Urinalysis Lab Session 1 - AJMAN UNIVERSITY PDF

9/1/2024 Urinalysis Lab Session 1 Amine BAHI, PhD...

9/1/2024 Urinalysis Lab Session 1 Amine BAHI, PhD September 3, 2024 1 Main Objectives Evaluate general health status through urinalysis, understanding its importance as a routine diagnostic tool Monitor diabetic patients for glycosuria, recognizing the implications of glucose in urine Utilize urinalysis for screening purposes, including detecting drugs of abuse, HCG, and doping substance Understand the correct procedures for urine specimen collection and the different examination procedures Understand the concept of urine specific gravity and how it’s calculated BIC111 – Lab Session 1 2 2 1  9/1/2024 What is Urinalysis? Urine consists of water (95%), urea, inorganic salts, ammonia, and pigmented products of blood breakdown such as urochrome (typical yellowish color) Urinalysis − a clinical laboratory test that evaluates the content, appearance, and concentration of urine This process helps in diagnosing various diseases and conditions such as urinary tract infections (UTI), kidney disorders, and metabolic issues It is also commonly used to monitor patient health, screen for drugs, and assess hydration levels BIC111 – Lab Session 1 3 3 Why Urinalysis? Monitoring of diabetic patients with diabetes Signs & symptoms of glycosuria typically reflect signs of excess blood glucose, including increased urination & frequency (i.e., polyuria), excessive thirst (i.e., polydipsia) Urinalysis is routinely used to screen for: Drugs of abuse (amphetamine, cocaine…) Pregnancy hormone (HCG: Human chorionic gonadotropin) Doping substances (anabolic steroids, EPO, adrenaline …) BIC111 – Lab Session 1 4 4 2  9/1/2024 Why Urinalysis? Physical Examination Biochemical Examination Microscopic Examination Volume Proteins Viruses Color Sugars Cells Odor Ketone bodies Crystals pH Bile salts/pigments Bacteria Specific gravity … Blood … Parasites … BIC111 – Lab Session 1 5 5 Collection of Urine Specimens Proper collection of a urine sample is crucial because it directly impacts the accuracy and reliability of the test results. Reasons why proper collection is important: Prevents Contamination: Proper techniques reduce the risk of contaminating the sample with bacteria, cells… Ensures Accurate Diagnosis: Proper collection helps in providing reliable test results Avoids Misinterpretation: Incorrect collection can alter the chemical composition or physical properties of the urine, potentially leading to misinterpretation of the results by healthcare providers leading to the need for repeat testing BIC111 – Lab Session 1 6 6 3  9/1/2024 Collection of Urine Specimens Appropriate containers include plastic disposable cups with a capacity of 30-50 ml Containers should be clean, dry, & wide mouthed Urine sample should be processed/analyzed within 2 h of collection otherwise refrigerate (Why???) BIC111 – Lab Session 1 7 7 Collection of Urine Specimens Urine sampling methods include: Random First morning Catheterization of the bladder Suprapubic bladder aspiration… BIC111 – Lab Session 1 8 8 4  9/1/2024 Random Specimen Random urine collection is a convenient and commonly used method for general health screenings and routine analysis. It is suitable for most diagnostic purposes The patient can collect the urine sample at any time of the day, without any special preparation Advantages Limitations Accessibility: Can be done in various settings, Variability: The concentration and composition of including clinics, hospitals, or even at home urine can vary throughout the day Convenience: Easy to perform and does not Contamination Risk: There is a higher risk of require any prior scheduling. Commonly used for contamination compared to more controlled routine urinalysis including drug screening, methods like catheterization or first-morning pregnancy tests… specimen collection BIC111 – Lab Session 1 9 9 First Morning Specimen The first morning urine specimen is collected immediately after waking up and is considered the most concentrated sample Reflects the