Assessment of the
Renal/Urinary System
Lectures
Petrenko N., MD, PhD
Elsevier items and derived items © 2006 by Elsevier Inc.
Anatomy and Physiology Review
• Kidneys
• Ureters
• Urinary bladder
• Urethra
Location and External Anatomy of Kidneys
• Located retroperitoneally
• Lateral to T12–L3 vertebrae
• Average kidney
– 11-13 cm tall, 5-7 cm wide, 3 cm thick
– Bean-shaped, brownish-red structures,
– right lower than left
• Renal capsule surrounds the kidney
• Hilus
– On concave surface
– Vessels and nerves enter and exit
Urinary anatomy and function
• http://www.youtube.com/watch?v=qxb2_d9il
Ew&NR=1&feature=fvwp
A.
Regions
1. Renal parenchyma
a. Cortex
• Glomeruli, proximal and distal convoluted
tubules, cortical collecting ducts, and
adjacent peritubular capillaries.
b. Medulla
• Pyramids (8- 18 pyramids/ kidney)
2.
2. Renal Pelvis
- it is the concave portion of the kidney through which the
renal artery enters and the renal vein exits
- composed of afferent arteriole and efferent arteriole
B. Nephrons
- Functional units of kidney:
a) Glomerulus
b) Bowman’s capsule
c) Proximal tubule
d) Distal tubule
e) Loop of Henle
f) Collecting ducts
Urinary anatomy and function
• http://www.youtube.com/watch?v=aQZaNXNr
oVY&feature=related
C.
D.
Calyx
•
Minor calyx- 4-13 minor calices
•
Major calyx- 2-3 major calices
Glomerulus
3 filtering layers:
1. Capillary endothelium
2. Basement membrane
3. Epithelium
General
Specific Function:
Function:
•
Urine formation
•
Excretion of waste products
•
Regulation of electrolyte excretion
•
Regulation of acid excretion
• Regulatory
•
Regulation of water excretion
•
Auto regulation of blood pressure
• Secretory
•
Regulation of red blood cell production
•
Renal clearance
•
Vitamin D synthesis
•
Secretions of prostaglandins
•
Urine storage
•
Bladder emptying
• Excretory
Ureters
• Fibromuscular tube that connect each kidney
to the bladder
• Narrow, muscular tubes, 24-30 cm long
–
3 narrowed areas:
• Ureteropelvic junction
• Ureteral segment
• Ureterovesical junction
- prevents reflux of urine
Urinary Bladder
•
Muscular, hollow- sac located just behind
the pubic bone
•
300- 600 ml of urine
4 layers of the urinary bladder:
1. Adventitia- outermost layer
2. Detrusor- beneath the adventitia
3. Lamina Propria- interface between
detrusor and urethelium.
1. Urothelium- innermost layer
Urethra
• Small tube leading
from the floor of
urinary bladder
• 1.5 inch in length in
females & 8 inch in
male
• Function:
passageway for
urine
& semen
Renal/Urinary System Changes Associated
with Aging
• Reduced renal blood flow causing kidney loss of cortical tissue by
80 years of age
• Thickened glomerular and tubular basement membranes, reducing
filtrating ability
• Decreased tubule length
• Decreased glomerular filtration rate
• Nocturnal polyuria and risk for dehydration
• Tubular changes are shown by a decreased ability to concentrate
urine, resulting in nocturia (increased need to urinate at night).
• The excretion and regulation of sodium, acids, and bicarbonate
remain effective but are less efficient because homeostasis is
slower.
•
Hormonal changes include a decrease in renin secretion,
aldosterone levels, and activation of vitamin D.
Renal/Urinary System Changes Associated
with Aging
• Urinary Changes
• Changes in the elasticity of the detrusor muscle may
cause decreased bladder capacity and a decreased
ability to retain urine.
• The sensation of the urge to void may cause immediate
bladder emptying because the urinary sphincters lose
muscle tone and often become weaker with age.
• In women, weakening muscles shorten the urethra,
which contributes to incontinence.
