component preparation

• A single blood donation can provide transfusion therapy to multiple patients in the form of red blood cells (RBCs), platelets, fresh-frozen plasma, and cryoprecipitate.
• Components may be prepared either by collecting whole blood and transforming into components using centrifugation or by collecting targeted components using apheresis, which involves centrifugation of whole blood at the donor’s bedside and the return of blood fractions that are not collected. Often, more of the target component can be collected by a single apheresis donation than can be obtained from collecting whole blood.
• Collection profiles include apheresis platelets (one donation can collect up to three adult doses of platelets, or 18 times the quantity that can be harvested from a single whole blood donation), apheresis plasma (one donation can collect up to 1 L of plasma, which is approximately three to four times the volume that can be harvested from a single whole blood donation), apheresis double-red blood cells (one donation can collect up to 2 units of red blood cells, double what can be harvested from a single whole blood donation)
• Equipment used in the component manufacturing laboratory is intended for one of three functions: manufacture, quality control, or storage.
• Documentation should include who performed each critical task, the equipment that was used, and if preparing time-sensitive components, the date and time that the task was completed.
• Component manufacturing centrifuges are typically either large floor units or large tabletop units that can spin a maximum of 6 to 12 units of whole blood at once. Component manufacturing centrifuges have programmable speed (RPM) and time settings that can be changed based on the components that are being manufactured.
• Manufacturing

  • Blood collection
  • Preparation of blood components to be manufactured (if present)
  • Quality control of each step
  • Presence of quality control measures will dictate the ability to separate the blood into usable results
• Centrifuge conditions for blood component preparation

