Chapter 16 The - PowerPoint Presentation

Slide1

Chapter

16

The

Genitourinary System

The

kidney is essential in maintaining water, salt, and electrolyte balance and is an endocrine gland that secretes at least three hormones. The kidney helps control blood pressure and is especially susceptible to damage if blood pressure is too high or too low.

Physiologic

Concepts

Renal

Blood Flow

The

kidneys receive approximately 1 L of blood per

minute,one

-fifth of the cardiac output. This high rate of blood flow is for allowing the kidney to adjust the blood composition continually. By adjusting the blood composition, the kidney is able to maintain blood volume; ensure sodium, chloride, potassium, calcium, phosphate, and pH balance; and eliminate products of metabolism such as urea and

creatinine

.

Slide2

Glomerular

Filtration

The process of filtration across the

glomerulus

is similar to that which occurs across all capillaries but the

glomerular

capillaries have increased permeability to small solutes and water. Also, unlike other capillaries, the forces favoring filtration of plasma across the

glomerular

capillary into Bowman's space are greater than the forces favoring

reabsorption

of fluid back into the capillary. Therefore, net filtration of fluid into Bowman's space occurs. This fluid then diffuses into Bowman's capsule and begins its journey through the rest of the

nephron

.

Slide3

Renal

Reabsorption

Reabsorption

is the second process by which the kidney determines the concentration of a substance filtered from the plasma.

Reabsorption

refers to the active (requiring energy and always being mediated by a carrier) or the passive (no energy required) movement of a substance filtered at the

glomerulus

back into the

peritubular

capillaries.

Reabsorption

may be total (e.g., glucose) or partial (e.g., sodium, urea, chloride, and water).

Renal Endocrine Function

1-The

kidney functions as an endocrine organ, not only with the production and release of

renin

but also with the production and release of two other hormones: 1,25-dihydroxyvitamin D

3

, important for bone mineralization; and erythropoietin, required for red blood cell production.

Slide4

2- 1,25-Dihydroxyvitamin D

3

The

kidney acts in conjunction with the liver to produce an active form of vitamin D, called 1,25-dihydroxyvitamin D

3

, from an inactive precursor consumed in the diet. The inactive form of vitamin D can also be produced in a reaction catalyzed by sunlight on a precursor present in the skin. Vitamin D is essential for maintenance of plasma calcium levels required for bone formation. The active form of vitamin D acts as a hormone by circulating in the blood and stimulating absorption of calcium and, to a lesser extent, phosphate across the small intestine and across the kidney tubules. Vitamin D also stimulates bone

resorption

(breakdown). Bone

resorption

releases calcium, and thus plasma calcium is increased by this mechanism as well.

Slide5

Parathyroid hormone is the stimulus for the kidney to play its role in activating vitamin D

3

. Parathyroid hormone is released from the parathyroid gland in response to decreased plasma calcium. This is an example of a negative feedback cycle: decreased plasma calcium leads to increased parathyroid hormone, which leads to increased renal activation of vitamin D

3

.

Activation of vitamin D

3

increases gut and kidney absorption of calcium, increasing plasma calcium and removing the stimulus for parathyroid release. Parathyroid hormone also directly stimulates bone

resorption

to release calcium into the plasma when necessary. Individuals who have renal disease frequently develop brittle, easily broken bones as a result of too little active vitamin D

3

.

Slide6

3- Erythropoietin

The hormone that stimulates the bone marrow to increase the production of erythrocytes (red blood cells) is called erythropoietin. The cells of the kidney responsible for synthesizing and releasing erythropoietin respond to renal hypoxia. Individuals who have renal disease frequently demonstrate chronic and debilitating anemia.

Slide7

Micturition

Micturition

is the process of urination, which is the elimination of urine from the body.

Micturition

occurs when the internal and the external urethral sphincters at the base of the bladder are relaxed.

The

bladder is composed of smooth muscle (the

detrusor

muscle), innervated by sensory neurons that respond to stretch, and parasympathetic fibers that travel from the sacral area to the bladder. An area of smooth muscle at the base of the bladder (the internal sphincter) is also innervated by parasympathetic nerves. An external sphincter composed of skeletal muscle is just below the internal sphincter and at the top of the urethra. When urine accumulates, stretch of the bladder is sensed by afferent fibers that send the information to the spinal cord. Parasympathetic nerves to the bladder are activated, causing contraction of the smooth muscle and opening of the internal sphincter. At the same time, the motor neurons going to the external sphincter are inhibited and the external sphincter is relaxed, causing

micturition

to occur.

