关键词: 鞘内吗啡, 布比卡因脂质体, 收肌管阻滞, 全膝关节置换术, 多模式镇痛, 阿片节约效应

Abstract:

Objective To evaluate the effects of low-dose intrathecal morphine （ITM） combined with liposomal bupivacaine adductor canal block （LB-ACB） on postoperative analgesia and opioid-sparing efficacy in patients undergoing total knee arthroplasty （TKA）. Methods In this randomized， double-blind， controlled trial， 80 TKA patients were allocated to either an intervention group （ITM 0.1 mg + LB-ACB， n = 40） or a control group （intrathecal saline + LB-ACB， n = 40）. Primary outcomes included resting/movement visual analog scale （VAS） scores at 6， 12， 24， 48， and 72 hours postoperatively， 48-hour morphine consumption， time to first rescue analgesia， and incidence of complications. Results （1） The intervention group showed significantly lower resting and movement VAS scores at 6， 12， 24， and 48 hours postoperatively compared with controls （all P < 0.05）， except at 72 hours （P > 0.05）. （2） The intervention group had a significant reduction in 48-hour morphine consumption （4.58 ± 1.0 mg vs. 9.34 ± 4.8 mg， P = 0.027）， a significantly lower rescue analgesia rate （15.0% vs. 47.5%， P = 0.002）， and a significantly prolonged time to first rescue analgesia （48.8 ± 7.5 h vs. 14.5 ± 5.5 h， P < 0.001）. （3） The intervention group demonstrated a significant decrease in the incidence of nausea （from 15.0% to 35.0%， P = 0.039） and vomiting （from 10.0% to 27.5%， P = 0.045）， but no significant differences were observed in the incidences of pruritus， urinary retention， or motor block （all P > 0.05）. Conclusion Low-dose ITM （0.1 mg） combined with LB-ACB significantly enhances early postoperative analgesia， reduces opioid consumption， and decreases nausea/vomiting risk， without increasing the risks of other complications. This regimen aligns with enhanced recovery after surgery （ERAS） principles.

Key words: intrathecal morphine, liposomal bupivacaine, adductor canal block, total knee arthroplasty, multimodal analgesia, opioid-sparing effect