Stone Disease of the Kidneys

Stone Disease of the Kidneys.

Stone formation in the kidneys is a common disease. About 1in 8 men and 1 in 20 women suffer from the symptomatic stone disease. Stone formation without symptoms is even more common.

About ¾ of the stones contain calcium and 10% have uric acid. Rest are due to combinations and rare diseases.

Calcium Stones

These contain calcium oxalate or calcium phosphate. Former is more common.

The risk factors for stone formation are

In Urine 

Low volume , High calcium in urine, high acid concentration and low citrate levels.

In Diet

Water and fluid intake is low, fruits are seldom eaten, food has high oxalate level or if calcium content of the diet is on the lower side.

Other diseases with high risk for stone formation are overweight, gout, diabetes, recurrent urinary tract infection etc. Bariatric surgery is a very significant risk factor.

If kidneys have certain diseases like the inability to excrete acid, a stone formation may occur.

Symptoms: Stones if they are in the urinary path (ureters or urethra) pain colicky in nature often radiating from back to lower abdomen or upto urine passage opening (urethra) may occur. This pain is at times very severe necessitating urgent consultation.

Urine may be passed in drops and is often red in colour due to blood.

If the passage of urine is blocked due to stone at any site, high pressure develops upstream of the blockage. If not treated early this may permanently damage the kidney.

In India, an untreated stone disease is a common cause of permanent renal failure.

Stone analysis, various urine tests aid in finding the underlying cause of stone formation. A cause is found in about ½ of the cases.

Prevention

Stone disease can usually be prevented by adequate water intake, fruits or fruit product ingestion, enough calcium and lower salt in the diet and early complete treatment of urinary tract infection.

Eating lower oxalates in the diet is of questionable value.

Small stones pass spontaneously with more fluid ingestion and alpha blockers. Large stones need to be removed by surgery.

Polycystic Kidney Disease

Polycystic Kidney Disease

Introduction and Genetics:

This is one of the commonest genetic disorders affecting kidneys. The disease runs in families. The reported incidence is 1 in 400 to 1in 1000. Both man and woman are affected. If one parent is affected the children of the patient have 50% chance of inheriting the disease.

One-quarter of patients may not provide a history of the disease in parents or siblings because of death prior to diagnosis, an undiagnosed disease in the other members or insufficient investigation of the other family members.

The disease can be found by genetic testing in the fetus. However as the disease has normal mentation and causes problems in adult life, genetic testing in a fetus are rarely carried out.

The disease is usually of two types. 85% suffer from an abnormality of Chromosome 16 and rest from Chromosome no 4. Type PKD 1 (ch 16 variety) is the more severe form. It causes renal failure at about 55 Yrs of age while Type PKD II at 70 Yrs of age.

Those patients with hypertension, males, with larger kidney size develop renal failure early.

There are hundred to thousands of cysts distributed in both kidneys in all areas. Liver and pancreas, and sometimes lungs may also have cysts. A fewhave intracranial aneurysms( dilatation of blood vessels). Cardiac valvular defects are also common. Affected kidneys may have a stone formation or these can be infected.

Patients may have initial symptoms of abdominal pain due to large kidneys, high blood pressure or urinary tract infections. USG done for unrelated symptoms sometimes reveals the diagnosis.

In affected families, the  no of cysts at various age groups helps in ascertaining the probability of disease. It has to be distinguished in initial cases (probands) where family history is not available, from other cystic diseases of the kidneys.

Treatment includes control of high blood pressure, statins, lower protein intake and general measures. Patients may waste salt in their urine and may suffer from low sodium levels. ACE inhibitors and ARBs are often used for the control of BP while care is taken to look for their side effects and safety.

A vasopressin inhibitor has been used increasingly for slowing/ Stopping the disease progression in ADPKD patients. It is more useful if started early before the s cr is very high.

Death is more often due to cardiac or strokes rather than kidney failure.

Drugs after Renal Transplant: II

Drugs after Renal Transplant: II

There are a number of other drugs used in transplant recipients after they are discharged from the hospital.

In the initial period these include:

Antibiotics to prevent urinary tract infections. These may need to be continued for 6 months. These (Trimethoprim + Sulfas) may prevent pneumocystis infection of the lungs as well.

A common infection in transplant recipients is due to cytomegalovirus. This can be prevented by a drug called Valgancyclovir. It is usually given for 90 – 100 days. It is a costly drug and the total treatment may cost about 25000 to 45000 ₹ depending on the dose and duration of CMV prophylaxis.