kidney’s ability to concentrate urine during overnight dehydration Urine is generally more concentrated (hypertonic). Also called an 8-hour specimen Often preferred for tests that require higher levels of certain substances or more consistent results (pregnancy tests, protein analysis, & microscopic examination…) Urine would contain higher levels of cellular elements & proteins The specimen of choice for biochemical & microscopic analysis BIC111 – Lab Session 1 10 10 5  9/1/2024 First Morning Specimen Patient Preparation: The patient should be instructed to collect the urine sample immediately after waking up, before consuming any food or beverages Bladder Emptying: The bladder should have been emptied before going to sleep to ensure that the collected specimen reflects overnight urine concentration Collection: The patient should collect the urine in a clean, dry, wide-mouthed container Storage and Transport: The sample should be transported to the laboratory as soon as possible. Otherwise, the sample should be refrigerated to preserve its integrity BIC111 – Lab Session 1 11 11 Bladder Catheterization Specimen Bladder catheterization is a method used to collect urine directly from the bladder when a clean-catch sample is difficult or impossible to obtain In patients who are unconscious, critically ill, or unable to urinate on their own Sterility: Provides a completely sterile urine sample, which is crucial for accurate bacterial culture and sensitivity test Accuracy: Ensures that the urine sample is not contaminated by the external genitalia in patients with open wounds or infections Diagnostic Utility: Especially useful for diagnosing UTIs, bladder/kidney conditions… BIC111 – Lab Session 1 12 12 6  9/1/2024 Bladder Catheterization Specimen BIC111 – Lab Session 1 13 13 Suprapubic Bladder Aspiration Specimen Suprapubic bladder aspiration is a highly sterile method of urine collection used when a completely uncontaminated urine sample is required, particularly in infants, young children, or adults where other methods (like catheterization) may not be suitable It is often employed when diagnosing UTIs or performing bacterial cultures in situations where avoiding contamination is crucial While it is invasive, its use is critical in situations where diagnostic precision is vital Proper technique and careful patient management are essential to minimize risks and ensure the procedure's success. BIC111 – Lab Session 1 14 14 7  9/1/2024 Suprapubic Bladder Aspiration Specimen Sterility: Provides the most sterile urine sample possible, as it bypasses the urethra, thereby avoiding contamination from external bacteria or cells Accuracy: Ideal for accurate diagnosis of UTIs, particularly in young children Specific Utility: Often used in pediatric patients or in cases where catheterization or clean-catch methods are not feasible or have failed Invasiveness: This is an invasive procedure, and though generally safe, it can cause discomfort and carries a risk of complications such as infection or injury to surrounding tissues BIC111 – Lab Session 1 15 15 Suprapubic Bladder Aspiration Specimen BIC111 – Lab Session 1 16 16 8  9/1/2024 Why Urinalysis? Physical Examination Biochemical Examination Microscopic Examination Volume Proteins Viruses Color Sugars Cells Odor Ketone bodies Crystals pH Bile salts/pigments Bacteria Specific gravity … Blood … Parasites … BIC111 – Lab Session 1 17 17 Physical Examination − Volume Normal − 1.2 to 2 Liters/day Polyuria − excess urination (output exceeding 3 Liters/day) Oliguria − below normal urination (less than 0.4 Liters/day) Anuria − absence of urination (less than 0.1 Liters/day) Hematuria − blood in urine Nocturia − urination at night Dysuria − painful urination BIC111 – Lab Session 1 18 18 9  9/1/2024 Physical Examination − Color Normal urine is yellow/amber in color Abnormal colors include bright yellow (Pus), yellow/orange (Bilirubin: bile pigment), pink/red (hemoglobin, RBC…) Can be brown, black/grey, red, blue & green (medications, dietary sources or diseases) BIC111 – Lab Session 1 19 19 