polycystic kidney disease


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Polycystic Kidney Disease

 

Definition

Polycystic kidney disease (PKD) is one of the most common of all life-threatening human genetic disorders. It is an incurable genetic disorder characterized by the formation of fluid-filled cysts in the kidneys of affected individuals. These cysts multiply over time. It was originally believed that the cysts eventually caused kidney failure by crowding out the healthy kidney tissue. It is now thought that the kidney damage seen in PKD is actually the result of the body's immune system. The immune system, in its attempts to rid the kidney of the cysts, instead progressively destroys the formerly healthy kidney tissue.

Description

A healthy kidney is about the same size as a human fist. PKD cysts, which can be as small as the head of a pin or as large as a grapefruit, can expand the kidneys until each one is bigger than a football and weighs as much as 38lb (17 kg).
There are two types of PKD: infantile PKD, which generally shows symptoms prior to birth; and adult onset PKD. Individuals affected with infantile PKD are often stillborn. Among the liveborn individuals affected with infantile PKD, very few of these children survive to the age of two. The adult onset form of PKD is much more common. The time and degree of symptom onset in the adult form of PKD can vary widely, even within a single family with two or more affected individuals. Symptoms of this form of PKD usually start to appear between the ages of 20 and 50. Organ deterioration progresses more slowly in adult onset PKD than it does in the infantile form; but, if left untreated, adult onset PKD also eventually leads to kidney failure.
One of the most common of all life-threatening genetic diseases, PKD affects more than 60,000 Americans. Over 12.5 million people worldwide are affected with PKD. Approximately one in every 400 to 1,000 people is affected with ADPKD. Another one in 10,000 affected with ARPKD. PKD is observed in equal numbers in both males and females. PKD is also observed with equal frequency among ethnic groups.

Causes and symptoms

Polycystic kidney disease is expressed as both a recessive and a dominant trait. A recessive genetic trait will not cause disease in a child unless it it inheritied from both parents. A dominant genetic trait can be inherited from just one parent. Those people affected with autosomal dominant PKD (ADPKD) have the much more common adult onset form. Those with autosomal recessive PKD (ARPKD) have the infantile form.
There are mutations on at least three genes that cause adult onset PKD. Approximately 85% of these cases are known to arise from mutations in the PKD1 gene that has been mapped to a region on the short arm of chromosome 16 (16p13.3-p13.12). Another 10-15% of cases of adult onset PKD are thought to be caused by mutations in the PKD2 gene that has been mapped to a region on the long arm of chromosome 4 (4q21-q23). As of early 2001, it is thought that the remainder of the cases of PKD are caused by mutations in the PKD3 gene, which has not yet been mapped. This unidentified "PKD3 gene" may, in fact, be more than one gene.
Adult onset PKD is transmitted from parents to their offspring as a non-sex linked (autosomal) dominant trait. This means that if either parent carries this genetic mutation, there is a 50% chance that their child will inherit this disease. In the case of two affected parents, there is a 75% probability that their children will be affected with adult onset PKD.
Infantile PKD is caused by a non-sex linked (autosomal) recessive genetic mutation that has been mapped to a region on the short arm of chromosome 6 (6p21). Both parents must be carriers of this mutation for their children to be affected with infantile PKD. In the case of two carrier parents, the probability is 25% that their child will be affected by infantile PKD.
A baby born with infantile PKD has floppy, low-set ears, a pointed nose, a small chin, and folds of skin surrounding the eyes (epicanthal folds). Large, rigid masses can be felt on the back of both thighs (flanks), and the baby usually has trouble breathing.
In the early stages of adult onset PKD, many people show no symptoms. Generally, the first symptoms to develop are: high blood pressure (hypertension); general fatigue; pain in the lower back or the backs of the thighs; headaches; and/or urinary tract infections accompanied by frequent urination.
As PKD becomes more advanced, the kidneys' inability to function properly becomes more pronounced. The cysts on the kidney may begin to rupture and the kidneys tend to be much larger than normal. Individuals affected with PKD have a much higher rate of kidney stones than the rest of the population at this, and later stages, of the disease. Approximately 60% of those individuals affected with PKD develop cysts in the liver, while 10% develop cysts in the pancreas.
Because the kidneys are primarily responsible for cleaning the blood, individuals affected with PKD often have problems involving the circulatory system. These include: an underproduction of red blood cells which results in an insufficient supply of oxygen to the tissues and organs (anemia); an enlarged heart (cardiac hypertrophy) probably caused by long term hypertension; and, a leakage of the valve between the left chambers (auricle and ventricle) of the heart (mitral valve prolapse). Less common (affecting approximately 5% of PKD patients) are brain aneurysms. An aneurysm is an abnormal and localized bulging of the wall of a blood vessel. If an aneurysm within the brain leaks or bursts, it may cause a stroke or even death.
Other health problems associated with adult onset PKD include: chronic leg or back pain; frequent infections; and herniations of the groin and abdomen, including herniation of the colon (diverticular disease). A herniation, or hernia, is caused when a tissue, designed to hold the shape of an underlying tissue, becomes weakened at a particular spot. The underlying tissue pushes against this weakened area until the area is no longer able to hold back the underlying tissue and the area forms an abnormal bulge through which the underlying tissue projects. Diverticular disease is caused by a weakening of the muscles that hold the shape of the organs of the digestive tract. These muscles weaken allowing these organs, particularly one section of the colon, to form sac-like projections that can trap feces and become infected, or rupture.
In the final stages of PKD, the major symptom is kidney (renal) failure. Renal failure is indicated by an increase of nitrogen (in the form of urea) in the blood (uremia, or uremic poisoning). Uremia is a rapidly fatal condition without treatment.

