Published in Panorama
When the Kidneys Fail
45 year old Vincent is hooked on to an apparatus that resembles an automated teller machine. He’s catching up on world news, looking comfortable in a recliner. A couple of needles poked into blood vessels near his wrist are attached to plastic tubes leading to the machine. The machine is a dialyser in one of the hemodialysis centers in his neighbourhood. This schedule, thrice a week, three to four hours each session, has been Vincent’s routine for the past four years. A victim of renal failure, thanks to dialysis, Vincent has nevertheless been leading a full and active life as a Sales Executive, traveling overseas, frequently.
Why dialysis? Dr.Talwalkar, Nephrologist, Bangalore Hospital explains, “All patients with kidney or renal failure require dialysis. Kidney failure itself, may be temporary and acute or permanent and chronic.”
What causes Acute or Temporary renal failure? Most commonly temporary renal failure occurs as a result of infection from malaria, jaundice, dengue fever, leptospirosis and diarrhoeal diseases, particularly common in the developing countries of the world. Another group of patients who suffer from acute renal failure are those who have been on potent, life-saving drugs, analgesics and painkillers used to fight pain and infection as in arthropathy, osteo-arthritis, etc. Once the drugs are withdrawn, the kidneys resume their normal functioning, explains Dr.Talwalkar.
Contrast medium used in diagnostic techniques as CT Scans and Angiogram which are important for making brain and cardiac evaluations, also have a damaging effect on the kidneys, reveals Dr.Talwalkar. “Especially elderly patients who are diabetics, have longstanding hypertension or those who have a borderline kidney dysfunction, are likely to develop progressive but temporary kidney failure after the use of this contrast medium.”
For those patients who suffer from temporary or acute renal failure, dialysis may be required till the kidneys recover their normal functions. This is a short lasting process, lasting for up to may be 3 months, reveals Dr.Talwalkar.
In contrast to this, permanent kidney damage may occur in patients with long standing hypertension and diabetes. These patients will require dialysis till they can find a kidney donor to undergo transplant.
What is Dialysis and how does it work? Dialysis is the process of removing toxins, either directly from the blood by Haemodialysis or indirectly via peritoneal fluid, termed Continuous Ambulatory Peritoneal Dialysis(CAPD), using diffusion across a semi-permeable membrane or ultrafiltration.
Dr.Talwalkar explains, “Haemodialysis is generally a hospital-based procedure wherein the patient needs to visit the dialysis unit to undergo dialysis for a period of 10-12 hours spread over these 3 days. The process involves blood being circulated outside the body and getting cleaned inside the dialysis machine or dialyser before returning to the patient. Once the procedure is complete, the patient can go home without further hospitalization. Being used in almost 90% of cases, the process is a very sophisticated one and generally well-tolerated by patients.”
The dialyser or artificial kidney is full of semi-permeable membranes. Blood is dialysed against a dialysis solution or dialysate, across these membranes. From either ends of the dialyser, blood and dialysate flow in, and exchange takes place between them whereby the dialysate removes the impurities and toxins from the blood. The purified blood is then returned to the patient. This dialysate basically consists of water and various other substances which we order, depending upon each patient, explains Dr. Talwalkar.
Before hemodialysis is done, the doctor must make an entrance into the patient’s blood vessel, known as access. “This surgery is generally done on the hand so as to allow us to draw the blood at a very high rate into the dialyser”, explains Dr.Talwalkar. Various parameters like temperature, purity of dialysate, dialyse rate are monitored by the machine to secure the patient’s safety.
In contrast to this, CAPD does not need any specialized machine. It allows patients to be mobile, travel anywhere around the globe, continue with their work, go out on picnics, cruises, whatever. These patients, without the assistance of a doctor or nurse, can dialyse themselves simply by carrying the peritoneal dialysis bag which comes in 1 and 2 litre packages.
CAPD takes place inside the body using the peritoneum, the natural lining of the abdomen, which acts as the dialysis membrane. General or local anesthesia is used to insert a catheter or Teflon tube into the abdomen. The dialysate bag is instilled by simple gravity. Exchange takes place between the blood in the peritoneal cavity and the dialysate for about 6 hours, during which time, the toxins are removed by a method of simple gravity. Most CAPD patients need four bag exchanges a day, explains Dr.Talwalkar.
What is the basis on which either form of dialysis is selected?
Hemodialysis is an expensive procedure which requires uninterrupted power supply and pure, treated water which is the main component of the dialysate. In the under developed countries water may be contaminated with a variety of impurities, bacteria, fungi, etc. and this contamination can be transmitted across to the patient in the dialysis process, explains Dr.Talwalkar.
“Haemodialysis could be risky on frail patients with advanced cardio-vascular disease and in patients whose heart’s pumping action is not working optimally. Because during the Haemodialysis, at any given point of time, about 300-400 cc of blood is outside the body. That blood loss, circulating extracorporeally, can cause or precipitate heart attacks. Also, generally these people suffer from anaemia and are therefore more likely to develop cardiac problems”, says Dr.Talwalkar.
Similarly, regardless of age, in people with severe liver disease, liver cirrhosis, their blood pressure continues to drop during Haemodialysis. CAPD is a better option in these cases. Also, some people may have an ‘access’ problem because their blood vessels are so difficult to canulate because they have advanced atherosclerosis. Such patients are better off with CAPD.
The main advantage of CAPD is that patients do not need to be hospitalised, they are mobile to carry on routine chores and the process itself is not painful. Technically it is difficult to insert tubes into a small child’s blood vessels, as required in hemodialysis. So CAPD is better suited to children.
