Storage of red cells causes a progressive increase in hemolysis. In spite of the use of additive solutions for storage and filters for leucoreduction, some amount of hemolysis is still inevitable. The extent of hemolysis, however, should not exceed the permissible threshold for hemolysis even on the 42nd day of storage.
Study Design and Methods:
Eighty units of packed red cells, 40 stored in SAGM post leucoreduction and 40 in ADSOL without leucoreduction filters, were evaluated for plasma hemoglobin by HemoCue Plasma Hemoglobin analyzer on the day of collection and on the 7th, 14th, 21st, 28th, 35th and 42nd days thereafter. The hemoglobin and hematocrit were also noted for all these units by the Beckman and Coulter analyzer. Percentage hemolysis was then calculated.
Hemolysis progressively increased with the storage period in all the stored red cell units (SAGM as well ADSOL). However, on day 42nd of storage, free hemoglobin in all the red cell units was within the permissible level (which is 0.8% according to the Council of Europe guidelines and 1% as per the US FDA guidelines). The mean percentage hemolysis was slightly higher in the SAGM-containing bags with an integral leucoreduction filter as compared to the bags containing ADSOL. However this difference was marginal and not statistically significant.
Hemolysis of the red cells increases with storage. However, maximum hemolysis does not exceed the permissible limits at any time thereby indicating the effect of optimum processing and storage conditions on red cell hemolysis.