Diagnosis

Many patients who have PKD do not have any symptoms. Their condition may not be discovered unless tests that detect it are performed for other reasons.
When symptoms of PKD are present, the diagnostic procedure begins with a family medical history and physical examination of the patient. If several family members have PKD, there is a strong likelihood that the patient has it too. If the disease is advanced, the doctor will be able to feel the patient's enlarged kidneys. Heart murmur, high blood pressure, and other signs of cardiac impairment can also be detected.
Urinalysis and a blood test called creatine clearance can indicate how effectively the kidneys are functioning. Scanning procedures using intravenous dye reveal kidney enlargement or deformity and scarring caused by cysts. Ultrasound and computed tomography scans (CT scans) can reveal kidney enlargement and the cysts that caused it. CT scans can highlight cyst-damaged areas of the kidneys. A sampling of the kidney cells (biopsy) may be performed to verify the diagnosis.

Treatment

There is no way to prevent cysts from forming or becoming enlarged, or to prevent PKD from progressing to kidney failure. Treatment goals include preserving healthy kidney tissue; controlling symptoms and, preventing infection and other complications.
If adult PKD is diagnosed before symptoms become evident, urinalysis and other diagnostic tests are performed at six-week intervals to monitor the patient's health status. If results indicate the presence of infection or another PKD-related health problem, aggressive antibiotic therapy is initiated to prevent inflammation that can accelerate disease progression; iron supplements or infusion of red blood cells are used to treat anemia; and surgery may be needed to drain cysts that bleed, cause pain, have become infected, or interfere with normal kidney function.
Lowering high blood pressure can slow loss of kidney function. Blood-pressure control, which is the cornerstone of PKD treatment, is difficult to achieve. Therapy may include antihypertensive medications, diuretic medications, and/or a low-salt diet. As kidney function declines, some patients need dialysis and/or a kidney transplant.
There is no known way to prevent PKD, but certain lifestyle modifications can help control symptoms. People who have PKD should not drink heavily or smoke. They should not use aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), or other prescription or over-the-counter medications that can impair kidney function. Individuals affected with PKD should eat a balanced diet, exercise regularly, and maintain a weight appropriate for their height, age, and body type. Regular medical monitoring is also recommended.

