Does dialysate flow in the opposite direction as blood in dialysis?

What is different between apheresis and dialysis?

Dialysis is the process of replacing kidney function. Diffusion is just the natural tendency of things to move from higher concentration to lower concentration. Example: You have two identical rooms next to each other and one is filled with smoke and the other is not. Now imagine there is a door that conects these two rooms together. What would happen if you opened the door? The smoke would move towards the smokeless room and clean air would rush into the smoke filled room until there is equal amount of smoke in both rooms. How does this apply to dialysis? The artificial kidney has two chambers one is for the blood (this includes the inside of the membrane) and the other is for dialysate (cleansing fluid). The blood flows through the membrane in one direction and the dialysate flows through the artificial kidney in the opposite direction. The membrane, wich is basically a large bundle of small tubes with a bunch of tiny holes all along the outside of it, (holes that are too small to let blood vessels escape, but will allow waste particles to escape) allows the cleansing of the blood by diffusion. Example, if the potassium in your blood is at 5.5 and the potassium in the dialysate is 2.0 what do you think will happen to the potassium level in the blood? Remember the smoke filled room? Any dialysis professional would say that there is way more to it than that, and they are right, but I have tried to put it in a nutshell and in layman's terms.

What type of machine is used to help people with kidney malfunctions?

The dialysis machine is the machine that performs dialysis of the blood. Dialysis removes the waste product from the blood by drawing it through a vein in the forearm called the arterio-venous fistula. The blood is pumped into the machine through plastic tubes and then goes through a series of events that cleanses the blood with a saline solution called dialysate. Once the blood has been cleansed, it is returned to the body.

Why does dialysis fluid kept at 40 degrees?

