Urinalysis

Subject: Medical and Surgical Nursing I (Theory)

Overview

A urine sample is examined during a urine analysis. Numerous conditions, including kidney disease, diabetes, and urinary tract infections are detected and evaluated using urinalysis. Its two varieties are microscopic and macroscopic urinalysis. Undergoing a macroscopic test are specific gravity (sp gr), pH, ketones, nitrite, leukocyte esterase, protein, and glucose. RBC, WBC, epithelial cell, casts, bacteria, yeast, and crystals are examples of microscopic tests.

A urine sample is examined during a urine analysis. Numerous conditions, including kidney disease, diabetes, and urinary tract infections are detected and evaluated using urinalysis. The physical, chemical, and microscopic analysis of urine is known as urinalysis. Numerous tests are required to find and quantify the many chemicals that travel through urine.

  • Microscopic urinalysis
    Direct visual observation constitutes the first stage of a urinalysis. Fresh urine should be clear and range in color from light to dark yellow or amber. A typical 24-hour urine volume ranges from 750 to 2000 ml. The presence of too much cellular matter or protein in the urine may be the cause of turbidity or cloudiness. Salts may also crystallize or precipitate when left at room temperature or in the refrigerator. After adding a small amount of acid, the specimen became clear, indicating that precipitation of salts is most likely what caused the turbidity. A reddish or reddish-brown (abnormal) color may result from ingesting fresh beets, taking a medication, or having either hemoglobin or myoglobin present. The sample would be cloudy if it was high in red blood cells.
  • pH
    Renal tubules and collecting ducts typically reduce the pH of the glomerular filtrate of blood plasma from 7.4 to around 6 in the final urine. Urinary pH, on the other hand, may range from 4.5 to 8.0 depending on the acid-base condition. The distal convoluted tubule and the collecting duct are where the change to the acid side of pH 7.4 is accomplished.

  • Specific Gravity (sp gr)
    The presence of solutes, which are represented by particles of different sizes, from small ions to bigger proteins, determines the specific gravity of urine. The total amount of dissolved particles, regardless of size, are counted by urine osmolality. Freezing point depression is the measurement technique used most frequently. Based on the size and concentration of the particles in a fluid, a refractometer measures the refraction, or change in direction of a light path. Larger particles like glucose and albumin will significantly alter refraction. The cationic concentration in urine affects the specific gravity measurement made with a urine dipstick most significantly.
  • Protein
    While whole urine is used for dipstick protein screening, semi-quantitative urine protein tests should be run on the supernatant of centrifuged pee because the cells suspended in normal urine can result in an incorrectly high protein estimate. The renal tubule typically only absorbs tiny plasma proteins that have been filtered at the glomerulus. Normal urine does contain a tiny quantity of filtered plasma proteins and the Tamm-Horsfall protein, which is released by the nephron. The average amount of total protein excreted in a single specimen is typically little more than 10 mg/100 ml or 150 mg/24 hours. Proteinuria is defined as more than 150 mg per day. Nephrotic syndrome is characterized by significant proteinuria (3.5 g/24 hours or more).
  • Glucose
    Glucosuria, or an excess of sugar in the urine, is typically a sign of diabetes mellitus.
  • Ketones
    Using dipsticks or test tablets containing sodium nitroprusside, ketones (acetone, acetoacetic acid, and beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other type of calorie restriction (starvation) are easily detected.
  • Nitrite
    A positive nitrite test means that there may be a lot of germs in the urine. E. coli and other gram-negative rods are more likely to result in a positive test.
  • Leukocyte Esterase
    White blood cells, whether whole or lysed, are required for a leukocyte esterase test to be positive. Even if the urine sample contains lysed or damaged WBCs, pyuria can still be identified. A negative leukocyte esterase test indicates that an infection is unlikely, and that microscopic examination and/or urine culture are not required in the absence of additional urinary tract infection evidence to rule out significant bacteriuria.
  • RBC (Red Blood Cells)
    Hematuria, which is the presence of abnormally high levels of red blood cells in the urine, can be brought on by kidney injury, urinary tract stones, renal infarcts, acute tubular necrosis, upper and lower uric urinary tract infections, nephrotoxins, physical strain, and glomerular damage. In addition, red blood cells can contaminate urine from the vagina in women who are menstruation or from injuries caused by bladder catheterization. Although theoretically there shouldn't be any red cells in the urine, even in extremely healthy people, some do. However, the specimen is likely abnormal if one or more red cells can be found in every high power field and contamination can be excluded.
  • White Blood Cell
    Pyuria is the term used to describe the presence of abnormally high levels of leukocytes in the urine, which may be caused by an infection of the upper or lower urinary tract or by acute glomerulonephritis. The WBCs are typically granulocytes. Urine can get contaminated by white cells from the vagina, particularly when there are vaginal and cervical infections present, or from the external urethral meatus in both men and women. In non-contaminated urine, the specimen is likely abnormal if it contains two or more leukocytes in each high power field. Leukocytes have granular cytoplasm and lobed nuclei.
  • Epithelial cell
    Renal tubular epithelial cells typically have a larger nucleus than granulocytes and slough into the urine in small quantities. The number of sloughed is elevated in conditions like nephrotic syndrome and tubular degeneration, though.
  • Casts
    Only the distal convoluted tubule (DCT) or the collecting duct can produce urinary casts (distal nephron). Cast formation does not occur in a loop of Henle or the proximal convoluted tubule (PCT). The main component of hyaline casts is a mucoprotein called Tamm-Horsfall protein, which is released by tubule cells.
  • Bacteria
    Due to the profusion of bacteria in the vagina or external urethral meatus and their capacity to grow quickly in urine left at room temperature, bacteria are frequently found in urine samples. Microbial organisms should therefore be interpreted in light of clinical symptoms if they are present in even the most meticulously collected urine samples.
    When a urinary tract infection is suspected, culture is necessary for the diagnosis of bacteriuria. To determine whether there are appreciable quantities of bacteria present, a colony count can also be performed. More than 100,000 of one organism per milliliter typically indicates severe bacteriuria. Numerous organisms demonstrate contamination. However, it should be understood that any organism found in specimens from suprapubic or catheterized taps is significant.
  • Yeast
    Yeast cells might be unclean or signify a real yeast infection. Although it can be challenging to tell them apart from red blood cells and amorphous crystals, they can be identified by their propensity to bud. They are typically Candida, which can colonize the vagina, urethra, and bladder.
  • Crystals
    Even in healthy people, calcium oxalate, triple phosphate crystals, and amorphous phosphates are common crystals to see. Cystine crystals in the urine of newborns with congenital cystinuria or severe liver disease, tyrosine crystals with congenital tyrosinase or marked liver impairment, and leucine crystals in patients with severe liver disease or maple syrup urine disease are just a few examples of very uncommon crystals.