Prognosis

There is no known cure for PKD. Those affected with infantile PKD generally die before the age of two. In adults, untreated disease can be rapidly fatal or continue to progress slowly, even after symptoms of kidney failure appear. About half of all adults with PKD also develop kidney failure. Unless the patient undergoes dialysis or has a kidney transplant, this condition usually leads to death within four years of diagnosis.
Although medical treatment can temporarily alleviate symptoms of PKD, the expanding cysts continue to increase pressure on the kidneys. Kidney failure and uremic poisoning (accumulation of waste products the body is unable to eliminate) generally cause death about 10 years after symptoms first appear.
Medications used to fight cancer and reduce elevated cholesterol levels have slowed the advance of PKD in laboratory animals. They may soon be used to treat adults and children who have the disease. Researchers are also evaluating the potential benefits of anti-inflammatory drugs, which may prevent the scarring that destroys kidney function.

Resources

Periodicals

Koptides, M., and C. Deltas. "Autosomal dominant polycystic kidney disease: Molecular genetics and molecular pathogenesis." Human Genetics August 2000: 115-26.
Pei, Y., A. Paterson, K. Wang, N. He, et al. "Bilineal disease and trans-heterozygotes in autosmal dominant polycystic kidney disease." American Journal of Human Genetics February 2001: 355-63.

Organizations

Polycystic Kidney Disease Foundation. 4901 Main Street, Kansas City, MO 64112-2634. (800) PKD-CURE. 〈http://www.pkdcure.org/home.htm〉.

Other

Brochert, Adam, MD. "Polycystic Kidney Disease." September 4, 2000. HealthAnswers. 〈http://www.healthanswers.com/library/library_fset.asp〉.
Cooper, Joel R. "Treating Polycystic Kidney Disease. What Does the Future Hold?" Coolware, Inc. http://www.coolware.com/health/medical_reporter/kidney1.html.
Online Mendelian Inheritance in Man (OMIM). February 15, 2001. http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?600595.
Polycystic Kidney Disease Access Center. http://www.nhpress.com/pkd/.

Key terms

Biopsy — The surgical removal and microscopic examination of living tissue for diagnostic purposes.
Cancer — A disease caused by uncontrolled growth of the body's cells.
Computed tomography (CT) scan — An imaging procedure that produces a three-dimensional picture of organs or structures inside the body, such as the brain.
Cyst — An abnormal sac or closed cavity filled with liquid or semisolid matter.
Diuretics — Medications that increase the excretion of urine.
Kidney — Either of two organs in the lumbar region that filter the blood, excreting the end products of the body's metabolism in the form of urine and regulating the concentrations of hydrogen, sodium, potassium, phosphate and other ions in the body.
Magnetic resonance imaging (MRI) — A technique that employs magnetic fields and radio waves to create detailed images of internal body structures and organs, including the brain.
Ultrasonogram — A procedure where high-frequency sound waves that cannot be heard by human ears are bounced off internal organs and tissues. These sound waves produce a pattern of echoes, which are then used by the computer to create sonograms or pictures of areas inside the body.
Uremic poisoning — Accumulation of waste products in the body.

polycystic

 [pol″e-sis´tik]
containing many cysts.
polycystic kidney disease either of two unrelated hereditary diseases in which there is massive enlargement of the kidney with cyst formation. It occurs in two forms, distinguished by age of onset and other characteristics.

Autosomal dominant polycystic kidney disease (ADPKD, formerly called adult polycystic kidney disease) is the most common type of cystic disease of the kidneys. It is usually manifested during the third decade of life. Renal failure may appear by the fifth decade, with terminal failure occurring in the next ten years, although in some cases it never appears. Although there is rarely any liver dysfunction accompanying this disorder, cyst formation in the liver does occur.

