PT - JOURNAL ARTICLE AU - Chutikant Vichainarong AU - Wirinaree Kampitak AU - Aree Tanavalee AU - Srihatach Ngarmukos AU - Nattaporn Songborassamee TI - Analgesic efficacy of infiltration between the popliteal artery and capsule of the knee (iPACK) block added to local infiltration analgesia and continuous adductor canal block after total knee arthroplasty: a randomized clinical trial AID - 10.1136/rapm-2020-101396 DP - 2020 Aug 21 TA - Regional Anesthesia & Pain Medicine PG - rapm-2020-101396 4099 - http://rapm.bmj.com/content/early/2020/08/21/rapm-2020-101396.short 4100 - http://rapm.bmj.com/content/early/2020/08/21/rapm-2020-101396.full AB - Background A combination of motor-sparing analgesia with local infiltration analgesia (LIA) and continuous adductor canal block (CACB) may improve postoperative pain and functional recovery for total knee arthroplasty (TKA). We hypothesized that the addition of a novel technique for posterior knee block, known as the infiltration between the popliteal artery and capsule of the knee (iPACK) block, to LIA with CACB would reduce opioid requirements.Methods In this double-blinded randomized controlled trial, 72 patients were assigned to receive either LIA with CACB (LIA+CACB group) or iPACK block with LIA and CACB (iPACK+LIA+CACB group). The primary outcome was cumulative postoperative intravenous morphine consumption within 24 hours. The secondary outcomes included numerical rating scale pain scores, incidence of posterior knee pain, performance test results, patient satisfaction, length of stay, and adverse events.Results Morphine consumption within 24 hours postoperatively showed no significant intergroup difference (LIA+CACB; 1.31±1.85 mg vs iPACK+LIA+CACB; 0.61±1.25 mg, p=0.08). There were no clinically significant differences in the overall pain scores between the groups. The lower Timed Up and Go test scores on postoperative days 1 and 2, along with a shorter duration of hospitalization, were found in the iPACK+LIA+CACB group (p<0.05).Conclusion The addition of an iPACK block to the LIA and CACB does not reduce the postoperative opioid consumption nor improve analgesia. However, it may improve immediate functional performance and reduce the length of hospitalization after TKA.Trial registration number TCTR20180702001.