Do Stored Blood Components Expire? Understanding the Lifespan of Banked Blood

Blood banks play a crucial role in ensuring a continuous supply of fresh and viable blood to meet the needs of emergency and non-emergency patients. The blood is safeguarded by segregating it into its respective components: red blood cells, white blood cells, and plasma. Each component has specific storage requirements and a defined expiration time to ensure its viability and safety.

Generally, blood banks segregate the blood into its components. Red blood cells, for instance, can remain viable for up to 42 days, while plasma can be stored for up to 1 year, provided they are stored in bags or containers with CPDA (Citrate Phosphate Dextrose Adenine), a solution that contains citric acid, sodium citrate, monobasic sodium phosphate, dextrose, and adenine. These components are refrigerated at temperatures between 2-6 degrees Celsius to prolong their viability.

Understanding the Storage Solutions

CPDA is a widely used preservation solution in blood banking. It helps to protect the blood cells from a process known as hemolysis, which occurs when red blood cells break down. This solution is vital for maintaining the integrity of the blood components during storage. Citric acid and sodium citrate prevent clotting, while dextrose provides energy, and adenine supports the metabolism of the stored cells.

The Degradation Process

Over time, the components of stored blood begin to degrade and lose their vital functions. Red blood cells, particularly, become less flexible and more rigid due to prolonged storage. This rigidity impairs their ability to carry oxygen effectively, which is crucial for cellular respiration and overall bodily functions. The white blood cells and plasma also undergo various changes, though they generally last longer and retain their viability for a more extended period.

The Emergency Paradox

In emergency settings, however, old blood might sometimes be life-saving. Although blood components are carefully monitored and regulated for expiration, there are instances where limited supplies necessitate the use of older blood. In such situations, healthcare providers must balance the risk of using potentially less viable blood against the immediate need to save a life.

Conclusion

Banked blood components do have an expiration time based on the specific conditions of their storage. Proper segregation, use of preservation solutions like CPDA, refrigeration, and regular testing ensure the viability and safety of donated blood. While there are mechanisms in place to maintain blood quality, the emergency context can sometimes necessitate the use of older blood, highlighting the importance of maintaining a well-organized blood supply system that can respond swiftly to the needs of patients.