Autosomal recessive polycystic kidney disease (ARPKD), formerly called childhood polycystic kidney disease, is diagnosed at birth or in the first ten years of life and is much less common than the autosomal dominant form. Both the kidney and the liver are involved, causing renal failure and liver failure with portal hypertension. Characteristic symptoms early in the process include pain, hematuria, urinary tract infection, kidney stones, and obstructive uropathy with anuria.

Treatment of both types of polycystic kidney disease is largely symptomatic. Renal dialysis and kidney transplantation during end-stage renal disease can prolong life but offer no cure. Families with histories of polycystic kidney disease require genetic counseling and may need help in coping with the prospect of future offspring afflicted with the disease.
polycystic ovary syndrome (PCOS) a clinical symptom complex associated with polycystic ovaries and characterized by oligomenorrhea or amenorrhea, anovulation (hence infertility), and hirsutism. Both hyperestrogenism (from peripheral conversion of androgen) and hyperandrogenism are present. Excretion of follicle-stimulating hormone and 17-ketosteroids is normal, but infertility is usually persistent, requiring treatment with wedge resection, clomiphene, or gonadotropins. Called also Stein-Leventhal syndrome.
polycystic renal disease polycystic kidney disease.

polycystic kidney disease (PKD)

an abnormal condition in which the kidneys are enlarged and contain many cysts. There are two unrelated hereditary diseases in which there is massive enlargement of the kidney with cyst formation: Autosomal dominant polycystic kidney disease (ADPKD), formerly called adult polycystic kidney disease, is the most common type of cystic disease of the kidneys. It is usually manifested during the third decade of life. Renal failure may appear by the fifth decade, with terminal failure occurring in the next 10 years, although in some cases it never appears. Although there is rarely any liver dysfunction accompanying this disorder, cyst formation in the liver does occur. Autosomal recessive polycystic kidney disease (ARPKD), formerly called childhood polycystic kidney disease, is diagnosed at birth or in the first 10 years of life and is much less common than the autosomal dominant form. Both the kidney and the liver are involved, causing renal failure and liver failure with portal hypertension Characteristic symptoms early in the process include pain, hematuria, urinary tract infection, kidney stones, and obstructive uropathy with anuria.
Treatment Treatment of both types of polycystic kidney disease is largely symptomatic. Renal dialysis and kidney transplantation during end-stage renal disease can prolong life but offer no cure. Families with histories of polycystic kidney disease benefit from genetic counseling and may need help in coping with the prospect of future offspring affected with the disease.
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Polycystic kidney disease

polycystic kidney

A nonspecific term for two morphologically similar but clinically and genetically distinct conditions:
(1) Autosomal dominant (“adult") polycystic kidney disease (OMIM:173900);
(2) Autosomal recessive (“infantile") polycystic kidney disease (OMIM:263200).

Polycystic Kidney Disease

DRG Category:659
Mean LOS:10.8 days
Description:SURGICAL: Kidney and Ureter Procedures for Non-Neoplasm With Major CC
DRG Category:699
Mean LOS:4.5 days
Description:MEDICAL: Other Kidney and Urinary Tract Diagnoses With CC

Although inherited polycystic diseases are not the only types of cystic diseases of the kidney, all types are a major contributor to chronic renal failure. Infantile autosomal recessive polycystic kidney disease (RPK) and autosomal dominant polycystic kidney disease (ADPKD) are two types of inherited polycystic kidney disease. Infantile (RPK) disease affects both kidneys, leads to renal failure, and causes biliary dilation and fibrosis in the liver. The basic pathology of cyst development is a weakening of the basement membrane, which possibly is caused by an abnormality of the extracellular connective tissue cells. Adult-onset disease (ADPKD) is a bilateral disorder, although it may have asymmetrical progression with multiple expanding cysts that destroy renal function. Renal deterioration eventually leads to uremia, chronic renal failure, and the need for chronic renal dialysis.

