Retraction Note: Intravenous lidocaine improves postoperative cognition in patients undergoing laparoscopic colorectal surgery: a randomized, double-blind, controlled study - Xian-xue Wang; Jing Dai; Qi Wang; Hui-wei Deng; Yun Liu; Gui-fan He; Hua-jing Guo; Ya-lan Li (BMC Anesthesiology)