Abstract
Purpose: The objective of this study was to examine the relationship between aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS) on postoperative blood loss following Total Knee Arthroplasty
Methods: We prospectively examined the pre-operative consumption of aspirin and NSAIDS and haematological parameters of 50 consecutive patients undergoing Total Knee Arthroplasty. 22 (44%) patients were on aspirin only, 17 (34%) patients on aspirin and another NSAID and 11 (22%) patients were taking neither aspirin nor a NSAID. (All patients received 150mg of aspirin the evening before surgery as DVT prophylaxis).
Results: The average pre-operative haemoglobin of the group taking aspirin and a NSAID, aspirin only and neither aspirin nor NSAID group was 12.9g/dl, 13,8g/dl and 13.49g/dl respectively. The drop between their pre-operative level and Day 3 Haemoglobin level was 3.788g/dl, 4.45g/dl and 4.28g/dl respectively.
The same trend was reflected in the PCV drops of 0.111, 0.133 and 0.1273 respectively. Transfusion rates for the three groups showed that those on aspirin and another NSAID had the highest rate with an average of 0.235 units per patient compared to 0.136 for those on aspirin only and 0.10 for those on neither aspirin nor NSAID.
Discussion: These findings indicate that the ingestion of aspirin or a NSAID preoperatively does not increase the amount of blood loss following total knee arthroplasty (TKA). The higher transfusion rates in the aspirin and NSAID group is because of the lower preoperative haemoglobin as compared to the other groups studied.
Conclusion: Observation of transfusion trends within our unit has shown a transfusion rate of 18% in patients with a preoperative Haemoglobin level of greater than 13.0g/dl as compared to 48% with a haemoglobin level of 13.0g/dl or less (review of 180 consecutive patients undergoing Total Knee Arthroplasty).
The ingestion of aspirin and NSAID does not increase blood loss following TKA but significantly have a lower preoperative Hb level. We feel that pre-operative Haemoglobin levels are the best predictors of transfusion requirements following total knee arthroplasty.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
