Final answer:
When monitoring a surgical patient receiving a blood transfusion, a sign to stop the infusion immediately is the occurrence of a strong, potentially lethal hypersensitivity reaction called hemolytic transfusion reaction (HTR) due to incompatible blood types.
Step-by-step explanation:
When monitoring a surgical patient receiving a blood transfusion, a sign that indicates a need to stop the infusion immediately is when the patient experiences a strong, potentially lethal type II hypersensitivity cytotoxic response called hemolytic transfusion reaction (HTR). This occurs when the transfused blood type is incompatible with the patient's ABO blood type.
Incompatible transfusion can lead to agglutination of the transfused red blood cells (RBCs) due to the presence of antibodies in the patient's plasma. This triggers an inflammatory response and hemolysis of the RBCs, which can result in fever, chills, itching, hives, difficulty breathing, hemoglobinuria, and low blood pressure. In severe cases, it can lead to shock, multi-organ failure, and death.
Monitoring for these signs and symptoms is crucial to prevent severe complications, and if they occur, the blood transfusion should be stopped immediately.