Department of Anaesthesiology, Hvidovre Hospital, Copenhagen, Denmark.
Anaesthesia. 2010 Oct;65(10):984-90. doi: 10.1111/j.1365-2044.2010.06452.x.
Wound administration of local anaesthetic may be effective for postoperative pain management in knee arthroplasty, but the analgesic efficacy of local anaesthetic in relation to volume vs concentration has not been determined. In a double-blinded trial, 48 patients scheduled for total knee arthroplasty were randomly assigned to receive either a high volume/low concentration solution of ropivacaine (20 ml, 0.5%) or a low volume/high concentration solution of ropivacaine (10 ml, 1%), 6 and 24 h postoperatively through an intracapsular catheter. Pain was assessed for 2 h after administration. Pain was reduced in both groups with ropivacaine administration 24 h postoperatively (p < 0.02), but with no difference in analgesia between groups at all time intervals. No reduction in pain scores was observed with ropivacaine injection 6 h postoperatively. The median (IQR [range]) dose of oxycodone administered was 12.5 (10-19 [0-35]) mg in the high volume/low concentration group, and 20 mg (16-40 [0-65]) mg in the low volume/high concentration group (p = 0.005). In conclusion, intracapsular administration of local anaesthetic may have limited analgesic efficacy with no volume vs concentration relationship after total knee arthroplasty.
关节内局部麻醉剂给药可能对膝关节置换术后的疼痛管理有效，但局部麻醉剂的镇痛效果与容量与浓度的关系尚未确定。在一项双盲试验中，48 名计划接受全膝关节置换术的患者被随机分为两组，分别接受高容量/低浓度罗哌卡因（20 ml，0.5%）或低容量/高浓度罗哌卡因（10 ml，1%）溶液，在术后 6 和 24 小时通过囊内导管给药。给药后 2 小时评估疼痛。两组患者在术后 24 小时使用罗哌卡因给药后疼痛均减轻（p < 0.02），但各时间点两组间镇痛效果无差异。术后 6 小时注射罗哌卡因后疼痛评分无降低。高容量/低浓度组中，接受羟考酮的中位数（IQR [范围]）剂量为 12.5（10-19 [0-35]）mg，低容量/高浓度组中为 20 mg（16-40 [0-65]）mg（p = 0.005）。总之，全膝关节置换术后囊内局部麻醉剂给药的镇痛效果有限，且与容量与浓度无关系。