The peritoneal membrane being a biological membrane has certain advantages over the artificial membrane in the dialyser. It can remove both, the smaller and the big molecules with equal efficiency unlike the hemodialysis which removes only the smaller molecules with good efficiency, not so the larger molecules. Generally the quality of life with CAPD is better than with Hemodialysis.
But CAPD also has some disadvantages, explains Dr.Talwalkar. “There is the possibility of peritoneal infection. If the weather conditions are very humid and hot, there is heavy perspiration, resulting in increased risk of infection of the peritoneal cavity. Also, the general atmospheric pollution can cause infections if the person does not take care to avoid these places. If infection can be prevented, this dialysis is very simple. In fact in the developed countries, even the totally blind people can do CAPD without any help”.
Elaborating on the disadvantages of CAPD, Dr.Talwalkar reveals, “The peritoneal fluid contains proteins. This protein is lost during CAPD, especially if there is infection. For people partaking of a lot of meat and high protein food, this does not matter. But in the less developed countries where protein intake in diet is generally low, especially for vegetarians, CAPD can pose mal-nutrition related problems. Also, when the catheter is put inside the peritoneal cavity, there will be some irritation of the cavity. But otherwise these people do much better and they remain very active and even small children can live and buy some time till they can undergo a transplant.”
The thrice a day, 6-8 hourly routine of CAPD often gives rise to the burnt-out phenomenon, thus making patients weary of the procedure. Then they opt for Hemodialysis. The burning out with Haemodialysis is far too less because the patient doesn’t do it himself or herself, explains Dr.Talwalkar.
What are the possible complications of dialysis itself?
The minor complications would be fever and body pain during dialysis. Sometimes patients may develop allergic reactions, get cramps in the muscles, vomiting during dialysis. But these are minor and non-recurrent, assures Dr.Talwalkar.
“The serious complications over which we are concerned is infection which chiefly occurs due to malnourishment of a number of patients dwelling in the under developed countries,” explains Dr.Talwalkar. “If the patient is anaemic, it will add to the aggravation of infections. Also, we are putting the needles into the blood vessels which have a very large blood flow. If due care is not taken during this process, serious infection can be introduced into the patient’s body. Infection will spread throughout the body since it is injected directly into the blood. Infections, in general, though not common, can be life threatening.”
The more serious problems relate to cardio-vascular morbidity, adds Dr.Talwalkar. “If the blood pressure falls during the hemodialysis, the heart may suffer an attack and sometimes you may not be able to reverse the heart attack. Fatal mishaps from Hemodialysis are known risks. Also we give heparin injections during Hemodialysis to prevent the blood from clotting. This is basically given to see that the blood when it flows outside the body does not clot; within the body it does not clot because of the body’s special mechanism. But this also brings with it its own problems: Heparin can have various side effects. For instance, if the patient’s blood pressure is high, and you give him heparin: it can cause bleeding in the brain and be fatal. It can cause strokes; in diabetics, heparin can worsen their vision to the extent of turning the patient blind. The patient can get a vitreous haemorrhage. Very, very rarely, patients who are on Hemodialysis for a really long period of time can develop cancer, especially cancer of the kidney. However, there are very many patients living for years with both types of dialysis. So certainly till a patient can find a suitable transplant prospect, dialysis today is a very good alternative.”
Does this mean that every patient on dialysis for permanent kidney damage, ultimately needs a transplant? Are there any contra-indications to a transplant? “Ideally, yes- transplant is the answer,” responds Dr. Talwalkar. “While there is no absolute contra-indication to a transplant, age may be a restraining factor. Even if a patient’s physical age is 70, but biologically he is very active and leading a productive life, we don’t deny the patient a transplant. Generally we set 65 years as the upper limit. The person should have life expectancy of at least 5 years after the transplant. Of course we are not hard and fast on 65 and world over transplants have been done in people above the age of 70. But the co-morbid conditions or associated illnesses makes it more difficult.”
“Young patients are best off with a transplant because that gives the best results,” explains Dr.Talwalkar. “If we have a diabetic person who is relatively healthy at the age of 55, then we will assess his cardiac status; if this is good, HD and CAPD will have the same results; there’s not much to choose from, except the mobility or the other personal choices of the patient. After 65, if the patient has cardiovascular or cerebro-vascular involvement, we prefer keeping them on dialysis than go in for transplant. Generally transplant patients are more productive than those on dialysis. So the selection of a patient for transplant depends largely on his chance of survival following the transplant. Also, it is technically very difficult to do transplant on very small children below the age of 3.”
What are the complications from transplant surgery?
Nobody dies during surgery because it is so simple, but the post operative complications from infections and rejection can kill a person, reveals DrTalwalkar. “Because of the medicines that we give, the patients are in an immuno-suppressed state and therefore infections can really flare up. In India, in fact, the commonest cause of death following a transplant is from infection rather than rejection. An elderly person will fight infection far less efficiently than a young person. Also, the very elderly have advanced blood vessel related disorders because of atherosclerosis, basically. The blood vessels are also very narrow and the blood supply to various important organs is already jeopardized. The medicines which we give after the transplant can hasten the process of atherosclerosis, making it worse, predisposing them to strokes and heart attacks. In fact one of the commonest cause of death after transplant in the developed countries is cardiac event, whereas in the under developed countries infection is the commonest cause. Transplants enhance the chance of cancer even more than dialysis because of the immuno-suppresive drugs which we give.”
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