Effect of multiple use of dialyzers on hepatitis B incidence in patients and staff.

Data pertaining to incidence of hepatitis B from a 1976 Center for Disease Control Study were matched with responses from a Renal Physicians Association survey on dialyzer reuse in the United States. Of 6,079 patients, 166 (2.7%) became positive for hepatitis B surface antigen (HBsAg) in 96 centers practicing reuse, whereas 495 (2.6%) of 18,947 became HBsAg positive in 439 centers practicing single use. Among staff, 75 (2.5%) of 3,049 became positive for HBsAg in centers practicing reuse vs 200 (2.3%) of 8,696 in centers not reusing dialyzers. Incidence of infection among staff associated with a center having at least one HBsAg-positive patient was 2.9% in centers practicing reuse vs 3.6% in centers practicing single use. Nearly all (95%) staff who became HBsAg positive were associated with centers having at least one HBsAg-positive patient. The practice of reusing dialyzers does not appear to be associated with increased risk of hepatitis B infection among patients and staff.

Dialysate delivery: historical, theoretical, and practical aspect.

Maintenance hemodialysis has progressed from a tentative therapy for a few patients in Seattle to a generally available treatment sustaining 100,000 patients around the world. The technical principles of dialysis are sufficiently understood to permit fabrication of disposable dialyzers in sheet, coil, or hollow-fiber configuration. Dialysate delivery systems can serve either single patients or groups of patients with high efficiency. Reduction in size of single-parent systems by incorporation of dialysate regeneration or miniaturization of components in a suitcase will promote patient mobility.

Design analyses of a new selective filtration system for removal of uremic toxins.

A new system for removal of uremic toxins is described, The system is based on selective removal of small (urea, creatinine) and large uremic toxins through a multimembrane filter/dialyzer unit. Theoretical calculations show that the system is capable of removing the desired range of molecules from uremic plasma, while retaining a large portion of non-toxic elements in the blood. The SElective DUal Filtration ARtificial Kidney can be optimized and assembled into a single compact unit, which is simple to use and requires minimal monitoring equipment. Preliminary clinical trials indicate that SEDUFARK is a feasible system for treatment of uremic patients.

Portable system for simultaneous measurements of blood electrolytes.

Miniature, rugged Chemfet sensors have been developed by coating field-effect transistors with ion-sensitive membranes. These sensors have been combined with a flow injection analysis manifold to demonstrate feasibility of a small portable system capable of simultaneous determinations in 10 seconds of hydrogen, potassium and calcium ion activities in 20 microliters samples of whole blood, serum or dialysate.

Aluminium transfer in bicarbonate dialysis using a sorbent regenerative system: an in vitro study.

Because of the known presence of aluminium oxide in the Redy cartridge and the increased solubility of aluminium (A1) in alkaline solution, an in vitro study was performed to measure the release of A1 from the Redy cartridge and its potential transfer across a dialyser membrane. The use of bicarbonate rinsed Redy cartridges was associated with significant release of A1 and its subsequent transfer across the cellulose acetate membrane. Bicarbonate dialysis with the Redy system is not recommended for maintenance haemodialysis.

Amberlite hemoperfusion in the treatment of acute drug intoxication.

Hemoperfusion is more effective than hemodialysis in clearing drugs from the blood of patients with acute overdose. In addition, the clinical improvement in the depth of coma is dramatic during hemoperfusion. There is normalization of the respiratory and circulatory systems usually within one hour, and response to verbal command within a few hours of initiating treatment. Amberlite XAD-4 is an unchanged polystyrene resin with a particular adsorptive attraction for lipid-soluble drugs. It is a more effective adsorbent than some of the coated or uncoated carbons in clearing blood of most of the drugs commonly involved in life-threatening acute overdose.

Leukopenia and hypoxemia. Unrelated effects of hemodialysis.

Hemodialysis-induced hypoxemia has been attributed to membrane-related complement activation leading to pulmonary leukostasis and to hypoventilation secondary to carbon dioxide losses via the dialyzer. We have separately assessed the role of membrane- and dialysis-related factors by using different dialyzers and sequential ultrafiltration and hemodialysis with first-use cellulose dialyzers produced both leukopenia and hypoxemia. With reused cellulose and polyacrylonitrile dialyzers, hypoxemia still occurred, but without leukopenia. Ultrafiltration produced leukopenia and no changes in Pao2; during the subsequent hemodialysis, hypoxemia developed as the leukocyte count increased by 50%. Our data indicate that leukopenia and hypoxemia are unrelated effects of hemodialysis, and favor hypoventilation as the major determinant of hypoxemia during hemodialysis.