Blood dialysis

Fig. 12. Schematic of hoUow-fiber membrane cartridge employed for blood dialysis. Courtesy of Cordis-Dow.

Merrill, E. W., Salzman, E. W., Lipps, B. J., Jr., Gilliland, E. R., Austen, W. G., and Joison, J., Antithrombogenic cellulose membranes for blood dialysis. Transactions—American Society for Artificial Internal Organs 12, 139-150 (1966). 

In medical applications, the dialysis SPM may be the patient s own stomach lining. A prepared solution is infused into the abdomen, stimulating osmotic flow of toxins across the stomach lining into the ingested solution, which is subsequently drained from the stomach. Alternatively, the dialyzer for blood dialysis (hemodialysis) may be a prepared membrane with special solution over which the blood flows to osmotically remove impurities. 

Elevated aluminum levels have been implicated as the cause of dialysis encephalopathy or dementia in renal failure patients undergoing long-term hemodialysis [85]. Some patients used aluminum-containing medications. Moreover, patients with renal failure cannot remove aluminum from the blood. Dialysis dementia can arise after three to seven years of hemodialysis treatment. Speech disorders precede dementia and convulsions. Since many hemodialysis units rely on systems to purify fluoridated tap water, it is likely that many patients are being exposed inadvertently to increased concentrations of fluoride and aluminum. Increased serum fluoride concentration and fluoride intoxication have been also observed in chronic hemodialysis patients. Arnow et al. [96] reported that 12 of 15 patients receiving dialysis treatment in one room became acutely ill, with multiple non-specific symptoms and fatal ventricular fibrillation. Death was associated with longer hemodialysis time and increased age compared with other patients who became ill. 

Certain pharmacodynamic properties of NaCS were evaluated using rats, rabbits, dogs, and cats. Administration of 1 mg kg-1 of two NaCS samples to dogs had no influence on blood pressure, heart rate, or respiration 25). Because 1 x 10 IU/mg of heparin is usually used for blood-dialysis for chronical renal insufficiency, about 1 mg kg, which was found to have no effect on the cardiac function of dogs, may have no influence on that on human beings. 

Cosmetics Biomedical and pharmaceutical materials Fungicide Skin and hair products Artificial skin Surgical structures Contact lens Treating major bums Blood dialysis membranes Artificial blood vesicles... 

In cases of loss of kidney function, mechanical devices—dialysis machines— mimic the action of the kidney The process of blood dialysis—hemodialysis— is discussed in A Clinical Perspective Hemodialysis on page 195. 

FIGURE 5.70 Schematic of a hollow-fiber membrane cartridge used for blood dialysis. 

FIGURE 29.2 Determination of blood/dialysis water (/fb/dw) partition coefficient. 

Deterniination of Blood/Dialysis Water Partition Coefficient... 

To understand the affinity of chlorinated compounds for dialysis fluid and blood as a model for the transfer of a lipophilic organic contaminant to the blood compartment, it is possible to calculate the blood/dialysis water partition coefficient (A b/dw) under static conditions (see Figure 29.2) ... 

We learned in Section 12.2 that polymers can be characterized by their physical properties. Elastomers are used as biomaterials in flexible tubing over leads for implanted heart pacemakers and as catheters (tubes implanted into the body to administer a drug or to drain fluids). Thermoplastics, such as polyethylene or polyesters, are employed as membranes in blood dialysis machines and as replacements for blood vessels. Thermoset plastics find limited but important uses. Because they are hard, inflexible, and somewhat brittle, they are most often used in dental devices or in orthopedic applications, such as in joint replacements. To fill a cavity, for example, the dentist may pack some material into the cavity, then shine an ultraviolet lamp on it. The light initiates a photochemical reaction that forms a hard, highly cross-linked thermoset polymer. 

CHE Chen, L.-W. and Young, T.H., EVAL membranes for blood dialysis, Makromol. 

As a consequence some membrane processes have already been applied at industry level and certain of them, for instance, water treatment (including water desalination), food purification and biomedical purposes (blood dialysis), are even industrially consolidated. 

Cupro fibers are of high fineness in their single filaments and have a silky shine and good handle. Cupro hollow fibers are especially suitable for membranes used in blood dialysis. The properties of cupro are summarized in Table 2.8. 

Production of cuoxam fiber began to decline in the early 1960 s due to the success of synthetic alternatives, outdated equipment and unresolved ecological problems (copper). Research was then focussed successfully on membranes and hollow fibers, which are now the standard materials worldwide for blood dialysis in artificial kidneys. There are only a few production plants serving this important specialty market. 

---