Urine Color Chart BIC111 – Lab Session 1 20 20 10  9/1/2024 Drugs & Urine Color BIC111 – Lab Session 1 21 21 Physical Examination − Odor & Appearance Normal urine has an aromatic odor. However, abnormal odors might include: Fruity/sweet odor − presence of ketones Pungent/fecal smell − presence of bacteria Maple syrup smell − metabolic disorders Normal urine is clear/transparent. However, cloudy urine can be observed following precipitation or crystals formation of: phosphate in alkaline urine urates in acidic urine BIC111 – Lab Session 1 22 22 11  9/1/2024 Physical Examination − Appearance Turbid − caused by the presence of WBCs, epithelial cells, bacteria, yeast… Reddish − caused by the presence of RBCs Milky − caused by the presence of Fat BIC111 – Lab Session 1 23 23 Physical Examination − pH The pH of urine is a measure of its acidity or alkalinity, with a range typically between 4.5 and 8 (pH 6 is considered normal) The pH of urine reflects the kidney’s role in maintaining acid-base balance in the body The kidneys play a critical role in maintaining the body's acid-base balance by excreting hydrogen ions & reabsorbing bicarbonate from urine BIC111 – Lab Session 1 24 24 12  9/1/2024 Physical Examination − Specific Gravity SG − a measure that compares the density of urine to the density of pure water It reflects the kidney's ability to concentrate or dilute the urine and provides important information about the body's hydration status and kidney function Normal Range typically varies from 1.005 - 1.030 Because the density of pure water is 1 g/mL; the numerical value of density and specific gravity of a substance are equal 𝒈 𝑫𝒆𝒏𝒔𝒊𝒕𝒚 𝒐𝒇 𝒖𝒓𝒊𝒏𝒆 ( ) 𝑺𝒑𝒆𝒄𝒊𝒄𝒊𝒇𝒄 𝒈𝒓𝒂𝒗𝒊𝒕𝒚 = 𝒎𝒍 𝒈 𝑫𝒆𝒏𝒔𝒊𝒕𝒚 𝒐𝒇 𝒘𝒂𝒕𝒆𝒓 ( ) 𝒎𝒍 BIC111 – Lab Session 1 25 25 Physical Examination − Specific Gravity Measures concentrating & diluting power of kidney Increases with low fluid intake but decreases with high fluid intake INCREASE OF SPECIFIC GRAVITY DECREASE OF SPECIFIC GRAVITY Diabetes mellitus (glucosuria; Diabetes insipidus (1.002-1.003) 1.045-1.050) over 10-15 L/day with severe cases Nephrotic syndrome (proteinuria ) Excessive water drinking Fever, Excessive sweating, Chronic renal failure - No ability to Dehydration water reabsorption Heart failure - decreased blood flow Pyelonephritis - inflammation of to the kidneys the kidney  frequent urination BIC111 – Lab Session 1 26 26 13  9/1/2024 Physical Examination − Specific Gravity Because urine is water that contains dissolved chemicals, SG of urine is a measure of the density of dissolved chemicals in the specimen (usually at 20C) SG is influenced not only by the number of particles present but also by their size Urinometer: Also called Hydrometer Device used to measure the specific gravity of urine by floating in a sample of urine The reading on the urinometer scale corresponds to the specific gravity The urinometer will float higher in urine than in water because the urine is denser Higher the specific gravity of a specimen, the higher the urinometer will float BIC111 – Lab Session 1 27 27 Physical Examination − Specific Gravity BIC111 – Lab Session 1 28 28 14  9/1/2024 Specific Gravity & Temperature The density of urine increases at low temperature BUT Decreases at high temperature This causes false reading of SG To correct the specific gravity reading, place the thermometer in the urine & note the exact temperature For every 3C above 20C, add 0.001 to the reading For every 3C below 20C, subtract 0.001 from the reading BIC111 – Lab Session 1 29 29 Specific Gravity & Temperature If the SG of the urine is 1.022 at 26C, and the urinometer has been calibrated at 20C, the correct reading is: 26C-20C = 6C  63 = 2  2x0.001 = 0.002 Specific gravity of the urine is measure at 1.022 Corrected specific gravity is: 1.022 + 0.002 = 1.024 BIC111 – Lab Session 1 30 30 15  9/1/2024 Online Resources https://www.youtube.com/watch?v=JravabiVnj8 https://www.youtube.com/watch?v=JravabiVnj8 https://www.youtube.com/watch?v=9hr1zUgEc4c BIC111 – Lab Session 1 31 31 Click to edit Master title style 9/1/2024 9/1/2024 32 16