Final answer:
If a major cross-match is not performed correctly during a blood transfusion, it can result in the destruction of red blood cells, inflammation, and organ damage. Complications may include fever, chills, itching, hives, low blood pressure, shock, and multi-organ failure.
Step-by-step explanation:
A major cross-match is performed before a blood transfusion to ensure compatibility between the donor and recipient. If the major cross-match is not performed correctly, it can lead to serious complications such as destruction of red blood cells, inflammation, and organ damage. For example, if a person with type B blood receives a transfusion of type A blood, their anti-A antibodies will bind to and agglutinate the transfused RBCs. This can result in fever, chills, itching, hives, low blood pressure, and even shock and multi-organ failure.