Slide8

Micturition

, however, can be voluntarily inhibited. This is possible because at the same time that the afferent nerves are conveying information on bladder stretch to the spinal cord, they are also sending information up the cord to the brainstem and cortex, allowing one to be conscious of the need to void. Descending neurons from the brain can inhibit or stimulate the spinal reflex to void. These descending pathways inhibit urination by causing contraction of the skeletal muscles of the pelvis as well as the external sphincter. Descending pathways also block the firing of parasympathetic nerves to the internal sphincter. For urination to be facilitated, skeletal muscles can be voluntarily relaxed. Voluntary control over

micturition

becomes functional in children by or before the time they become 3 or 4 years of age. However, it may become interrupted at any time by central nervous system disease or injury or from spinal cord trauma.

Slide9

Tests of Renal Function

Blood Urea Nitrogen

Urea

is a nitrogenous waste product of protein and amino acid metabolism. One important job of the kidney is to eliminate this potentially toxic substance from the body. With declining renal function, blood urea nitrogen (BUN) levels increase. Measuring BUN therefore provides an indication of kidney health.

BUN, however, is not only determined by renal function. It can also be affected by circumstances not associated with the kidney, such as increased or decreased dietary protein intake, or any unusual cause of an increased protein breakdown, such as a muscle injury. Likewise, liver disease may decrease BUN, because the liver is necessary to convert ammonia to urea

Slide10

. Because BUN levels are affected by these other factors, BUN level alone may be an indiscriminate indicator of renal disease. Therefore, often the ratio of BUN to serum

creatinine

is reported as well. Normally BUN and

creatinine

co-vary, keeping this ratio at approximately 10:1. If BUN is affected by other than renal factors, however, this ratio may change. Ratios greater than 15:1 suggest a non-renal cause of urea elevation. Ratios less than 10:1 occur with liver disease

Slide11

Serum

Creatinine

Creatinine

is a product of muscle breakdown.

Creatinine

is excreted by the kidney through a combination of filtration and secretion. The concentration of

creatinine

in the plasma remains nearly constant from day to day. It varies slightly from approximately 0.7 mg/100

mL

of blood in a small woman to 1.5 mg/l00

mL

in a muscular man. Levels greater than these suggest the kidney is not clearing

creatinine

and indicate renal disease. Serum

creatinine

is very indicative of renal function. As a rough guide, a doubling of serum

creatinine

levels indicates a 50% reduction in renal function. Likewise, a tripling of normal

creatinine

levels indicates a 75% reduction in renal function.

Slide12

Urinalysis

A

urine sample may be easily obtained and evaluated for the presence of red blood cells, protein, glucose, and leukocytes, all of which are normally minimal to absent in the urine. Urine casts, which occur in the presence of high amounts of urine protein, may also be observed under some conditions of renal disease or injury. Urine

osmolality

(specific gravity) is measurable and should range between 1.015 and 1.025. Dehydration causes increased urine

osmolality

as more water is reabsorbed back into the

peritubular

capillaries.

Overhydration

results in decreased urine

osmolality

.

Slide13

Cystoscopy

Cystoscopy

is the process in which a lighted scope (

cystoscope

) is inserted up the urethra into the bladder. Bladder lesions, stones, and biopsy samples may be taken.

Voiding

Cystourethrography

Voiding

cystourethrography

involves bladder catheterization and infusion of a radioactive dye to study the shape and size of the bladder. It can be used to detect and grade the degree of

vesicoureteral

reflux. If used inappropriately,

cystourethrography

may spread an unresolved bladder infection into the

ureters

or kidney.

Slide14

Intravenous

Urography

Intravenous

urography

is a technique in which a radiologic dye is injected intravenously, and x-ray films are taken sequentially as the dye filters through the kidney. Obstructions to flow in the

glomeruli

or tubules,

vesicoureteral

reflux, and stones may be visualized. A drawback to the use of this technique is the finding that some individuals are allergic to the dye and may suffer an anaphylactic reaction. High doses of radiation are involved.

