The natural course of hemoglobin levels after allogenic blood transfusion in total knee arthroplasty.

We retrospectively investigated the natural course of hemoglobin levels after allogenic blood transfusion in total knee arthroplasty. All patients were treated according to the same clinical pathway, and blood tests were performed on the same day. All blood tests were done on pre-op, immediate post-op, midnight of op day, 1st, 2nd, 3rd, 5th, 7th, and 11th day after surgery. Of the total 593 cases, a total of 197 cases (33.2%) were performed within 3 days of surgery. Hemoglobin level was significantly lowest on the 3rd day after surgery and tended to increase afterwards in the non-transfusion group. In the case of blood transfusion on the day of surgery, the hemoglobin level showed an increase on the next day and then showed a minimum value on the fifth day of surgery and then increased. The same pattern was identified when blood transfusion was done on the 1st and 2nd day of surgery. However, when blood transfusion was done on the 3rd day, the hemoglobin level showed a steady increase afterwards. The hemoglobin level of total knee arthroplasty patients with no blood transfusion was the lowest on the 3rd day after surgery and increased afterwards. If blood transfusion was done within 2 days after surgery, the hemoglobin level was the lowest on the 5th day after surgery and increased afterwards. If blood transfusion was done on the 3rd day after surgery, the hemoglobin level increased afterwards.