What is a potential consequence of performing a transfusion without proper crossmatching?

Performing a transfusion without proper crossmatching can lead to a hemolytic reaction. This occurs when the recipient's immune system recognizes the donor red blood cells as foreign, triggering an immune response. The most common cause of this reaction is the presence of donor red blood cells that are incompatible with the recipient's blood type, particularly with respect to the ABO and Rh blood group systems.

When incompatible blood is transfused, the recipient's antibodies can bind to the antigens on the surface of the transfused red blood cells, leading to their destruction (hemolysis). This can result in severe complications such as fever, chills, back pain, and dark urine, and in serious cases, it may lead to acute kidney injury or even death.

While hypotensive shock, infection, and electrolyte imbalance are all potential complications that can occur due to blood transfusions, they are not direct consequences of the incompatibility issues that arise from inadequate crossmatching. Hemolytic reactions specifically link to the issue of incompatible blood types, making it the correct answer to the question.