Chronic kidney disease (CKD)
Chronic Kidney disease is a term used by doctors to include any abnormality of the kidneys, even if there is only very slight damage. ‘Chronic’ means a condition that does not get completely better. Some people think that ‘chronic’ means severe. This is not the case, and often CKD is only a very slight abnormality in the kidneys.
What are the causes of CKD in children?
Chronic Kidney disease in children can be caused by
- birth defects (multicystic dysplastic kidney)
- hereditary diseases (Poly cystic kidney disease)
- infection (recurrent pyelonephritis, glomerulonephritis)
- nephrotic syndrome
- systemic diseases (Lupus – SLE)
- Urine blockage or reflux (posterior urethral valve, vesico ureteric reflux)
From birth to age 4, birth defects and hereditary diseases are the leading causes of kidney failure. Between ages 5 and 14, kidney failure is most commonly caused by hereditary diseases, nephrotic syndrome, and systemic diseases. Between ages 15 and 19, diseases that affect the glomeruli are the leading cause of kidney failure, and hereditary diseases become less common
Measuring kidney function – eGFR
A test called the eGFR (estimated glomerular filtration rate) is used to measure kidney function. The eGFR is calculated by the laboratory from the level of a chemical called creatinine in the blood.
A normal eGFR is about 100 ml/min in young adults, so the eGFR is sometimes referred to as the percentage of normal kidney function, as the number is the same.
Some young adults with normal kidneys will have an eGFR as low as 75 ml/min, and this falls by about 1 ml/min per year as people get older, so many healthy people aged 75 will have an eGFR of 50-60 ml/min.
Most laboratories now report eGFR alongside their measurements of blood creatinine levels and this is the most reliable way to obtain an eGFR result. However, different laboratories use different methods to measure serum creatinine, and each of these methods gives slightly different answers.
What are the stages of CKD?
CKD is divided into 5 stages:-
- CKD stage 1 is eGFR greater than 90 mls/min, with some sign of kidney damage on other tests (if all the other kidney tests are normal, there is no CKD).
- CKD stage 2 is eGFR 60-90 with some sign of kidney damage (if all the kidney tests are normal, there is no CKD).
- CKD stage 3a is eGFR 45-59 ml/min, a moderate reduction in kidney function
- CKD stage 3b is eGFR 30-44 ml/min, a moderate reduction in kidney function
- CKD stage 4 is eGFR 15-29 ml/min, a severe reduction in kidney function
- CKD stage 5 is e GFR less than 15 ml/min, established kidney failure, when dialysis or a kidney transplant may be needed.
Proteinuria
Leakage of protein into the urine increases the risk of any kidney disease. Everyone with CKD should therefore have a urine test to measure the amount of protein in the urine, and if this level is high, they will receive more careful treatment and possibly more extensive investigations.
How is kidney disease in children diagnosed?
A health care provider diagnoses kidney disease in children by completing a physical exam, asking for a medical history, and reviewing signs and symptoms. To confirm diagnosis, the health care provider may order one or more of the following tests:
Urine Tests
Dipstick test for albumin. The presence of albumin in urine is a sign that the kidneys may be damaged. Albumin in urine can be detected with a dipstick test performed on a urine sample. The urine sample is collected in a special container in a health care provider’s office or a commercial facility and can be tested in the same location or sent to a lab for analysis. With a dipstick test, a nurse or technician places a strip of chemically treated paper, called a dipstick, into the person’s urine sample. Patches on the dipstick change color when albumin is present in urine.
Urine albumin-to-creatinine ratio. A more precise measurement, such as a urine albumin-to-creatinine ratio, may be necessary to confirm kidney disease. Unlike a dipstick test for albumin, a urine albumin-to-creatinine ratio—the ratio between the amount of albumin and the amount of creatinine in urine—is not affected by variation in urine concentration.
Blood test. Blood drawn in a health care provider’s office and sent to a lab for analysis can be tested to estimate how much blood the kidneys filter each minute, called the estimated glomerular filtration rate or eGFR.
Imaging studies. Imaging studies provide pictures of the kidneys. The pictures help the health care provider see the size and shape of the kidneys and identify any abnormalities.
Kidney biopsy. Kidney biopsy is a procedure that involves taking a small piece of kidney tissue for examination with a microscope. Biopsy results show the cause of the kidney disease and extent of damage to the kidneys.
How is CKD managed in children?
Treatment for kidney disease in children depends on the cause of the illness. A child may be referred to a pediatric nephrologist—a doctor who specializes in treating kidney diseases and kidney failure in children—for treatment.
