Comparison of hemodialysis and hypertonic hemodiafiltration on cardiac function [corrected]

This study compared the acute and chronic effects on cardiac function of treatment with hypertonic hemodiafiltration (H HDF) and hemodialysis (HD). Cardiac function was assessed before, during and after a run of H HDF and HD using echocardiography and impedance cardiography in 10 patients in a randomized cross-over sequence, two months after stabilization on each treatment. Blood biochemistry was performed before and after each run. Ejection fraction and fractional shortening were significantly higher before the H HDF run, compared to the HD run, and this difference persisted during and after the treatment runs (both P less than 0.05). There was a corresponding significant difference in the increase of the velocity of circumferential fiber shortening and in the reduction of end systolic diameter during and after H HDF (P less than 0.05). Heart rate, stroke volume, cardiac output, systemic vascular resistance and mean arterial pressure did not differ significantly between the two treatments. Plasma calcium and bicarbonate were significantly higher (P less than 0.03) at the start of H HDF and this difference was enhanced at the end of the run. In conclusion, H HDF compared with HD, is associated with a better myocardial function in both the short and long term treatments. The evidence suggests that this may be due to improved levels of plasma calcium, bicarbonate, and/or the removal of an as yet unidentified myocardial toxin.

Selective removal of high level cryoglobulins (CG) and immune complexes (IC) by a large pore membrane

The investigated membranes having a pore size of 3 micron or less can retain over 95% of cryoprecipitable proteins and immune complexes with nearly complete passage of other plasma proteins at 4 degrees C. Based on this result, the G-3 module consisting of V-3000 membrane was chosen for further study. The G-3 module (0.148 m2 of surface area) processed a 10 times higher plasma volume per unit surface area with higher selectivity than the Asahi Plasmaflo AP 06M. Separation efficiency of cryoprecipitable proteins and immune complexes in cryoglobulinemic plasmas by cryofiltration at 4 degrees C is related to the composition of the cryoprecipitable protein; three of four plasmas contained cryoprecipitable proteins that were removable by cryofiltration. Cryoprecipitation was too slow in one of four plasmas. For this plasma SDS PAGE showed its light chain to be of higher molecular weight than other plasmas. Two of four plasmas had elevated amounts of IC that were removed by cryofiltration.

Comparison of three different methods used in the preparation of leukocyte-poor platelet concentrates

We compared three methods for preparing leukocyte-poor platelet concentrates from random donors: the centrifugation procedure 400 g/6 min, the filtration by Immugard TFIG 500 Y and the Cutter Leukotrap platelet pooling system. The most efficient method with regard to removal of leukocytes and platelet yield could be obtained by filtration through the Immugard filter. Platelet loss was less than 10% and the residual leukocyte count was lower than 10 X 10(6).

Monitoring of platelet contamination in filtered red blood cell concentrates. Use of a radioimmunoassay detecting the platelet glycoprotein IIb-IIIa complex

Monitoring of contaminating platelets, granulocytes, and lymphocytes in leukocyte-poor red blood cell concentrates is usually done by counting in an electronic particle counter. Sensitivity and specificity of this technique are compromised by the contamination of the preparations with other cell types and particles thereof. In this report we studied platelet contamination in filtered red blood cell concentrates by use of a radioimmunoassay for detection of the platelet glycoprotein complex IIb-IIIa. Our results indicate that platelets and/or fragments thereof, not detectable for particle counters, are present in blood cell concentrates. This finding might have important implications for the preparation of pure red blood cell concentrates to avoid unwanted immunization after transfusion.

Continuous arteriovenous hemofiltration in infants

Renal replacement therapy is sometimes necessary in small infants with acute renal failure or severe metabolic disorders. Of the available methods hemodialysis and peritoneal dialysis are not always feasible in small infants. We used continuous arteriovenous hemofiltration as renal replacement therapy in five small infants. This report describes the technique and efficiency of this new extracorporal treatment modality. Azotemia and hypervolemia can be controlled easily by spontaneous or suction supported arteriovenous hemofiltration. Furthermore it allows adequate parenteral nutrition in anuric infants and eliminates toxic products in amino acid disorders. Arteriovenous hemofiltration is well tolerated by small infants and can be performed in every pediatric intensive care unit.

Cascade filtration with reverse rinse of the secondary filter

With cascade filtration (CF) secondary filter plugging may render some procedures difficult, particularly with cryoglobulinemia or macroglobulinemia patients, when filters are subjected to the most consistent burden. To prevent plugging, in the initial management of seven patients with cryoglobulinemia or macroglobulinemia we employed polymethylmethacrylate secondary filters produced by Toray Industries Inc., Tokyo, with pores calculated at 0.1 micron (QS-12-70). In the subsequent sessions, when circulating macroproteins were reduced to more acceptable levels, secondary filters with pores of 0.06 micron were used (QS-12-50). The filtration efficiency of both filters was maintained throughout the procedures with reverse rinses carried out when the transmembrane pressure from the values of 80-130 mm Hg reached the values of 250 mm Hg. With this improved technique, 2.6-3.31 liters of plasma could be treated, producing adequate clinical benefits. From a laboratory point of view, the differential sieving for albumin and macroglobulins was 61% for the QS-12-50 filters and 56% for the QS-12-70 models.

Predilution hemofiltration for the removal of protein bound antigens

In cancer, tumor antigen (Ag) and the antigen-antibody immune complexes (IC) have been implicated with the inhibition of macrophage or lymphocyte function, interleukin generation and induction of suppressor cells and immunosuppressants. Plasma exchange depletes both Ag and antibodies (Ab) from the circulation. However, the Abs might be cytotoxic to cancer cells. Hence, a better treatment would be to remove the Ag without depleting the Abs. Such a procedure involves dissociation of Ag from Ab either by a change in pH of the plasma or by a hemodilution of the blood followed by removal of both the free and the dissociated Ag by ultrafiltration. The present work presents a theoretical analysis of the predilution hemofiltration system designed to remove the antigens which are weakly bound to proteins. A single pool model for the patient was assumed. The variables which effect the clearance of Ag are the protein binding constant (K), the extent of dilution of blood, the initial ratio between Ag and Ab concentrations. A computer simulation of the derived mass balance equations shows that the clearance of total Ag from the plasma pool decreases with (i) increase in the value of K, but it can be off set by increasing the extent of hemodilution, and (ii) decrease in initial Ag/Ab ratio, but this effect can be minimized by increasing the hemodilution fluid flow rate.

A clinical trial of removal of bilirubin in blood by Evaflux-2A

We performed both free and albumin-bound bilirubin removal therapy using the Evaflux-2A and evaluated its clinical effects. The removal rates of total bilirubin in the first and second sessions were 31.4%, and 31.0%, respectively. Our clinical data suggested that plasma exchange using Evaflux-2A and an albumin-added electrolyte solution as the substitute fluid was useful in the treatment of hyperbilirubinemia.