Hemoperfusion

Hemoglobin S Hemoglobins Hemolysis Hemoperfusion Hemophan Hemophilia... 

The rationale for the development of such fibers is demonstrated by their appHcation in the medical field, notably hemoperfusion, where cartridges loaded with activated charcoal-filled hoUow fiber contact blood. Low molecular weight body wastes diffuse through the fiber walls and are absorbed in the fiber core. In such processes, the blood does not contact the active sorbent direcdy, but faces the nontoxic, blood compatible membrane (see Controlled RELEASE TECHNOLOGY, pharmaceutical). Other uses include waste industrial appHcations as general as chromates and phosphates and as specific as radioactive/nuclear materials. 

Hollow Fiber with Sorbent Walls. A cellulose sorbent and dialy2ing membrane hoUow fiber was reported in 1977 by Enka Glan2stoff AG (41). This hoUow fiber, with an inside diameter of about 300 p.m, has a double-layer waU. The inner waU consists of Cuprophan ceUulose and is very thin, approximately 8 p.m. The outer waU, which is ca 40-p.m thick, consists mainly of sorbent substance bonded by ceUulose. The advantage of such a fiber is that it combines the principles of hemodialysis with those of hemoperfusion. Two such fibers have been made one with activated carbon in the fiber waU, and one with aluminum oxide, which is a phosphate binder (also see Dialysis). 

A variety of therapies for thallium poisoning have been suggested by neutralising thallium in the intestinal tract, hastening excretion after resorption, or decreasing absorption. Berlin-Blue (fertihexacyanate) and sodium iodide in a 1 wt % solution have been recommended. Forced diuresis hemoperfusion and hemodialysis in combination results in the elimination of up to 40% of the resorbed thaHous sulfate (39). 

In studies of mice, rats, and dogs, diisopropyl methylphosphonate was rapidly absorbed into plasma (Hart 1976). The plasma data indicate that all three species rapidly absorbed diisopropyl methylphosphonate, although the exact rate was species specific. Although no studies were located regarding human absorption, diisopropyl methylphosphonate is also likely to be absorbed rapidly into the plasma of humans. The ability of porous polymeric sorbents, activated carbon, and dialysis to remove diisopropyl methylphosphonate from human plasma has been studied (McPhillips 1983). The grafted butyl-XAD-4 was found to be the most efficient sorbent for the removal of diisopropyl methylphosphonate from human plasma. Hemoperfusion of plasma over synthetic XAD-4 or butyl-XAD-4 sorbent resin was more efficient than dialysis/ultrafiltration for the removal of diisopropyl methylphosphonate from human plasma the smaller surface of the packed resins provided less area to minimize damage to molecular constituents of the plasma. These methods are useful in reducing diisopropyl methylphosphonate concentrations in the plasma. However, since diisopropyl methylphosphonate and its metabolites are not retained by the body, the need for methods to reduce body burden is uncertain. 

Self-forming microspheres polymercaptol 0.8 Oral and hemoperfusion for treatment of heavy metal poisioning Mercaptol... 

Pond, S.M., S.C. Johnston, D.D. Schoof, E.C. Hampson, M. Bowles, D.M. Wright, and JJ. Petrie. 1987. Repeated hemoperfusion and continuous arteriovenous hemofiltration in a paraquat poisoned patient. Clin. Toxicol. 25 305-316. 

S. M. Wagner, A. C. Nogueira, M. Paul, D. Heydeck, S. Klug, and B. Christ. The isolated normothermic hemoperfused porcine forelimb as a test system for transdermal absorption studies. J. Artif. Organs 6 183-191 (2003). 

In the biomedical area, SPHs and SPH composites can be used to make various biomedical devices, such as artificial pancreas, artificial cornea, and artihcial skin, articular cartilage, soft tissue substitutes, cell growth substrates in tissue engineering, burn dressings, surgical augmentation of the female breast, or hemoperfusion in blood detoxification and in the treatment of uremia. 

Metabolism/Excretion - In the first 24 hours, approximately 75% of a dose is excreted in urine by glomerular filtration. Elimination half-life is 4 to 6 hours in adults and 2 to 3 hours in children. About 60% of an intraperitoneal dose administered during peritoneal dialysis is absorbed systemically in 6 hours. Accumulation occurs in renal failure. Serum half-life in anephric patients is approximately 7.5 days. Vancomycin is not significantly removed by hemodialysis or continuous ambulatory peritoneal dialysis, although there have been reports of increased clearance with hemoperfusion and hemofiltration. 

Hemoperfusion is like hemodialysis except that blood is circulated extracorporeally through a column with adsorbent material like resin or charcoal, which binds molecules electrostatically. The molecules likely to be removed are characterized as poorly dialyzable, lipid-soluble, protein bound. Among the indications for hemoperfusion in the management of poisoning include the presence of a poison in a patient with impairment of excretory system (i.e. damaged kidneys), intoxication of a drug known to produce delayed toxicity or metabolized to a more toxic metabolite (i.e. paraquat or methotrexate), deterioration of the clinical state of the poisoned patient despite conservative therapy (i.e. convulsions or cardiac arrhythmias following theophylline intoxication), or development of coma as a complication. 

