Professional Nursing I / PN 1
MODULE 3
❖ Kidney Anatomy and physiology
• 2 kidneys function to maintain volume and composition of body fluids by filtering
blood
• Urine is the waste product excreted by the kidneys. Composed of nitrous wastes,
inorganic salts and water.
❖ Ureters
• 2 tubes (one from each kidney) that carry the urine from the kidneys to the
bladder
❖ Bladder
• Smooth muscle sac that is a reservoir for urine
• Composed of 3 layers of muscles known as detrusor muscle
• Urine is under pressure – when volume increases the pressure in the bladder
increases.
• When bladder pressure increases enough to stimulate the stretch receptor – urge to
void occurs
❖ Urethra
• Tube that carries urine from the bladder to the exterior of the body
• Female urethra 1-1/2 to 2-1/2”
• Male urethra 6-8”
❖ Nephron Function
• Functional unit of kidney
• 1 million per kidney
• 1200 mL blood pass through the kidney/min
• Wastes cannot be excreted as solids; must be excreted in solution
• Normal urine production = 1 ml / minute
• Kidneys must produce 30 ml/hr minimum
• Blood filtered through glomerulus
• this filtrate moves into Bowman’s capsules
• proceeds into proximal tubule where water /electrolytes/glucose & protein are
reabsorbed
• Loop of Henley – water and solutes such as sodium & chloride, are reabsorbed
(urine becomes more concentrated)
• Distal convoluted tubules allows for water and NA reabsorption. Controlled
reabsorption (by ADH antidiuretic hormone) regulates fluid & electrolyte
balance…..collecting duct
,❖ Urine Characteristics
• Amount: 1200-1500 ml/day average (50-60 ml/hr)
• Color: pale yellow-amber
• pH ranges from acid 4.6 –to alkaline 8.0; 6.0 average
- Acidic due to foods high in protein, meds, cranberry juice, meat
- Alkaline due to standing around, dairy products, citrus fruits, meds
• Turbidity: clear; translucent if fresh; becomes cloudy if stands
• Specific gravity: Concentration of normal urine 1.010 – 1.025
- Dilute (below 1.010) pale yellow, lighter in color
➢ Diabetes, diuretics, malnutrition
- Concentrated (above 1.020) darker in color……dehydration
• Constituents: Normally composed of urea, creatinine, pigments, Sodium,
Potassium, Calcium
- Urea is formed by the liver as an end product of protein metabolism
• Aromatic: Description of normal smell of urine
• Ammonia?
Concentrated urine due to lack of adequate water OR
Presence of bacteria in urine OR
Standing urine (urea converts to ammonia when exposed to oxygen)
• Foul smelling: Infection
• Eau D’ Asparagus? Asparagus contains a sulfur compound called mercaptan.
(It's also found in rotten eggs, onions, garlic, and in the secretions of skunks.)
When your digestive tract breaks down this substance, by-products are released
that cause the funny scent.
