Guará Sobrinho Hireno, Garcia João Batista Santos, Vasconcelos Jose Wanderley, Sousa José Carlos Amaral, Ferro Letácio Santos Garcia
Residency Training Program in Orthopedics and Traumatology, Hospital Universitário da Universidade Federal do Maranhão.
Rev Bras Anestesiol. 2012 Sep-Oct;62(5):665-75. doi: 10.1016/S0034-7094(12)70165-4.
Total knee arthroplasty (TKA) is associated with significant postoperative pain. Many intra-articular (IA) agents have been used for postoperative analgesia with inconsistent outcomes. Ketamine's enantiomer S(+), S(+)- ketamine, was recently introduced commercially, with higher analgesic potency and less side effects than the racemic form. An experimental prospective randomized double-blind study was conducted to evaluate the analgesic efficacy of intra-articular S(+)- ketamine in patients undergoing primary TKA.
In total, 56 patients were evaluated and allocated into three groups: Group A (n=19) received 0.25mg.kg(-1) of S(+)- ketamine diluted in 20mL of saline solution 0.9%; Group B (n=17) received 0.5mg.kg(-1) of S(+)- ketamine diluted in the same way; and Group C (n=20) received only 20mL of intra-articular saline 0.9%, immediately after surgery and drain placement. All patients had access to rescue analgesic therapy, with the use of intravenous morphine alone. Evaluations were made 2, 6, 12, and 24 hours postoperatively, with measurement of pain intensity by Visual Analogue Scale (VAS), use of rescue medication by the evaluation of the time elapsed between the intra-articular injection of the solution and first dose of rescue, total consumption within 24 hours, and adverse effects.
The S(+)- ketamine groups had lower pain scores compared with the saline group. The lowest dose of intra-articular S(+)- ketamine (Group A: 0.25mg.kg(-1)) resulted in better pain scores and less rescue analgesia, with longer time to first request. Adverse effects were infrequent. The results with lower pain scores in groups using S(+)- ketamine are a trend, as there was no statistical significance between groups.
In this study, with this sample, the analgesic effect of IA S(+)- ketamine was not superior to saline solution in the postoperative period of TKA.
全膝关节置换术（TKA）术后疼痛显著。许多关节内（IA）药物已用于术后镇痛，但效果不一。氯胺酮的对映体S(+) - 氯胺酮（S(+)-ketamine）最近已商业化推出，其镇痛效力高于消旋体且副作用更少。本研究进行了一项前瞻性随机双盲试验，以评估关节内注射S(+)-氯胺酮对初次行TKA患者的镇痛效果。
共纳入56例患者并分为三组：A组（n = 19）接受0.25mg·kg⁻¹的S(+)-氯胺酮用20mL 0.9%的盐溶液稀释；B组（n = 17）接受0.5mg·kg⁻¹的S(+)-氯胺酮以同样方式稀释；C组（n = 20）仅在术后及放置引流管后接受20mL关节内注射0.9%的盐溶液。所有患者均可接受补救镇痛治疗，仅使用静脉注射吗啡。术后2、6、12和24小时进行评估，通过视觉模拟评分法（VAS）测量疼痛强度，通过评估关节内注射溶液至首次使用补救药物的时间、24小时内的总用量以及不良反应来评估补救药物的使用情况。
与盐溶液组相比，S(+)-氯胺酮组的疼痛评分更低。关节内注射最低剂量的S(+)-氯胺酮（A组：0.25mg·kg⁻¹）导致更好的疼痛评分和更少的补救镇痛，首次需求时间更长。不良反应较少。使用S(+)-氯胺酮的组疼痛评分较低的结果只是一种趋势，因为组间无统计学意义。
在本研究的样本中，TKA术后关节内注射S(+)-氯胺酮的镇痛效果并不优于盐溶液。
