Renal Flashcards
(4 cards)
Acute Glomerulonehritis
Post Infection
Acute glomerulonephritis most often occurs as a complication of a throat or skin infection with streptococcus, a type of bacteria. Acute glomerulonephritis that occurs after a streptococcal infection (poststreptococcal glomerulonephritis) typically develops in children between the ages of 2 and 10 after recovery from the infection. Infections with other types of bacteria, such as staphylococcus and pneumococcus, viral infections, such as chickenpox, and parasitic infections, such as malaria, can also result in acute glomerulonephritis. Acute glomerulonephritis that results from any of these infections is called postinfectious glomerulonephritis.
About half of the people with acute glomerulonephritis have no symptoms. If symptoms do occur, the first to appear are tissue swelling (edema) due to fluid retention, low urine volume, and production of urine that is dark because it contains blood. Edema may first appear as puffiness of the face and eyelids but later is prominent in the legs. Blood pressure increases as kidney function becomes impaired. Some people become drowsy or confused. In older people, nonspecific symptoms, such as nausea and a general feeling of illness (malaise), are more common.
Acute poststreptococcal glomerulonephritis resolves completely in most cases, especially in children. About 1% of children and 10% of adults develop chronic kidney disease.
Glomerulonephritis
Often, chronic glomerulonephritis seems to result from some of the same conditions that cause acute glomerulonephritis, such as IgA nephropathy or membranoproliferative glomerulonephritis. Sometimes, acute glomerulonephritis does not resolve and instead becomes long lasting (chronic). Occasionally, chronic glomerulonephritis is caused by hereditary nephritis, an inherited genetic disorder. In many people, the cause of chronic glomerulonephritis cannot be identified.
When rapidly progressive glomerulonephritis develops, weakness, fatigue, and fever are the most frequent early symptoms. Loss of appetite, nausea, vomiting, abdominal pain, and joint pain are also common. About 50% of people have a flu-like illness in the month before kidney failure develops. These people have edema and usually produce very little urine. High blood pressure is uncommon and rarely severe when it does occur.
Because chronic glomerulonephritis usually causes only very mild or subtle symptoms, it goes undetected for a long time in most people. Edema may occur. High blood pressure is common. The disease may progress to kidney failure, which can cause itchiness, decreased appetite, nausea, vomiting, fatigue, and difficulty breathing.
Diagnosis
Doctors investigate the possibility of acute glomerulonephritis in people whose laboratory test results indicate kidney dysfunction or blood in the urine and in people who develop symptoms of the disorder. Laboratory tests show variable amounts of protein and blood cells in the urine and often kidney dysfunction, as shown by a high concentration of urea and creatinine (waste products) in the blood.
In people with rapidly progressive glomerulonephritis, casts (clumps of red blood cells or white blood cells) are often visible in a urine sample that is examined under a microscope. Blood tests usually detect anemia.
When doctors suspect glomerulonephritis, a biopsy of a kidney is usually done to confirm the diagnosis, help determine the cause, and determine the amount of scarring and potential for reversibility. Kidney biopsy is done by inserting a needle in one of the kidneys under ultrasound or computed tomography (CT) guidance to obtain a small amount of kidney tissue. Although kidney biopsy is an invasive procedure and occasionally can become complicated, it is usually safe.
Additional tests are sometimes helpful for identifying the cause. For example, in the diagnosis of postinfectious glomerulonephritis, a throat culture may provide evidence of streptococcal infection. Blood levels of antibodies against streptococci may be higher than normal or progressively increase over several weeks. Acute glomerulonephritis that follows an infection other than strep throat is usually easier to diagnose because its symptoms often begin while the infection is still obvious. Cultures and blood tests that help identify the organisms that cause these other types of infections are sometimes needed to confirm the diagnosis.
Treatment
When a bacterial infection is suspected as the cause of acute glomerulonephritis, antibiotics are usually ineffective because the nephritis begins 1 to 6 weeks (average, 2 weeks) after the infection, which has, by then, usually resolved. However, if a bacterial infection is still present when acute glomerulonephritis is discovered, antibiotic therapy is started. Antimalarial drugs may be beneficial if glomerulonephritis is caused by malaria. Some autoimmune disorders that cause glomerulonephritis are treated with corticosteroids, drugs that suppress the immune system, or both.
For rapidly progressive glomerulonephritis, drugs to suppress the immune system are started promptly. High doses of corticosteroids are usually given intravenously for about a week, followed by a variable period of time when they are taken by mouth. Cyclophosphamide, an immunosuppressant, may also be given. In addition, plasma exchange is sometimes used to remove antibodies from the blood. The sooner treatment occurs, the less likely are kidney failure and the need for dialysis. Kidney transplantation is sometimes considered for people who develop chronic kidney disease with kidney failure, but rapidly progressive glomerulonephritis may recur in the transplanted kidney.