Slide15

Renal

Ultrasound

Renal

ultrasound uses the reflection of sound waves to identify renal abnormalities, including structural abnormalities, kidney stones, tumors, and other masses. Because it is non-invasive and does not involve radiation exposure, this technique is frequently used to evaluate renal function in children who have had a urinary tract infection. It does not, however, offer sufficient detail to evaluate

vesicoureteral

reflux, renal scarring, or inflammation.

Slide16

Pathophysiologic

Concepts

Alterations in

Glomerular

Filtration

Glomerular

filtration depends upon the summation of forces favoring filtration of plasma out of the

glomerulus

and forces favoring

reabsorption

of filtrate into the

glomerulus

. Anything that affects the forces of filtration or the forces of

reabsorption

affects net

glomerular

filtration. Forces favoring filtration are capillary pressure and interstitial fluid colloid osmotic pressure. Forces favoring

reabsorption

are interstitial fluid pressure and plasma colloid osmotic pressure

Slide17

Tubular Obstruction

One cause of increased interstitial fluid pressure is tubular obstruction. Obstruction present in the

nephron

causes fluid to back up into Bowman's capsule and the interstitial space. Unrelieved tubular obstruction can collapse the

nephrons

and capillaries and can lead to irreversible damage, especially to the renal papillae, which are the final site for urine concentration. Causes of obstruction include renal calculi (stones) and scarring from repeated kidney infections.

Slide18

Azotemia

Azotemia

refers to abnormal elevation of nitrogenous waste products in the blood such as urea, uric acid, and

creatinine

.

Azotemia

indicates a decrease in GFR, occurring either acutely or with chronic renal failure.

Azotemia

is an early sign of renal damage.

Uremia

Uremia is not a single event, but rather a syndrome (a constellation of symptoms) that develops in an individual who has end-stage renal disease. Because the kidney is pivotal in maintaining water, acid-base, and electrolyte balance and in removing toxic waste products, the symptoms of uremia are widespread and affect all the organs and tissues of the body. Common symptoms include fatigue, anorexia, nausea, vomiting, and lethargy. Intractable itching (

pruritus

) may occur. Hypertension,

osteodystrophy

, and uremic encephalopathy develop as well, with central nervous system changes, including confusion and psychosis, characterizing end stages.

Slide19

Nephrotic

Syndrome

Nephrotic

syndrome is the loss of 3.5 g or more of protein in the urine per day. Under normal circumstances, virtually no protein is lost in the urine.

Nephrotic

syndrome usually indicates severe

glomerular

damage. Diabetic nephropathy is the most common cause of

nephrotic

syndrome. Clinical manifestations may include increased susceptibility to infections (caused by

hypoimmunoglobulins

) and generalized edema, called

anasarca

.

Slide20

Anasarca

Defined as a generalized edema in individuals suffering from

hypoalbuminemia

as a result of

nephrotic

syndrome or other conditions,

anasarca

is caused by a systemic decrease in capillary osmotic pressure. With a decrease in this major force favoring

reabsorption

of interstitial fluid back into the capillaries, edema of the interstitial space throughout the body occurs. The edema is usually soft and pitting and occurs early in the

periorbital

(surrounding the eye) regions, the ankles, and the feet.

Slide21

Renal

Osteodystrophy

Demineralization

of bone occurring with renal disease is known as renal

osteodystrophy

. Renal

osteodystrophy

has many causes, including decreased renal activation of vitamin D

3

, leading to decreased calcium absorption across the gut, and subsequent reduced serum calcium levels. Decreased serum calcium levels also stimulate parathyroid hormone release. An elevated bone breakdown contributes to easy bone fracturing.

Slide22

Metabolic Acidosis/Renal Acidosis

Metabolic acidosis is a decrease in plasma pH not caused by a respiratory disorder. Chronic renal disease results in metabolic acidosis as a result

of reduced

H

+

excretion and altered bicarbonate

reabsorption

. The result is increased plasma H

+

and lowered

pH.

The respiratory system is stimulated by the increase in hydrogen.