References

  • A Textbook of Adult Health Nursing (2nd ed.). Mandal, G. (August 2013). Dilllibazar kathmandu: Makalu publication house. Retrieved August 2013
  • austincc.edu/mlt/ua/Urinalysis05-24-06.doc
  • blog.divmelar.biz/2016/05/page/2/
  • documentslide.com › Documents
  • library.med.utah.edu/WebPath/TUTORIAL/URINE/URINE.html
  • naturalhealthtechniques.com › Health Basics › Basics of Health
  • scribd.com/document/33650229/Clinical-Pharmacology-and-Forensic-Toxicology
  • spot.pcc.edu/anatomy/PPT/Lab_32.ppt
  • quizlet.com/69294870/ap-urinary-system-flash-cards/
  • vaskulitis.org/dirkbiddle/vasc-art-e/1-8-12.html
Things to remember
  • A urine sample is examined during a urine analysis.
  • The physical, chemical, and microscopic analysis of urine is known as urinalysis.
  • 7.4 to about 6 pH range in the finished urine
  • Proteinuria is defined as more than 150 mg per day.
  • More than 100,000 of one organism per milliliter typically indicates severe bacteriuria.
Questions and Answers

A urine sample is examined during a urine analysis. Numerous conditions, including kidney disease, diabetes, and urinary tract infections are detected and evaluated using urinalysis. The physical, chemical, and microscopic analysis of urine is known as urinalysis. Numerous tests are required to find and quantify the different compounds that pass through urine.

Direct visual observation comes first in a urinalysis. Normal, fresh urine is colorless and clear, ranging from light to dark yellow or amber. 750–2000 ml/24 hours of urine is considered normal. If there is too much protein or cellular material in the urine, turbidity or cloudiness may result. Salts may also crystallize or precipitate when left at room temperature or in the refrigerator. The specimen clearing up after a small amount of acid was added suggests that precipitation of salts is most likely the root cause of tubidity. The presence of either myoglobin or hemoglobin can cause an abnormal red or red-brown color, as can the consumption of fresh beets, certain medications, or food dyes. If there were a lot of red blood cells in the sample, it would be cloudy.

pH:

Renal tubules and collecting ducts typically reduce the pH of the glomerular filtrate of blood plasma from 7.4 to around 6 in the final urine. Urinary pH, on the other hand, may range from 4.5 to 8.0 depending on the acid-base condition. The distal convoluted tubule and the collecting duct are where the change to the acid side of pH 7.4 is accomplished.

