A colleague in Arkansas wonders what the policy is at other institutions regarding the maximum duration allowed for the infusion for various blood products, such as red cells, platelets and plasma. This question has come up because her institution is aware of 'other places' that have implemented an expiration policy of 4 hours from the time an RBC product leaves the blood bank. Currently her institution's policy is to limit the 'infusion time' for red cells to 4 hours. She is aware that the Circular of information states "If the container is entered in a manner that violates the integrity of the system, the component expires 4 hours after entry if maintained at room temperature."  Their nursing policy states that the nurse has 30 minutes to get the blood from the blood bank and get the transfusion started, after which there is a maximum of 4 hours to transfuse the product.

Editor's Note: In the Editor's opinion the desirable rate and duration of infusion depends on the patient’s blood volume, their cardiac status, and their hemodynamic condition. In his experience most red cell units are transfused within 1 to 2 hours, whereas platelet or plasma transfusions are commonly administered over a shorter period (30 to 60 minutes). If rapid transfusion is needed, RBCs, plasma and platelets can be infused as rapidly as the patient’s circulatory system tolerates and the type of vascular access allows. From time to time it can be anticipated that a transfusion may take longer than 4 hours, in which case consultation with a transfusion service physician may be desirable to assess the specific clinical situation and potential options, such as splitting a dose into aliquots. At the Editor's institution, the clinical staff are advised that unless a unit of RBCs is dispensed in a controlled temperature igloo, the product 'expires' four hours after it has been entered or 6 hours after it has been dispensed, which ever time comes first.

The following comments have been received.

ADDENDA Nov 7, 2004

1. A colleague in Iowa has expressed concern over the policy at the Webmaster's institution (see above) that allows a unit of RBCs to be transfused up to 6 hours after being dispensed, so long as the transfusion is completed within 4 hours of entering the product container. The Iowa colleague wondered if the aforementioned policy would allow a unit of RBCs to be issued and then sit around on a nursing floor (under conditions unknown to the lab) for up to two hours before the product's infusion was started; his concern is based on a belief that if a unit cannot be started within 30 minutes of issue, that it should be returned to controlled storage in the blood bank.

2. The Editor acknowledges that the Iowa colleague is correct in the interpretation of the aforementioned policy, and that a unit of RBCs might potentially 'sit around for some time' at the Editor's institution on a ward before being started. The Editor wonders if colleagues have had the opportunity to observe how units of blood are handled once dispensed or to talk to nursing staff about the transfusion process, because such a review would reveal that there are occasionally legitimate reasons for delaying the start of a transfusion, yet insufficient time or staff to return the affected product to the lab within 30 minutes. It is the belief of the Editor's institution that if a unit of RBCs is kept at room temperature unopened for 2 hours (due to an unavoidable delay, such as a code blue), so long as the transfusion of that unit is completed within 4 hours of entering the container, the product should not be compromised. If there are data to the contrary, the Editor would appreciate the references. Keep in mind that platelets are intentionally stored at room temperature for much longer than 6 hours without expiring. In addition, according to the DRAFT proposed STANDARDS FOR PERIOPERATIVE AUTOLOGOUS BLOOD COLLECTION AND ADMINISTRATION 2nd Edition, Reference Standard 5.1.7A - Handling, Storage, and Expiration of Perioperative Autologous Blood Products, the following Perioperative Autologous Blood Products do not expire for at least six hours if kept at room temperature from the start of their collection: Acute normovolemic hemodilution (whole blood), Intraoperative blood salvaged without processing, Shed blood under postoperative or post-traumatic conditions with or without processing, and Red blood cells intended for transfusion.

ADDENDA Nov. 8, 2004

3. A colleague affiliated with the UK National Blood Service points out that what is considered to be 'room temperature' is not necessarily a standardized metric. For example, he points out that in the UK, where air conditioning is anything but universal, 'room temperature' can vary between about 16 C (60 F) and 25 C (77 F) and occasionally in heat waves be as high as 35 C (95 F). He does acknowledge, however, that most internal temperatures in institutions will be in the 18 - 22 C range, most of the time. He agrees that if a unit of RBCs is out of controlled refrigeration, and the product is still unopened, intact and kept reasonably secure, its integrity is unlikely to be compromised for a 2 hour delay before its infusion is initiated; transfusing the product over the next 4 hours is probably safe. However, he does caution that if the unit is close to its expiry date (say within 2 days) and if that unit had a history of previously being dispensed and returned to the lab, the cumulative period 'out-of-fridge' might compromise the product. He reports twice being before a coroner when a unit of blood transfused on the day before expiry transmitted a bacterial infection which was rapidly fatal. Post-transfusion audit of the implicated products revealed that both units had undergone several 'matching exercises', during each of which a considerable out-of-fridge time had accumulated. By bad luck they had also gotten infected probably at source (donor skin). Finally, he asks if someone could remind him of the origin of the '30-minute rule' about 'out-of-fridge' blood. They have the same rule in the UK, but when applied conscientiously it creates havoc!

