Hope for kidney sufferers
Posted on 27 November 2014
Without kidneys, the body’s purification plant, you’d be like a coffee machine without a filter. But there is hope: here we explain how dialysis could take over the kidneys’ function.
Until the mid-20th century, patients suffering from renal failure did not live long. Thanks to the Dutch doctor Willem Kolff, who fashioned the first artificial kidney in 1943, our chances of survival if our superfilters threw in the towel are much improved today.
Willem experimented with orange-juice tins, blood-filled sausage casings and even a washing machine in the process of designing one of the most important inventions of modern medicine. In 1945, the first patient connected to his dialysis machine survived – the 67-year-old woman, who’d been a coma due to renal failure, lived on for another seven years.
Before dialysis can commence…
If your kidneys don’t function properly, toxins accumulate in your body, your blood pressure rises, and excess fluids cause your limbs to swell.
However, according to Dr Derek Miller, a renal specialist at Mediclinic Constantiaberg, few South Africans experience deterioration of kidney function to the extent that the person becomes eligible for dialysis and a kidney transplant. It is only once a patient’s kidney function dips below 15% that dialysis would be considered – and even then, treatment can only commence if they’re showing symptoms of renal failure or if the toxicity levels in their blood are so high that they become life-threatening.
The big question
Next, it will be determined whether the patient should receive haemodialysis or peritoneal dialysis. Haemodialysis would be done three times a week for approximately four hours at a dialysis unit, where a dialysis machine imitates some of the kidneys’ functions.
Peritoneal dialysis involves running a special fluid through a catheter into the abdominal cavity. Waste products flow from small blood vessels into this fluid, which is then drained and replaced with purified fluid. You administer the treatment yourself, four times a day, and it can be done at home, at work or even while you’re travelling.
Should haemodialysis be the chosen treatment, the person will need to be hooked up to a dialysis machine. For quick access tot the circulation system, a haemodialysis line can be tunnelled under the skin under local or mild anaesthesia, explains Dr Theo Hattingh, a nephrologist at Mediclinic Panorama. However, it is ideal to create an arteriovenous fistula – a connection between the artery and the superficial vein – in the arm that could be punctured with a needle three times a week, Dr Hattingh adds, but this process could take about three months.
At the dialysis unit…
1. As soon as a patient is ready for dialysis, they report to their local unit, where they’ll be weighed have their temperature, blood pressure and pulse rate taken.
2. Once the person lies down comfortably, a nursing sister will insert two needles in their arm.
3. Their blood will travel along one needle and a special tube into a dialyser – a type of artificial kidney with thousands of tiny hollow fibres inside. The blood flows through these fibres while a fluid known as dialysate flows in the opposite direction outside the fibres. ‘The toxins pass into the dialysate through diffusion,’ Dr Hattingh explains.
4. The purified blood then returns to the body along another tube and the second needle.
5. After the treatment, the sister will remove the needles and dress the wounds to prevent bleeding.
Dialysis could extend someone’s life by many years but cannot replace the full function of a healthy kidney. Not everyone is lucky enough to qualify for a kidney transplant – but technology and Willem’s legacy makes it possible to lead a normal life even without a new kidney.
Renal failure: red alerts
Someone with renal failure would feel nauseous, lose their appetite and suffer significant weight loss. Other symptoms include high blood pressure, headaches and swelling of the limbs.
‘The idea is to detect kidney problems early on, rather, by having your GP test your urine tested for blood and protein regularly,’ advises Dr Derek Miller, a renal specialist at Mediclinic Constantiaberg. ‘If your GP is concerned about the results, they’ll screen your blood for toxins the kidneys normally get rid of.’
Should this test indicate renal failure, a renal specialist will establish whether it is acute or chronic.
How do your kidneys work?
The kidneys are two bean-shaped organs, each about as big as your fist, on either side of the spine. Blood flows through the renal arteries to the kidneys and exit them through the renal veins. Inside each kidney is a network of filters (nephrons) that filter toxins from the blood and convert them into urine. About 180 litres of blood is filtered this way per day!
The kidneys also regulate the pH levels of your blood, your blood pressure and the amount of water in the body, and excrete hormones that stimulate the formation of red blood cells.
Did you know?
The body’s full blood supply circulates through the kidneys approximately 12 times per hour.