Tachypnea

(increased respiratory rate) occurs in an attempt to blow off the excess hydrogen as carbon dioxide. The respiratory response to renal acidosis is called respiratory compensation.

Slide23

Uremic Encephalopathy

Uremic encephalopathy refers to neurologic changes seen in severe renal disease. Symptoms include fatigue, drowsiness, lethargy, seizures, muscle twitching, peripheral neuropathy (pain in the legs and feet), decreases in memory, and coma. Uremic encephalopathy appears to be caused by accumulation of toxins, alterations in potassium balance, and decreased

pH.

Slide24

Renal Dialysis

The process of adjusting blood levels of water and electrolytes in a person who has poor or non-functioning kidneys is called renal dialysis. In this procedure, blood is directed past an artificial medium containing water and electrolytes in predetermined concentrations. The artificial medium is the dialyzing fluid. By simple diffusion across a selectively permeable membrane, water and electrolytes in the blood move down their individual concentration gradients into or out of the dialyzing

solution.There

are two types of dialysis

:

Slide25

Hemodialysis

Dialysis

is performed outside the body. Blood is passed from the body, through an arterial catheter, into a large machine. Two chambers separated by a

semipermeable

membrane are inside the machine. Blood is delivered to one chamber, dialyzing fluid is placed in the other, and diffusion is allowed to occur.

It

takes about 3 to 5 hours and is required approximately three times per week.

Hemodialysis

contributes to problems of anemia because some red blood cells are destroyed in the process. Infection is also a risk.

Slide26

Peritoneal Dialysis

The

individual's own peritoneal membrane is used as a natural,

semipermeable

barrier. Prepared

solution

(approximately 2 L) is delivered into the peritoneal

cavity.

The solution is allowed to remain in the peritoneal cavity for a predetermined amount of time (usually between 4 and 6 hours). During this time, water and electrolytes diffuse back and forth between the circulating blood. The person can usually continue activity while the exchange takes place.

Slide27

Kidney Transplantation

Kidney transplantation involves placement of a donor kidney into the abdominal cavity of an individual suffering from end-stage renal disease. Transplanted kidneys can come from living or dead donors. The more similar the antigenic properties of the donated kidney are to the patient, the more likely the transplantation will be successful. With appropriate follow-up, approximately 94% of kidneys transplanted from cadavers and 98% from living donors function well after surgery. Long-term graft survival (10 years) is similar for both (approximately 78% for grafts from living donors versus 76% for grafts from cadavers).

Individuals receiving kidney donation must remain on a variety of immunosuppressant medications for life to prevent organ rejection. I

Slide28

Conditions of Disease or Injury

Hypospadias

Hypospadias

is a congenital defect in males

,

the opening of the urethra

is on the

ventral side. This condition may be slight or extreme. Some infants demonstrate the urethral

meatus

(opening) in the scrotal or

perineal

area. Ejaculatory dysfunction in the adult male may occur.

Treatment

Surgical correction may be necessary, preferably before the child is 1 or 2 years old. Circumcision should be avoided in the newborn so that the foreskin may later be used for repair.

Slide29

Renal agenesis

Failure of the kidneys to develop during gestation

,may

be unilateral or bilateral. Bilateral agenesis is incompatible with life.

Unilateral agenesis results in hypertrophy of the remaining kidney as it adapts to compensate functionally for the absent kidney.

Clinical

Manifestations

With unilateral renal agenesis, no symptoms are apparent if the remaining kidney is healthy. The remaining kidney may compensate and grow almost twice as big as otherwise expected. If the remaining kidney functions poorly, however, various disease manifestations may be present.

Slide30

Diagnostic Tools

Prenatal ultrasound can often detect renal agenesis.

After birth, computerized axial tomography (CAT) scan or renal ultrasound is used to diagnose the condition.

Treatment

No treatment is required for unilateral agenesis if the remaining kidney is healthy.

If structural or functional defects are present in the remaining kidney, surgery may be required.

Slide31

Renal Calculi

Renal calculi refer to stones that occur anywhere in the urinary tract. Calculi are most commonly made up of calcium crystals. Renal calculi can be caused by either increased urine pH (e.g., calcium carbonate stones) or decreased urine pH (e.g., uric acid stones).

