Policies for storage of previously irradiated red cell units intended for transfusion to neonates 

A colleague on the East Coast reports that their pediatric open heart surgeon requires irradiated products for neonatal open heart patients. Consequently, the blood bank irradiates two CPDA1 units just prior to surgery and sends the blood to the OR. The surgeon requires that the blood be in the OR prior to the start of the case, which is why the blood bank irradiates the blood prior to the surgery beginning, because they cannot wait to irradiate the blood at the time it will be transfused. Not unsurprisingly, they get many irradiated units returned from the OR unused, but the post-op patients often continue to use blood for several days. They are trying to determine if it is safe to use an irradiated RBC unit for several days to avoid exposure to multiple donors. The inquiring colleague is aware that the product is allowed to be stored beyond the day it was irradiated, per the FDA, but is unsure if such RBCs are safe for neonates. She asks if others share their protocols addressing the length of time irradiated units are allowed to be stored for neonates, particularly those with heart disease.

• After units are irradiated, do you use them for up to 12 hours, 24 hours or beyond, to limit donor exposure?
• If the units are used postoperatively are they used only for small volume transfusions?
• Do you worry about the potassium leakage and therefore restrict the length of time a unit is used, as opposed to large volume transfusions where you irradiate just prior to use?

Forum members are encouraged to review a related discussion previously posted in this section.

The following responses have been received.

ADDENDA May 4, 2004

1. A colleague in Boston reports that her hospital sets a 3 day outdate to all red cell units that have been irradiated for patients in the NICU. Generally they irradiate one aliquot at a time. On rare occasions they will irradiate an entire unit for surgery. In both cases they make an attempt to use aliquots from the same unit to limit donor exposures.
   
   
2. Ronald E. Domen, MD of the Milton S. Hershey Medical Center Penn State University College of Medicine reports that several years ago he did an in-house evaluation of irradiated blood for neonatal heart surgery (this was at a prior institution). The Pediatric Cardiac Surgeon required fresh, heparinized blood. The protocol was to collect, test, and irradiate the blood just prior to its release, which was usually within 24 hours or less from the time of collection. In order to see if they could extend the shelf-life from 24 to 48 hours, they looked at LDH, pH, sodium, potassium, and plasma hemoglobin in split units collected for therapeutic phlebotomy. From the cardiac standpoint, the potassium concentration was the main concern. Ten units of whole blood were collected. The units were split and one half of the unit was irradiated and the other half was not. Measurements were performed at time 0, 24 hrs, 48 hrs, and 72 hrs. For 10 unirradiated units, at time 0 the mean potassium concentration was 4.1 mmol/L (range, 3.1-9.5); at 24 hours, 7.5 (range, 5-11.6); at 48 hours (n = 9), 11.8 (range, 7.2-16.4); and, at 72 hours (n = 6), 16.6 (range, 10.4-24.5). For the irradiated units at 24 hours (n = 10) the mean potassium was 16.5 +/- 10.6 (range, 7.4-46.9); at 48 hours (n = 7), 17.7 +/- 4.1 (range, 11.6-24.8; two units were >20 and not included in the calculation); and, at 72 hours (n = 5), 29.6 +/- 5.8. At 48 hours in the unirradiated units the plasma free hemoglobin level was 43.1 +/- 39.1. All other measurements were felt to be satisfactory. Dr. Domen says that they concluded that in the unirradiated state, units could be stored for up to 48 hours prior to irradiation. At 48 hours even the irradiated units had potassium levels of 20.0 or less in 6 of 9 units. None of this was acceptable to the cardiac surgeon who felt that potassium levels remained too high at 48 hours and so the 24 hour shelf-life was maintained. His suggestion to the East Coast colleague is to perform an in-house study and to evaluate any concerns based on the study data with the cardiac surgery staff.

ADDENDA May 5, 2004

3. At the Editor's institution at the Los Angeles County+USC Medical Center, the expiration date of irradiated red cells is normally 28 days from the date of irradiation or the original expiration date, whichever comes first. However, if the RBCs are to be used for infants less than four months old, the expiration date of the RBCs (usually aliquots) is 21 days from the date of unit collection.

ADDENDA Apr. 10, 2005

4. A transfusion medicine physician in Minnesota reports that his facility is implementing a policy that 100% of cellular blood components for neonatal transfusions must be irradiated. This new policy is motivated by a desire to minimize the risk of missing special blood product needs for neonatal transfusion recipients.Therefore, all neonates will receive leukocyte-reduced, irradiated cellular blood components. For ease of operation, and also to minimize the potential for errors, they are planning to irradiate platelets and RBCs in their blood component laboratory prior to distribution to the hospital transfusion services.It has been their practice with neonatal RBC transfusions to use "dedicated units" for individual recipients and draw aliquots for transfusion from these units throughout their shelf life. They would like to continue this practice provided it is safe. The question the Minnesota physician is posing, therefore, is the following: "For small volume RBC transfusions in neonates, is it safe to transfuse aliquots from what amounts to a "prestorage irradiated unit" throughout its 28-day shelf life?" He requests that colleagues share their experience and/or provide data or references to published articles.

ADDENDA Apr. 11, 2005

5. The General Supervisor of a Blood Bank in Southern California reports that her hospital irradiates all cellular products for patients under two years of age as a matter of policy, plus they transfuse these patients with RBC that are less than 10 days old. Irradiated RBC units outdate at 28 days and are handled upon return from surgery like any other unit, being returned to inventory provided the blood was not out of proper temperature control. RBC aliquots are irradiated immediately prior to being dispensed and are never placed back into inventory if returned (due to temperature considerations). Some of their pediatric cardiac surgeons request that the irradiated RBCs also be washed (even units <5 days old) when attempting complex surgical procedures on very small patients, because the surgeons feel that the supernatant plasma has too much potassium.

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