• Urinalysis provides important clinical information about kidney function and helps diagnose other diseases, such as diabetes.
• Urine culture determines whether bacteria are present in the urine, as well as their strains and concentrarion.
• Urine culture and sensitivity also identify the antimicrobial therapy best suited for the particular strains identified, taking into consideration the antibiotics that have the best rate of resolution in that particular geographic region.
COMPONENTS NORMAL VALUES
Color Pale to deep amber
Turbidity Clear
Specific Gravity 1.002-1.035
pH 4.5 – 8.0
Glucose Negative
Ketones Negative
Protein Negative
Bilirubin Negative
RBC 0 -3
WBC 0-4
Bacteria None
Casts None
Crystals None
• Several abnormalities such as hematuria and proteinuria, produce no symptoms but may be detected during a routine urinalysis using a dipstick.
• Normally, about 1 million RBCs pass into the urine daily (equivalent to 1-3 RBCs per high- power field).
• Hematuria (more than 3 RBCs per high-power field) can develop from an abnormality anywhere along the genitourinary tract (more common in women than in men).
• Common causes of hematuria include:
- acute infection (cystitis, urethritis, or prostatitis)
- renal caculi
- neoplasm
- systemic disorders (bleeding disorders and malignant lesions)
- medications – warfarin (Coumadin) and heparin (Heparin Sodium)
• Hematuria may be initially detected using a dipstick test, further microscopic evaluation is necessary.
• Proteinuria may be a benign finding, or it may signify serious disease.
• Occasional loss of up to 150 mg/day of protein in the urine, primarily albumin, is considered normal and usually does not require further evaluation.
• A dipstick examination (can detect 30 t0 1000 mg/dL of protein) should be used as a screening test only, because urine concentration, pH, hematuria, and radiocontrast materials all affect the results.
• Dipstick analysis does not detect protein concentrations of less than 30 mg/dL, test cannot be used for early detection of diabetic nephropathy.
• Microalbuminuria (excretion of 20 to 200 mg/dL of protein in the urine) is an early sign of diabetic nehropathy.
• Common benign causes of transient proteinuria are: fever, strenuous exercise, and prolonged standing.
• Causes of persistent proteinuria include:
- glomerular diseases
- collagen diseases
- diabetes mellitus
- preeclampsia
- hypothyroidism
- heart failure
- exposure to heavy metals
- use of medications (NSAIDs and ACE
inhibitors)
• Measures the density of a solution compared to the density of water which is 1.000.
• Specific gravity is altered by the presence of blood, protein, and casts in the urine.
• The normal range of urine specific gravity is 1.010 to 1.025.
• Methods of determining specific
gravity :
- Multiple-test dipstick (most
common method)
- Urinometer (least accurate
method)
- Refractometer (an instrument
which measures differences in
the speed of light passing
through air and the urine sample)
• Urine specific gravity depends largely
on hydration status.
- ↓ fluid intake (specific gravity ↑)
- ↑ fluid intake (specific gravity ↓)
• In patients with kidney disease, urine specific gravity does not vary with fluid intake, and the patient’s urine is said to have a fixed specific gravity.
• Disorders or conditions that cause decreased urine specific gravity:
- diabetes insipidus
- glomerulonephritis
- severe renal damage
• Conditions that can cause increased specific gravity include:
- diabetes mellitus
- nephritis
- fluid deficit
• Is the most accurate measurement of the kidney’s ability to dilute and concentrate urine.
• It measures the number of solute particles in a
kilogram of water.
• Serum and urine osmolality are measured simultaneously to assess the body’s fluid status.
• In healthy adults serum osmolality is 280 to 300 mOsm/kg, and normal urine osmolality is 200 to 800 mOsm/kg.
• For a 24-hour urine sample, the normal value is 300 to 900 mOsm/kg.
• Are used to evaluate the severity of the kidney disease and to assess the status of the patient’s kidney function.
• It also provides information about the effectiveness of the kidney in carrying out its excretory function.
• Renal function test results may be within normal limits until the GFR is reduced to less than 50% of normal.
• Common tests include: renal concentration tests, creatinine clearance, and serum creatinine and blood urea nitrogen levels.
• Patient knowledge
• Psychosocial and emotional factors; fear,
anxiety
• Urologic function; include voiding
habits/pattern
• Fluid intake
• Hygiene
• Presence of pain or discomfort
• Allergies
• Knowledge deficiency
• Pain
• Fear
• Patient goals may include
understanding of procedures, tests,
and expected behaviors; decreased
pain or absence of discomfort; and
decreased apprehension and fear.
• Patient teaching: provide a description of the tests and procedures in language the patient can understand.
• Use appropriate, correct terminology. • Encourage fluid intake unless contraindicated. • Instruct patient in methods to reduce discomfort:
sitz baths, relaxation techniques. • Administer analgesics and antispasmodics as
prescribed. • Assess voiding and provide instruction related to
voiding practices and hygiene. • Provide privacy and respect.
Kidney, Ureter, and Bladder
Studies May be performed to
delineate the size, shape,
and position of the kidneys
and reveal any abnormalities, such as
calculi (stones) in the kidneys
or urinary tract,
hydronephrosis (distention of the pelvis of the kidneys),
cysts, tumors, or kidney
displacement by
abnormalities in surrounding tissues.
A noninvasive procedure
that uses sound waves
passed into the body through a transducer to
detect abnormalities of
internal tissues and organs.
• Structure • Abnormalities such as fluid
accumulation , masses,
congenital malformations,
changes in organ size, or obstruction, can be
identified.