Hemofiltration is similar to hemoperfusion but where the blood enters a filter pumped by anteri-ovenous pressure difference. There is a lack of controlled clinical investigations to study the efficacy of all these techniques and there are inherent risks to these procedures, including hypotension, bleeding, air embolism and metabolic imbalance. 

Cutler RE, Forland SC, Hammond, P, and Evans, JR. Extracorporeal removal of drugs and poisons by hemodialysis and hemoperfusion. Annu Rev Pharmacol Toxicol 1987 27 169-191. 

Consider forced diuresis, urine acidification, or alkalinization if specific antidotes are not available Hemodialysis or charcoal hemoperfusion may be appropriate for rapid elimination if antidotes are not available... 

A high fatality rate associated with this disease suggests that the effectiveness of conservative and surgical treatment is not sufficient in the case of acute pancreatitis. New methods of extracorporeal detoxification using hemoperfusion over carbon sorbents has made it possible to improve the outcome of pancreatitis treatment. However, hemosorption leads to only a transient decrease in blood proteolytic activity and does not correct the imbalance in the protease-inhibitor system, and the carbon hemosorbents are nonspecific. The development and application of antiprotease hemosorbents with specific bioligands therefore has potential in pancreatitis treatment. 

Table 28.1 Biochemical parameters of patients with acute destructive pancreatitis treated with hemoperfusion over Ovosorb... 

Blood perfusion through a column with a biospecific hemosorbent at a flow rate of 50-70 ml min" after 30 min achieved a significant decrease in LPS level from 66.7 3.1 to 30.5 2.2 pgmL" (P<0.01). By the end of hemoperfusion sessions stabilization of systemic hemodynamics was observed (Table 28.2), which permitted... 

Hanasawa K, Tani T, Oka T, Kodama M (1984) A new treatment for endotoxemia with direct hemoperfusion by polymyxin-immobilized fiber. Artif Organs 8(3) 397-398... 

Fig. 29.11 Inlet and outlet concentration of total bibrubin (a) and cumulative (conjugated and unconjugated) bilirubin extraction (b) by hemoperfusion column containing 10 g of HSGD hemo-sorbent...

It was snggested that the ON solution possesses hypocoagulation properties [8,9], therefore an additional study was undertaken to assess the effect of hemoperfusion throngh the modified carbon sorbent on the blood coagulation system and key homeostasis parameters. Tendency for normalization of blood indices in patients of the treatment group was noticeable after the first HS session, and after the second session full normalization was evident (Table 31.1). 

Table 31.1 Effect of hemoperfusion through the modified activated carbon sorbent on the blood coagulation system...

The described modified extracorporeal hemoperfusion promotes stimulation of cellular and humoral immunity and mobilization of protective systems of an organism. Therefore the HS through the modified sorbent is more effective and has an effect on the main parameters of the hemostasis system when compared with conventional techniques. This procedure of blood purification also acts as a replacement for the functions of a failed organ of the patient. 

Various CNS adverse effects have been reported with CBZ and include sedation, dizziness, ataxia/clumsiness, blurred vision/diplopia, and impaired task performance. Although uncommon, fatal CBZ toxicity does occur. CBZ overdose is characterized by neurological symptoms such as diplopia, dysarthria, ataxia, vertigo, nystagmus, and coma. Infrequently, cyclic coma with biphasic fluctuations of consciousness, seizures, respiratory depression, cardiac conduction defects, and the need for artificial ventilation may occur. Plasma levels are only moderately correlated to severity, but as noted earlier, more than 15 pg/ml in children or 20 pg/ml in adults should be considered serious. Charcoal hemoperfusion or gastric lavage with activated charcoal has been used in such cases, whereas benefit from plasmapheresis is controversial (77, 114, 368). 

An acute overdose of CBZ can produce significant neurological symptoms. Diplopia may be a useful clinical indicator of developing toxicity, since severity is not necessarily correlated with plasma levels. Life-threatening seizures and coma may occur when levels exceed 20 to 25 pg/ml. Lower levels can produce drowsiness, ataxia, blurred vision, dysarthria, choreiform movements, or behavioral changes (374374 and 375). Gastric lavage, hemoperfusion, and plasmapheresis may be beneficial, especially in more serious cases (77, 376). 

Diazinon is rapidly metabolized, with an estimated mammalian biological half-life of 12-15 hours (Iverson et al. 1975 Mucke et al. 1970). Consequently, efforts at reducing body burdens of poisoned persons may not be critical to the outcome. Dialysis and hemoperfusion are not indicated in organophosphate poisonings because of the extensive tissue distribution of the absorbed doses (Mucke et al. 1970 Poklis et al. 1980). 

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