Complications include liver, pancreatic, spleen, and lung cysts; aneurysms of the cerebral artery or abdominal aorta; colonic diverticula; and mitral valve prolapse. Approximately 40% of adult patients die of coronary or hypertensive heart disease. About 10% to 40% of people with ADPKD have berry aneurysms, and 9% die as a result of subarachnoid hemorrhages.

Causes

RPK and ADPKD are genetically inherited. In RPK, siblings of either sex have one chance in four of having the disease. ADPKD has a 100% incidence because it is an autosomal dominant trait. An average of half of the affected individuals have children with ADPKD.

Genetic considerations

ADPKD is an autosomal dominantly transmitted disorder with renal cysts, liver cysts, and intracranial aneurysm. It is caused by mutations in different genes, with one locus (PKD1) being responsible for the most common form. ADPKD accounts for approximately 90% of cases with onset between ages 30 and 40. The PKD form that is inherited in an autosomal recessive (ARPKD) pattern is much less common, with symptoms beginning in the earliest months of life or prenatally. ARPKD is caused by mutations in the fibrocystin gene.

Gender, ethnic/racial, and life span considerations

RPK always becomes apparent during childhood in boys and girls, usually before age 13. An infant born with active RPK usually dies within the first 2 months of life as a result of uremia or pulmonary complications. Renal failure and hypertension develop more slowly when the disease occurs later in childhood. Most patients with ADPKD are identified between ages 30 and 50, although newborns can be diagnosed with the disease. A neonate with ADPKD is likely to be stillborn or die from renal failure within 9 months. In most men and women with ADPKD, the disease progresses to end-stage renal failure by the time the patient reaches the age of 40 to 50. ADPKD is more severe in males than in females. There are no known racial and ethnic predispositions for polycystic kidney disease.

Global health considerations

Polycystic kidney disease is responsible for up to 10% of cases of end-stage renal disease in developed nations and is the most common cause of inherited end-sate renal disease. Few data are available for developing nations.

Assessment

History

Children with RPK are apt to have a lengthy medical history, including multiple system complications and frequent hospitalizations. Because children with ADPKD usually experience cardiopulmonary complications, ask the parents about respiratory distress or increased blood pressure during checkups. The child can also have bleeding varices; ask the parents if the child has ever spit up blood.

When you take a history from adults with ADPKD who are approximately 40 years old, note that they may have one of two forms of presenting symptoms: pain or hypertension. Pain can occur in one or both kidneys and can vary from a vague sense of heaviness or a dull ache to severe, knifelike pain. Some patients describe flank pain from renal colic, bloody urine from the passage of renal calculi, signs of a urinary tract infection (burning or pain on urination, urinary frequency and urgency, fever), and gastrointestinal symptoms (nausea, vomiting, diarrhea, constipation) from compression by the enlarged kidneys. Patients with the second type of ADPKD often develop hypertension as the initial clinical sign. Changes in urinary output and concentration may accompany hypertension because of developing renal insufficiency. Some children have a history of urinary tract infections and perinephric abscesses.

Physical examination

The most common symptom is abdominal pain. The infant with RPK has pronounced epicanthal folds (vertical skin folds that extend from the root of the nose to the median end of the eyebrow), a pointed nose and small chin, and low-set ears. When you palpate the child’s kidneys, you are able to feel huge, tense, bilateral masses on both flanks. These children usually have multiple assessment findings from many malfunctioning organ systems, such as bleeding esophageal varices, pulmonary congestion, hypertension, and oliguria or anuria.

Adult patients with ADPKD may have a healthy appearance but may have urine that is foul-smelling, cloudy, or bloody because of a urinary tract infection. If the blood vessels that surround the kidney cysts rupture into the renal pelvis, the patient may have moderate to severe hematuria. The patient probably has had hypertension for years before any renal damage occurs. As the disease progresses, the patient develops a widening abdomen, which is tender when palpated. In advanced stages, palpation reveals grossly enlarged kidneys.

