Preoperative versus postoperative ultrasound-guided rectus sheath block for acute postoperative pain relief after laparoscopy: A retrospective cohort study.

Although rectus sheath block (RSB) is routinely used in laparoscopic surgeries to reduce mid-abdominal pain, whether RSB should be performed before or after surgery remains unclear. Herein, the optimal timing for RSB in patients undergoing laparoscopic surgery was investigated. This retrospective cohort study analyzed the data of patients who underwent RSB during laparoscopic procedures at our hospital between January 2013 and December 2018.