Engineering and Construction
Haemodialysis side-effects and improvements
In depth Understanding of Haemodialysis.
g) Identify the major side-effects specifically caused by haemodialysis (1 and half pages), and evaluate (quantitatively) the prospects for alternative designs or operating procedures that could potentially reduce these side-effects. This evaluation should take account of the level of (scientific) certainty/uncertainty regarding the effectiveness of proposed new design features/operating procedures, and identify areas for further investigation/development(2 and half pages). You are advised to concentrate your efforts in relation to reducing side-effects, on potential engineering/physical science solutions, rather than on broader improvements that fall within the expertise of medical professionals.
The report must be typed using 1.5 line spacing with 11 point font.
Haemodialysis refers to the dialysis of the kidneys whereby the blood of a patient with dysfunctional kidneys is purified. The process uses a machine that filters out the wastes, fluid and salts from the blood which are the functions of the kidneys (3). Consequently, this treatment method can treat kidney failure by controlling blood pressure as well as maintaining the balance of fluids and other minerals in the body. Hence enabling such patients carry on a normal life.
Common causes of kidney failure include diabetes, kidney inflammation, kidney cysts, blood vessel inflammation and high blood pressure. The treatment method has several side effects. This review looks at some of these side effects as well as carrying out a quantitative evaluation of alternate operation procedures and designs which aim at reducing the side effects of Haemodialysis.
The side effects of Haemodialysis
Short term side effects.
The side effects of Haemodialysis usually differ depend on how long the dialysis therapy is carried out, the duration of the session and how often they are carried out. At early stages of the treatment process, experience convulsions, vomiting, general body stress, tiredness and low pressure blood pressure (4). These are experienced due to changes in the minerals in the body as well as the hydration levels of the body. These side effects however ease with time after starting the dialysis session. It may take between 3 – 6 months for the body to be more receptive to these treatment methods.
Long term side effects
Long term dialysis treatment methods can lead to physical deterioration of the body and other complications. Cardiac Insuffiency is one such disorder. The dialysis method leads to the accumulation of water and sodium in the body. As the amount of sodium and water in the body increases, the volume of blood that circulates in the body also increases (4). The result of this is increases cardiac activity. That in turn leads to increased heart beat rate and stroke volume. If the issue is not rectified, the heart tissues get exhausted leading to decreased functionality.
The second issue is hypertension. Like cardiac insufficiency, it is caused by excessive sodium and water in their diets. If hypertension is present in the body for a long period of time, the resistance of blood vessels increases. As a result of this, the patient suffers from cardiac insufficiency and cerebral haemorrhage. The third complication is Hyperkaleamia. The disease is characterised by excessively high levels of potassium in blood. High levels of potassium in the blood can critically damage the body. Some of the effects include abnormal heart beat rate as well as rhythm (5). High concentrations of potassium in blood leads to a lot of water being drawn from the blood resulting in anaemia.
During the actual dialysis procedure some of the side effects include dialysis disequilibrium. Despite the fact that dialysis effectively removes waste compounds from blood, it takes longer to remove body waste from the brain. Consequently, the osmotic pressure in the brain increases (3). The brain then absorbs water and becomes swollen. It leads to neurological side effects. The problem is however reversed by eliminating the waste from the brain by diffusion and it being transported in the blood.
Arrhythmia is another side effect caused by an electrolyte imbalance in blood. The problem causes irregular heart rhythm and beat rate. In fact about 10 % of deaths of dialysis patients are caused by this side effect (3). Finally irregular blood pressure is a side effect. During dialysis, about 150-250 ml of blood are drawn per minute. The process is usually independent of the patient’s heart beat rate. The result is falling of blood pressure leading to a fluid imbalance.
Alternate designs and operation procedures that can reduce the side effects of Haemodialysis
Use of Nano fibre technology
Current dialysis machines, require a patient to lie on a bed for 3-4 hours for about 3 times a week. This is expensive, time consuming and tiresome. Researchers have however come up with a Nano-fibre mesh a cheaper alternative to dialysis (6). The device works by continually filtering blood by just attaching it to the patient’s skin.
The treatment method, is a take over from the current dialysis machines which requires a large quantity of dialysis fluid to remove uremic toxins which have a low molecular weight. It does this by utilising a high surface area to weight ratio of nanofibre in comparison to the uremic toxin’s absorption rate of zeolite (6). The development makes use of an unwoven fabric made out of biocompatible polymer. The fabric also has pore which enables it to absorb toxins selectively. Research has shown that using 25 g of the fibre, can successfully remove about 50 mg of creatinine. The technology is important in maintaining homeostasis during dialysis and thus remove the dialysis disequilibrium especially in the brain. Furthermore, the uremic toxins to be removed can be varied by using different types of zeolite.
A study on End stage renal disease Patient Outcome was carried out to compare mortality rates in total of 738 patients. They had a baseline serum albumin of less or equal to 4 gm/dL (2). They were assigned to either high flux or a low flux membrane haemodialysis method. The analyses method did away with the possibility of confounding results as a result of an inadequate dialysis dose by regularly controlling the Kt/V which quantifies peritoneal and haemodialysis treatment adequacy to about 1.2. At the end of the study, there was a 37 % risk reduction in mortality rate.
Figure 1: Comparison between High flux membrane and low flux membrane (1)
From figure 1 above, it can be seen that high flux membrane has a higher sieving coefficient as compared to the low flux membrane relative to the molecular weight size. Furthermore, the high flux membrane method just works like a normal human kidney. This is because the High-flux haemodialysis utilises a dialysis membrane that has an efficiency of about 10 times higher than that of the low flux membrane which are used in dialysis currently (1). Consequently, minerals and water are filtered out more quickly. Furthermore, large molecules are removed effectively from the body. The technology solves most of the common side effects of dialysis methods such as low blood pressure and Arrhythmia.
1. Ledebo I, Blankestijn P. Haemodiafiltration–optimal efficiency and safety. Clinical Kidney Journal. 2009;3(1):8-16.
2. Merritt L. High-Flux Hemodialysis Has Advantages [Internet]. Renal and Urology News. 2007 [cited 9 April 2018]. Available from: https://www.renalandurologynews.com/news/high-flux-hemodialysis-has-advantages/article/58146/
3. How dialysis is performed [Internet]. nhs.uk. 2014 [cited 9 April 2018]. Available from: http://www.nhs.uk/Conditions/Dialysis/Pages/How-haemodialysis-is-performed.aspx
4. Longmore J, Wilkinson I, Baldwin A, Wallin E. Oxford handbook of clinical medicine. Oxford University Press; 2014.
5. H S. High-flux dialyzers, backfiltration, and dialysis fluid quality. – PubMed – NCBI [Internet]. Ncbi.nlm.nih.gov. 2011 [cited 9 April 2018]. Available from: https://www.ncbi.nlm.nih.gov/pubmed/21299628
6. Development of High-performance Fiber as an Alternative to Dialysis during Disasters | NIMS [Internet]. National Institute for Materials Science (NIMS). 2014 [cited 9 April 2018]. Available from: http://www.nims.go.jp/eng/news/press/2014/04/p201402190.html