  1. Red blood cells + plasma: 5,000 × g, 5 minutes

  2. Red blood cells + platelet-rich plasma: 2,000 xg, 3 minutes

  3. Harvesting platelets or cryoprecipitate from plasma: 5,000 xg, 7 minutes
• 1. units of gravity. Please note: The RPM is based on your centrifuge's rotor diameter to achieve the relative centrififigal force (g).
• lasma expressors are mechanical devices that apply pressure to the blood bag, which allows blood components to flow from one bag to another by way of the integrated tubing system. Basic expressors are nothing more than spring-loaded Plexiglas. Automated expressors are also commercially available, such as the Compomat G5 (Fenwal)
• Some components, like plasma, must be labeled within 10% of the actual volume of the component. Scales should be validated to ensure that they produce accurate and reliable results. Quality control of each scale using calibrate standard weights should be performed periodically.
• The tubing that connects blood bags is usually made of polyvinyl chloride (PVC). PVC will melt upon exposure to radio frequency energy.
• . Blood component tubing sealers, sometimes incorrectly referred to as “heat sealers,” use a combination of targeted radio frequency energy and pressure to melt and seal the tubing.
• When making segments on red blood cell components, the seal is usually placed at strategic locations such that each segment contains a serial number
• When making a series of seals along a section of tubing, it is critical to start at the closed end and work toward the open container to avoid pressure buildup within the tubing with each seal that is made, which will eventually cause the tubing to rupture during sealing.
• Sterile connection devices (SCDs) allow two separate blood bags to be connected via their PVC tubing without breaching the integrity of either container. Each piece of tubing is placed in a channel and clamped
• When the SCD is used to connect two containers, the expiration of the original/target component is maintained.
• To freeze plasma, liquid components may be placed in a standard –18°C or colder freezer and allowed to freeze until solid. To maximize throughput in the freezing process and to enhance clotting factor recovery, rapid freezing devices may be utilized.
• Blast freezers use circulating cooled air to rapidly freeze plasma units that are placed flat on a tray. In contrast, immersion baths circulate an antifreeze and water mixture around protective pockets, into which the plasma units are placed either standing upright or lying flat.
• Blood component storage devices should be carefully selected and validated to ensure that they are capable of maintaining the FDA-regulated storage temperatures. Temperatures must be continuously monitored, recorded at least every 4 hours, and the device should alert the user if an unacceptable temperature condition occurs.
• Storage devices include refrigerators, freezers, and platelet agitators. An optional piece of equipment is an environmental chamber that maintains platelet storage at 20° to 24°C. This type of device can be omitted if the room in which platelets are stored is constantly monitored and maintained at 20° to 24°C
• Whole blood is collected in a ratio of 14 mL of anticoagulant-preservative for every 100 mL of whole blood targeted for collection. Depending on the collection system used
• a whole blood component typically contains either 450 mL (±10%) of whole blood with 63 mL of anticoagulant-preservative or 500 mL (±10%) of whole blood with 70 mL of anticoagulant preservative, collected from blood donors with a minimum hematocrit of 38%.
• Occasionally, units of other volumes are collected; the collection volume is stated on the label. Whole blood transfusions provide both oxygen-carrying capacity and volume expansion
• By far, most whole blood donations are manufactured into components, red blood cells, platelets, plasma, cryoprecipitate, or some combination of these components. If the donation remains as whole blood, it must be stored at 1° to 6°C, and the shelf life is dependent on the anticoagulant/preservative used.
• Whole blood collected in acid-citrate-dextrose formula A (ACD-A), citrate-phosphate dextrose (CPD), or citrate-phosphate-double dextrose (CP2D) has a shelf life of 21 days. Whole blood collected in citrate phosphate-dextrose-adenine (CPDA-1) has a shelf life of 35 days.
• RBCs are separated from whole blood by centrifugation, apheresis, or less commonly, sedimentation
• Although RBCs may be prepared from whole blood donations at any time during the whole blood shelf life, they are typically prepared shortly after donation to allow the manufacture of platelet concentrates, frozen plasma, or cryoprecipitate, which must be prepared within designated time periods after collection, usually 8 to 24 hours.
• If additive solutions (AS) are employed, as much of the plasma is removed as possible, and the AS must be added to the RBC component within 3 days of collection, resulting in a finished product with a hematocrit of 55% to 65%. If an additive solution is not used, the volume of plasma removed is targeted such that the finished RBC product has a hematocrit of 65% to 80%. RBC components typically have a final red cell volume of 160 to 275 mL or 50 to 80 g of hemoglobin suspended in the residual plasma and/or additive solution.
• Red blood cells must be stored at 1° to 6°C. In the absence of additive solution, RBCs have the same shelf life as whole blood, either 21 (CPD, CP2D, ACD-A) or 35 (CPDA-1) days. The addition of additive solution to the prepared RBCs extends the shelf life to 42 days
• Red blood cells without additive solution must have a finished hematocrit of less than 80%. Component hematocrit can be measured with a commercial hematology analyzer or manually using a capillary tube spun in a microhematocrit centrifuge
• Red blood cells with additive solution are not required to undergo hematocrit testing, as the addition of 100 mL or more of additive solution will result in a component with a hematocrit of approximately 55%.
• AABB Standards for Blood Banks and Transfusion Services state that red blood cells collected by apheresis must contain a mean of at least 60 g of hemoglobin or 180 mL of RBC volume, and 95% of units tested must contain greater than 50 g of hemoglobin or 150 mL of RBC volume,
• Platelet components can be produced from whole blood donations by apheresis.
• Whole blood used to prepare platelet concentrates must be drawn by a single nontraumatic venipuncture, and the concentrate must be prepared within 8 hours of collection.
• Platelets from donors who are taking a platelet-inhibiting drug such as aspirin may not be used as the sole source of platelets for a patient
• Whereas platelets derived from whole blood are typically called random-donor platelets (RDPs) the platelet product obtained from an apheresis donation is referred to as single-donor platelets (SDPs)
• Collection bag systems that include a platelet storage container are slightly more expensive than collection bag systems not intended for platelet manufacturing because the platelet storage container must be made of a plastic that allows for oxygen exchange to maintain the appropriate pH throughout the storage period
• The second spin also adds expense in the form of additional labor to manipulate the bags and harvest the additional components. Apheresis collections tend to be very expensive, with an upfront cost to purchase and maintain the apheresis equipment, specialized disposable kits, and solutions for each donation, and staff labor to monitor the donation for up to 2 hours.
• RDPs may be maintained as individual components for small-volume transfusions or pooled together for adult transfusions. SDPs are generally indicated for patients who are unresponsive to random platelets due to HLA alloimmunization or to limit the platelet exposure from multiple donors, but they must be divided into aliquots if small-volume transfusions are required. Due to centrifuge conditions, RDPs are prone to RBC contamination, whereas apheresis platelets contain very few RBCs