General Anaesthesia With Multimodal Principles Versus Intrathecal Analgesia With Conventional Principles in Total Knee Arthroplasty: A Consecutive, Randomized Study

BACKGROUND: Postoperative outcomes following major surgery are influenced by surgical and anaesthesiological factors. While techniques of minimal invasive surgery have been associated with improved outcome, the techniques of minimal invasive, multimodal anaesthesia have not been adequately investigated. The aim of this study was to compare intrathecally based anaesthesia (ITA) including standardized, traditional intraoperative and postoperative care, with, general anaesthesia (GA) combined with intraoperative glucocorticoids, exclusion of intraoperative tourniquet and indwelling urethral catheter, and, an accelerated postoperative care regime. Outcome variables in the study were pain, requirement of analgesics, global satisfaction score and length-of-hospital stay. METHODS: Sixty patients were included and randomized to the ITA or the GA group. The ITA group received intrathecal bupivacaine (12.5 - 15.0 mg)/morphine (0.1 mg)/clonidine (0.03 mg), a standard surgical procedure, local infiltration analgesia (LIA) with ropivacaine (110 mg) /epinephrine (0.5 mg)/morphine (10 mg), an indwelling urethral catheter and mobilization with start Day 1 after the surgery. The GA group received a target-controlled infusion of propofol/remifentanil, betamethasone 4 mg i.v. intraoperatively, surgery was performed without a tourniquet, an indwelling urethral catheter was not used, LIA was with ropivacaine (250 mg)/epinephrine (0.3 mg) and mobilization was planned with start ≤ 2 hrs. after end of surgery. Outcomes were followed daily for the first 96 hrs. and at visits 3 months and 12 months postoperatively. RESULTS: Requirement of analgesics was decreased in the ITA group in the immediate postoperative period (P < 0.05). Pain scores were significantly lower in the ITA group (P < 0.01) between 0 - 12 hrs and in the GA group (P < 0.05) between 12 - 24 hrs after surgery. Fifteen of the patients in the GA group had to be intermittent catheterized due to bladder volumes > 400 mL. The LOS in the ITA group was significantly longer compared to the GA group (P < 0.01). There was no difference in global satisfaction score. CONCLUSION: General anaesthesia combined with intraoperative glucocorticoids and accelerated postoperative care, compared with, intrathecal blockade and traditional postoperative care, seems to generate the same overall pain ratings and a decrease in length-of-hospital stay, in patients undergoing elective total knee arthroplasty.