Psychosocial

When a child is diagnosed with RPK, assess the siblings for the disease as well. With both types of polycystic disease, the patient and partner need genetic counseling. Children of parents diagnosed with ADPKD should have an ultrasound or genetic testing because approximately half also have ADPKD. There is a great strain on individuals and their families with both types of polycystic kidney disease because of the poor prognosis of children with RPK and the knowledge that ADPKD worsens throughout life.

Diagnostic highlights

TestNormal ResultAbnormality With ConditionExplanation
Genetic testingNo mutations on genes of interestPKD1, PKD2, PKD3 genes may have mutations that lead to ADPKDGenetic alterations lead to ADPKD
Renal ultrasoundNormal renal structureMarkedly enlarged kidney with dilated cystsCyst development leads to altered tubular epithelium, cell proliferation, and fluid secretion

Other Tests: Computed tomography, magnetic resonance imaging, serum blood urea nitrogen and creatinine, urinalysis, glomerular filtration rate, intravenous pyelogram

Primary nursing diagnosis

Diagnosis

Pain (acute) related to compression of tissues, trauma to structures from calculi, inflammation, and infection

Outcomes

Comfort level; Pain control behavior; Pain: Disruptive effects; Pain level

Interventions

Pain management; Analgesic administration; Positioning; Teaching: Prescribed activity/exercise; Teaching: Procedure/treatment; Teaching: Prescribed medication

Planning and implementation

Collaborative

Because there is no cure for polycystic kidney disease, care centers around alleviating symptoms and slowing the onset of renal impairment. Infants with RPK need management of airway, breathing, and circulation because of the extent of the multiple system involvement. Patients who survive past infancy need treatment for hypertension, congestive heart failure, renal failure, and hepatic failure.

As renal impairment progresses, patients require hemodialysis and renal transplantation. Allografts from siblings may be used only after appropriate genetic screenings have ruled out the possibility that the sibling also has the disease. For those with ADPKD, surgery may decrease the pressure caused by enlarging cysts. This procedure sometimes removes functioning nephrons and may contribute to the loss of renal function, but it also controls hypertension and decreases pain. An alternative is percutaneous aspiration of the cysts.

Infections need to be prevented when possible and treated vigorously because they are difficult to cure, and the residual scarring can further worsen the disease. Usually, the patient needs a diet high in carbohydrate content and with prescribed limits of fluid, sodium, potassium, phosphorus, and protein.

Pharmacologic highlights

Medications are administered to manage complications: hypertension, infection, renal insufficiency, and end-stage renal disease. Analgesic drugs may be needed for control of the flank pain associated with enlarged kidneys, and hypertension may be controlled with angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonist blockers or by calcium channel blockers.

Independent

One of the most important nursing roles is to promote the patient’s comfort. Encourage tepid baths, relaxation techniques, and other nonpharmacologic methods to improve comfort. Because many patients retain fluid from impaired renal regulatory mechanisms, fluid restriction may be necessary. Work with the patient to determine a personal schedule for fluid intake. If the patient desires, allot some of the fluid intake for ice chips. If possible, administer medications with meals to allow the patient to consolidate fluid intake.

The disease can be emotionally draining for the patient and family. Try to provide quiet time each day to talk with the patient. Answer questions, provide teaching materials, and listen to concerns. If the patient or family is not able to cope effectively, refer for counseling.

Teach the patient to use measures to prevent urinary tract infections. Explain the need to empty the bladder completely when voiding. Encourage female patients to wipe from front to back after having a bowel movement. Explain the mechanism of action of all antibiotics to the patient and stress the need to take them on schedule to maintain blood levels and to take all of them. Teach the patient to notify the primary healthcare provider if any of the following symptoms recur: burning, frequency, urgency, cloudy or red urine, foul-smelling urine.

