FACTORS AFFECTING PRE-OPERATIVE HAEMOGLOBIN AND SUBSEQUENT AFFECTS ON TRANSFUSION RATES FOLLOWING TOTAL KNEE ARTHROPLASTY.

Abstract

Objective: To examine the impact of aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) on preoperative haemoglobin levels and perioperative transfusion rates in patients undergoing total knee arthroplasty (TKA).

Methods: We examined the pre-operative haemoglobin (Hb) and haematocrit (Hct) of a consecutive series of 81 patients, looking at the relationship between the pre-operative use of Aspirin/NSAIDs on preoperative Hb, postoperative Hb deficit and the perioperative transfusion rate. A single surgeon performed all procedures using an LCS TKR (Depuy, Leeds UK). A standardised transfusion protocol was used.

Results: The patients were grouped according to their pre-operative use of aspirin or a NSAID, singly or in combination. The patient groups are as shown in the table below. All groups were comparable for age, BMI and ASA grade.

Results show a significantly higher transfusion rate (p=0.048) in the group of patients who received a combination of aspirin and a NSAID compared to the other groups. The patients on aspirin or a NSAID alone also had an increased transfusion rate but the increase was not statistically significant (p=0.12 and p=0.07 respectively).

Conclusion: The use of both aspirin and an NSAID in combination leads to a lower preoperative Hb and an increased post-operative transfusion requirement following total knee arthroplasty.