Be careful, the bag is now open!

Be careful, the bag is now open!
Peace and blessings be upon you all,

A new colleague in the blood bank, just starting out in this field, was preparing a unit of red blood cells and taking a sample from the bag. Unfortunately, the bag opened. He quickly ran and sealed it with the sealer he had, but his more experienced colleague told him, “Be careful, the bag is now open.” The new colleague was hearing this term “open” for the first time and didn’t know what it meant. He also didn’t know what would happen to the bag or what the term “closed system” refers to.

Let’s explore these important terms together to understand what they mean and the difference between them.

First Term: Closed System

• The concept here is that the blood, its components, or the blood collection process itself is maintained under proper sterility. This means the sterility hasn’t been compromised at all (i.e., the sterile chain has not been broken).
• For example, as shown in the first image, some bags come prepackaged from manufacturers. These bags are designed to be sterile and sealed between each compartment. After the blood components are separated, each component remains in its individual compartment, and separation is done using a sealer, ensuring the sterility of all components. This is the closed system.

Scenario 1: Maintaining a Closed System

If we want to perform a specific procedure on a blood component (as we’ll see below) while preserving its sterility, we can use a special device like the welder shown in the second image. This device allows us to maintain the closed system for the units, just like in their original bag (from the first image).

• By maintaining a closed system, the units retain their original expiration dates without any changes.

Examples of procedures performed within a closed system:

• Aliquoting (e.g., 50 mL) from a red cell unit or dividing it into smaller units.
• Filtering a red cell unit with a laboratory filter.
• Pooling or dividing platelet units into smaller units.
• Separating cryoprecipitate from FFP.
• Other similar procedures.

Second Term: Open System

• This occurs when the sterile chain of the components is broken. When this happens, the unit is exposed to potential bacterial contamination. For example, in our scenario, when the blood bank colleague accidentally opened the bag, the sterility of the unit was compromised, and its expiration date was reduced—it no longer retains the original expiration date.

Examples of situations where an open system occurs:

• Washing red cell or platelet units.
• Separating red cells or platelets units directly from the bag without using a welder.
• Filtering units with a laboratory filter without using a welder.
• Separating cryoprecipitate from FFP without using a welder.
• Any component opened either during initial separation or at any later stage during its storage period.

Effect on Component Expiry

As mentioned, the expiration date of components in an open system changes as follows:

1. Whole Blood Unit

1. • If samples are drawn from the unit (for donor testing) in an improper manner, the unit expires within 24 hours.

2. Red Cell Unit

1. • Expires 24 hours after it becomes an open system. For example, if the unit is opened at 12:00 PM, it must be used by 12:00 PM the following day. During this time, it must be stored in its standard refrigerator. If 24 hours pass without use, the unit must be discarded.

3. Platelet Unit

1. • Expires 4 hours after becoming an open system.

4. Plasma Unit

1. • If thawed and becomes an open system, it expires within 24 hours, similar to red cells.
   • If it’s opened before freezing, it can still be frozen normally. After thawing, its expiration is 24 hours.

5. Cryoprecipitate Unit

1. • Expires 4 hours after becoming an open system.
   • If separated from FFP without using a welder, it also expires within 4 hours.

6. Platelet Storage at 1–6°C (in some facilities):

1. • If they become an open system, they expire within 24 hours, similar to red cells.

Important Note:

If a blood transfer set is connected to a component for transfusion to a patient, this does not classify as an “open system.” Instead, it is considered an open unit, and its expiration is 4 hours from the time the transfer set is connected. It’s crucial to differentiate between the two scenarios.

Conclusion

Understanding these cases is essential because, as demonstrated, each scenario affects the shelf life of components differently when used for transfusion to patients.