Q: My father's CT scan findings are suggestive of slightly poor excretion of I.V. contrast by kidney, due to CRF. What are the reasons of kidney failure? What is CRF? How does dialysis work and how can we judge the frequency at which dialysis is required? What is a shunt operation?

A:Kidneys get affected by diseases like uncontrolled diabetes, uncontrolled high blood pressure, inflammation in the kidney called glomerulonephritis, certain nephrotoxic drugs like aminoglycosides & non steroidal anti-inflammatory drugs, urinary tract infection and urinary stones. Dialysis is a method of cleansing blood of waste products not removed by the failing kidneys. Arterio-venous shunt or fistula preferably is required to be made in the forearm 4-6 weeks before dialysis is required to get a blood flow of 250-300 ml/minute for dialysis. Dialysis is required usually once kidney function falls to less than 10-15% and in ordinary circumstances is done thrice a week. In India, because of cost constraints and availability, a compromise is made and twice a week dialysis is provided. It is usually inadequate and leads to poor quality of life, malnutrition and poor survival due to inadequate dialysis. Thus 12-15 hours of dialysis/week given at least thrice a week. Kidneys work 24 hours and do not rest, thus intermittent dialysis will never be as good as normal kidney function.