• In men, an enlarged prostate gland causes difficulty in
starting the urine stream and may cause urinary
retention.
Assessment Techniques
• Family history and genetic risk assessment
• Demographic data and personal history
• Diet history
• Socioeconomic status
• Current health problems
COMMONLY USED RENAL AND URINARY
TERMS
• anuria Total urine output of less than 100 mL In 24
hours
• azotemia Increased blood urea nitrogen and serum
creatinine levels suggestive of renal impairment but
without outward symptoms of renal failure
• dysuria Discomfort or pain associated with micturition
• frequency Feeling the need to void often, usually
voiding small amounts of urine each time; may void
every hour or even more frequently than hourly
• hesitancy Difficulty in initiating the flow of urine, even
when the bladder has sufficient urine to initiate a void
and the sensation of the need to void is present
COMMONLY USED RENAL AND URINARY
TERMS
• micturition The act of voiding
• nocturia Awakening prematurely from sleep because of the need
to empty the bladde
• roliguria Decreased urine output; total urine output between 100
and 400 mL in 24 hours
• polyuria Increased urine output; total urine output usually
greater than 2000 mL in 24 hours
• uremia Full-blown signs and symptoms of renal failure;
sometimes referred to as the uremic syndrome, especially if the
cause of the renal failure is unknown
• urgency A sudden onset of the feeling of the need to void
immediately; may result in incontinence if the client is unable to
locate or get to toileting facilities quickly
Assessment Techniques
Current health problems
• The client is asked about
• any changes in the appearance (color, odor, clarity) of the urine,
• pattern of urination,
• ability to initiate or control voiding,
• and other unusual symptoms.
• urine color (reddish, dark brown or black, greenish, or
otherwise different from the usual yellowish, straw color)
• a change in odor quality, or a decrease in urine clarity
• changes in urination patterns, such as nocturia, frequency, or an
increase or decrease in the amount of urine.
• The normal urine output for adults is 1 mL/kg/hr, or
approximately 1500 to 2000 mL/day.
Assessment Techniques
Current health problems
• The client is asked about
• difficulty initiating urine flow
• a burning sensation or other discomfort is present on urination
• the force of the urine stream is decreased (in men)
• any loss of urinary continence. Situations that increase intraabdominal pressure (e.g., coughing and sneezing) may result in the
involuntary passage of urine.
• a persistent dribbling of urine.
Assessment Techniques
Current health problems
• The client is asked about
• pain in the flank, in the lower abdomen or pelvic region, or in the perineal are.
(the onset, intensity, and duration of the pain, its location, and its association
with any activity or event).
• Pain associated with renal or ureteral irritation is often severe and spasmodic.
• Pain that radiates into the perineal area, groin, scrotum, or labia is described as
renal colic. Renal colic pain is usually associated with distention or spasm of
the ureter, such as in an obstruction or the passing of a stone. Renal colic pain
may be intermittent or continuous and may even be systemic with pallor,
diaphoresis, and hypotension. These general symptoms occur because of the
location of the nerve tracts associated with the kidneys and ureters.
• Because the kidneys are close to the GI organs and the nerve pathways are
similar, GI symptoms may be part of the client's presenting history. These
renointestinal reflexes often complicate the detailed description of the renal
problem.
• Uremia results from the accumulation of nitrogenous waste products in the
blood, a result of renal failure. Symptoms include anorexia, nausea and
vomiting, muscle cramps, pruritus (itching), fatigue, and lethargy.
Physical Assessment
• assessment of general appearance,
• a general review of body systems,
• specific structure and functions of the
renal/urinary systems
 Inspection
 Auscultation
 Palpation
 Percussion
 Assessment of the urethra
Physical Assessment
assessment of general appearance
• the general appearance of the client and checks for a
yellowish skin color and the presence of any rashes, bruising,
or other discoloration.
• edema, which with renal disorders may be detected in the
pedal (foot), pretibial (shin), sacral tissues, and around the
eyes.
• The lungs are auscultated to determine whether fluid is
present.
• Weight and blood pressure measurements are obtained for
comparison purposes.
