El Sherif Fatma A, Abdel-Ghaffar Hala, Othman Ahmed, Mohamed Sahar, Omran Mervat, Shouman Samia, Hassan Nivin, Allam Ayat, Hassan Sahar
Anesthesia, Intensive Care and Pain Management Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt.
Anesthesia and Intensive Care Department, Faculty of Medicine, Assiut University, Assiut, Egypt.
J Pain Res. 2022 Jan 4;15:1-12. doi: 10.2147/JPR.S335806. eCollection 2022.
Despite the growing interest in dexmedetomidine as an adjunct to truncal blocks, little is known about the systemic absorption of dexmedetomidine after these blocks and its role in analgesia and in hemodynamics.
We investigated the pharmacokinetics and pharmacodynamics of dexmedetomidine as an adjunct to transversus abdominis plane (TAP) block in patients undergoing lower abdominal cancer surgery.
Twenty-four adult patients were randomized to receive a bilateral single-injection TAP block before surgery with 20 mL of bupivacaine 0.5% (TAP group, n = 12) or combined with 1 µg/kg dexmedetomidine (TAP-DEX group, n = 12) and diluted with saline to a volume of 40 mL (20 mL on each side). Plasma concentrations of dexmedetomidine and its pharmacokinetics were investigated using non-compartmental methods, postoperative analgesia, hemodynamics, and adverse events (nausea, vomiting, itching, hypotension, bradycardia, and respiratory depression).
Dexmedetomidine was detected in the plasma of 11 patients in the TAP-DEX group. The mean dexmedetomidine peak plasma concentration (Cmax) was 0.158 ± 0.085 (range, 0.045-0.31) ng/mL. The median time to reach peak plasma concentration of dexmedetomidine (Tmax) was 15 (15-45) min. From 2 to 8 h postoperatively, visual analog pain scale (VAS) scores at rest and during movement were significantly lower in the TAP-DEX group. Analgesia time was (11.3 ± 3.12 vs 9.0 ± 4.69 h; P = 0.213) and postoperative morphine consumption was (7.4 ± 3.24 vs 11.5 ± 4.46 mg; P = 0.033) in TAP-DEX and TAP groups, respectively. Lower mean heart rate and mean blood pressure were recorded in the TAP-DEX group intraoperatively and 2 h postoperatively (P < 0.05). Except for mild nausea and vomiting, no adverse events were recorded in either group.
Systemic absorption of dexmedetomidine administered in a TAP block is common. Direct central effects on the locus coeruleus caused by this systemic absorption may play a role in the analgesia and hemodynamic effects produced by TAP-dexmedetomidine in addition to local mechanisms.
ClinicalTrial.gov (identifier: NCT03328299).
尽管右美托咪定作为躯干阻滞辅助用药越来越受到关注，但对于右美托咪定在这些阻滞术后的全身吸收情况及其在镇痛和血流动力学中的作用知之甚少。
我们研究了右美托咪定作为腹横肌平面（TAP）阻滞辅助用药在接受下腹部癌症手术患者中的药代动力学和药效学。
24例成年患者被随机分为两组，术前接受双侧单次注射TAP阻滞，其中一组注射20 mL 0.5%布比卡因（TAP组，n = 12），另一组联合1 μg/kg右美托咪定（TAP-DEX组，n = 12），并用生理盐水稀释至40 mL（每侧20 mL）。采用非房室模型方法研究右美托咪定的血浆浓度及其药代动力学、术后镇痛、血流动力学和不良事件（恶心、呕吐、瘙痒、低血压、心动过缓和呼吸抑制）。
TAP-DEX组11例患者血浆中检测到右美托咪定。右美托咪定的平均血浆峰浓度（Cmax）为0.158±0.085（范围0.045 - 0.31）ng/mL。右美托咪定达到血浆峰浓度的中位时间（Tmax）为15（15 - 45）分钟。术后2至8小时，TAP-DEX组静息和活动时的视觉模拟疼痛量表（VAS）评分显著更低。TAP-DEX组和TAP组的镇痛时间分别为（11.3±3.12 vs 9.0±4.69小时；P = 0.213），术后吗啡用量分别为（7.4±3.24 vs 11.5±4.46 mg；P = 0.033）。TAP-DEX组术中及术后2小时记录到较低的平均心率和平均血压（P < 0.05）。除轻度恶心和呕吐外，两组均未记录到其他不良事件。
TAP阻滞中给予的右美托咪定发生全身吸收很常见。这种全身吸收对蓝斑产生的直接中枢效应除局部机制外，可能在TAP - 右美托咪定产生的镇痛和血流动力学效应中起作用。
ClinicalTrial.gov（标识符：NCT03328299）。