Children with a kidney disease that is causing high blood pressure may need to take medications to lower their blood pressure. Improving blood pressure can significantly slow the progression of kidney disease. The health care provider may prescribe
- angiotensin-converting enzyme (ACE) inhibitors, which help relax blood vessels and make it easier for the heart to pump blood
- angiotensin receptor blockers (ARBs), which help relax blood vessels and make it easier for the heart to pump blood
- diuretics, medications that increase urine output
As kidney function declines, children may need treatment for anemia and growth failure. Anemia is treated with a hormone called erythropoietin, which stimulates the bone marrow to produce red blood cells. Children with growth failure may need to make dietary changes and take food supplements or growth hormone injections.
Birth Defects
Children with renal agenesis or renal dysplasia should be monitored for signs of kidney damage. Treatment is not needed unless damage to the kidney occurs. Those with single kidney status (absent by birth/ removed due to non functioning/ multi cystic dysplastic kidney) should avoid medications that could damage their kidneys like – NSAID (Ibuprofen, diclofenac). Aminoglycosides (gentamicin/amikacin) may need careful monitoring of dose and levels to prevent damage to the only kidney functioning. Several native medications (siddha, ayurveda etc) may have multiple ingredients that could potentially damage the kidney and are best avoided.
Hereditary Diseases
Children with PKD tend to have frequent urinary tract infections, which are treated with bacteria-fighting medications called antibiotics. PKD cannot be cured, so children with the condition receive treatment to slow the progression of kidney disease and treat the complications of PKD.
Alport syndrome also has no cure. Children with the condition receive treatment to slow disease progression and treat complications until the kidneys fail.
Infection
Treatment for hemolytic uremic syndrome includes maintaining normal salt and fluid levels in the body to ease symptoms and prevent further problems. A child may need a transfusion of red blood cells delivered through an intravenous (IV) tube. Some children may need dialysis for a short time to take over the work the kidneys usually do. Most children recover completely with no long-term consequences.
Children with post-streptococcal glomerulonephritis may be treated with antibiotics to destroy any bacteria that remain in the body and with medications to control swelling and high blood pressure. They may also need dialysis for a short period of time.
Nephrotic Syndrome
Nephrotic syndrome due to minimal change disease can often be successfully treated with corticosteroids. Corticosteroids decrease swelling and reduce the activity of the immune system. The dosage of the medication is decreased over time. Relapses are common; however, they usually respond to treatment. Corticosteroids are less effective in treating nephrotic syndrome due to focal segmental glomerulosclerosis or membranoproliferative glomerulonephritis. Children with these conditions may be given other immunosuppressive medications in addition to corticosteroids. Immunosuppressive medications prevent the body from making antibodies.
Systemic Diseases
Lupus nephritis is treated with corticosteroids and other immunosuppressive medications. A child with lupus nephritis may also be treated with blood pressure-lowering medications. In many cases, treatment is effective in completely or partially controlling lupus nephritis.
Diabetic kidney disease usually takes many years to develop. Children with diabetes can prevent or slow the progression of diabetic kidney disease by taking medications to control high blood pressure and maintaining normal blood glucose levels.
Urine Blockage and Reflux
Treatment for urine blockage depends on the cause and severity of the blockage.
- Posterior urethral valves may need valve ablation
- Vesico ureteric reflux may need endoscopic or open surgical treatment
What is the treatment for CKD?
Eating, Diet, and Nutrition
For children with CKD, learning about nutrition is vital because their diet can affect how well their kidneys work. Parents or guardians should always consult with their child’s health care team before making any dietary changes. Staying healthy with CKD requires paying close attention to the following elements of a diet:
- Protein. Children with CKD should eat enough protein for growth while limiting high protein intake. Too much protein can put an extra burden on the kidneys and cause kidney function to decline faster. Protein needs increase when a child is on dialysis because the dialysis process removes protein from the child’s blood. The health care team recommends the amount of protein needed for the child. Foods with protein include: eggs, milk, cheese, chicken, fish, red meats, beans, yogurt, cottage cheese
- Sodium. The amount of sodium children need depends on the stage of their kidney disease, their age, and sometimes other factors. The health care team may recommend limiting or adding sodium and salt to the diet. Foods high in sodium include: canned foods,some frozen foods, most processed foods, some snack foods, such as chips and crackers.
