Urinalysis

Urinary System

PURPOSE General evaluation of health –

urine is filtered blood. Diagnosis of disease or disorders

of the kidneys or urinary tract. Diagnosis of other systemic

diseases that affect kidney function.

Monitoring of patients with Diabetes.

Screening for drug use/abuse.

Collection of Urine Specimens The first voided morning urine (the

most common for specific testing). Random urine (for emergency). Clean-catch, midstream urine (for

urine culture).

Attention Need to be examined within 1 hour

for most accurate results – especially with more specific advanced testing.

Types Of Urinalysis Physical examination Chemical examination Microscopic

examination

Physical Examination

Appearance• Colour• Clarity• Odour

Urine volume

Appearance : Colour

Color and Clarity Color : normally pale to dark yellow (Urochrome) Abnormal color : some drugs cause color changes 1. Red urine: causes: Hematuria - Blood Hemoglobinuria - Hemoglobin Myoglobinuria - Myoglobin 2. Yellow-brown or green-brown urine: Bilirubin Cause : Obstructive Jaundice

Urine Colour

Microscopic Hematuria • Urinary tract source

Urethra or bladder Prostate Ureter or Kidney

• Non-Urinary tract source Vagina Anus or Rectum

Pseudohematuria (non-hematuria related red urine) • Myoglobinuria • Hemoglobinuria • Phenolphthalein :Laxatives • Foods (Beets, Blackberries,

Rhubarb)

Urine Color is influenced by colored metabolic wastes (called urochromes), presence of cells or proteins, fluid volume (hydration status), and diet and medications.  -Normal carnivores typically have light colored urine, while herbivores have darker amber colored urine due to the presence of food pigments. Urine color is most frequently assessed by measuring out a standardized volume and visually examining it.  Descriptions should accurately convey the shade and intensity of the urine color

Red Urine

May Indicate Serious Problems Acute Cystitis (23%) Bacterial or

Fungal infections of the Bladder. Bladder Cancer (17%) Benign Prostatic Hyperplasia (12%) Nephrolithiasis Kidney Stones (10%) Benign Hematuria (10%) Prostatitis (9%) Renal cancer (6%) Pyelonephritis (4%)- UTInfections

that ascend up into Kidney Prostate Cancer (3%) Urethral Stricture (2%) – often UTI

related.

- Often indicates that blood is in the urine – but WHY ?

Appearance : Clarity Clarity: normally clear, transparent. - When translucent/cloudy :Causes: 1. Crystals or Non-pathologic salts such as phosphates, carbonates in alkaline urine, also uric

acid in fairly acidic urine.2. Various cellular elements: leukocytes, RBCs, epithelial cells

Urine Volume The average adult : 1000ml to 2000ml/24h Increased Volume – “Polyuria” ---more than

2000ml of urine in 24 hours. Causes:

1. Physiological states: water intake, some drugs –diuretics (alcohol/caffeine), intravenous solutions.

2. Pathologic states:

Diabetes Mellitus- Blood sugar related, either Type I or Type II.

Diabetes Insipidus – Usually Hormonal, example: Lack of production of ADH.

Urine Odour Urine Odour is affected by many

things including sex hormones (males generally have a stronger urine odor) and species (such as cats).  There are few diagnostically significant odors, but an ammonia-like odour indicates the presence of bacteria and a sweet or fruity odor is associated with ketones (diabetes mellitus)-Ketosis – Metabolizing fats in the absence of carbohydrates– Starvation diet.

Chemical Examination

Urine pH Protein Glucose Ketones Blood Bilirubin Urobilinogen Nitrites

Specific gravity (SG)

Reflect the density of the urine Range of 1.001 to 1.040 Increased SG: Causes: DEHYDRATION, Fever, Vomiting, Diarrhea, Diabetes

mellitus, Congestive Heart Failure

Kidney failure (urine volume↓ and SG↑) Decreased SG: diabetes insipidus – Hormonal

problems or nephritis

(urine volume↑ and SG ↓)

Urine pH Normal pH The average is about 6 Range from 5~9 (depends on diet) Higher pH---Alkaline urine 1.Drugs: containing sodium bicarbonate 2.Blood Alkalosis (metabolic or respiratory

causes) Lower pH---Acidic urine 1.Drugs: containing ammonium chloride 2. Blood Acidosis (metabolic or respiratory)

Protein in Urine Reference value

Should be Negative/Trace Urine proteins often come in when plasma proteins enter into filtrate when kidneys

are damaged. Glomerularnephritis often leads to PROTEINUREA Foamy Pee !

Proteinuria Causes – Just a Starting Point Glomerular Causes (Increased glomerulus

permeability) Primary Glomerulonephropathy

• Minimal Change Disease • IgA Nephropathy • Idiopathic membranous

Glomerulonephritis • Focal segmental Glomerulonephritis • Membranoproliferative

Glomerulonephritis • Heavy metals

Tubular Causes (Decreased tubular reabsorption)

Hypertensive nephrosclerosis Uric Acid nephropathy Acute hypersensitivity Interstitial Nephritis Fanconi Syndrome Heavy metals Sickle Cell Anemia NSAIDs Antibiotics

Secondary Glomerulonephropathy • Diabetes Mellitus (

Diabetic Nephropathy) • Systemic Lupus Erythematosus (

Lupus Nephritis) • Amyloidosis • Preeclampsia (

Pregnancy Induced Hypertension) • Infection

HIV Infection Hepatitis B Hepatitis C Poststreptococcal

Glomerulonephritis Syphilis Malaria Endocarditis

• Lung Cancer • Gastrointestinal Cancer • Lymphoma • Renal transplant rejection

Glucose in Urine Reference value

Should be NEGATIVE “Glycosuria”--- qualitative test is positive

1.Hyperglycemia: usually diabetes mellitus (Type I or Type II)

2.Without hyperglycemia: renal tubular dysfunction, such as pyelonephritis (infection of renal pelvis)

Ketones in Urine Including three ketone bodies:

acetoacetic acid 20%

acetone 2%

β-hydroxybutyric acid 78% The products of fat metabolism - Reference value:

qualitative method: negative Classified as “Ketonuria”--- often related to starvation

diets – when carbohydrates are no longer readily available.

Nitrites In Urine Urinary tract bacterial infections are often

associated with the presence of NITRITES in the urine.

These bacteria put out nitrites as a metabolic waste product.

Urobilinogen - When the liver is stressed, often extra Bilirubin is

put out or ends up having to go somewhere else in the body.

- Bacteria in the gut often metabolize the Bilirubin into Urobilinogen which ends up getting into the blood and then into the urine.

MICROSCOPIC Analysis – Secondary Testing

Microscopic Analysis In this test, urine is spun in a special

machine (centrifuge) so the solid materials (sediment) settle at the bottom. The sediment is spread on a slide and looked at under a microscope.

Healthy: No bacteria, yeast cells, squamous cells, or parasites are present in the urine. Very few or no white or red blood cells or casts are seen. A few crystals may normally be seen.

How to Use the TEST STRIPS - Each indicator is an enzymatic test, so

timing is CRUCIAL !

If you under- or over- time your tests, your readings will be under- or over- exaggerated!

Dip Time Read Record After dipping in the urine, hold the strip

horizontally so that reactants from one pad don’t run into and taint the reactions going on in another pad.