Effect of cool temperature dialysate on the quality and patients' perception of haemodialysis Abdelbasit Ayoub1 and Mary Finlayson2 1Renal Dialysis Unit, Waikato Hospital, Hamilton and 2School of Nursing, University of Auckland, Auckland, New Zealand Correspondence and offprint requests to: Abdelbasit Ayoub, Renal Dialysis Unit, Waikato Hospital, Hamilton, New Zealand. Email: abdelbasit87@hotmail.comAbstract TopAbstractIntroductionSubjects and methodsResultsDiscussionReferencesBackground. The effects of cool dialysate on the urea reduction ratio (URR) in high efficiency haemodialysis have not been completely studied. After reviewing the literature, it appeared that patients' perceptions of cool dialysis have not been studied. Since patients' perception have an impact on patient satisfaction, this motivated the authors to research this area of practice. Methods. This study was designed to determine whether a high URR and haemodynamic stability could be achieved by using cool dialysate in two groups of patients. The first group of five patients were known to have hypotension episodes during dialysis, and the second group of five patients were documented as having stable blood pressure (BP) during and after dialysis, after excluding vascular access recirculation and any other problems. Each patient was dialysed for three sessions using cool dialysate (35°C) followed by another three sessions using a standard dialysate temperature (36.5°C). All other dialysis session parameters were maintained. Results. The results show that the dialysate cooling resulted in an increased ultrafiltration in the low BP group (P = 0.05). Cool dialysis had neither an adverse nor a beneficial effect on urea removal in the two groups (P = NS). The mean arterial pressure post- and intra-dialysis was significantly higher in dialysis with cool dialysate in the low BP group (P < 0.01 and P < 0.007, respectively). The mean arterial pressure in the stable BP group remained unchanged when cool dialysate was used (P = NS). The intra-dialytic pulse rates in the low and stable BP groups were similar. A total of seven episodes of symptomatic hypotension were observed in the low BP group, but none in the stable BP group (P < 0.0001). Patients' perceptions about cool dialysate were measured by a questionnaire which showed that 80% of them felt more energetic after dialysis and requested to be always dialysed with cool dialysate. Conclusion. Cool dialysate improves tolerance for dialysis in hypotensive patients and helps increase ultrafiltration while maintaining haemodynamic stability during and after dialysis. Patients' perceptions were positive, as most of the selected sample felt more energetic and generally well during and after dialysis, and this had a positive impact on their activities of daily living. Keywords: cool dialysate; haemodynamic stability; hypotensive episodes; standard dialysate; urea reduction ratioIntroduction TopAbstractIntroductionSubjects and methodsResultsDiscussionReferencesCooling dialysate below 36.5°C has been recognized as an important factor contributing to haemodynamic stability of patients during haemodialysis [1-5]. Many studies show that cool dialysate improves cardiovascular tolerance of haemodialysis and reduces hypotension episodes during haemodialysis [2,6-8]. During standard dialysis and ultrafiltration, the combination of low blood volume and loss of peripheral vascular resistance causes hypotension [9]. Blood cooling is used to stabilize blood pressure (BP) during very high efficiency haemodialysis with a high ultrafiltration rate, and helps to maintain BP without compromising the efficacy of haemodialysis [10]. A number of studies have shown that the use of cool dialysate resulted in fewer hypotensive episodes [11,12,13]. Increased BP associated with cool dialysate is due largely, if not entirely, to increased total peripheral resistance and increased venous tone [14]. Cooler temperature dialysate improves left ventricular contractility, independently of pre-load and after-load [11]. A lower dialysate temperature during routine haemodialysis might be justified as an intervention in treating the hypotension episodes during haemodialysis [15]. Moreover, the groups who appear to benefit most from cool dialysate are women, patients over 55 years of age, patients with low body surface area and patients with cardiovascular disease [16]. The aim of this research was to study the effect of using cool dialysate on the urea reduction ratio (URR) and on haemodynamic parameters in two groups of patients being dialysed in the InCentre Hemodialysis Unit at Waikato Hospital. The study was designed to determine whether a high URR and haemodynamic stability could be achieved by body temperature cooling during haemodialysis. The experiment involved dialysing the selected sample of patients randomly using either a standard dialysate temperature (36.5°C) or a cool temperature dialysate (35°C) for three dialysis sessions each. Patients were informed about the temperature of each dialysis session, as they can feel the cool dialysis. Moreover, patients were told what they may experience during the study as explained on the information sheet which was given to them in order to gain consent for the study.Subjects and methods TopAbstractIntroductionSubjects and methodsResultsDiscussionReferencesThe Waikato Ethics Committee approved the research project, and informed consent was obtained from each patient. Patients who met the criteria for the study were selected from a chronic dialysis population of 50 patients in the Incentre Hemodialysis Unit. A total of 10 haemodialysis patients ranging in age from 38 to 72 years (mean 59.8 ± 5.5) were selected. One group (hypotension-prone, n = 5) was characterized by having episodes of hypotension during dialysis, a systolic pressure of 90 mmHg accompanied by any of the following symptoms: nausea, vomiting, muscle cramps, dizziness or fainting. The second group of patients (n = 5) had stable BP during dialysis. The 10 patients were selected after excluding recirculation or vascular access problems. Patients were not eligible for participation in the study if