Anaesthesia for elective total knee arthroplasty

Abstract

Editor—We thank Dr Reed for his letter on our clinical investigation.1Harsten A Kehlet H Toksvig-Larsen S Recovery after total intravenous general anesthesia or spinal anaesthesia for total knee arthroplasty.Br J Anaesth. 2013; 111: 391-399Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar 2McCarteny CJL Choi S Does anaesthetic technique really matter for total knee arthroplasty?.Br J Anaesth. 2013; 111: 331-333Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar We agree that the administration of i.v. oxycodone to our target-controlled infusion (TCI) anaesthesia group could have influenced the postoperative pain scores. However, administering i.v. opioids towards the end of a TCI anaesthetic is almost to be considered as the modus operandi for TCI anaesthesia due to the fact that remifentanil has a very short-lasting analgesic effect. Hence, this could almost be considered as a part of the TCI technique. Whether patients with a BMI of 35 or more should have been excluded or not in this study is an interesting and relevant question. By excluding patients with a BMI exceeding 35, one might argue that our sample population does not perfectly reflect the general population undergoing total knee replacement. It is true that our study was written before the publication of the study by Memtsoudis and colleagues.3Memtsoudis SG Sun X Chiu Y et al.Perioperative comparative effectiveness of anesthetic technique in orthopedic patients.Anaesthesiology. 2013; 118: 1046-1058Crossref PubMed Scopus (315) Google Scholar However, as pointed out by an editorial4Neuman DN et al.Trust, but verify. Examining the role of observational data in perioperative decision-making.Anesthesiology. 2013; 118: 1008-1009Crossref PubMed Scopus (4) Google Scholar in the same issue of Anesthesiology, the trial by Memtsoudis and colleagues is observational rather than experimental in nature. As such, treatment assignment was non-random, creating the real possibility that the authors’ findings may reflect the confounding effects of differences in patient severity rather than effects attributed to anaesthesia type per se. None declared.