Ultrasonography requires
a full bladder, therefore, fluid intake should be encourage
before the procedure.
• Is a noninvasive method of measuring the volume of urine in the bladder.
• It may be indicated for the following situations:
- urinary frequency - inability to void after the removal of an
indwelling catheter
- measurement of postvoiding residual urine volume
- inability to void postoperatively
- assessment of the need for catheterization during the initial stages of an intermittent catheterization program
Are noninvasive techniques that provide
excellent cross-
sectional views of the
kidney and urinary tract. They are used in
evaluating genitourinary
masses, nephrolithiasis,
chronic renal infections, renal or urinary tract
trauma, metastatic
disease, and soft tissue
abnormalities.
Nuclear scans require injection of a radioisotope into the circulatory system, which is then monitored as it moves throughout the blood vessels of the kidneys. A scintillation camera is placed
posterior to the kidney with the patient in a supine, prone, or seated position. Indicated to evaluate acute and chronic renal failure, renal masses, and blood flow before
and after kidney transplantation.
• Intravenous urography includes various specific test:
- excretory urography
- intravenous pyelogram or intravenous
urogram (shows kidneys, ureter, and
bladder) → radiopaque contrast is
administered intravenously
- infusion drip pyelography requires an
intravenous infusion of a large volume of a
dilute contrast agent to opacify the renal
parenchyma and completely fill the urinary
tract.
• Intravenous urography is conducted as
part of the initial assessment of any
suspected urologic problem (lesions in
the kidneys and ureters).
• It provides a rough estimate of renal
function.
• In retrograde pyelography, ureteral catheters are advanced through the ureters into the renal pelvis by means of cystoscopy. • Contrast agent is then injected. • Usually performed if intavenous urography provides inadequate visualization of the collecting systems. • May also be used before ESWL or in patients with urologic cancer who need follow-up and are allergic to intravenous contrast agents. • Complications: infection, hematuria, and perforation of the ureter. • Used less frequently because of improved techniques in excretory urography.
• Aids in evaluating vesicouretral reflux
(backflow of urine from
the bladder into one or
both ureters) and assess for bladder injury.
• Catheter is inserted into
the bladder, and contrast
agent is instilled to outline the bladder wall.
• Performed in conjunction
with simultaneous pressure recordings inside the
bladder.
• Uses a fluoroscopy machine to visualize the lower urinary tract and examine urine storage in the bladder. • Used as a diagnostic tool to identify vesicoureteral reflux. • Urethral catheter is inserted, and a contrast agent is instilled into the bladder.
• A renal angiogram, or renal arteriogram,
provides an image of the renal arteries.
• The femoral (or axillary) artery is pierced
with a needle , and a catheter is
threaded up through the femoral and
iliac arteries into the aorta or renal artery.
• A contrast agent is injected to opacify
the renal artery supply.
• Renal Angiography is used to:
- evaluate renal blood flow in
suspected renal trauma
- to differentiate renal cysts from
tumors
- to evaluate hypertension
- it is also used preoperatively for
renal transplantation
• It can be performed in one of two ways: (1) by a cystoscope inserted into the urethra, or (2) percutaneously through a small incision.
• Cystoscopic examination is used to visualize the urethra and bladder directly.
• Small ureteral catheters can be passed through the cystoscope, allowing assessment of the ureters and the pelvis of each kidneys.
• It permits the urologist to obtain urine specimen from each kidney to evaluate kidney function.
• Cup forceps can be inserted into the cystoscope for biopsy.
• Calculi may be removed from the urethra, bladder, and ureter using cystoscopy.
• Renal and Ureteral Brush Biopsy
- Brush biopsy techniques provide specific information when abnormal x-ray findings of the ureter or renal pelvis raise questions about whether the defect is a tumor, a stone, a blood clot, or an artifact.
- First, a cystoscopic examination is conducted. Then the suspected lesion is brushed back and forth to obtain cells and surface tissue fragments for histologic analysis.
• Kidney Biopsy
- Used in diagnosing and evaluating the extent of kidney disease.
- Indications for biopsy include: unexplained acute renal failure, persistent proteinuria or hematuria, transplant rejection, and glomerulonephritis.
- A small section of renal cortex is obtained either percutaneously through the skin and into the renal tissue or by open biopsy through a small flank incision.
• Provides an accurate evaluation of
voiding problems.
• Useful in evaluating urinary retention
of unknown cause.
• Effects of medication on bladder
function
• Neuropathic bladder dysfunction.
• Incontinence
• Bladder outlet obstruction
• Recurrent UTIs
• Uroflowmetry (flow rate) is the record of the volume of urine passing through the urethra per time unit (milliliters per second).
• Cystometrogram (CMG) is a graphic recording of the pressures in the bladder.
The major diagnostic portion of urodynamic testing and is divided into 2 portions: filling and emptying of the urinary bladder.
• Urine pressure-flow study presently considered
the standard urodynamic test. Bladder pressure, urine flow, and sphincter electromyography are measured simultaneously. This allows for a detailed picture of the voiding dysfunction.
• Electromyography is used to evaluate neuromuscular function of the lower tract. It is usually performed at the same time as the CMG.
• Video fluorourodynamic study is the simultaneous visualization of the lower urinary tract, allowing for a complete and detailed assessment of the voiding dysfunction.
• Urethral pressure profile measures the amount of urethral pressure along the length of the urethra needed to maintain continence.
• Valsalva’s leak-point pressure test assesses internal
sphincter function. While in a sitting or standing position, the patient is asked to cough or perform Valsalva’s maneuver until urine leakage occurs.