Specific Gravity (sp gr):

The presence of solutes, which are represented by particles of different sizes, from small ions to bigger proteins, determines the specific gravity of urine. The total amount of dissolved particles, regardless of size, are counted by urine osmolality. Freezing point depression is the measurement technique used most frequently. Refraction is the measurement of the deviation of a light path (depending on particle concentration and size in a fluid) by a refractometer. Larger particles like glucose and albumin will significantly alter refraction. The cationic concentration in urine affects the specific gravity measurement made with a urine dipstick most significantly.

Protein:

While whole urine is used for dipstick protein screening, semi-quantitative urine protein tests should be run on the supernatant of centrifuged pee because the cells suspended in normal urine can result in an incorrectly high protein estimate. The renal tubule typically only absorbs tiny plasma proteins that have been filtered at the glomerulus. Normal urine does contain a tiny quantity of filtered plasma proteins and the Tamm-Horsfall protein, which is released by the nephron. The average amount of total protein excreted in a single specimen is typically no more than 10 mg/100 ml or 150 mg/24 hours. Proteinuria is defined as more than 150 mg per day. Nephrotic syndrome is characterized by severe proteinuria (3.5 g/24 hours or more).

Glucose:

Excess sugar in the urine, or glucoseuria, is typically a sign of diabetes mellitus.

Ketones:

Using dipsticks or test tablets containing sodium nitroprusside, ketones (acetone, aceotacetic acid, beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other type of calorie deprivation (starvation) are easily detected.

Nitrite:

A positive nitrite test means that there may be a lot of bacteria in the urine. E. coli and other gram-negative rods are more likely to result in a positive test.

Leukocyte Esterase:

White blood cells, whether whole or lysed, are required for a leukocyte esterase test to be positive. Even if the urine sample contains lysed or damaged WBCs, pyuria can still be identified. A negative leukocyte esterase test indicates that an infection is unlikely, and that microscopic examination and/or urine culture are not required in the absence of additional urinary tract infection evidence to rule out significant bacteriuria.

RBC (Red Blood Cells):

Hematuria, which is characterized by abnormally high levels of red blood cells in the urine, can be brought on by glomerular damage, tumors that obliterate the urinary tract anywhere along its length, kidney injury, urinary tract stones, renal infarcts, acute tubular necrosis, upper and lower urinary tract infections, nephrotoxins, and physical strain. In addition, red blood cells can contaminate urine from the vagina in women who are menstruation or from injuries brought on by bladder catheterization. Although theoretically there shouldn't be any red cells in the urine, even in extremely healthy people, some do. However, the specimen is likely abnormal if one or more red cells can be found in every high power field and contamination can be excluded.

White Blood Cell:

Pyuria, which can result from an infection of the upper or lower urinary tract or from an acute glomerulonephritis, is the word used to describe the presence of abnormally high quantities of leukocytes in the urine. Typically, the WBCs are granulocytes. White cells from the vagina, particularly when vaginal and cervical infections are present, or from the external urethral meatus in both men and women can contaminate urine. If the sample in non-contaminated urine has two or more leukocytes in each high power field, it is probably abnormal. Granular cytoplasm and lobed nuclei are features of leukocytes.

Epithelial cell:

Renal tubular epithelial cells typically have a bigger nucleus than granulocytes and slough into the urine in tiny quantities. The number of sloughed is elevated in disorders such nephrotic syndrome and tubular degeneration, though.

Casts:

Only the distal convoluted tubule (DCT) or the collecting duct can produce urinary casts (distal nephron). Cast formation does not occur in the loop of Henle or the proximal convoluted tubule (PCT). The main component of hyaline casts is a mucoprotein called Tamm-Horsfall protein, which is secreted by tubule cells.

Bacteria:

Due to the profusion of bacteria in the vagina or external urethral meatus and their capacity to grow quickly in urine left at room temperature, bacteria are frequently found in urine samples. Microbial organisms should therefore be interpreted in light of clinical symptoms if they are present in even the most meticulously collected urine samples.

When a urinary tract infection is suspected, culture is necessary for the diagnosis of bacteriuria. To determine whether there are appreciable quantities of bacteria present, a colony count can also be performed. More than 100,000 of one organism per milliliter typically indicates severe bacteriuria. Numerous organisms demonstrate contamination. However, it should be understood that the presence of any organism in suprapubic or catheterized tapspecimens is significant.

Yeast:

Yeast cells might be unclean or signify a real yeast infection. Although it can be challenging to tell them apart from red blood cells and amorphous crystals, they can be identified by their propensity to bud. They are typically Candida, which can colonize the vagina, urethra, and bladder.

Crystals:

Even in healthy patients, calcium oxalate, triple phosphate crystals, and amorphous phosphates are common crystals to see. Very rarely occurring crystals include leucine crystals in patients with severe liver disease or maple syrup urine disease, tyrosine crystals with congenital tyrosinosis or marked liver impairment, and cystine crystals in the urine of newborns with congenital cystinuria or severe liver disease.

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