1.What is hemodialysis all about?
Hemodialysis is performed using an extracorporeal circulation device such as a dialyzer. Dialysis is performed by introducing the patient’s blood and dialysis fluid containing certain chemical components into the dialyzer at the same time, and dialysis is performed across a semi-permeable membrane to eliminate metabolites, purify the blood and replenish the necessary substances, thus playing the role of an artificial kidney.
2.Why should patients with uremia receive dialysis treatment?
Various reasons, such as chronic glomerular disease, diabetes, hypertension, cystic kidney disease and other end-stage renal damage cases, the kidney’s ability to excrete various metabolites (such as creatinine, urea nitrogen) and water outside the body gradually decreases, which will lead to a series of clinical symptoms, such as hypertension, edema, nausea, vomiting and so on. Hemodialysis is equivalent to help the kidneys will do the above work, and therefore, is an alternative treatment.
By analogy, if a normal kidney is equivalent to hiring a nanny at home to clean the house 24 hours a day, then hemodialysis is equivalent to hiring a part-time worker to clean the house 2-3 times a week.
3. Should I choose dialysis or kidney transplant?
Hemodialysis is also an alternative treatment for UTI, but each has its own advantages and disadvantages.
(Table: Pros and cons of dialysis and kidney transplant)
For each patient, both alternative treatments can be considered. However, there are some factors to be considered in combination as follows.
Age, in general, younger patients may be more suitable for kidney transplantation;
The need to return to the community, if the need to return to the community is strong, kidney transplantation is more appropriate;
Primary disease, if the primary disease is diabetes mellitus, glucocorticoid treatment after kidney transplantation is less favorable for blood sugar control, therefore, kidney transplantation is not recommended;
Economic situation, if the economic situation is not good, kidney transplantation is not recommended.
4. How long can hemodialysis last?
This is a question often asked by patients. At present, in many good dialysis units in China, there are many cases of patients who have maintained dialysis for more than 30 years, and there are many patients who have been on dialysis for about 20 years. In our hospital, there are several cases of dialysis patients who have been on dialysis for more than 10 years. Theoretically, as long as the various complications of uremia are handled well, long-term dialysis to maintain life and even have a better quality of life is a completely achievable goal.
In 2006, during my training at Nanjing Military General Hospital, Director Ji Daxi once had a saying: If God gives you a life span of 100 years, we blood purification medical personnel have the responsibility to keep you from dying before the age of 99. Of course, this requires that all patients can better follow the medical staff’s instructions.
5.How many times should I dialyze?
Generally speaking, regular and adequate hemodialysis should be performed at least 3 times/week, or 2 times/week or 5 times/2 weeks for some patients with high urine output, good general condition and good blood pressure control.
6.How much water should I take off?
This question is related to the concept of “dry weight”. The dry weight of a dialysis patient refers to the weight without excess water in the body and without dehydration. Dry weight is not static and can change depending on your condition. In our clinic, dry weight is more often overestimated and the amount of water removed is often not set enough. However, there are cases when the dry weight rises after the improvement of the diet, in which case it would be a bit too much to dehydrate at the original weight. Some uncomfortable symptoms may occur, such as post-dialysis fatigue, loss of appetite, etc.
For patients who are on dialysis three times a week, each weight gain is usually 5-7% of dry weight, for example, for a 60 kg patient, the weight gain should not exceed 3-4 kg. If it is higher than this figure, it means that the weight gain is too fast, the drinking is not well controlled and various complications are likely to occur. A simpler calculation is that the water should not rise more than 1kg per day.
7.Is the urine volume getting less and less after hemodialysis?
Not necessarily. As long as the clinical situation allows, many patients with sufficient urine volume (called “dry uremia” by Director Zhou) can be dehydrated without dehydration or with very little dehydration during dialysis, and in this case, the urine volume usually does not decrease. However, if the urine volume may gradually decrease as the disease worsens, in this case, it is necessary to consider starting dehydration treatment.
8.I still have urine, why do I need dehydration?
Some patients have more urine, but they have other discomforts, such as uncontrollable high blood pressure, poor sleep, breathing difficulties or even coughing. This indicates that although there is urine, the amount of urine is not enough to get rid of all the excess water in the body. Therefore, proper dehydration is also required. In fact, this is a case of over-estimation of dry weight.
9. What is hemodialysis filtration and haemoperfusion?
As we mentioned earlier, the primary mode of clearance for hemodialysis is diffusion, while convection is the mode of hemofiltration. What we usually call “hemofiltration” actually refers to “hemodialysis filtration”, which is a combination of both diffusion and convection to better remove medium and large molecules. Therefore, it has more adequate clearance than hemodialysis alone. Qinhuangdao’s medical insurance policy is to reimburse the cost of hemodialysis filtration treatment once a month, so the majority of patients can consider hemodialysis filtration once a month.
Hemoperfusion refers to a perfuser that is connected in series with the dialysis process. The component in this perfuser is a resin component, which acts as an adsorption. This is somewhat similar to the role of activated carbon in a gas mask. As the blood passes through the perfuser, some of the medium to large molecules of toxins can be adsorbed away.
The perfusion apparatus has saturation problems, so it is usually not possible to continue doing it for 2 hours and there is not too much benefit in doing it again. The main application of early perfusion is drug and toxin poisoning, but currently we also perform blood perfusion therapy intermittently in the clinic, with the aim that this treatment has some therapeutic effect on secondary hyperparathyroidism, pruritus, encephalopathy, etc.
The disadvantage of hemoperfusion is that it is prone to allergy and coagulation and therefore requires the necessary anti-allergic and anticoagulant treatment.