Blood transfusion reaction refers to the adverse effects caused by the injection of blood or its products or commonly used infusion supplies during or after the entire process of intravenous injection. Below, I will introduce several common blood transfusion reactions.

1. Fever reaction. Fever reaction is the most common reaction in intravenous injection, which often occurs within 1 to 2 hours after intravenous injection or during intravenous injection. Symptoms include chills, fear of cold, or shivering, fever, body temperature reaching 40°C, accompanied by skin redness, headache, nausea, vomiting, and so on. Symptoms may alleviate after 1 to 2 hours. In mild cases, the symptoms can be relieved by reducing the drip rate. In severe cases, the intravenous injection should be terminated, close monitoring of the electrocardiogram should be performed, and symptomatic treatment should be given, and the doctor should be notified. If necessary, analgesics and antiallergics such as promethazine or adrenocorticotropic hormone should be taken according to the doctor’s instructions.

2. Allergic symptoms. The key reasons for the occurrence of allergic symptoms include the patient being an allergic constitution, the heterologous protein in the blood causing the body to react with the protein of the allergic skin, resulting in complete antigens and sensitization; donors using allergenic drugs or food before donation, causing allergens to be present in the blood. The symptoms may vary from mild to severe, from mild skin itching, urticaria, and mild to moderate angioedema, to severe difficulty breathing due to laryngeal edema, wet rales in both lungs, and even anaphylactic shock. When allergic symptoms occur, the injection rate should be reduced slowly and observed again in mild cases, and immediately terminate intravenous injection in severe cases.

3. Hemolytic reaction. Hemolytic reaction is one of the most serious reactions in intravenous injection. The causes of hemolytic reaction include: injecting incompatible blood, injecting contaminated blood, adding hypertonic or hypotonic solutions to the blood, or adding drugs that can affect the pH change of blood, leading to the destruction of a large number of blood cells. Typical symptoms occur after injecting 10-20ml of blood and become more severe with the increase of blood injection volume. It can cause headache, numbness in the limbs, severe pain in the lumbar and back area, chest tightness and shortness of breath, jaundice, and hemoglobinuria. In addition, it may be accompanied by chills, high fever, difficulty breathing, and low blood pressure. Some may cause renal tubular damage and obstruction, leading to symptoms of subacute renal insufficiency such as oliguria and anuria. In severe cases, it can cause death.

These types of reflections are all common and require attention.