Evidence-Based Practice and Health Policy

Helal, I., McFann, K., Reed, B., Yan, X.D., & Schrier, R.W. (2013). Changing referral characteristics of patients with autosomal dominant polycystic kidney disease. The American Journal of Medicine, 126(9), 832.e7-832.e11. doi 10.1016/j.amjmed.2012.12.018

  • The availability of long-acting renin-angiotensin-aldosterone system inhibitors since the early 1990s has allowed for more aggressive blood pressure control and better preservation of kidney function in patients with polycystic kidney disease.
  • An analysis of the clinical data of 837 patients treated during two different time periods, 1961 to 1990 and 1991 to 2011, revealed that patients treated during the later time point had significantly lower mean blood pressure (129/82 mmHg versus 142/91 mmHg; p < 0.001), less mean proteinuria (0.25 g/24 hr versus 0.90 g/24 hr; p < 0.0001), lower mean serum creatinine (1.6 mg/dL versus 4.02 mg/dL; p < 0.0001), and were less likely to have hematuria (41.5% versus 52.5%; p = 0.0087).

Documentation guidelines

  • Physical findings: Pain, fluid intake and output, daily weights, serial vital signs, laboratory findings (renal function tests and electrolytes in particular), appearance of urine
  • Response to pain medications and nonpharmacologic methods of pain relief, fluid and dietary restrictions
  • Presence of complications: Urinary tract infection, edema, cardiac disease, intracranial hemorrhage

Discharge and home healthcare guidelines

Teach the patient how to recognize a urinary tract infection and prevent its recurrence: Maintain fluid intake as allowed; complete perineal cleansing; avoid long, hot baths; empty the bladder completely. Teach the patient to notify the physician about the following because of possible deterioration in renal function: nausea, vomiting, and weight loss; changes in the pattern or urinary elimination; pruritus; headaches; a weight gain of more than 5 pounds in 1 week; edema; difficulty in breathing; and decreasing urine output. Stress the need to keep follow-up appointments. Teach the patient how to maintain any prescribed diet restrictions and include the family. Explain all medications, including the dosage, action, side effects, and route.

kidney

either of the two organs in the lumbar region that filter the blood, excreting the end-products of body metabolism in the form of urine, and regulating the concentrations of hydrogen, sodium, potassium, phosphate and other ions in the extracellular fluid. Bean-shaped in the dog, cat, sheep and laboratory animals, lobed in the ox and some fetal animals such as the horse; irregularly lobed in birds. See also renal.
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Dog kidney. By permission from Sack W, Wensing CJG, Dyce KM, Textbook of Veterinary Anatomy, Saunders, 2002

