Any strips showing evidence of deterioration, contamination, or improper storage should be discarded. As with reagent strips, tablet or chemical tests performed in the urinalysis laboratory must have quality control materials run to ensure the integrity of the reagents and the technique used in testing. The range provided on the strips is from pH 5.0 to pH 9.0 in 0.5- or 1.0-pH increments, depending on the manufacturer. [CDATA[ */ (Patients should not be allowed to submit urine specimens in their own "clean" jars.) Compare and contrast the mechanisms for and the clinical significance of the following types of proteinurias: Discuss the clinical features of the nephrotic syndrome and Fanconis syndrome, including the specific renal dysfunctions involved. The strip must be properly oriented to the chart before results are determined. Commercial or laboratory-prepared materials can serve as acceptable negative controls. Because pH values greater than 8.0 and less than 4.5 are physiologically impossible, they require investigation when obtained. As with reagent strips, tablet or chemical tests performed in the urinalysis laboratory must have quality control materials run to ensure the integrity of the reagents and the technique used in testing. urinary tract infection (UTI) Riley RS, McPherson RA. Depending on the test, results are reported (1) in concentration (milligrams per deciliter); (2) as small, moderate, or large; (3) using the plus system (1+, 2+, 3+, 4+); or (4) as positive, negative, or normal. Reagent strips are available with a single test pad (e.g., Albustix, a single-protein test pad) or with a variety of test pad combinations. Despite being a physical characteristic of urine, specific gravity is often determined during the chemical examination using commercial reagent strips. In this lecture material the routine urine test, physical, chemical and microscopic examination of urine are briefly discussed and it is a preparation which is intended to solve the critical shortage of reference materials on the subject for students and health professionals. Individuals with a history of stone formation can monitor their urine pH and use this information to modify their diets if necessary. In contrast, all reactions on Chemstrip brand strips are stabilized and can be read at 2minutes. follows rigorous standards of quality and accountability. Polyelectrolyte: see Appendix B, Table B.1 Table 6.3 hematuria; heme moiety For detailed information about how to prepare for the test, how the test will feel, risks with the test, and normal and abnormal values, please see the test your provider ordered: Normal value ranges may vary slightly among different laboratories. A urinalysis involves checking the appearance, concentration and content of urine. The presence of interferences must be known to enable alternative testing when possible or to appropriately modify the results to be reported. Urinalysis: A Comprehensive Review | AAFP Some instruments, however, are unable to identify and compensate for urine that is highly pigmented owing to medications. leukocyturia if ( 'undefined' !== typeof windowOpen ) { Medications used to induce: ammonium chloride, ascorbic acid, methionine, mandelic acid Most pH meters perform this temperature compensation automatically. Urine Specimens | Labcorp In the latter situation, efforts should be made to ensure adequate hydration of the patient to prevent in vivo precipitation of normal urine solutes (e.g., ammonium biurate crystals), which can cause renal tubular damage. Appropriate Manual Reagent Strip Testing Technique Linking to and Using Content from MedlinePlus, U.S. Department of Health and Human Services. 9th ed. 12. ), renal tubular acidosis Because the kidneys constantly maintain the acidbase balance of the body, ingestion of acids or alkali or any condition that produces acids or alkali directly affects the urine pH. A urine test is any medical test performed on a urine specimen. Specimen collection and handling guide - UCHealth Reagent strip test 4. For most patients with proteinuria (prerenal and renal), the protein present at an increased concentration is albumin, although to varying degrees. pH; hydrogen ion concentration Note that color changes appearing only along the edge of a reaction pad or after 2minutes are diagnostically insignificant and should be disregarded. Some labs use different measurements or test different samples. Linking to and Using Content from MedlinePlus, U.S. Department of Health and Human Services. Various indicator papers with different pH ranges and sensitivities are commercially available. Philadelphia, PA: Elsevier; 2020:chap 106. Some manufacturers also include a pad to account for urine color when automated reagent strip readers (i.e., reflectance photometers) are used. This difference causes a change in the potential difference between the indicator and the reference electrodes. Quality control testing of reagent strips not only ensures that the reagent strips are functioning properly, but also confirms the acceptable performance and technique of the laboratorian using them. Methods available for measuring specific gravity differ in their ability to detect and measure solutes. Urine chemistry is a group of one or more tests done to check the chemical content of a urine sample. The renal system, the pulmonary system, and blood buffers provide the means for maintaining homeostasis at a pH compatible with life. Multistix: 1.0001.030 Henry's Clinical Diagnosis and Management by Laboratory Methods. Commercial reagent strips are routinely