they had experienced recent surgical intervention, severe anaemia, problems related to vascular access, coronary artery disease, acute renal failure or recent illnesses. The study was initiated in April 2002 and finished in June 2002. Each patient was used as a control for him/herself. The aetiology of renal failure in the patients selected for this study included diabetes mellitus (four), hypertension (two), glomerulonephritis (two), uncertain aetiology (one) and polycystic kidney disease (one). Five patients were taking antihypertensive medicines; these were not routinely taken on the day of haemodialysis. Regular medications for the selected sample included phosphate binders. Design and procedureThe experimental design was single-subject multiple probes across participants in each group, over six haemodialysis sessions. In three sessions, the dialysate temperature was normal (36.5°C) and in the other three sessions the dialysate temperature was low (35°C). The dialysate temperature was set as per the Fresenius machine manual; no extra devices such as a blood temperature monitor were used. Apart from changing the temperature to 35°C, all other dialysis parameters remained the same during the study. In each session, an F8HPS disposable dialyser with an ultrafiltration coefficient of 11.1 ml/h/mmHg composed of polysulfone was used. The dialysate flow rate was set at the desired level according to the manufacturer's guidelines at 500 ml/min. The dialysate consisted of the following constituents: sodium 141 mmol/l, potassium 2.0 mmol/l, calcium 1.3 mmol/l, magnesium 0.2 mmol/l, chloride 108.0 mmol/l, acetate 3.0 mmol/l and bicarbonate 35.0 mmol/l. A Fresenius model 4008B or 4008S dialysis machine equipped with a volumetric ultrafiltration control system was used in each dialysis. Fluid removal was calculated as the difference between the patients' weight before dialysis and their target dry weight. Blood flow rates were maintained constant for standard temperature and cool dialysis for each patient. Pre-dialysis body weight, blood pressure, pulse rate and oral temperature were measured before ingestion of food and drink. BP (measured by an electronic digital sphygmomanometer), pulse rate, arterial line pressure, venous line pressure, blood flow rate, trans-membrane pressure and fluid loss were all measured hourly during dialysis. Weight, BP, pulse rate and temperature were recorded post-dialysis. Blood flow during dialysis was slowed to 100 ml/min before collecting post-dialysis blood samples for urea, and the samples were analysed in Waikato Hospital's biochemistry laboratory. The URR was calculated using the formula: (urea pre - urea post/urea pre x 100%). Mean arterial pressure was calculated as the diastolic pressure plus one-third of the pulse pressure. Dialysis dose was measured by equilibrated Kt/V (Kt/Veq). The single-pool Kt/V (Kt/Vsp) was determined from the Daugirdas second-generation formula [17]. Kt/Veq = (1 - 0.47/t) x Kt/Vsp + 0.02. and Kt/Vsp = -In(R -0.008 x t) + (4 - 3.5 x R) x UF/W, where R = urea post/urea pre (in fractions of 1); UF = ultrafiltration volume in kg; T = treatment time in h; and W = body weight in kg. Patient's perceptions about their experiences of the cool temperature dialysate were measured after completion of the six dialysis sessions. A questionnaire, using both a closed question and two open-ended questions, was given to the patients. The questions were: How did you feel while being dialysed on cool temperature? Compared with normal temperature dialysis of 36.5°C, did you feel any differences while being dialysed on cool temperature? If yes, what were the differences? Would you like to continue cool temperature dialysis? The data were sorted and entered into Microsoft Excel then analysed using the analysis of variance (post hoc ANOVA) test. A probabilty of 1.2, and it reflects that patients had good clearance when dialysed in the two treatment modules. As in earlier studies [4], we found cool dialysis had neither an adverse nor a beneficial effect on urea removal in the two groups. Ultrafiltration, BP, pulse and post-dialysis temperatureThe cool dialysate in this study resulted in an increased ultrafiltration rate compared with neutral dialysate (P < 0.05). The ultrafiltration rate was calculated as the difference between the patients' weight before dialysis and the patients' dry weight. A similar study [11] showed that patients with large intra-dialytic weight gains could be dialysed on cool temperature dialysate (35°C), without the patients having hypotension episodes during dialysis. However, the ultrafiltration volume remained relatively unchanged in the stable BP group. In a prospective study done on 11 patients, Cruz et al. found that a cool dialysate (35.5°C) significantly increased the lowest intra- and post-dialysis BP, and significantly reduced the number of nursing interventions, as well as the volume of saline infused for treating intra-dialytic hypotension [18]. These findings were replicated in this study. As in the low BP group, the mean arterial pressure post- and intra-dialysis was significantly higher with the cool dialysate than with the standard dialysate. However, cool dialysate did not make any significant statistical difference in the stable BP group. The stability of BP during cool dialysis could be attributed to preservation of central blood volume and cardiac output [19]. The intra- and post-dialytic pulse was relatively lower in both groups, but this difference was not statistically significant. A study has found that cool dialysis increases left ventricular contractility in haemodialysis patients, which may be a potential mechanism whereby haemodynamic tolerance to the dialysis procedure can be improved [12]. A rise of 0.7°C body temperature in the low BP group and 0.4°C in the stable BP group has been observed in this study. Similar findings were noticed in a study where body temperature changed by 0.51°C when cool dialysate was used [4]. Episodes of symptomatic hypotension and patients' perceptionA total of seven episodes of symptomatic hypotension requiring nursing intervention in which blood pressure was

