Anesthesia in Enhanced Recovery Pathways for Hip and Knee Arthroplasty: Where Is the Evidence?

To the Editor Soffin et al1,2 have undertaken a huge effort to review the evidence for anesthetic/analgesic techniques to recommend specific components of care for enhanced recovery after surgery (ERAS) in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). Unfortunately, the details of the approach to the systematic review of literature are not provided, and it appears that much of the evidence was included based on author preferences. Thus, it is not surprising that many recommendations in these reviews are in variance with previously published, rigorously performed systematic reviews, particularly with regard to the analgesic components.3,4 Also, the 2 reviews1,2 lack scientific discussion on the design of included randomized controlled trials, such as the limitations of a strict placebo-controlled design versus the efficacy when evidence-based basic simple analgesia had been included as active comparators. The statements such as local infiltration analgesia “maybe useful when other regional techniques are not available”1,2 are also indicative of lack of critical analysis because local infiltration analgesia is simple, safe, and effective as clearly demonstrated in TKA but not effective in THA when combined with basic analgesia.4 Although the authors admit that there is limited or no procedure-specific evidence in THA and TKA, they provide several recommendations or considerations. For example, the recommendation for preoperative carbohydrate loading is neither procedure specific nor updated. Also, the authors provide a variable degree of recommendations—for TKA, they state, “there is sufficient evidence for benefit, … to recommend CHO…,” while for THA, they state, “CHO loading may be considered.…” Of note, preoperative carbohydrate loading lacks definitive evidence even in colorectal surgery, a procedure that has been studied the most. Another example of inadequate literature review is suggested by the lack of mention of the benefits of preoperative high-dose steroids despite several randomized controlled trials published before June 2017. Overall, there is little new evidence included in these reviews and a lack of critical analysis of the available evidence. This is unfortunate because the aim of these 2 reviews is to provide evidence-based recommendations to busy clinicians who have no time to read the extensive literature. Consequently, the huge efforts made by Soffin et al1,2 could have benefited from a critical analysis of the ERAS literature related to THA and TKA that have reduced hospital length of stay to 1–2 days. In fact, these procedures are increasingly being performed also on an outpatient basis in several places with excellent safety data. However, many of these programs have not included components such as preoperative carbohydrate loading, goal-directed fluid therapy, special regional and analgesic techniques, or use of systemic lidocaine or ketamine. Thus, a detailed analysis of studies of fully implemented ERAS programs would have been useful to obtain a balanced view rather than a focus on transferable evidence from procedures not relevant to THA or TKA. Henrik Kehlet, MD, PhD, FACS (Hon)RigshospitaletSection of Surgical PathophysiologyCopenhagen, Denmark[email protected] Girish P. Joshi, MBBS, MD, FFARCSIDepartment of AnesthesiaUniversity of Texas Southwestern Medical CenterDallas, Texas