Adding Dexamethasone to Adductor Canal Block Combined With IPACK Block Improve Postoperative Analgesia of Total Knee Arthroplasty

Objective: Both adductor canal block (ACB) and infiltration between the popliteal artery and capsule of the knee (iPACK) block are mainly sensory blocks, preserving muscle strength and the ability to ambulate. This study was designed to evaluate whether adding dexamethasone to ropivacaine could improve postoperative analgesia after total knee arthroplasty (TKA).

Materials And Methods: This prospective double-blind randomized controlled trial included 60 patients who underwent unilateral TKA under general anesthesia. All patients who received ACB and iPACK block were randomly divided into a dexamethasone group (Group D, ropivacaine combined with dexamethasone) and a control group (Group C, ropivacaine only). The primary outcome was the time to first administration of rescue analgesic drugs. The secondary outcomes included the total amount of rescue analgesic drugs and the pain scores at different time points within 72 hours postoperatively; the time to first getting out of bed; the quality of recovery scale (QOR-15 score); and the levels of plasma inflammatory markers (interleukin-6 and C-reactive protein) on postoperative day 1.

Results: Compared with Group C, the time to first administration of rescue analgesic drugs in Group D was significantly extended by ∼10.5 hours. Patients in Group D had significantly lower pain scores at different postoperative time points and consumed significantly less total morphine within 72 hours postoperatively. In addition, patients in group D reported significantly higher QoR-15 scores on postoperative days 1 and 3, earlier first time of getting out of bed, and significantly lower levels of C-reactive protein and interleukin-6 on postoperative day 1.

Conclusions: Compared with using ropivacaine alone, ultrasonic-guided ACB combined with iPACK using ropivacaine and dexamethasone could prolong the duration of postoperative analgesia and strength analgesic intensity and promote the early rehabilitation exercise of patients undergoing TKA.