RESUMO
BACKGROUND AND OBJECTIVES: To understand the mechanisms related to both the onset and correction of severe anaemia after orthopaedic surgery, we analysed all the full blood counts (FBCs) for patients on one orthopaedic ward during a one-year period in an academic hospital. METHODS: FBCs were screened and the medical records of those patients for whom a postoperative haemoglobin (Hb) concentration below 8 g/dL was recorded at least once were reviewed. The onset of postoperative anaemia was determined by calculating the various time intervals delineated by surgery, the time at which the transfusion threshold was reached and the time at which the lowest Hb level (nadir) and transfusion (if any) occurred. RESULTS: A total of 6573 FBCs drawn from 1255 patients were screened. The medical records of 74 consecutive patients with at least one Hb value < 8 g/dL were analysed. The postoperative Hb nadir was 7.4 (± 0.6) g/dL (mean - SD). The medians (IQR 25-75) of the calculated intervals were: (surgery - nadir): 72 (48-144) h, (nadir - transfusion): 7 (5-21) h and (transfusion threshold - transfusion): 26 (11-51) h. CONCLUSIONS: Delayed transfusion (defined as > 12 hours between the time at which the transfusion threshold was reached and actual transfusion) was observed in 57% of severely anaemic patients after orthopaedic surgery.
