What is the earliest time frame in which symptoms of an ABO blood group incompatible transfusion reaction may become apparent?

The earliest time frame in which symptoms of an ABO blood group incompatible transfusion reaction may become apparent is within the first 15 minutes of starting the transfusion. This is critical because acute hemolytic reactions, caused by the destruction of red blood cells due to incompatibility, can onset rapidly following transfusion initiation.

In the initial moments of transfusion, the recipient's immune system may quickly recognize foreign ABO antigens present on the transfused red blood cells, prompting an immune response. This prompt reaction can lead to severe symptoms such as fever, chills, hypotension, and even back pain. Observing patients closely during this initial period is crucial for early detection and intervention, which can greatly impact patient outcomes.

When considering the other timeframes suggested, reactions occurring after the transfusion has finished may indicate other types of delayed reactions, which are generally less immediate and would not be classified as the earliest signs of incompatibility. Similarly, symptoms only manifesting during the first 15 minutes of the first blood pack does not take into account the possibility of reactions occurring at any time during the initial transfusion period. Lastly, stating that symptoms are more frequently seen at the end of a transfusion does not align with the urgency of detecting acute reactions when