Is hemodialysis the same as dialysis?

Hemodialysis is one of the types of dialysis. There are two primary types of dialysis, hemodialysis and peritoneal dialysis, and a third investigational type, intestinal dialysis. In hemodialysis, the patient's blood is pumped through the blood compartment of a dialyzer, exposing it to a semipermeable membrane. The cleansed blood is then returned via the circuit back to the body. Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer membrane. This usually is done by applying a negative pressure to the dialysate compartment of the dialyzer. This pressure gradient causes water and dissolved solutes to move from blood to dialysate, and allows the removal of several litres of excess fluid during a typical 3 to 5 hour treatment. In short, Hemodialysis (he-mo-di-AL-i-sis) is a procedure to remove excess water and harmful chemicals and wastes from your blood. Hemodialysis helps clean up the blood when the kidneys cannot function properly, such as in chronic kidney failure. For more details, I would suggest you contact the medical expers from some renowned medical center like Ocean Medical Center.

What treatment is used for people who have kidneys that no longer can filter waste from the blood?

Dialysis is.

What is the difference between a blood infusion and dialysis?

What is the difference between a blood transfusion and dialysis

How does a kidney dialysis machine filter blood?

The dialysis machine is really a 2-part machine, serving two basic functions. First it acts as a blood pump, and second, it pumps a solution known as dialysate. The machine has a very accurate metering system that combines ultra-purified water, bicarbonate, and a potassium "bath" together. The patient is hooked up to the machine via what is known as the extra-corporeal circuit (meaning outside of the body) via two large-bore needles (or a semi-permanent central catheter). The lines go to the machine, and into a pump. No blood actually goes into the machine, but rather stays in the blood tubing. There is a larger diameter section of the line that fits in the blood pump, and the pump moves the blood by squeezing the larger section of the line at regular intervals. The blood comes from the patient through the pump, and into the artificial kidney (the dialyzer). The dialyzer is made of thousands of microscopic fiber tubes. These tubes can be likened to drinking straws that have small holes punched in the sides of the straws. These holes in the fibers are too small to allow the blood cells to pass through (much like a colander will let water out, but not your spaghetti noodles). The dialyzer is hooked to larger hoses that flow the dialysate through the area around the fibers in the dialyzer (usually in the opposite direction from the blood flow), and by pressure and osmosis, the fluid around the cells in the blood that contains the urea (waste) passes out of the blood and into the dialysate and to the waste system (drain). Dialysis is only about 10% to 15% as efficient as a working kidney, so patients need to dialyze frequently (usually 3 times per week or more, usually for 3 to 4 hours per treatment). Also, because of this, their blood levels of essential electrolytes like potassium, calcium, and sodium, as well as phosphorus, vitamins and other essential minerals must be continually monitored because they are lost during dialysis. Additionally, most patients need a drug to stimulate the production of red blood cells. A drug called Epogen is commonly used. It is very expensive, as much as $1000 USD to $2000 USD per shot, usually at each treatment. Many patients can gain 2 to 4 kilograms of fluid weight (4.4 to 8.8 lbs) in only 2 days. Access to the patient is usually gained through what is known as a fistula. A surgeon ties an artery to a vein, and this makes the vessel grow very large, sometimes as large in diameter as a thumb (or larger). This is done because the patient has to have needles inserted every other day as long as they are on dialysis. The machine monitors many parameters such as the blood flow, dialysate flow, arterial and venous pressures, the conductivity of the dialysate solution, the temperature and pressure in the artificial kidney (dialyzer) and will set off an alarm if anything is out of normal parameters.

Blood in veins is kept flowing in one direction by the presence of?

Valves, allown blood through in one direction when the pressure builds up but close when pressure is applied in the opposite direction.

What happens in peritoneal dialysis?

peritoneal dialysis work on the same principle except abdomen has a peritoneal cavity, lined by a thin epithelium called as peritoneum. peritoneal cavity is filled with dialysis fluid that enters the body through a catheter. excess water and waste pass through the peritoneum into the dialysis fluid. this process is repeated several times in a day.

What happens during kidney dialysis?

Toxins and waste are filtered from the kidneys

Why Blood cannot flow out during dialysis process?

during dialysis the blood is is flowin through a closed system

Does dialysate flow in the opposite direction as blood in dialysis?

Add your answer:

What is dialyse?