• general level of consciousness and level of alertness, noting
deficits in concentration, thought processes, or memory.
• Family members may report subtle changes. Such cognitive
changes may be the result of an insufficient clearance of
waste products when renal disease is present.
Physical Assessment
Inspection
•
The nurse inspects the abdomen and the flank
regions with the client in both the supine and the
sitting position.
• The client is observed for asymmetry (e.g., swelling)
or discoloration (e.g., bruising or redness) in the
flank region, especially in the area of the
costovertebral angle (CVA). The CVA is located
between the lower portion of the twelfth rib and the
vertebral column
Physical Assessment
Auscultation
The nurse listens for a bruit over each renal
artery on the midclavicular line.
A bruit is an audible swishing sound produced
when the volume of blood or the diameter of
the blood vessel changes. A bruit is usually
associated with blood flow through a narrowed
vessel, as in renal artery stenosis
Physical Assessment
Palpation
•
Renal palpation identifies masses and areas of tenderness in or
around the kidney. The abdomen is lightly palpated in all quadrants.
The nurse asks about areas of tenderness or discomfort and
examines nontender areas first. The outline of the bladder may be
seen as high as the umbilicus in clients with severe bladder
distention. Special training and practice under the guidance of a
qualified practitioner are necessary; therefore appropriate education
is essential before attempting the procedure. If tumor or aneurysm
is suspected, palpation may harm the client.
•
Because the kidneys are deep, posterior structures, palpation is
easier in thin clients who have little abdominal musculature. For
palpation of the right kidney, the client assumes a supine position
while the nurse places one hand under the right flank and the other
hand over the abdomen below the lower right part of the rib cage.
The lower hand raises the flank, and the upper hand depresses the
anterior abdomen as the client takes a deep breath. The left kidney
is deeper and rarely palpable. A transplanted kidney is readily
palpable in either the lower right or left abdominal quadrant. The
kidney should feel smooth, firm, and nontender
Physical Assessment
Palpation
• http://www.youtube.com/watch?v=jXmwrvi07
ME
• http://www.youtube.com/watch?v=5BzbMc5w
CZo&feature=related
Physical Assessment Percussion
–A distended bladder sounds dull when percussed. After gently
palpating to determine the general outline of the distended
bladder, the nurse begins percussion on the skin of the lower
abdomen and continues in the direction of the umbilicus until
dull sounds are no longer produced.
–If the client identifies flank pain or tenderness, the nontender
flank is percussed first. The client assumes a sitting, side-lying,
or supine position, and the nurse forms one hand into a
clenched fist. The heel of the other hand and the little finger
form a flat area with which a firm thump to the CVA area can
be quickly administered. Costovertebral tenderness is highly
suggestive of kidney infection or inflammation. Clients with
inflammation or infection in the kidney or adjacent structures
may describe their pain as severe or as a constant, dull ache.
Physical Assessment
Assessment of the urethra
Using a good light source and wearing gloves,
the nurse inspects the urethra by examining the
meatus and surrounding tissues.
Any unusual discharge such as blood, mucus,
and purulent drainage is noted.
The skin and mucous membranes of
surrounding tissues are inspected, and the
presence of lesions, rashes, or other
abnormalities of the penis or scrotum or of the
labia or vaginal orifice is documented.
Urethral irritation is suspected when the client
reports discomfort with urination.
LAB TESTS Blood Tests
• Serum creatinine is a measurement of the end product of
muscle and protein metabolism. Creatinine is filtered by the
kidneys and excreted in the urine. Because muscle mass and
metabolism are usually constant, the serum creatinine level is
an excellent indicator of kidney function
• ↑ indicates renal impairment.
• ↓ may be caused by a decreased muscle mass
• Males; 0.6-1.2 mg/dL (80-115 mmol/L)
• Females: 0.5-1.1 mg/dL (44-97 mmol/L)
• Older Adults: may be decreased
LAB TESTS Blood Tests
• Blood urea nitrogen (BUN) measures the renal
excretion of urea nitrogen, a by-product of protein metabolism in
the liver. Urea nitrogen is produced primarily from food sources of
protein, which undergo metabolism by the liver. The kidneys filter
urea nitrogen from the blood and excrete the nitrogenous waste in
urine. BUN levels indicate the extent of renal clearance of this
nitrogenous waste product.
