Hill Companies, Inc All rights reserved 4745 In Summary (cont.) 47.2 Instructions for obtaining specific types of specimens will vary according to the test The general instructions for urine specimen collection are: urinate into the container indicated by the laboratory; if the collection container contains liquid or powdered preservative, not pour it out; always refrigerate the labeled collection container or keep it in a cooler or pail filled with ice; be sure to keep the lid on the container © 2011 The McGraw-Hill Companies, Inc All rights reserved 4746 In Summary (cont.) 47.3 The general guidelines for collecting a urine specimen include: follow the procedure that is specified for the urine test that will be performed; use the type of specimen container indicated by the laboratory; properly label the specimen container; explain the procedure to the patient when assisting in the collection process; wash your hands before and after the procedure and wear gloves during the procedure; and complete all necessary paperwork © 2011 The McGraw-Hill Companies, Inc All rights reserved 4747 In Summary (cont.) 47.4 Several types of urine specimens are collected in the medical office Each specimen has a slightly different collection method The various specimens include random, first morning, clean-catch midstream, timed, and 24-hour 47.5 Urinary catheterization involves inserting a plastic drainage tube into the kidney, the ureter, or the bladder 47.6 When the medical assistant obtains a urine specimen from a patient or takes a history of a patient who may have a urinary problem, she or he needs to consider the patient’s sex, condition, and age © 2011 The McGraw-Hill Companies, Inc All rights reserved 4748 In Summary (cont.) 47.7 When collecting a chain-of-custody specimen, the following safeguards should be used: positively identify the donor; have the donor remove outer clothing and empty pockets, displaying all items; add bluing agent to the water in the toilet and turn off other water sources; remain by the door while the specimen is being obtained; measure and record the temperature of the specimen within four minutes; have the donor witness the specimen transfer; complete additional information on the form; sign the CCF; give a copy of the CCF to the donor; place the specimen in a leak-proof bag with a copy of the form; and release the specimen to the courier service © 2011 The McGraw-Hill Companies, Inc All rights reserved 4749 In Summary (cont.) 47.8 Proper preservation and storage of specimens are essential A specimen should not be left unpreserved for more than hour Refrigerate a specimen if it cannot be tested within an hour Bring the specimen back to room temperature before testing 47.9 Urinalysis is the evaluation of urine by various types of testing methods to obtain information about body health and disease © 2011 The McGraw-Hill Companies, Inc All rights reserved 4750 In Summary (cont.) 47.10 The physical characteristics of normal urine include color and turbidity, volume, odor, and specific gravity 47.11 The chemicals that may be found in urine specimens include ketones, nitrite, bilirubin, glucose, and protein 47.12 During microscopic urine examination, elements that are categorized and counted include the cells, casts, crystals, yeast, bacteria, and parasites © 2011 The McGraw-Hill Companies, Inc All rights reserved 4751 End of Chapter 47 A human being: an ingenious assembly of portable plumbing ~ Christopher Morley, 1890-1957 © 2011 The McGraw-Hill Companies, Inc All rights reserved ... reserved 47 7 Role of the Medical Assistant • Safety – Standard Precautions – PPE as needed – Handle and dispose of specimens properly – Dispose of used supplies and equipment properly – Sanitize,... Urine • 95% water • 5% waste products • Other dissolved chemicals – – – – – Urea Uric acid Ammonia Calcium Creatinine – – – – – Sodium Chloride Potassium Sulfates Phosphates Hydrogen... disinfect, and/ or sterilize reusable equipment © 2011 The McGraw-Hill Companies, Inc All rights reserved 47 8 Anatomy and Physiology of the Urinary System • Organs – Kidneys – remove excess water and