Summary

Cold agglutinins are autoantibodies that agglutinate red blood cells at low temperatures, leading to haemagglutination and haemolysis. They are generally of no clinical significance. However, when people with cold agglutinins undergo cardiac operation with hypothermia and cold cardioplegia, they can experience complications. Thus, different perioperative management is required for such patients. We describe a 74-year-old man with cold agglutinins incidentally detected on the preoperative screening test. He had never experienced any complications or developed a haematological disease. Since cold agglutinins were incidentally detected on the preoperative test, a special strategy was used to manage the temperature of cardiopulmonary bypass (CPB) and cardioplegia. He successfully underwent normothermic cardiac operation with warm cardioplegia. A continuous retrograde hyperkalaemic infusion and intermittent antegrade infusion of warm cardioplegia with normothermic CPB is one of the best methods to avoid hypothermia and excessive activity and metabolism of the heart, and to provide a suitable operative field.