used for chemical analysis of urine. A pH meter consists of a silversilver chloride indicator electrode with a pH-sensitive glass membrane connected by a salt bridge to a reference electrode (usually a calomel electrode, HgHg2Cl2). Manufacturers do not use the same reporting terminology. This voltage difference is registered by a voltmeter and is converted to a pH reading. Please discuss with your doctor any questions or concerns you may have. The relation between disease and urine was recognized by physicians since the earliest civilization BC. The specific gravity and the pH are exceptions; these results are estimated in their respective units. Remove excess urine by drawing edge of strip against rim of container or by blotting strip edge on absorbent paper. Editorial team. Before the development of the first dry chemical dipstick test for glucose in the 1950s, all chemical tests on urine were performed individually in test tubes. These combinations vary from 2 to 10 testpads per reagent strip and enable health-care providers to selectively screen urine specimens for only those constituents that interest them (e.g., Chemstrip 2 LN and Multistix 2 have only two pads: leukocyte esterase and nitrite tests). Respiratory acidosis (e.g., emphysema, chronic lung disease)Urinary system disorders: UTI with acid-producing bacteria (Escherichia coli), chronic renal failure, uremia Timing intervals can differ among reagent strips from the same manufacturer and among different manufacturers of the same test. 18. 6.1). A pH meter consists of a silversilver chloride indicator electrode with a pH-sensitive glass membrane connected by a salt bridge to a reference electrode (usually a calomel electrode, HgHg2Cl2). Reagent strips should be stored in their original containers at temperatures below 30C (86F); they are stable until the expiration date indicated on the label. The end result is that the proteins in normal urine consist of about one-third albumin and two-thirds globulins. A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). Indicators: see Appendix B, Table B.1 windowOpen = window.open( jQuery( this ).attr( 'href' ), 'wpcomfacebook', 'menubar=1,resizable=1,width=600,height=400' ); Quality control testing of reagent strips not only ensures that the reagent strips are functioning properly, but also confirms the acceptable performance and technique of the laboratorian using them. Ascorbic acid Four commonly used brands of commercial reagent strips are Multistix (Siemens Healthcare Diagnostics Inc., Deerfield, IL), Chemstrips (Roche Diagnostics, Indianapolis, IN), and Aution Sticks (Arkray Inc., Kyoto, Japan). See Chapter 5 and Table 5.6 for a detailed discussion and comparison of the specific gravity methods: refractometry and reagent strip method. Care and Storage IndOxidizeddyeyellow+H+ionsHIndReduceddyegreen to blue Equation 6.1. } chapter 47 Flashcards | Quizlet pH,88 Philadelphia, PA: Elsevier Saunders; 2016:chap 114. Preanalytical Variables. Because the kidneys constantly maintain the acidbase balance of the body, ingestion of acids or alkali or any condition that produces acids or alkali directly affects the urine pH. Performing urine testing: Clinical skills notes - Osmosis var sharing_js_options = {"lang":"en","counts":"1"}; }); /* ]]> */ The average individual excretes slightly acidic urine of pH 5.0 to 6.0 because endogenous acid production predominates. This observation is known as the, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), on Routine Urinalysisthe Chemical Examination, Reflex Testing and Result Correlation,116. Basic examination of urine. A urinalysis may be done: As part of a routine medical exam to screen for early signs of disease. }); Diet: high protein, cranberry ingestion, Metabolic acidosis (e.g., ketoacidosis, starvation, severe diarrhea, uremia, poisonsethylene glycol, methanol), Respiratory acidosis (e.g., emphysema, chronic lung disease)Urinary system disorders: UTI with acid-producing bacteria (Escherichia coli), chronic renal failure, uremia, Medications used to induce: ammonium chloride, ascorbic acid, methionine, mandelic acid, Diet: vegetarian, citrus fruits, low carbohydrate, Metabolic alkalosis (e.g., vomiting, gastric lavage), Respiratory alkalosis (e.g., hyperventilation), Urinary system disorders: UTI with urease-producing bacteria (Proteus sp., Pseudomonas sp. Normal daily metabolism generates endogenous acids and bases; in response, the kidneys selectively excrete acid or alkali. Indication or Cause In addition, lyophilized chemistry controls or laboratory-made control materials can be used. 1.000 Similarly, positive controls can be purchased commercially or prepared by the laboratory. Keep in mind that only ionic solutes are involved in the renal concentrating and secreting ability of the kidneys and therefore this test has diagnostic value (see Chapter 4). Because of similar color changes by several of the test pads, improper orientation of the strip to the color chart is a potential source of error. Editorial team. Log In or, manufacturer, qualitative results for each reaction are determined. var WPGroHo = {"my_hash":""}; Goldman-Cecil Medicine. For example, a protein concentration of 1g/dL would be inappropriate as a control material because it far exceeds the desired critical detection level of 10 to 15mg/dL. The specimen can be tested in the original collection container or after an aliquot is poured into a labeled centrifuge tube. Basic examination of urine. Urobilinogen To ensure tablet integrity, an appropriate quality control program