artificial kidney
an extracorporeal device used as a substitute for nonfunctioning kidneys to remove endogenous metabolites from the blood, or as an emergency measure to remove exogenous poisons such as barbiturates. Called also hemodialyzer.
balloon kidney
meat hygiene term for cystic kidney.
basal lamina kidney
part of the filtration barrier of the kidney; is much thicker than most basal laminae.
cake kidney
a solid, irregularly lobed organ of bizarre shape, formed by fusion of the two renal anlagen. Called also lump kidney.
cicatricial kidney
a shriveled, irregular and scarred kidney due to suppurative pyelonephritis.
contracted kidney
an atrophic kidney that may be scarred and granular.
duplicate kidney
occurs in most species, without apparent increase in total renal mass.
enlarged kidney
may be due to polycystic kidney disease, hydronephrosis, pyelonephritis or congenital absence of one kidney resulting in hypertrophy of the other.
fatty kidney
one affected with fatty degeneration.
floating kidney
one that is freely movable, especially a human kidney (normally more firmly fixed than those in quadrupeds); called also hypermobile kidney. See also nephroptosis.
Enlarge picture
Bovine kidney. By permission from Sack W, Wensing CJG, Dyce KM, Textbook of Veterinary Anatomy, Saunders, 2002
fused kidney
a single anomalous organ developed as a result of fusion of the renal anlagen.
giant kidney worm
Goldblatt kidney
one with obstruction of its blood flow, resulting in renal hypertension. Produced experimentally in dogs.
horseshoe kidney
an anomalous organ resulting from fusion of the corresponding poles of the renal anlagen.
hypermobile kidney
one that is freely movable; called also floating kidney. See also nephroptosis.
lump kidney
cake kidney.
kidney meridian points
acupuncture points on the kidney meridian.
pelvic kidney
a kidney which has failed to ascend from its primordial site to the roof of the abdomen.
polycystic kidney disease
the most common congenital renal defect but most cases are sporadic and do not cause clinical illness because there is still sufficient renal mass to avoid uremia. In some cases the enlarged kidney is detected incidentally during a clinical examination. Rarely both kidneys are badly involved and the animal is dead at birth or dies soon afterwards. In some cases, there are signs of progressive renal failure, perhaps not until later in life. The defect is inherited in Persian cats, Cairn terriers and pigs. In Cairn terriers, cysts may also occur in the liver. See also feline perirenal cysts.
pulpy kidney disease
see Clostridium perfringensenterotoxemia.
kidney scan
radioimaging of a kidney by the use of a rectilinear scanner after the intravenous administration of a radiopaque material.
kidney stones
supernumerary kidney
additional kidneys which develop as a consequence of two ureteric buds arising from one mesonephric duct so that two kidneys develop on the one side.
kidney transplant
commonly and successfully performed in experimental dogs. Increasingly used as a therapeutic procedure in clinical veterinary medicine for renal failure in cats and dogs.
turkey egg kidney
a speckled pattern caused by hemorrhagic glomeruli in diseases such as porcine erysipelas.
wandering kidney
floating or hypermobile kidney. See also nephroptosis.
waxy kidney
amyloid kidney.
white-spotted kidney
focal nonsuppurative interstitial nephritis, seen most commonly in calves.

polycystic

containing many cysts.

polycystic kidney disease
see polycystic kidney disease.
polycystic liver
congenital anomaly in which cystic remnants of the bile duct occur in the liver; the bile duct is patent; seen in kittens, pups, piglets.
polycystic ovarian disease
multiple thin-walled cysts in one or both ovaries of the mature bitch; may cause hyperestrogenism.
polycystic pancreas
cystic pancreatic and bile ducts and polycystic kidneys may occur in the same patient.
polycystic renal disease
see polycystic kidney disease.
References in periodicals archive ?
Sonographic assessment of the severity and progression of autosomal dominant polycystic kidney disease: The Consortium of Renal Imaging Studies in Polycystic Kidney Disease (CRISP).
The significance of this patent is that it relates to both nucleic acid-based and antibody-based methods for diagnosing polycystic kidney disease," said Mark Boshar, associate general counsel and chief patent counsel of Millennium.
TreatmentTrends([R]): Polycystic Kidney Disease is a syndicated annual report that provides a view of the current and expected future management of PKD based on primary research fielded with 100 nephrologists in the United States.
Currently, there are several clinical trials ongoing internationally to test the safety and efficacy of rapamycin and related drugs in polycystic kidney disease, explained Jonathan Shillingford, first author on the paper.
Although we will miss having Dan at the helm, we are also excited about the future that new leadership will help us create, and the difference that the PKD Foundation can continue to make in the lives of those with Polycystic Kidney Disease.
They hope that the new discovery would be a crucial step towards a cure for fatal polycystic kidney disease.
Understanding the genetic make-up of the cilia-like structures, through studying the complete genetic code in microorganisms, helps scientists gain a better understanding of polycystic kidney disease (PKD)," Stolc said.
The researchers fed small daily doses of the protein mixture to laboratory rats with polycystic kidney disease, a severe form of kidney disease used as a model for research on CKD.

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