Anything

that obstructs urine flow, leading to urine stasis anywhere in the urinary tract, increases the likelihood of stone formation.

Slide32

Clinical Manifestations

Pain is often colicky (rhythmic), especially if the stone is in the

ureter

or below. The pain may be intense. The location of pain depends on the site of the stone.

A stone in the kidney itself may be asymptomatic unless it causes obstruction or an infection develops.

Hematuria

, caused by irritation and injury of the renal structures, is common with calculi.

Decreased urine output results if obstruction to flow occurs.

Slide33

Diagnostic Tools

Radiograph

, ultrasound, or intravenous

urography

may locate a stone.

Complications

Urinary obstruction

can

lead to

hydroureter

, that is, abnormal distension of

ureter

with urine. Unrelieved

hydroureter

can lead to

hydronephritis

, swelling of the renal pelvis and collecting-duct system.

leading

to electrolyte and fluid imbalance.

Obstruction causes increased interstitial hydrostatic pressure and can lead to a decrease in GFR. Renal failure may develop if both kidneys are involved.

The

chance of a bacterial infection increases.

Renal cancer may develop from repeated inflammation and injury.

Slide34

Treatment

High fluid intake in individuals prone to calculi may prevent their formation.

Increased

fluid intake increases urine flow and helps wash out the stone.

Appropriate

alteration of urine pH may encourage stone breakdown.

Lithotripsy

(shock wave therapy) or laser therapy may be used to break apart the stone.

Surgery may be necessary to remove a large stone or to place a diversion tube around the stone to relieve obstruction.

Slide35

Urinary Tract Infection

A urinary tract infection is an infection anywhere in the urinary tract, including the kidney

itself.

Most

urinary tract infections are bacterial in origin, but fungi and viruses also may be implicated

.

The most common bacterial infection is by Escherichia coli, a fecal contaminant commonly found in the anal area.

Urinary tract infections are especially common in girls and women.

One

cause is the shorter urethra in the female, which allows the contaminating bacteria to gain access more easily to the bladder.

Slide36

Individuals who have diabetes also are at risk of frequent urinary tract infections because of the high glucose content of the urine and poor immune function.

Persons

who have a spinal cord injury or anyone using a urinary catheter to void are at increased risk of infection.

Types of Urinary Tract Infections

Urinary tract infections may be divided into

cystitis

and

pyelonephritis

.

Cystitis is an infection of the bladder, the most common site for an infection.

Pyelonephritis

is an infection of the kidney itself and can be either acute or chronic

.

Slide37

Acute

pyelonephritis

usually occurs as a result of an ascending bladder infection. It may also occur as a result of a blood-borne infection. Infections may be in both or in one kidney.

Chronic

pyelonephritis

may result from repeated infections and is usually found in individuals who have frequent calculi, other obstructions, or

vesicoureteral

reflux.With

chronic

pyelonephritis

, extensive scarring and obstruction of the tubules result. The ability of the kidneys to concentrate urine decreases as tubules are lost. The

glomeruli

are usually unaffected. Chronic renal failure may develop.

Slide38

Clinical Manifestations

Cystitis

typically presents with

dysuria

(pain on urination), increased frequency of urination, and a sense of urgency to urinate.

Lower back or

suprapubic

pain may occur, especially with

pyleonephritis

.

Fever accompanied by blood in the urine in severe cases.

Symptoms of infection in infants or young children may be non-specific and include irritability, fever, lack of appetite, vomiting, and very strong-smelling diapers.

Slide39

Acute

pyelonephritis

typically presents with

Fever.

Chills.

Flank pain.

Dysuria

.

Chronic

pyelonephritis

may have manifestations similar to acute

pyelonephritis

. However, it can also include hypertension and may eventually lead to signs of renal failure.

Slide40

Diagnostic Tools

Urine culture and sensitivity of the microorganism allow for identification and treatment.

White blood cells will be present in the urine with infection anywhere. White cell casts present in the urine suggest

pyleonephritis

rather than cystitis, since they indicate that white cells have been

lysed

in the tubules.

Complications

Renal or

perirenal

abscess formation may occur.

Renal failure may develop after repeated infections if both kidneys are involved.

Slide41

Treatment

Women and girls in particular should be encouraged to drink fluids

frequently.