Anti Hypertensive drugs, sugar lowering drugs may be required in cases of Hypertensives and diabetics.

Hypertension in Dialysis Patients

Hypertension in Dialysis Patients I

About ½ of dialysis patients have high BP while on regular dialysis. A pre-dialysis BP > 140/90 mm Hg is required for the diagnosis of hypertension in this group.

Mortality, cardiovascular events including heart attacks, congestive heart failure, strokes are more common in hypertensive dialysis patients.

Systolic BP < 110 mm Hg Or >160 mm Hg is also associated with poor outcome in dialysis patients. Hence the BP has to be optimised and kept somewhere between these two limits.

Causes of high BP in dialysis population:

Expansion of body water and blood volume

Reduced blood supply to kidneys

Salt accumulation

High Calcium level

Thickened arteries

Preexisting essential hypertension

Increased sympathetic nervous activity

Poor water compliance

Poor drug compliance.

BP is measured before and after dialysis. For better overall BP, 24-hour ambulatory recordings are made.

Coming up Treatment of hypertension in the dialysis population.

Life After Kidney Transplant

Life After Kidney Transplant

Kidney transplant is preferable to lifelong dialysis as it usually provides a better quality of life. After initial 14 days, the risk of death is less in transplant recipients compared to patients on dialysis.

The human body tries to throw out the transplanted kidney as it is perceived as a foreign body by the tissues.

To overcome this tendency of the body, drugs are required to be taken lifelong by transplant recipients. These drugs are called immunosuppressives.

These drugs also reduce body's reaction in case an infectious agent gains access to the body. Hence infections can occur more often, with smaller doses of bacteria and viruses. These infections may be severe and life threatening. At times bacteria and viruses which do not cause infections in other healthy individuals may also cause infections in transplant recipients.

These infections have to be suspected more often, investigated more aggressively and treated vigorously with appropriate antibiotics by a physician. In India, most  deaths take place with a functioning graft due to infections. Hence the importance of preventing these.

How to prevent infections in transplant recipients:

Infections spread by food, water, contact and by inhalation of droplets containing pathogens( bacteria, virus, fungi etc). They can also be introduced during surgery, by IV lines, tubes placed in the body and during various medical procedures.

Infections from water are prevented by drinking filtered / RO and clean water only. Tubewells, river, ponds, most municipal water in cities and towns may be having infectious agents. Hence it is not safe to drink untreated water. In case of dire necessity, boiled water as in tea can be consumed.

Food should be fresh, made from clean ingredients in clean utensils and consumed early. Food kept in refrigerator (especially as power cuts are common place) can be contaminated and when consumed may cause infectious diarrhoea.

Close contact of persons with obvious respiratory infections eg common cold, influenza, pneumonia, chickenpox, measles, sore throat etc should be avoided. Good quality masks (as used for preventing the spread of swine flu) are used for prevention of respiratory infections. Vaccines against pneumonia are similarly useful to protect against pneumonia.

Hygiene should be immaculate. In hospitals etc ensure absolute asepsis to prevent any infections during sampling, IV infusions, injections or surgical procedures.

If adequate care is taken a person can lead an active life. He can live a normal long, productive and useful life.

Next coming up

Various drugs after a transplant.

 Renal Transplant : Survival after kidney transplant.

Renal Transplant : Survival after kidney transplant.

Renal transplant is the treatment of choice for patients of End Stage Renal Disease. Compared to Hemodialysis and peritoneal dialysis, the patients live longer and overall have a better quality of life. After the 1st 2 weeks of transplant, the death rate in transplant patients is lower than patients on dialysis.

In the USA, survival recipients of living donor kidneys at 5 yrs is now 91 % while in the case of cadaver kidneys, it is 84 %. If not so well functioning kidneys (called extended donor kidneys ) are transplanted survival at 5 yrs is 70%. This does not mean that all kidneys are working, but the patients are living.

Survival is better in children and less in those over 40, men compared to women, smokers, those suffering from diabetes and heart diseases.

The death when it occurs is usually due to heart diseases or due to infections. The no of cancers also increases after transplant and this is another major cause.

Compared to normal population , renal transplant still is a serious risk for mortality. For example in US in the 1st year after transplant death risk in patients is 14 times compared to age and sex matched population.