• ↑ may indicate hepatic or renal disease, dehydration or decreased
renal perfusion, a high-protein diet, infection, stress, steroid use, Gl
bleeding, or other situations in which there is blood in body tissues.
• ↓ may indicate malnutrition, fluid volume excess, or severe hepatic
damage
• 10-20 mg/dL (2.1-7.1 mmol/L)
• Older Adult: 60-90 yr; 8-23 mg/dL (2.9-8.2 mmol/L);
•
over 90 yr: 10-31 mg/dL (3.6-11.1 mmol/L)
LAB TESTS Blood Tests
• Ratio of blood urea nitrogen to serum
creatinine determines whether factors such as dehydration or lack
of renal perfusion are causing the elevated BUN level. When a blood
volume deficit (dehydration) or hypoperfusion exists, the BUN level rises
more rapidly than the serum creatinine level. As a result, the ratio of BUN
to creatinine is increased.
• When both the BUN and serum creatinine levels increase at the same rate,
the BUN/creatinine ratio remains normal. However, the elevated serum
creatinine and BUN levels suggest renal dysfunction that is not related to
acute volume depletion or hypoperfusion.
• Mass ratio: 12:1 to 20:1;
• mole ratio: 48.5:1 to 80.8:1
• ↑ may indicate fluid volume deficit, obstructive uropathy, catabolic state,
or a high-protein diet.
• ↓ may indicate fluid volume excess or acute renal tubular acidosis.
• No change in the ratio with increases in both the BUN and creatinine levels
indicates renal impairment.
LAB TESTS Urinalysis
•
•
•
•
•
•
• Color - Pale yellow
Dark amber indicates concentrated urine.
Very pale yellow indicates dilute urine.
Dark red or brown indicates blood in the urine;
brown also may indicate increased urinary bilirubin level;
red may also indicate the presence of myoglobin.
Other color changes may result from diet or medications.
• Odor - specific aromatic odor, similar to ammonia
• Foul smell indicates possible infection, dehydration, or ingestion of certain
foods or drugs.
• turbidity Clear
• Cloudy urine indicates infection or sediment or high levels of urinary
protein
LAB TESTS Urinalysis
• Specific gravity measures the concentration or density of urine compared to
water
• Usually 1,010-1.025; (possible range 1.000-1.030;)
• after 12-hr fluid restriction > 1.025
• Older adult; Decreased because of decreased concentrating ability
• ↑ with dehydration, decreased kidney perfusion, or the presence of
antidiuretic hormone (ADH). In each of these situations the expected
kidney response is to reabsorb water and decrease urine output. As a result,
the urine produced is more concentrated.
• ↓ in specific gravity occurs with increased fluid intake, diuretic
administration, and diabetes insidious. In each of these situations, the
normal kidney response is to excrete more water; thus urine output is
increased.
• ↓ in kidney disease (chronic renal insufficiency, diabetes insipidus,
malignant hypertension, diuretic administration, and lithium toxicity), the
specific gravity decreases because there is less solute, and it does not vary
with changes in plasma osmolality
LAB TESTS Urinalysis
• pH Average: 6; possible range: 4.6-8
• Changes are caused by diet, the administration of medications,
infection, freshness of the specimen, acid-base imbalance, and
altered renal function.
• Glucose is filtered at the glomerulus and is reabsorbed in the
proximal tubule of the nephron. When the blood glucose level rises
above 220 mg/dL, the renal threshold for reabsorption is usually
exceeded, and glucose is excreted in the urine
• <0.5 g/day (<2.78 mmol/L)
• Presence reflects hyperglycemia or a decrease in the renal
threshold for glucose.