Girls should be taught at a young age to wipe from front to back after urination to avoid contamination of the urethral opening with fecal bacteria.

Women should be encouraged to urinate after sexual intercourse to wash out ascending microorganisms.

Antibiotic therapy with

to

repeat urinalysis during or after drug therapy is required.

If chronic

pyelonephritis

is caused by an obstruction or reflux, surgical treatment specific to relieve these problems is necessary.

Slide42

Glomerulonephritis

Glomerulonephritis

is an inflammation of the

glomerulus

. Types of

glomerulonephritis

include

:

I-Acute

Glomerulonephritis

occurs

as a result of deposition of antibody-antigen complexes in the

glomerular

capillaries. Complexes usually develop 7 to 10 days after a pharyngeal or skin

streptococcal infection

(

poststreptococcal

glomerulonephritis

) but may follow any infection. An inflammatory reaction is initiated in the

glomerulus

after deposition of antibody-antigen complexes.

Slide43

It usually

resolves with specific antibiotic therapy, especially in children.

II-Rapidly

Progressive

Glomerulonephritis

Is

an inflammation of the

glomeruli

that occurs so rapidly that there is a 50% decrease in GFR within 3 months of disease onset. Rapidly progressive

glomerulonephritis

can occur from a worsening of acute

glomerulonephritis

, from an autoimmune disease, or may be idiopathic (unknown) in origin.

Slide44

III-

Chronic

Glomerulonephritis

Is the

long-term inflammation of the

glomerular

cells. It may occur as a result of unresolved acute

glomerulonephritis

, or it might develop spontaneously.

It commonly

occurs after years of subclinical

glomerular

injury and inflammation, associated with only slight

hematuria

and

proteinuria

.

Clinical Manifestations

All

types of

glomerulonephritis

are associated

with:

Decreased urine volume.

Blood in the urine (brownish-colored

urine).

Fluid retention.

Slide45

Diagnostic Tools

Hematuria

as measured by urinalysis.

Red blood cell casts in the urine.

Proteinuria

greater than 3 to 5 g/day.

Decreased GFR as measured by

creatinine

clearance.

In

poststreptococcal

glomerulonephritis

,

antistreptococcal

enzymes, such as

antistreptolysin

-O and

antistreptokinase

, will be present.

Complications

Renal failure may develop.

Slide46

Treatment

If the condition develops following acute

poststreptococcal

glomerulonephritis

, antibiotic therapy is required.

Autoimmune destruction of the

glomeruli

may be treated with corticosteroids for

immunosuppression

.

Anticoagulants to decrease fibrin deposits and scarring can be used in rapidly progressive

glomerulonephritis

.

Strict glucose control in diabetics has been shown to slow or reverse the progression of

glomerulonephritis

.

 

Slide47

Renal Failure

Renal failure is the

loss of function in both kidneys

.

The stages of kidney disease are as follows:

Stage 1

:

abnormalities

in blood or urine tests

with

normal or near-normal

glomerular

filtration rate

.

Stage 2

:

Glomerular

filtration rate approximately 50% of normal, with evidence of kidney damage.

Stage 3

:

Glomerular

filtration rate between 25 to 50% of normal.

Stage 4

:

Glomerular

filtration rate between 12 to 24% of normal, .

Stage 5

: End-stage renal failure;

glomerular

filtration rate of less than 12% of normal

Slide48

Renal failure also is categorized as

acute

or

chronic

renal

failure

Acute

Renal Failure

Causes

of acute renal failure have been separated into three general categories:

prerenal

,

intrarenal

, and

postrenal

.

Prerenal

failure

occurs as a result of conditions unrelated to the kidney but that damage the kidney by affecting renal blood flow. Causes of

prerenal

failure include

myocardial infarct, an anaphylactic reaction, severe blood loss or volume depletion, a burn, or sepsis (a blood-borne infection).

Slide49

Intrarenal

failure

,result from

primary damage to kidney tissue itself. It has many causes, including

glomerulonephritis

and

acute

pyelonephritis

,

.

Postrenal

failure

result from conditions

that affect the flow of urine out of the kidneys and includes injury to or disease of the

ureters

,

bladder, or urethra. The usual cause of

postrenal

failure is obstruction.