Taking either an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin II receptor blocker (ARB) often slows progression of chronic glomerulonephritis and tends to reduce blood pressure and the excretion of protein in the urine. Reducing blood pressure and sodium intake are considered beneficial. Restricting the amount of protein in the diet is modestly helpful in reducing the rate of kidney deterioration. End-stage kidney failure can be treated with dialysis or a kidney transplant.
Pyelonephritis
Inflammation of the kidney tissues, calyces and renal pelvis
Commonly caused by bacterial infection that has spread up the urinary tract or travelled through the blood stream to the kidneys
Severe cases can lead to pyonephrosis (pus around kidney), sepsis, kidney failure and even death
Symptoms fever tachycardia painful urination abdominal pain radiating to back nausea tenderness at costovertebral angle
Causes E. coli E. faecalis coliform bacteria and enterococci DM immunocompromised
Diagnosis
Analysis of urine. Presence of nitrite and WBCs
Acute Pyelonephritis
an exudative purulent localised inflammation of the renal pelvis. tubules are damaged by exudate. radiations of bleeding and suppuration
Chronic pyelonephritis
implies recurrent kidney infections, and can result in scarring of the renal parenchyma
Tumours of the Kidney
Kidney cancer accounts for about 2 to 3% of cancers in adults, affecting about 50% more men than women. About 65,000 people develop kidney cancer each year and about 13,000 die of it. Smokers are about twice as likely to develop kidney cancer as nonsmokers. Other risk factors include exposure to toxic chemicals (for example, asbestos, cadmium, leather tanning and petroleum products) and obesity. People who are undergoing dialysis and develop cystic kidney disease and people with certain inherited disorders are also at higher risk of kidney cancer. People affected are usually between 50 and 70 years of age.
Most solid kidney tumors are cancerous, but purely fluid-filled tumors (cysts) generally are not. Almost all kidney cancer is renal cell carcinoma. Another kind of kidney cancer, Wilms tumor, occurs in children
Symptoms
Symptoms may not occur until the cancer has spread (metastasized) or become very large. Blood in the urine is the most common first symptom, but the amount of blood may be so small that it can be detected only under a microscope. On the other hand, the urine may be visibly red. The next most common symptoms are pain in the area between the ribs and hip (the flank), fever, and weight loss. Infrequently, a kidney cancer is first detected when a doctor feels an enlargement or lump in the abdomen.
The red blood cell count may become abnormally high (polycythemia) because high levels of the hormone erythropoietin (which is produced by the diseased kidney or by the tumor itself) stimulate the bone marrow to increase the production of red blood cells. Symptoms of a high red blood cell count may be absent or may include headache, fatigue, dizziness, and vision disturbances. Conversely, kidney cancer may lead to a drop in the red blood cell count (anemia) because of slow bleeding into the urine. Anemia may cause easy fatigability or dizziness. Some people develop high levels of calcium in the blood (hypercalcemia), which may cause weakness, fatigue, slowed reaction times, and constipation. Blood pressure may increase, but high blood pressure may not cause symptoms.
Diagnosis
Most kidney cancers are discovered by chance when an imaging test such as computed tomography (CT) or ultrasonography is done to evaluate another problem, such as high blood pressure. If doctors suspect kidney cancer based on a person’s symptoms, they use CT or magnetic resonance imaging (MRI) to confirm the diagnosis. Ultrasonography or intravenous urography may also be used initially, but doctors must use CT or MRI to verify the diagnosis. If cancer is diagnosed, other imaging tests (for example, chest x-ray, bone scan, or CT of the head, chest, or both) as well as blood tests may be done to determine whether and where the cancer has spread. However, sometimes cancer that has recently spread cannot be detected. Occasionally, surgery is needed to confirm the diagnosis.
Treatment
When the cancer has not spread beyond the kidney, surgically removing the affected kidney provides a reasonable chance of cure. Alternatively, surgeons may remove only the tumor with a rim of adjacent normal tissue, which spares the remainder of the kidney. Although some nonsurgical means of destroying cancer cells are being studied, surgery is usually preferred.
If the cancer has spread into adjacent sites such as the renal vein or even the large vein that carries blood to the heart (vena cava) but has not spread to lymph nodes or distant sites, surgery may still provide a chance for cure. However, kidney cancer has a tendency to spread early, especially to the lungs, sometimes before symptoms develop. Because kidney cancer that has spread to distant sites may escape early diagnosis, metastasis sometimes becomes apparent only after doctors have surgically removed all of the kidney cancer that could be found.