must be employed. First morning specimen or 8-hour specimen Goldman-Cecil Medicine. The advantage of automated instruments in reading reagent strips is their consistency in timing and color interpretation regardless of room lighting or testing personnel. See, and should be disregarded. A urinalysis test is performed by collecting a urine sample from the patient in a specimen cup. ADH, Antidiuretic hormone, also known as arginine vasopressin (AVP). Urinary system disorders: UTI with urease-producing bacteria (Proteus sp., Pseudomonas sp. The chemical principles used on reagent strips are basically the same, with some manufacturers differing only in the determination of urobilinogen. Your health care provider will tell you what type of urine sample is needed. The laboratorian should know the sensitivity, specificity, and potential interferences for each test. Common interferences encountered in the chemical examination of urine and the effects these interferences have on urinalysis results are discussed for each reagent strip test in this chapter. Intralaboratory duplicate testing can also be used to evaluate the technical competency of laboratorians. A urinalysis is a test of your urine. The three most common reasons for a urine pH greater than 8.0 are (1) a urine specimen that was improperly preserved and stored, resulting in the proliferation of urease-producing bacteria and resultant increased pH; (2) an adulterated specimen (i.e., an alkaline agent was added to the urine after collection); and (3) the patient was given a highly alkaline substance (e.g., medication, therapeutic agent) that was subsequently excreted by the kidneys. all of the above The accepted abbreviation for a urine culture is: U/C In an O&P test, stool is examined for: parasites and their eggs Most pH meters perform this temperature compensation automatically. Improperly stored urine specimen If the urine specimen has been refrigerated, it should be allowed to warm up to room temperature before testing with reagent strips to avoid erroneous results. Urine chemistry is a group of one or more tests done to check the chemical content of a urine sample. Both of these actions can produce erroneous test results. Principle The reagent strip specific gravity test does not measure the total solute content but only those solutes that are ionic. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Some labs use different measurements or test different samples. Compare and contrast the sensitivity, specificity, and potential interferences of each commercial reagent strip and tablet test. However, protein excretion is not an exclusive feature of renal disorders, and other conditions can also present with proteinuria. Correlation of urine pH with a patients condition aids in the diagnosis of disease (e.g., production of an alkaline urine despite a metabolic acidosis is characteristic of renal tubular acidosis). 4. ketonuria However, protein excretion is not an exclusive feature of renal disorders, and other conditions can also present with proteinuria. False-positive results of immunoassays . Postrenal proteinuria The indicator combinations produce color changes from yellow or orange (pH 5.0) to green (pH 7.0) to blue (pH 9.0). Reagent strips have significantly (1) reduced the time required for testing, (2) reduced costs (e.g., reagents, personnel), (3) enhanced test sensitivity and specificity, and (4) decreased the amount of urine required for testing. Accurate pH measurements require that the pH meter be calibrated using at least two different standards in the pH range of the test solution and that adjustment for the temperature of the test solution be made manually or automatically. 10. Dip reagent strip briefly into urine to wet all reaction pads and start timing device. It is a very common test that can be performed in many health care settings, including doctors' offices, urgent care facilities, laboratories, hospitals, and even at home. These combinations vary from 2 to 10 testpads per reagent strip and enable health-care providers to selectively screen urine specimens for only those constituents that interest them (e.g., Chemstrip 2 LN and Multistix 2 have only two pads: leukocyte esterase and nitrite tests). }); Interlaboratory duplicate testing checks the entire urinalysis procedure and detects innocuous changes when manual urinalyses are performed, such as variations in the speed of centrifugation and in centrifuge brake usage. If you have signs of diabetes or kidney disease, or to monitor you if you are being treated for these conditions. Normally, the urine pH varies from 4.5 to 8.0. In: Bennett JE, Dolin R, Blaser MJ, eds. Chemical and tablet tests are generally performed (1) to confirm results already obtained by reagent strip testing, (2) as an alternative method for highly pigmented urine, (3) because they are more sensitive for the substance of interest than the reagent strip test (e.g., Ictotest tablets), or (4) because the specificity of the test differs from that of the reagent strip test (e.g., Clinitest, SSA protein test). Outline When control materials are tested, acceptable test performance is defined by each laboratory. Commercial tablet tests (e.g., Ictotest, Clinitest, Acetest [all from Siemens Healthcare Diagnostics Inc.]) must be handled and stored according to the inserts provided by the manufacturers. Oct 18, 2022 | Posted by admin in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Routine Urinalysisthe Chemical Examination Double-pH indicator system. Some instruments, however, are unable to identify