Clinical

Manifestations

Oliguria

results from decreased GFR.

Slide50

Diagnostic Tools

Azotemia

(increased nitrogenous compounds in the blood

).

elevated

BUN and

creatinine

.

hyperkalemia

(increased potassium in the blood) and acidosis are common.

Complications

Fluid retention

may

lead to edema, congestive heart failure, or water intoxication.

Alterations in electrolytes and pH may cause uremic encephalopathy.

If the

hyperkalemia

is severe ( 6.5

mEq

/L),

dysrhythmia

and muscle weakness may occur.

Slide51

Treatment

Prevention

of acute renal failure is essential.

Individuals

experiencing shock should be quickly treated with fluid replacement to support blood pressure.

Prevention

of

oliguria

.

Chronic

Renal Failure

Is

the progressive destruction of renal structure.

Clinical

Manifestations

In stage 1 renal failure, no symptoms may be apparent.

As disease progresses, reduced production of erythropoietin causes chronic fatigue, and early signs of tissue hypoxia

.

As disease progresses,

polyuria

(increased urine output) occurs as the kidneys are unable to concentrate the urine.

During the final stages of renal failure, urine output decreases because of low GFR.

Slide52

Diagnostic Tools

Radiographs or ultrasound

.

Serum BUN,

creatinine

, and GFR will be abnormal.

Hematocrit

and hemoglobin are reduced.

Plasma pH is low.

An elevated respiratory rate indicates respiratory compensation for metabolic acidosis.

Complications

With progression of renal failure, volume overload, electrolyte imbalance, metabolic acidosis,

azotemia

, and uremia occur.

In stage 5 renal failure (end-stage disease), severe

azotemia

and uremia are present. Metabolic acidosis worsens, which significantly stimulates respiratory rate.

Slide53

Hypertension, anemia,

hyperkalemia

, uremic encephalopathy, and

pruritus

(itching) are common complications.

Decreased production of erythropoietin may lead to anemia .

Congestive heart failure may develop.

Without treatment, coma and death result.

Treatment

Prevention of renal failure is the most important goal. Prevention includes lifestyle changes and drugs when necessary to control hypertension, good

glycemic

control in diabetics, and the avoidance of

nephrotoxic

drugs whenever possible.

Slide54

Childhood

Kidney Cancer:

Wilms

' Tumor

Wilms

' tumor is a cancer of

the

kidney that typically develops in children younger than 4 years of age.

It can

grow to a

large size

. It may be

encapsulated

(contained within the capsule of the kidney

).

-

Encapsulation

is associated with a favorable prognosis, whereas spread of the tumor outside of the abdominal area to the lungs is associated with a poorer

outcome.

-Overall

, prognosis is good, with an approximately 90% survival rate.

Clinical

Manifestations

A large abdominal mass may be noted by parents or a health-care provider.

Vomiting, abdominal pain, and

hematuria

may be present.

Slide55

Diagnostic Tools

A careful history can raise suspicion of

Wilms

' tumor.

Physical examination may identify the mass.

CT scan or ultrasound may confirm the diagnosis.

Treatment

Chemotherapy and surgery are used aggressively to destroy the tumor.

Slide56

Adult

kidney cancer

This

cancer is especially common in the

sixth

or

seventh

decade of life, and is more common in males than in females

.

Risk factors

include

repeated kidney stone irritation, smoking, and obesity.

Symptoms include

hematuria

and the presence of a flank mass.

Treatment

and outcomes depend on staging, with outcomes ranging from 85% survival for stage I tumors to less than 10% survival for stage IV tumors.

Slide57

Clinical Manifestations

Hematuria

is the most common manifestation. It may be frankly visible or may be microscopic and sporadic.

A flank mass may be palpable. Flank pain may be present as well.

Polycythemia

may be present, reflecting alteration in the renal control of

hematopoiesis

.

Fever may accompany the cancer.

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Diagnostic Tools

CT

scanning

.

Ultrasound, renal angiography, and MRI may confirm the diagnosis.

Complications

Metastasis to the lungs or elsewhere may precede diagnosis.

Treatment

Surgery.

Chemotherapy and immunotherapy may be used as well.