Summary
The selective use of aspirin as thromboprophylaxis in patients considered at low risk of TEEs appears acceptable after unilateral THA or TKA following a FTP. The recommendations of the ESA can therefore be considered valid.
Abstract
Introduction
The aim of this study was to validate the most recent recommendations of the European Society of Anaesthesiology (ESA) by comparing the thromboembolic and haemorrhagic risk in a population of unselected patients undergoing unilateral total hip (THA) or knee (TKA) arthroplasty who followed a fast-track procedure (FTP), according to the thromboprophylactic medication given: either systematic low molecular weight heparin (LMWH - control group), or aspirin or LMWH depending on the patients’ risk factors (study group). The primary hypothesis was that the risk of postoperative TEE would be greater after the patient-specific administration of aspirin or LMWH than after systematic administration of LMWH.
Methods
All patients who underwent unilateral THA or TKA between January 2018 and December 2020, and who were operated on by the principal investigator, were eligible for inclusion in the study group. The control group was extracted from a historic series of 1949 patients who were operated on between October 2016 and October 2017. The patients were matched in the two groups by propensity score matching using logistic regression, including age, sex, body mass index (BMI), ASA classification, personal history of a TEE, previous use of anticoagulant medication and the intervention performed.
All patients followed a FTP. In the control group, patients received treatment with LMWH. In the study group, aspirin was administered if the patient was not morbidly obese and had no previous history of a serious TEE, or LMWH was administered for other patients according to the same protocol as the control group.
The primary evaluation criterion was the rate of TEEs in the 90 days after the intervention. The secondary criterion was the rate of haemorrhagic complications in the 90 days after the intervention.
Results
203 consecutive patients were included into the study group: 81 males (43%) and 122 females (57%), with a mean (SD) age of 68 ± 13 years and a mean (SD) BMI of 30.2 ± 5.8 kg/m². The matched control group, extracted from the historic series, consisted of 79 males (39%) and 124 females (61%), with a mean (SD) age of 67 ± 12 years and a mean (SD) BMI of 29.8 ± 5.7 kg/m². There were no significant differences in preoperative criteria between the control and study groups except for the prophylactic treatment administered.
Results
are summarized in table 1. Two TEEs occurred in the control group (1%) and three in the study group (1%) (P=0.65): 2/51 patients treated with LMWH and 1/152 patients treated with aspirin (P=0.09). Five haemorrhagic complications occurred in the control group (2%) and four in the study group (2%): 2/51 patients treated with LMWH and 2/152 patients treated with aspirin (P=0.77).
Conclusion
The selective use of aspirin as thromboprophylaxis in patients considered at low risk of TEEs appears acceptable after unilateral THA or TKA following a FTP. The recommendations of the ESA can therefore be considered valid.