ADDENDA Nov. 18, 2004

4. In the experience of a colleague in Utah (no data or literature reference provided), in his environment it takes only about 15 minutes at room temperature for RBCs in current plastic bags to exceed the 10C limit.  He points out that the AABB Standards no longer make mention of a 30 minute rule.

5. In the opinion of a colleague in the Gulf Coast of the USA, the "30-minute rule" for how long a unit of RBCs is allowed to be out of refrigeration stems from the AABB Standard requiring blood to be maintained at 1-10C during transport.  In contrast to the colleague in Utah, she states (without providing a literature reference) that the time required for a unit of blood at room temperature to reach 10C after being removed from refrigeration is approximately 30 minutes.  However, she reports that her institution has evaluated blood bag temperature indicators (Safe-T-Vue) and found that the time required to reach 10C is between 30 and 33 minutes.  They are actually planning to do their official validation of these devices in the near future.  Their Hospital Services and Components departments have also determined the time allowed for blood to be out of the refrigerator during component preparation and packing for shipment, and found the same time frame.

ADDENDA Nov. 26, 2004

6. A colleague in Virginia reports that she has observed first hand why it is important to realize that the AABB Standards do not mention a '30 minute' rule (as pointed out by others above), but rather limit the temperature that a unit of RBCs can achieve (no less than 1C; no greater than 10 C) and still be eligible to be placed back into inventory. While performing validations on digital temperatures and temperature 'dots', she observed that in some locations within a hospital a blood product's temperature could exceed the 10C cut-off in as few as 12-15 minutes.

ADDENDA Nov. 29, 2004

7. A colleague in North Carolina reports that a discussion of the origin of the "30-minute rule" can be found in the following excerpt from the AABB Collected Questions and Answers sixth edition, edited by Dr. Mark E. Brecher. "Apparently, the original concern of units rising above 10C was diminished viability, however, in recent years the concern has been with the risk of bacterial overgrowth. The basis for the 30-minute rule was a paper by Pick and Fabijanic from Transfusion in 1971 (see below). This paper showed that in 14 units of blood stored in plastic bags that the average core/surface temperature was 6.9/10.5C at 30 minutes and 8.6/11.8C at 45 minutes and concluded that the core temperature would exceed 10C between 45 minutes and 1 hour during storage. Presumably the 30-minute rule was taken as a conservative cut-off. From a statistical point of view, this would not stand close scrutiny today for the surface of the bag. However, for the core temperature, a case can be made that 30 minutes is adequate. Thus, it should be expected that in many cases the surface temperature, but not the core temperature will exceed 10C after 30 minutes of storage at room temperature. Since it is not practical to measure the core temperature, for times exceeding 30 minutes, the surface temperature is taken as an approximation of the core temperature. The efficacy of the 30-minute rule for the prevention of bacterial overgrowth has been called into question (see Hamill)."

Pertinent references:

• Hughes-Jones, NC. Storage of red cells at temperatures between +10C and -20C. Brit J Haemat 1958:4:249.
• Pick P. Fabijanic J. Temperature changes in donor blood under different storage conditions. Transfusion. 1971;11:213-5
• Hamill TR. The 30-minute rule for reissuing blood: are we needlessly discarding units? Transfusion. 1990;30:58-62. Review. Erratum in: Transfusion 1990;30:103.

ADDENDA Dec. 12, 2004

8. In addendum #5 of November 18, 2004, a colleague in the Gulf Coast of the USA, reported that her institution was planning to do a validation of the Safe-T-Vue indicators. The data from that validation (n = 8 RBC units) showed that it took between 31-36 minutes for a unit to increase its temperature to 10C, after being removed from the refrigerator and sitting at room temperature (22C); the corresponding color change was observed for the Safe-T-Vue indicators.  They had previously tested 2 RBC units, with times of 30 and 33 minutes, respectively. Their Hospital Services and Components departments have also determined the time it takes for blood outside of the refrigerator to reach 10C during component preparation and packing for shipment, and found a similar time frame.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator