Infusionstherapie und Transfusionsmedizin
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Infusionsther Transfusionsmed · Dec 1992
[Cryopreservation of human erythrocytes with hydroxyethyl starch (HES)--Part 2: Analysis of survival].
Red blood cells (RBC) were obtained from 5 whole blood units by centrifugation and were purified using a simple washing procedure. Hematocrit and HES concentration in the 108-ml samples to be frozen were adjusted to 40% (v/v) and 12% (w/w), respectively. Cooling was performed by submerging into liquid nitrogen using containers to generate a flat sample geometry (3 mm thickness). ⋯ ATP was reduced by 16%, but this had completely recovered after 3 h resuspension in autologous plasma. Some morphological changes present after thawing (e.g. stomatocytes, echinocytes) also recovered after 1.5 h. In conclusion, those RBC which survived the preservation process can be considered to be fully viable with regard to the parameters investigated.
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Infusionsther Transfusionsmed · Dec 1992
[Cryopreservation of human erythrocytes with hydroxyethyl starch (HES)--Part 1: The procedure].
Although the efficacy of hydroxyethyl starch (HES) as a cryoprotectant for human red blood cells (HRBC) was demonstrated in 1967, no clinical application has evolved so far. In contrast to glycerol, which has been widely used for this purpose, HES offers the advantage of being nontoxic if administered intravenously. ⋯ For a volume of 40 ml, the optimal combination of important parameters [e.g. cooling rate 200-250 K/min, warming rate 400 K/min, hematocrit 40%, HES concentration 12% (w/w)] has led to a survival after thawing in terms of saline stability of 93 +/- 1% (n = 10). Additionally, the age prior to cryopreservation (0-3 days) had an influence on postthaw survival, but at least 90% survival can be obtained if the samples are washed 3-5 times before freezing.