• Ketone bodies absent
• Presence reflects incomplete metabolism of fatty acids, as in
diabetic ketoacidosis, prolonged fasting, anorexia nervosa
LAB TESTS Urinalysis
• Protein is not normally present 8-18 mg/dL (10-140 mg/L)
• ↑ may indicate stress, infection, recent strenuous exercise, or glomerular
disorders
• The glomerular membrane is semipermeable to small molecules; protein
molecules are too large to pass through this semipermeable membrane. When
permeability of the glomerular membrane is increased, protein molecules pass
through and are excreted in the urine. Increased glomerular membrane
permeability may be caused by infection, inflammation, or immunologic
problems.
• Certain systemic processes result in the production of abnormal proteins, such
as globulin. These proteins are not detected with routine urinalysis procedures;
urine protein electrophoresis or other tests are necessary to detect these unusual
proteins.
• Microalbuminuria is the presence of albumin in the urine that is not
measurable by a urine dipstick or conventional urinalysis procedures.
Specialized immunoassay tests can quickly analyze a freshly voided urine
specimen for microscopic levels of albumin.
• The normal microalbumin levels in a freshly voided random specimen should
range between 2.0 to 20 mg/mmol for men and 2.8 to 28 mg/mmol for women.
• Higher levels indicate microalbuminuria and could mean the presence of very
early kidney disease, especially in clients with diabetes mellitus.
• For 24-hour urine specimens, levels of 30 to 300 mg/24 hr, or 20 to 200 xg/min,
indicate microalbuminuria.
LAB TESTS Urinalysis
•
•
•
•
•
Bilirubin (urobilinogen) None
Presence suggests hepatic or biliary disease or obstruction.
Cells Types of cells abnormally present in the urine may include:
 tubular cells (from the tubule of the nephron),
 epithelial cells (from the lining of the urinary tract),
 red blood cells (RBCs), 0-2 per high-power field
↑ are normal with indwelling or intermittent catheterization or menses but may
reflect tumor, stones, trauma, glomerular disorders, cystitis, or bleeding
disorders.
 white blood cells (WBCs) Males: 0-3 per high-power field, Females: 0-5 per
high-power field
↑ amounts may indicate an infectious or inflammatory process anywhere in the
renal/urinary tract, renal transplant rejection, fever, or exercise.
Casts are described by the type of element in the structure (e.g., RBC cast, WBC
cast, tubular epithelial cast) or the stage of degeneration. The degeneration of casts
refers to the stage of breakdown of the internal element. Casts are described as
"granular" (coarse or fine) and "waxy.“
↑ indicate the presence of bacteria or protein, which is seen in severe renal
disease and could also indicate urinary calculi
LAB TESTS Urinalysis
• crystals in the urine come from various salts. These particles may be
a result of diet, drags, or disease. The salts may be composed of
calcium, oxalate, urea, phosphate, magnesium, or other substances.
Certain drugs, such as the sulfates, can also produce crystals. None
• Presence of normal or abnormal crystals may indicate that the
specimen has been allowed to stand
• Bacteria in a urine sample multiply quickly, so the specimen must be
analyzed promptly.
• Normally urine is sterile or <1000 colonies/mL, but it can be
contaminated easily by perineal bacteria or airborne pathogens
during collection
• Increased amounts indicate the need for urine culture to
determine the presence of urinary tract infection.
• Presence of Trichomonas vaginalis indicates infection, usually
of the urethra, prostate, or vagina
Other Urine Tests
• Urine for culture and sensitivity - determination of
the number and types of pathogens. When bacterial
colonies are present, they are placed in a medium
containing different antibiotic drugs to determine
which drugs are effective in killing or stopping the
growth of the bacteria (sensitivity)
• Composite urine collections quantitative and
qualitative analysis of one or more substances
(urinary creatinine or urea nitrogen, sodium, chloride,
calcium, catecholamines, or other components)
Other Urine Tests
•
•
•
•
•
•
•
•
•
•
•
Creatinine clearance is a calculation of glomerular filtration rate. It is the best indication of overall
kidney function. The amount of creatinine cleared from the blood (e.g., filtered into the urine) is
measured in the total volume of urine excreted in a defined period.