- Potassium. Potassium levels need to stay in the normal range for children with CKD, because too little or too much potassium can cause heart and muscle problems. Children may need to stay away from some fruits and vegetables or reduce the number of servings and portion sizes to make sure they do not take in too much potassium. The health care team recommends the amount of potassium a child needs. Low-potassium fruits and vegetables include: apples, cranberries, strawberries, blueberries, raspberries, pineapple, cabbage, boiled cauliflower, mustard greens, uncooked broccoli
High-potassium fruits and vegetables include: oranges, melons, apricots, bananas, potatoes, tomatoes, sweet potatoes, cooked spinach, cooked broccoli - Phosphorus. Children with CKD need to control the level of phosphorus in their blood because too much phosphorus pulls calcium from the bones, making them weaker and more likely to break. Too much phosphorus also can cause itchy skin and red eyes. As CKD progresses, a child may need to take a phosphate binder with meals to lower the concentration of phosphorus in the blood. Phosphorus is found in high-protein foods. Foods with low levels of phosphorus include: liquid nondairy creamer, green beans, popcorn, unprocessed meats from a butcher, lemon-lime soda, root beer, powdered iced tea and lemonade mixes, rice and corn cereals, egg white, sorbet
- Fluids. Early in CKD, a child’s damaged kidneys may produce either too much or too little urine, which can lead to swelling or dehydration. As CKD progresses, children may need to limit fluid intake. The health care provider will tell the child and parents or guardians the goal for fluid intake.
Treatment for CKD stages 1 and 2
The blood pressure should be treated carefully. If it is high for the age, tablets are usually needed, and the aim is to get the blood pressure down to normal. A blood test to check eGFR should be performed once a year. If the urine tests show a lot of protein in the urine, or the kidney function is declining over time, the case will be discussed with a kidney specialist, or a referral may be made to a kidney specialist.
Treatment for CKD stage 3a and 3b
Treatment as in CKD stages 1 and 2, but with more careful monitoring for declining kidney function. Often at this stage medications are added to improve haemoglobin (iron supplements) treat acidosis (sodium bicarbonate) and treat calcium deficiency (calcium supplements). Medication (ACE inhibitors) may be added to control BP and minimise protein loss in urine.
Treatment for CKD stages 4 and 5
Any medications should be reviewed, as the dose may need to be altered and some drugs may need to be avoided as they could damage the kidneys further. This should include prescribed drugs and any drugs bought at the chemist and complementary therapies. In CKD stages 4 and 5 it is usually necessary to get advice from a kidney specialist, especially in stage 5
Dialysis and Kidney Transplant
What Is Dialysis?
When someone’s kidneys can no longer do their job, beyond stage 5 CKD and can’t get better, a person has End Stage Renal Disease (ESRD) and the doctor might say the kidneys are failing. This means they are not working well and the person may need help. The person may be losing weight or feeling tired and sick.
A medical treatment called dialysis (say: dye-AL-ih-sis) can take over the job of filtering your blood. Through dialysis, a person is hooked up to an artificial filtering system that removes waste from the blood.
How Does Dialysis Work?
There are two dialysis methods: hemodialysis and peritoneal dialysis.
Hemodialysis uses a filtering machine to remove waste and extra fluid from the blood.
Peritoneal dialysis, the actual filtering is done by the lining (peritoneum) of the person’s belly! Kids who need dialysis are most likely to get this type.
With hemodialysis, the person’s blood travels through tubes to the machine — called a dialyzer — which removes extra fluids and waste. Once the blood is cleaned, the machine sends it back to the person through another tube. This process typically takes about 4 hours and has to be done three times each week in a dialysis clinic. A central venous line may be inserted in the neck for temporary hemodialysis. Those who need long term haemodialysis may be advised to undergo a minor surgery called AV fistula, which makes it easy for dialysis each time..
The most commonly used type of peritoneal dialysis for kids, called continuous cyclic dialysis, uses a machine to put a cleansing solution called dialysate in the person’s belly, usually eight to 12 times each night. As blood flows naturally through the blood vessels in the belly, extra fluid and waste products in the blood seep out into the dialysate in the belly. Meanwhile, the dialysate cleanses the blood and rebalances the blood’s chemistry. After about an hour, the machine drains the dialysate from the belly. A procedure called PD catheter insertion may be required to facilitate peritoneal dialysis.
Some kids can sleep through dialysis. Others might find it uncomfortable and inconvenient, so a different type of peritoneal dialysis might be used. The good news is that afterward, body fluid levels are balanced and waste is gone.
Other Options: Kidney Transplantation
In some cases, a kid can get a new kidney. This is called a transplant, which means receiving an organ from another person’s body. This operation can be a big help to kids with kidney disease because after the surgery they may no longer need dialysis treatments.