Ultrasound-Guided Adductor Canal Block Improves The Postoperative Quality Of Recovery After Arthroscopy Knee Surgery

Background: Patients undergoing arthroscopic knee surgery may experience uncomfortable, distress and pain after surgery, with approximately 70% incidence of postoperative moderate-to-severe pain after arthroscopic knee surgery. The adductor canal block was demonstrated that reduce pain and morphine consumption after arthroscopic knee surgery with only minor effects on muscle strength. We hypothesis that pre-operative ultrasound-guided ACB could improve the quality of recovery after arthroscopic knee surgery.Methods: Sixty-two enrolled patients(18–60 years old,ASA I-II) were randomized to ACB group and the control group by using a Excel-generate random code, with the ratio was 1:1. All patients were performed block under the ultrasound guidance probe 30 min prior to general anesthesia. ACB group was performed 10 ml of 0.5% ropivacaine and the control group was 10 ml isotonic saline. The primary outcome was the difference of Qo R-40 scores between ACB group and the control group on postoperative 24 h. The secondary outcome were postoperative pain during 45 degrees flexion of the knee(at30min, 1, 2, 8 and 24h), times of pressing PCIA, opioid consumption, patient’s satisfaction and the incidences of PONV.Results: The Qo R-40 score at postoperative 24 h was significantly higher scores in ACB group(186.5 ± 5.3) than the control group(176.6 ± 5.4). Among the five dimensions of the Qo R-40, pain(31.8 ± 1.9 vs 28.4 ± 2.4, P<0.05), physical comfort(53.9 ± 2.8 vs 49.1± 4.3, P<0.001)and emotional state(41.6 ± 1.7 vs 40.4 ± 1.8, P=0.01)were significantly better in the ACB group. In contrast, with no significant difference between ACB group and the control group on psychological support, physical independence(P>0.05).There was a significant downward trend of pain score at 30 min, 1h, 2h, 4h and 8h during 45 degrees flexion of the knee. While measures postoperative patient’s pain, no significant differences were found between ACB group and the control group at 24h.Compared with the control group, a significantly difference were observed in ACB group for cumulative opioid consumption, times of pressing PCIA and the patient’s satisfaction(P<0.05). No significant difference was observed on PONV while compared ACB and the control group.Conclusion: This randomized clinical trial demonstrate that for arthroscopic knee surgery, the presence of preoperative ACB treatment not only improved the quality of recovery after surgery, but also relief postoperative pain, reduce opioid consumption and improve patient’s satisfaction.