Blood Cold Chain From Collection To Transfusion

Blood transfusion, when indicated, is an essential therapeutic intervention. It may be needed for patients in emergency, but some patients need regular transfusions for survival. The purpose of blood transfusion is to improve the physiological status of the patient.

The collection of blood from donors may take place within the blood bank or during mobile blood collection drives. Blood collected is at body temperature, i.e., +37°C. In order to maintain its vital properties, it must be cooled and kept at the right temperature until its use. It could be during transportation or when stored in the center; hence, the term blood cold chain, which begins the moment the blood is collected and continues until it is transfused. If blood is stored or transported outside of these temperatures for long, it loses its ability to transport oxygen or carbon dioxide to and from tissues respectively upon transfusion. Various blood components can be prepared from a single donation of whole blood, like red cells, platelets, plasma, and cryoprecipitate. The blood is tested and processed as per the SOP and components are stored at appropriate temperatures.

The major equipment to maintain blood cold chain for whole blood are refrigerators and transport boxes; freezers are essential for transfusion centers that store plasma. Platelet incubator and agitator is required when platelets are to be stored. Other vital devices and accessories include stand-by generators and temperature monitors with alarm system fitted in all the equipment. The alarm is meant to warn health personnel as soon as the blood stock approaches unacceptable temperatures. The storage and transportation of reagents or blood samples is also very critical to get the desired results.

An efficient system must be in place to ensure that correct temperature is maintained while blood and blood components are transported from or received into a blood bank. Blood centers should procure transport boxes with temperature-monitoring system to transport different components.

Red blood cell components must be kept at a temperature of +2°C to +6°C during transportation. In the absence of refrigerated containers, ice packs should be placed above the blood bags. Ice should not be allowed to come into direct contact with the blood as the red cells in contact with ice may freeze and get hemolyzed. Platelets are transported at +20°C to +24°C and plasma at -18°C or below, or else there should be enough ice packs in the cold box to keep it in frozen state while transporting, to retain labile clotting factors.

Whole blood collected in outdoor camps should be transported to the blood center in appropriate conditions of temperature. Whole blood collected should be cooled to between +2°C and +10°C. If the blood is to be used for the preparation of platelets, it should not be cooled to below +20°C as platelets will lose their viability. The time between blood collection and centrifugation process for component preparation should not exceed 6 hours. Refrigerated transport boxes for transporting blood are an essential component for all the blood banks, and more important for those collecting blood at outdoor camps. Besides effective screening of donors and blood processing, quality of blood depends on the effective cold-chain maintenance after blood donation.

After component separation, red cells can be stored at 1°C to 6°C for 35 to 42 days depending on the additive; platelets at 22°C to 24°C in platelet incubator and agitator for 5 days; and plasma at temperatures of -20°C, or below, can be stored in the freezer for up to 1 year.

Besides having good processes in place, every blood bank should have all the required equipment for processing, storage, and transportation of blood, to maintain the desired quality of blood and blood components.

Lastly, the most critical aspect is to have a back-up energy source.