Department of Anesthesia and CCM, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
Clin Ther. 2011 Jul;33(7):863-73. doi: 10.1016/j.clinthera.2011.05.094. Epub 2011 Jul 1.
Ketamine induces a short-term effect on postoperative pain when administered intravenously immediately before or during acute pain. Repeated administration of low-dose ketamine may induce long-term pain relief in chronic pain syndromes.
The aim of our study was to determine whether ketamine's effect on acute postoperative pain could be enhanced and prolonged and analgesia consumption reduced if it was administered intramuscularly in repeated and escalating subanesthetic doses many hours before surgery.
Patients who were scheduled for tumor resection under general anesthesia were randomly and blindly given preoperative IM ketamine (K) or normal saline (placebo [P]) following 1 of 3 consecutive protocols (2 groups/protocol, 20 patients/group): 1 dose (25-mg ketamine or 1-mL saline) at 4 hours preoperatively (K1 or P1); 2 doses (10- and 25-mg ketamine or 1-mL saline twice) at 11 and 4 hours (K2 or P2); or 3 doses (5-, 10-, and 25-mg ketamine or 1-mL saline thrice) at 17, 11, and 4 hours preoperatively (K3 or P3). No other preoperative medications were given. Postoperatively, all patients received morphine (1.5 mg/bolus) via an intravenous patient-controlled analgesia (PCA) device.
A total of 120 patients took part in the study. Patients' ages ranged from 15 to 75 years; mean weight (76 [14] kg; range, 50-120), gender (69 men, 51 women), and race were equally distributed among the groups. There were no significant differences in intraoperative parameters among the groups. The patients' mean self-rated 48-hour pain scores on a numerical rating scale were lower in the K2 and K3 groups than in their corresponding placebo groups (K2: 1.67 [1.04] vs P2: 3.62 [1.93] [P = 0.0004]; K3: 2.22 [1.37] vs P3: 3.25 [1.76] [P = 0.046]). These groups also used ∼35% less morphine compared with the placebo groups (K2: 28.4 [20.4] mg, K3: 26.6 [16.0] mg vs P2: 42.4 [30.4] mg, P3: 40.9 [21.2] mg [P ≤ 0.02]). Intravenous PCA usage among K2 and K3 patients was ∼50% less than the usage among their placebo counterparts (P < 0.05). The 1-ketamine-injection patients' pain scores and analgesic consumption were similar to those of their placebo groups. The 25-mg-ketamine injections caused dizziness that lasted up to 2 minutes.
Our 48-hour data suggest that 2 or 3 escalating subanesthetic doses of IM ketamine injected consecutively hours before surgery attenuated postoperative pain and reduced morphine consumption in these subjects.
静脉注射氯胺酮可在急性疼痛发生前或发生时对术后疼痛产生短期影响。重复给予低剂量氯胺酮可能会在慢性疼痛综合征中诱导长期疼痛缓解。
我们的研究目的是确定如果在手术前数小时以重复递增亚麻醉剂量肌内注射氯胺酮，是否可以增强和延长其对急性术后疼痛的作用，并减少镇痛药物的消耗。
接受全身麻醉下肿瘤切除术的患者被随机和盲目给予术前肌内氯胺酮（K）或生理盐水（安慰剂[P]），分为 3 个连续方案中的 2 个方案（每组 20 名患者）：术前 4 小时给予 1 剂（25 毫克氯胺酮或 1 毫升生理盐水）（K1 或 P1）；11 小时和 4 小时给予 2 剂（10-和 25-毫克氯胺酮或 1 毫升生理盐水两次）（K2 或 P2）；或术前 17、11 和 4 小时给予 3 剂（5-、10-和 25-毫克氯胺酮或 1 毫升生理盐水三次）（K3 或 P3）。没有给予其他术前药物。术后，所有患者均通过静脉患者自控镇痛（PCA）装置接受吗啡（1.5 毫克/推注）。
共有 120 名患者参加了这项研究。患者年龄从 15 岁到 75 岁不等；平均体重（76 [14] 公斤；范围，50-120）、性别（69 名男性，51 名女性）和种族在各组之间分布均匀。各组之间术中参数无显著差异。K2 和 K3 组患者自我报告的 48 小时疼痛评分（数字评分量表）明显低于其相应的安慰剂组（K2：1.67 [1.04] vs P2：3.62 [1.93] [P = 0.0004]；K3：2.22 [1.37] vs P3：3.25 [1.76] [P = 0.046]）。与安慰剂组相比，这些组还使用了约 35%的吗啡（K2：28.4 [20.4] 毫克，K3：26.6 [16.0] 毫克 vs P2：42.4 [30.4] 毫克，P3：40.9 [21.2] 毫克[P ≤ 0.02]）。K2 和 K3 患者的静脉 PCA 使用率比其安慰剂组低约 50%（P < 0.05）。单次 1 剂氯胺酮注射的患者疼痛评分和镇痛药物消耗与安慰剂组相似。25 毫克氯胺酮注射引起的头晕持续长达 2 分钟。
我们的 48 小时数据表明，在手术前数小时内连续递增给予 2 或 3 次递增亚麻醉剂量的肌内注射氯胺酮可减轻这些患者术后疼痛并减少吗啡的消耗。