• Sweet? Fruity – keytones = uncontrolled Diabetes
• Musty? Liver Disease
❖ Factors that Affect voiding
• Food/fluid intake + loss
• Developmental factors
- Children urinate more frequently
- May have “accidents” through early childhood years
- Older adults – loss of muscle control
• Retention/incontinence
• Activity/Muscle tone
• Stress interferes with the ability to relax perineal muscles and sphincter
• UTI
• Medications (diuretics)
• Prostate issues
• Kidney stones
• Neurological conditions
• Spinal cord injury
• Job/Lifestyle: opportunity to void regularly or travel
❖ Urinary Specimen Collection
• Routine urinalysis
• Clean-catch/midstream urine
• Sterile specimen (catheterization or from indwelling catheter)
, • 24 hr. urine
- Discard first void
- All urine must be kept on ice or refrigerated
- Foley bags kept on ice and emptied regularly into a container that is kept
on ice
❖ Lab Results for Urinary System
• Urinalysis
- Abnormal: Blood, pus, WBC, RBC, protein, glucose, bacteria, ketones
➢ Ketones are produced when there is excessive fat metabolism;
➢ Occurs when patient has an impaired ability to metabolize
carbohydrates, inadequate carbohydrate intake, inadequate insulin
levels
• Specimen: Serum (blood)
- BUN (blood, urea, nitrogen) end product of protein metabolism… 10-20
mg/dL
➢ Increased BUN (azotemia) signifies impaired kidney function
➢ Affected by diet (high protein intake) and fluids (dehydration)
- Kidney disease causes inadequate excretion of urea
➢ Causes BUN to increase
- Liver disease causes decreased synthesis of urea
➢ Causes BUN to decrease
• Many drugs elevate BUN (antibiotics, lasix)
• Specimen: Serum (blood)
• Serum creatinine - byproduct of muscle metabolism…excreted entirely by
kidneys… Normal = 0.5-1.2 mg/dL
Increased levels signify kidney impairment
• BUN: Creatinine ratio- 20:1… when both rise together indicates kidney failure or
disease
❖ Altered Urinary Function Terms to Know
• Anuria: failure of kidney function; less than 100 mL/24 hours
• Dysuria: difficult or painful urination
• Enuresis: involuntary urination; usually children at night
• Frequency: increased incidence of voiding
• Glycosuria: glucose in the urine
• Hematuria: blood in the urine
• Hesitancy: delay or difficulty to void
• Nocturia: urination at night
• Oliguria: decreased urine production; scant 100-400 mL/24 hours
• Polyuria: excessive urination
• Proteinuria: protein in the urine
• Pyuria: pus in urine; WBC or green with pseudomonas
• Urgency: need to suddenly void
• Retention: unable to urinate; incomplete emptying of the bladder
- distended bladder due to nerve impulses not perceived or muscles unable
to function
- May lead to infection, hydroureter, and hydronephrosis
, - Assessment: Pt voids small amounts often, firm distended bladder
- Interventions: Straight cath or bladder scan to determine how much urine
- Treatment – treat the underlying cause; remove obstruction
• Incontinence:
- inability to hold urine in the bladder; involuntary release; brain is not
receiving impulse or loss of external sphincter control
➢ Leads to impaired skin integrity, infection, rashes, UTI, social
isolation, depression, increased risk for falls & injury
❖ Assessing Urinary Retention
• Feeling of fullness
- Urine not being excreted
- Distended bladder; Discomfort
- Voiding less than 50 mL at a time
- At 1000 mL, bladder tissue damage can result because muscles become
thin, tear and bleeding can result
- Patient can die within 8 hours if ruptured bladder that is not surgically
repaired
• Normal intake/inadequate output
• Bladder Scan
If > 300 ml should catheterize
❖ Incontinence
• Functional: Inability of a usually continent person to reach the toilet in time to
avoid unintentional loss of urine.
- Factors: physical disability, altered mobility, inability to get to the toilet,
wardrobe problems, problems in thinking or communicating that prevent a
person from reaching a toilet, confusion, disorientation, pain, more….
• Overflow: loss of urine in combination with distended bladder
- Factors: fecal impaction, neurological disorders, enlarged prostate
• Stress: Involuntary loss of small amounts of urine with increased intra-abdominal
pressure, in the absence of overactive bladder
- Factors: pregnancy, childbirth, obesity, chronic constipation, straining
during defecation, loss of muscle tone, exercise, laughing, sneezing,
coughing, lifting
• Reflex: due to neurological deficits (neuro signals to/from the brain)
• Urge: Involuntary loss of larger amounts of urine accompanied by a strong urge
to void
• Total: continuous loss of urine due to a fistula
❖ Nursing Interventions Related to Urinary Elimination
• Maintain voiding habits
- Scheduling, positioning, privacy, comfort, allow adequate time to void,
assist with hygiene
• Promote fluid intake
- 2000 mL/day
• Strengthen muscle tone
- Kegels 30-80/day for 6 weeks
• Stimulate urination