One of the events associated with red cell storage at 4 degrees C is the development of an increasing proportion of echinocytes. Vesicles also may bud off the spicules, presumably leading to a decreased surface-to-volume ratio and decreased deformability. Pursuing the hypothesis that increasing the surface tension of the cells by increasing their volume might reduce the tendency toward echinocytosis and extend refrigerated storage time, packed red cells were resuspended in a solution hypotonic (210 mOsm) with respect to solutes that do not penetrate the cell. Since a reduced ionic concentration results in increased membrane permeability for cations, normal ionic concentration was maintained by the addition of NH4C1, which readily penetrates red cells and therefore contributes no osmotic support. Adenine, glucose, mannitol, citrate, and phosphate also were included. Unexpectedly, the predominant effect of red cell storage in this solution was a remarkable elevation of adenosine triphosphate (ATP). At 4, 8, and 10 weeks, (ATP) levels averaged 165, 135, and 110 percent of initial values, respectively. At 16 weeks, ATP still averaged 50 percent of initial values. Twenty-four-hour in vivo survival of red cells measured at 12 to 18 weeks ranged between 70 and 80 percent, and hemolysis ranged from 0.3 to 7.1 percent. Both the hypotonicity and the ammonium salt appear to be necessary for the high ATP.

Red cells washed and stored in a citrate-phosphate-glucose-adenine solution at pH 7.4-7.6 demonstrate excellent maintenance of adenosine triphosphate, elevation of 2,3-diphosphoglycerate well above normal levels for more than 6 weeks, reduced hemolysis and 24-hour in vivo survival comparable to that of cells stored in ADSOL. These results can be attributed in part to a chloride shift in which the washout of intracellular chloride is associated with an influx of OH-, which increases intracellular pH and thereby increases the rate of glycolysis. The phosphate functions primarily as a buffer to maintain both extra- and intracellular pH. Reducing the effective osmolality of the storage solution reduces hemolysis and improves cell morphology.

Bacteria were intentionally introduced into units of whole blood. Platelet concentrates (PC) which were made from these units were stored at either room temperature (22 C) or at 4 C. In order to isolate small numbers of bacteria from a PC (i.e., 1 to 10 organisms per ml), substantial contamination (42 to 125 organisms per ml) of the whole blood was required. If the PC were stored at room temperature, all organisms except Pseudomonas aeruginosa, which was apparently killed, grew out of control within 48 hours. Storage of PC at 4 C resulted in the general maintenance of bacterial numbers. Since gross contamination of PC has only occasionally been reported, we conclude that past reports of modest contamination of platelet concentrates are primarily sampling artifacts.

No abstract

Units of blood were intentionally contaminated with suspensions of either Aerobacter aerogenes, Escherichia coli, Bacillus subtilis, Enterobacter cloacae, Pseudomonas aeruginosa, Sarcina lutea, Seratia marcesens, Staphylococcus epidermidis, Streptococcus faecalis, Paracolaba cterum aerogenoides (Enterobacter ha friae), M i m a polymorpha or Acinetobacter calcoaceticus.When inoculation was made prior to glycerolization, the subsequent glycerolization, freezing, thawing, and deglycerolization resulted in roughly a two log reduction in the number of bacteria. When inoculation was made with a final concentration of between 10' and 10' organisms per milliliter, immediately following deglycerolization or following washing without glycerolization and freezing, no increase in the number of bacteria was seen after 72 hours storage at 4 C. Three of the 12 organisms studied decreased in number during 72 hours of storage. These data suggest that the current 24-hour limit on the postthaw storage of frozen red blood cells may be unnecessarily restrictive.