Ultrasound-guided H-FICB for Arthroscopic Knee Surgery： What is the Optimal Dose of Dexmedetomidine?

Total knee replacement (TKR) is among the most commonly performed orthopedic procedures, and a six-fold increase in the number of TKR cases world-wide is projected within a decade as the aging of the populations . As the number of the TKR procedures increases, various approaches increasing the satisfaction and comfort of the patient and the surgeon are of interest in order to provide improved pain management, in-hospital stay, and recovery with the development of modern anesthesiology and pain management techniques.This study aimed to investigate the clinical effect of ultrasound-guided high fascia iliaca compartment block(H-FICB) in patients undergoing knee arthroscopy and to compare it with the normal method which is femoral nerve block combined with a sciatic nerve block to choose the better way. A double-blind, randomized controlled trial was conducted with 44 patients, aged 18-65 years, ASA I-III, who were scheduled to undergo arthroscopic knee surgery in our hospital were selected, the patients were divided into Group A and Group B by random number table method, with 22 patients in each group. Group A was subjected to the H-FICB under ultrasound guidance before general anesthesia, given 0.375% ropivacaine+0.5ug/kg Dexmedetomidine 30 ml. Group B was subjected to the H-FICB under ultrasound guidance before general anesthesia, given 0.375% ropivacaine+1ug/kg Dexmedetomidine 30 ml. The mini-mental State Examination was used to assess all the patients' primary cognitive status one day before surgery. The initial acting time and the degrees of sensory block and motor block were recorded after the nerve block was completed. Perioperative variables were recorded to be compared. The investigators used the visual analog scale to assess patients' pain degree with postoperative, recorded the occurrence of adverse events such as postoperative nausea and vomiting(PONV), delayed emergence from anesthesia, and respiratory depression. The confusion assessment method was used