A urine specimen for a creatinine clearance test is usually collected for 24 hours, but it can be
collected for shorter periods (e.g., 8 or 12 hours). The calculation requires a comparison with the
blood creatinine level, and therefore a blood specimen for creatinine must also be collected.
The laboratory or the physician calculates the creatinine clearance. Because the client's age, gender,
height, weight, diet, and activity level influence the expected amount of creatinine to be excreted,
these variables are considered in the interpretation of creatinine clearance test results.
The following formula is used to calculate creatinine clearance:
Creatinine clearance = U x V/P x T
where U is creatinine in urine (mg/dL), V is volume of urine (mL/24 hr), P is creatinine in plasma or
blood (mg/dL), and T is time (minutes).
The rate of creatinine clearance is expressed as milliliters per minute per 1.73 m2 of body surface
area. The range for normal creatinine clearance is 90 to 139 mL/min for adult males and 80 to 125
mL/min for females.
Creatinine clearance measurements are necessary to determine the client's current kidney function.
Decreases in the creatinine clearance rate may require modification of drug dosing and often signifies
the need for further investigation of the cause of kidney deterioration
Urine electrolytes
Osmolarity, blood/plasma osmolarity, urine osmolarity
Osmolality is a measure of the concentration of particles in solution, in this case the concentration of
solutes in urine. These solutes include electrolytes and solutes such as glucose, urea, and creatinine
Radiological examination
• Kidney, ureter, and bladder x-rays – to screen for the
presence of two kidneys, to measure the kidneys' size,
shape, relaionship to other parts of the urinary tract, to
detect gross obstruction
• Computed tomography - measuring the size of the
kidneys, evaluating contour to assess for masses or
obstruction
• Intravenous urography
(Excretory urography) - to measure the
kidneys' size, to detect obstruction,
to assess parenchymal mass
• Bowel preparation, allergy information
Intravenous urography
• Intravenous
urography
demonstrating
crossed renal ectopy.
The "left" kidney is
located below the
right kidney.
Cystography and Cystourethrography
• Instilling dye into bladder via urethral catheter
• Voiding cystourethrogram
• Monitoring for infection
• Encouraging fluid intake
• Monitoring for changes in urine output and for
development of infection from catheter
placement
Renal Arteriography (Angiography)
• Possible bowel preparation
• Light meal evening before, then nothing by
mouth
• Injection of radiopaque dye into renal arteries
• Assessment for bleeding
• Monitoring of vital signs
• Absolute bedrest for 4 to 6 hours
• Serum creatinine measured for
several days to assess effects of test
Renal Biopsy
• Percutaneous kidney biopsy
• Clotting studies
• Preprocedure care
• Follow-up care
– Assessment for bleeding for 24 hours
– Strict bedrest
– Monitoring for hematuria
– Comfort measures
Renography
• Small amount of radioactive
material, a radionuclide, used
• Procedure via intravenous
infection
• Follow-up care:
– Small amount of radioactive
material may be excreted.
– Maintain standard
precautions.
– Client should avoid
changing posture rapidly
and avoid falling.
Ultrasonography
• Bedside sonography/bladder scanners checking postvoid residual volumes and
determine the need for intermittent
catheterization based on the amount of urine in
the bladder.
Cystoscopy and cystourethroscopy
Procedure is invasive.
– Consent is required.
– Postprocedure care
includes monitoring
for airway patency,
vital signs, and urine
output.
– Monitor for bleeding
and infection.
– Encourage client to
take oral fluids.
Cystoscopy
• http://www.youtube.com/watch?v=iLeqYPJy
G_A
Retrograde Procedures
• Retrograde procedures go against the normal
flow of urine.
• Procedure identifies obstruction or structural
abnormalities with the instillation of dye into
lower urinary tract.
• Monitor for infection.
• Follow-up care is the same as for a cystoscopic
examination.
Urodynamic Studies
• Studies that examine the process of voiding
include:
– Cystometrography
– Urethral pressure profile
– Electromyography
– Urine stream test