静脉注射右美托咪定对臂丛神经阻滞时上肢止血带所致疼痛的影响

EFFECT OF INTRAVENOUS DEXMEDETOMIDINE ON ALLEVIATING TOURNIQUET PAIN IN PATIENTS UNDERGOING UPPER EXTREMITY SURGERY WITH BRACHIAL PLEXUS BLOCK

目的观察静脉注射右美托咪定对腋路臂丛神经阻滞时上肢止血带所致疼痛的影响。方法采用前瞻性随机对照的研究方法，选取同一麻醉医生拟行腋路臂丛神经阻滞麻醉的白天择期上肢手术病例，止血带应用时间60～90min，患者男女不限，体重指数（Body Mass Index，简称BMI）男20～25、女19～24，年龄18-45岁，ASAI级。随机分为右美托咪定组（D组）和对照组（C组）。麻醉成功后D组患者微量泵泵入负荷量右美托咪定（4μg／m1）0.8μg／（kg·15min），在手术开始前将负荷量输注完毕，然后以0.3μg／（kg·h）维持，持续输入至手术缝皮。C组患者不给予任何药物。记录患者入室时的平均动脉压（MAP），心率（HR），呼吸频率（RR），血氧饱和度（SpO2），Ramsay评分（TO），并连续监测HR，RR，SpO2，每5min测量MAP。记录手术开始时（T1），止血带使用后30min（T2），止血带使用后60min（T3）的MAP、HR、RR、SpO2、Ramsay评分、止血带部位的VAS评分。记录术中患者最高和最低Ramsay评分，最高止血带部位VAS分。记录术中术后发生的SpO2〈90％、低血压（MAPG60mmHg）、低心率（HR〈45次／min）的情况。结果纳入病例数90例，D组45例，C组45例。二组间患者年龄，性别，BMI，入室MAP、HR、RR、SpO2、Ramsay评分、止血带应用时间情况差异无统计学意义（P〉0.05）。二组患者T0时点MAP、HR、RR、SpO2、Ramsay评分比较差异无统计学意义（P〉0.05）。T1～T3时点MAP、HR、RRD组较c组低（P〈0.05），Ramsay评分D组较C组高（P〈0.05）、止血带部位的VAS评分D组较C组低（P〈0.05）。二组间SpO2差异无统计学意义（P〉0.05）。二组患者最高和最低Ramsay评分D组较C组高，差异有统计学意义（P〈0.05）。最高止血带部位VAS评分D组较C组高，差异有统计学意义（P〈0.05）。二组患者术中和术后均未发生SpO2〈90％、低血压（MAP〈60mmHg）、低心率（HR〈45次／min）。结论静脉注射右美托咪定可以减轻腋路臂丛神经阻滞时上肢止血带部位的疼痛，提供良好的镇静效果并具有可靠的安全性。

Objective To investigate the effect of intravenous dexmedetomidine on alleviating tourniquet pain in patients undergoing upper extremity surgery with brachial plexus block. Methods The prospective randomized controlled study was used. Patients who scheduled for day upper extremity surgery with axillary brachial plexus block by the same anesthetist were selected, upper limb tourniquet application time rangedg from 60 to 90 minutes, the gender was all right, the BMI of male ranged from 20 to 25, and women ranged from 19 to 24, the aged of the subjects ranged from 18 to 45 years,and ASA Ⅰ. All subjects were randomly divided into dexmedetomidine group （D group） and control group （C group）. After success of anesthesia, patients were immediately intravenously injected with loading dose of dexmedetomidine （4μg / ml- 1） at 0.8μg / kg- 1 / 15min- 1 with micro- pump in group D. The loading dose infusion must be completed before the start of surgery. Then 0.3μg / kg- 1 / h - 1 to maintain, ongoing input till the surgical skin closure. Group C patients received no medication. The mean arterial pressure （MAP）, heart rate （HR）, respiratory rate （RR）, oxygen saturation （SpO2）, Ramsay score （TO） were recorded when patient got in, and then continuous monitored the HR, RR, SpO2; MAP was also measured every 5 minutes. The MAP, HR, RR, SpO2, Ramsay score, VAS scores of tourniquet site were recorded at start of surgery （T1）, 30 minutes after tourniquet used （T2）, 60 minutes after tourniquet used （T3）. The highest and lowest intraoperative Ramsay score, the highest VAS score of the tourniquet site were recorded, and SpO2〈90%, hypotension （MAP 〈60 mmHg）, low heart rate （HR〈45 times o min- 1） when intraoperative and postoperative occurrence were also recorded. Results The number of included cases was 90, 45 in group D, 45 in group C. Between the two groups, the difference on age, sex, BMI, burglary, MAP, HR, RR, SpO2, Ramsay score, tourniquet application time had no statistically significant （P〈0.05）. The difference on T0, MAP, HR, RR, SpO2, Ramsay score between the two groups had no significant too（P 〈0.05）. The T1 - T3 ,MAP, HR, RR were lower in group D than in group C （P〈0.05）. The ramsay score was higher in group D than in group C （P〈0.05）. The VAS score of tourniquet site was lower in group D than in group C （P〈10. 05）. The SpO2 difference between the two groups had no significant （P〈 0.05）. The highest and lowest Ramsay score in group D were higher than in group C, the difference had statistically significant （P〈0.05）. The highest VAS scores of tourniquet site was lower in group D than in group C, the difference had statistically significant （P〈0.05）. All patients in two groups during and after surgery were not showed SpO2〈90%, hypotension （MAP〈60mmHg）, low heart rate （HR〈45times o min- 1）. Conclusion Intravenous dexmedetomidine can alleviate tourniquet pain when upper extremity surgery is performed with axillary brachial plexus block, and provide a fine sedative effect without any adverse event.