Plasma, the liquid component of blood, is essential for medical treatments. It carries proteins, antibodies, and clotting factors. Proper storage is vital to maintain its therapeutic effectiveness and support patients.
Understanding Plasma and Its Medical Role
Plasma constitutes approximately 55% of total blood volume, appearing as a pale yellow liquid when separated from blood cells. It is primarily 92% water, with the remaining 8% consisting of dissolved proteins (e.g., albumin, globulins, fibrinogen), electrolytes, hormones, and vitamins. This composition enables plasma to maintain blood pressure and volume, aid in clotting, and transport nutrients and waste products.
In medical settings, plasma is used for many interventions. Transfusions are given to trauma patients with significant blood loss, burn victims, or those with severe liver disease. Plasma also provides clotting factors for patients with bleeding disorders like hemophilia and reverses certain anticoagulants. It is also processed into life-saving therapies like immunoglobulins for immune deficiencies and albumin for volume expansion.
Critical Factors Influencing Plasma Storage
The integrity of plasma components, particularly clotting factors and proteins, depends on precise storage conditions. Temperature is a key factor, with freezing essential for long-term preservation. Rapid freezing methods, such as for Fresh Frozen Plasma (FFP), minimize damage, ensuring activity retention.
Anticoagulants, added during blood collection, maintain plasma stability by preventing clot formation. Specialized medical freezers maintain consistent ultra-low temperatures, preserving plasma’s therapeutic properties. Temperature fluctuations can denature proteins and reduce clotting factor activity, compromising efficacy.
Standard Storage Durations and Conditions
Guidelines govern plasma product storage for safety and effectiveness. Fresh Frozen Plasma (FFP) is prepared by rapidly freezing plasma from whole blood to -18°C or colder within 8 hours of collection. At this temperature, FFP can be kept for up to one year, maintaining coagulation factor activity. Some regulations permit storage at -65°C or colder for up to seven years, especially for rare blood types.
Once thawed, FFP requires refrigerated storage between 1°C and 6°C. Thawed FFP typically has a 24-hour shelf life, after which certain clotting factors (e.g., factor V, factor VIII) may decline. However, if relabeled as “Thawed Plasma,” it can be stored for up to five days at the same temperature, though its use may be limited to situations needing less labile factors. Adherence to these guidelines is important for product quality.
Consequences of Exceeding Storage Limits
Storing plasma beyond its shelf life or under improper conditions reduces its therapeutic value. The main consequence is degradation of labile clotting factors. As these factors break down, plasma’s ability to promote coagulation diminishes, making it less effective for patients with bleeding or clotting deficiencies. This loss of activity means transfused plasma may not achieve the desired clinical outcome, potentially prolonging recovery or worsening conditions.
Exceeding storage limits or improper temperature control introduces safety concerns beyond reduced efficacy. While FFP is rarely contaminated by bacteria due to low temperatures, thawing or breaches in sterile handling can increase bacterial contamination. Prolonged storage, especially of whole blood, can form micro-aggregates. Though filters can remove some, they pose a risk of microvascular occlusion if transfused, potentially affecting organ function.