and compensate for urine that is highly pigmented owing to medications. windowOpen = window.open( jQuery( this ).attr( 'href' ), 'wpcomtwitter', 'menubar=1,resizable=1,width=600,height=350' ); Commercial reagent strips, regardless of the manufacturer, are based on a double indicator system that produces varying color changes with pH (Equation 6.1). Tubular proteinuria The tests detect and/or measure several substances in the urine, such as byproducts of normal and abnormal metabolism, cells, cellular fragments, and bacteria. In: Goldman L, Schafer AI, eds. Physiologically impossible; indicates Because reducing agents such as ascorbic acid have the potential to adversely affect several reagent strip test results, it is important that these and other potential interferences are detected or eliminated. Chemical reactions take place after the strip is wetted with urine. As protons are released, the pH decreases and produces a color change of the bromthymol blue indicator from blue-green to yellow-green. For example, a protein concentration of 1g/dL would be inappropriate as a control material because it far exceeds the desired critical detection level of 10 to 15mg/dL. The urinalysis offered by labo- ratories depends on the type of dipstick that is used. Urine chemistry is a group of one or more tests done to check the chemical content of a urine sample. Although reagent strips are easy to use, proper technique is imperative to ensure accurate results. At the appropriate read time, results are determined by comparing the color of each reaction pad with the appropriate analyte on the color chart. Tablet and Chemical Tests 17. jQuery(document).ready(function() { A special strip (dipstick) is used to test for substances in the urine sample. Dilute urine; associated with increased water intake or water diuresis (e.g., diuretics, inadequate secretion/action of ADH) No interferences known; unaffected by protein concentration bacteriuria Chemstrip: 5.09.0, in 1.0-pH increments These products are susceptible to deterioration from exposure to light, heat, and moisture. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Multistix: 5.08.5, in 0.5-pH increments The indicator papers do not add impurities to the urine. Differentiate between hematuria and hemoglobinuria. St Louis, MO: Elsevier; 2017:chap 28. Related window.WPCOM_sharing_counts = {"https:\/\/basicmedicalkey.com\/routine-urinalysis-the-chemical-examination\/":543384}; ), renal tubular acidosis, Medications used to induce: sodium bicarbonate, potassium citrate, acetazolamide, Presence of an iatrogenic alkaline substance (intravenous medication or agent), Contamination with an alkaline chemical (preservative). It's used to detect and manage a wide range of disorders, such as urinary tract infections, kidney disease and diabetes. Multistix: pH 6.5; add 0.005 what is the primary goal in collecting, storing, and preserving urine specimens? The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Falsely low: Copyright 1997-2023, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited without authorization. Various pH meters are available; the manufacturers operating instructions supplied with the instrument must be followed to ensure proper use of the pH meter and valid results. 1.0251.035 (1.040maximum) Normal proteins: Some commercial controls for reagent strips can also be used to check the integrity of Clinitest, Ictotest, and Acetest tablets. The specimen can be tested in the original collection container or after an aliquot is poured into a labeled centrifuge tube. A pH meter is calibrated with the use of two or three commercially available standard buffer solutions. 16. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. However, erroneous results can occur from pH changes caused by (1) improper storage of the specimen with bacterial proliferation (a falsely increased pH); (2) contamination of the specimen container before collection (a falsely increased or decreased pH depending on the agent); or (3) improper reagent strip technique, causing the acid buffer from the protein test pad to contaminate the pH test area (a falsely decreased pH). If the urine specimen has been refrigerated, it should be allowed to warm up to room temperature before testing with reagent strips to avoid erroneous results. proteinuria High-molecular-weight proteins (>90,000) are unable to penetrate a healthy glomerular filtration barrier. The indicator combinations produce color changes from yellow or orange (pH 5.0) to green (pH 7.0) to blue (pH 9.0). Manufacturers do not use the same reporting terminology. Therefore it is important that health-care providers are informed of the test method usedits principle, sensitivity, specificity, and limitations. Most commercial reagent strips are available with single or multiple test pads on a reagent strip, which allows flexibility in test selection and cost containment. This can lead to false-positive reagent strip test results because the true color reaction is masked by the pigment present. albuminuria ascorbic acid (also called vitamin C) Reagent strips enable rapid screening of urine specimens for pH, protein, glucose, ketones, blood, bilirubin, urobilinogen, nitrite, and leukocyte esterase. Abnormal results may mean you have an illness, such as: Your provider can discuss the results with you. Specificity In the latter situation, efforts should be made to ensure adequate hydration of the patient to prevent in vivo precipitation of normal urine solutes (e.g., ammonium biurate crystals), which can cause renal tubular damage.