An evaluation of intra-operative and post-operative blood loss in total knee arthroplasty at the National Orthopaedic Hospital, Lagos.

Background: Total knee replacement is a rewarding and reliable procedure, producing a lasting relief to severe knee pains. However, significant blood loss usually in the post-operative period may be a challenge, necessitating prompt restoration of circulating blood volume to minimize morbidity and mortality. The aim of this study was to evaluate blood loss after total knee replacement.

Patients and Methods: A prospective study of blood loss after Total Knee Arthroplasty in 53 patients in the National Orthopaedic Hospital, Lagos. Consecutive patients with established indications, presenting for total knee arthroplasty were recruited into the study after obtaining their consent.

Results: The mean intra-operative blood loss was 342.4 mls, with a range of 50 - 1500 mls. The mean post-operative blood loss and total blood loss were 603.6 mls and 940.3 mls respectively, showing a strong positive correlation (r = 0.884, p < 0.01). The average pre-operative and post-operative haemoglobin concentration were 12.5 ± 1.2 g/dl and 9.8 ± 0.9 g/dl, respectively. The mean haemoglobin loss was 2.6 ± 1.2 g/dl (r = 0.46, p < 0.001).

Conclusion: Post-operative blood loss as measured by suction drainage, is a good predictor of total blood loss, showing a strong and positive correlation.