Dr. Maddux, statistics show that the number of people with chronic kidney failure is rising steadily. Why is this?
Firstly, the number of unreported or unrecognized cases is no longer as high as it used to be. Medical advances have made kidney failure much easier to diagnose. Another reason is the aging population : The percentage of people suffering from kidney failure increases with age. In addition, in many parts of the world, more and more people are suffering from diseases that can lead to kidney failure, such as diabetes, obesity, and high blood pressure. A combination of all these factors is pushing up the number of patients with kidney disease as a public health condition. Fortunately, though, we are now in an ever better position to effectively help these patients with their care.
Through dialysis, for instance. How does dialysis work?
In dialysis, a machine connected to an “artificial kidney” cleanses the blood. In this process, the blood is transported out of the body, runs through the dialyzer, where it is cleansed, and is then returned safely to the body. The physical principles of diffusion and ultrafiltration play a key role in this.
Patients need a vascular access before they can receive treatment. Why is this access so important?
Because it isn’t a one-time treatment. We have to be able to perform blood cleansing and purification every one to two days on a long-term basis, which is why choosing the best access to the blood stream is crucial. Safety and efficiency are our top priorities; so a stable vascular access that is placed in the arm must be regularly checked and well maintained.
What different types of access are there?
There are three types of vascular access : an AV fistula, an AV shunt, and a central venous catheter. The fistula is always the first and best choice. In a minor surgical procedure, a vein and an artery are joined together on the patient’s wrist, arm or leg. This “bypass” causes the blood to flow particularly fast and profusely. A well maintained, clean, and patent fistula can be used for decades. We train our patients to take close care of this lifeline and check that the fistula is working properly on a regular basis.
Some patients’ veins are not strong enough for this kind of vascular access. What happens then?
In this case, physicians usually revert to the arteriovenous ( AV ) shunt. This is a small plastic tube that is inserted between an artery and a vein. We use a material similar to material found in winter clothing : Goretex. This method is the second-best option. Artificial AV shunts are somewhat more susceptible to infection and get blocked more quickly than fistulas with natural blood vessels. The third option is a central venous catheter. In this case, a plastic tube is inserted in the neck under local anesthetic into the large blood vessels, and can be used for dialysis treatment afterwards. The advantage is immediate access to the bloodstream. The disadvantage is the far greater danger of infection and the risk of catheter blockage with lower rates of blood flow.
How does the physician decide which access method is best for the patient?
The physician and the patient jointly decide on the most suitable access method on a case-by-case basis. The most important criteria are the patient’s general state of health and possible vascular disease. However, timing is also a factor : The catheter can be used on the same day, whereas the fistula usually takes four to six weeks to develop. In an emergency situation, that is too long.
For dialysis patients, choosing the right medications and dietary supplements is also crucial. What is an example of medications that patients with kidney disease need?
Many dialysis patients suffer from anemia. This is because healthy kidneys produce the hormone erythropoietin, which stimulates the formation of red blood cells. If the kidneys don’t work properly, anemia leads to reduced transportation of oxygen to the organs. Consequently, patients feel fatigued, have trouble concentrating and can have substantially reduce levels of energy. For dialysis patients, it is therefore important to replace the hormone with medications to avoid becoming dependent on blood transfusions. The body also needs sufficient iron for the production of red blood cells. Blood transfusions can often be prevented through a combination of good medication, a balanced diet, and regular monitoring of blood cell and iron levels.
Fresenius Medical Care recently reorganized the medication of dialysis patients at its own clinics for the management of anemia. What have you improved?
Previously, we treated our patients in the U. S. with a short lasting erythropoietin medication, which was administered every time the patient underwent dialysis. The drug had been well received for many years. However, for some time now, we have been looking for a more efficient, longer-lasting formula. The new drug only has to be dispensed once every two weeks or every month instead of during each dialysis treatment. This makes things a lot easier for physicians, staff and patients while maintaining a smooth control of the blood cell production for patients.
Kidney failure often also leads to bone disease. What medications help to combat this?
A key vitamin in the calcium and bone make-up is vitamin D; this is normally activated by the healthy kidney. Generally, kidney failure patients can no longer activate enough vitamin D, which often results in an insufficient control of the bone and mineral chemicals within the body. To compensate for this deficiency, the body extracts calcium from the bones weakening them. To stop the bones from becoming diseased, we have to ensure that patients have enough active vitamin D, which is then administered orally or intravenously. Ensuring the right medication and diet takes time and, above all, lots of discussions between patients, dietititans, and nephrologists. We are constantly working to optimize the therapy and treatment outcomes and the efficient use of these therapies.
Treatment of kidney failure has a long history. Some things have certainly changed for the better compared to the early years – what were the most important milestones?
Kidney failure used to be a fatal disease in almost all cases, whereas today, we can treat lots of people with kidney failure successfully. Dialysis as a machine-based process goes back to the 1940 s. Back then, the Dutch internist Willem Kolff noted that if two fluids are separated by a semipermeable membrane, the fluids will have the same chemical composition over time. Based on this knowledge, he built the first “artificial kidney” for blood purification. Another major step was the development of the Scribner shunt. Belding Scribner developed the first long-term use shunt, a vascular access device for dialysis treatment that takes his name, at the University of Washington in Seattle in 1960.
Some of the key innovations in dialysis over the last 50 years have come from Fresenius Medical Care …
That’s right. Machines that can control and precisely determine the fluid status are among the most important innovations by Fresenius Medical Care. The use of bicarbonate as a buffer substance in the dialysate fluid was equally innovative. This has the advantage of reducing the side effects of treatment, such as lower blood pressure, nausea, or cramps. Other innovations have included the evolution of blood volume devices like the BVM and CritLine devices that help maintain safe leves of fluid removal during dialysis, devices to assist in forms of home dialysis, and the evolution of the hollow fiber dialyzer from the original flat plate dialysis with biocompatible dialysis membrane in these dialyzers.
You and your wife set up the “Nephrology Oral History Project”. Tell us about this.
My wife is a nephrologist working on a variety of Kidney Diseaes Initiatives for Fresenius Medical Care. Many years ago, she started recording the voices of early pioneers of dialysis. Together, we collected interviews with physicians, nephrologists, patients, and nurses and put them on a website. We are particularly interested in what motivated them – and their courage was simply remarkable.
So much for the past. What will the future bring, in your opinion?
In the future, we aim to give our dialysis patients even better and more wide-ranging opportunities to live productive lives with their disease and to use our resources to improve their quality of life with kidney failure or chronic kidney disease. They spend so much time of their lives with their disease that we feel an organized system of care that recognizes each patients unique needs will provide a way to constantly improve the opportunity to meet their goals through coordinated therapies. Our aim is to provide them with the best treatment and to help them with practical aspects of their daily life.