Objective The present paper discusses the feasibility of dexmedetomidine in assisting sevoflurane-controlled hypotension in endoscopic sinus surgery. Methods Forty-eight patients (ASA I or II) scheduled for endoscopic sinus surgery were randomly assigned into two groups (n=24): control group (group I) and dexmedetomidine group (group II). In both groups adopted intravenous injection of midazolam, propofol, fentanyl, and atracurium besilate was given to induce anesthesia. Propofol, fentanyl, atracurium besilate, together with sevoflurane inhalation were used to maintain anesthesia. The radial artery was cannulated to monitor the mean invasive arterial pressure (MAP). Controlled hypotension was induced by adjusting the sevoflurane concentration in group I. In group II, within Ismin to 30min before the induction of anesthesia, dexmedetomidine was administered in a dose of 0.8 μ g/kg via intravenous pump infusion, then maintained at 0.4μ- g/(kg · h). Sevoflurane concentration was adjusted to maintain the target blood pressure at the beginning of surgery. The MAP was maintained at 65mmHg to 75mmHg up to the end of operation. Meanwhile, the heart rate (HR), MAP, Epinephrine (E), and Norepinephrine (NE) concentrations were recorded at the induction of anesthesia (T0), the beginning of controlled hypotension (T1), at 30min (T2), and extubation (T3). Blood gas analysis and determination of lactic acid concentration were conducted using the blood drawn from the radial artery during the operation. The surgical field quality was assessed based on Fromme scores of surgical field quality (SSFQ). Meanwhile, the dose of sevoflurane, propofol, and fentanyl, MAP, the recovery time of anesthesia, and the incidence rate of untoward effects were recorded. Results The dosage of propofol, fentanyl, sevoflurane, and MAC value in group II was significantly diminished compared with group I (P<0.0l). In addition, the surgical field quality was better, whereas SSFQ was obviously lower (P<0.05). The HR at the time of T0 to T3 was obviously lower compared with group I. The MAP, E, and NE at the time of T0 and T3 were obviously lower (P<0.05). The results of blood gas analysis and determination of lactic acid at the time of regaining consciousness and extubation showed no statistical differences between the two groups (P>0.05). Moreover, the incidence rates of expanding pain in sinus, headache, delirium, and chill were obviously lower in group II (P<0.05). However, the incidence rate of bradycardia demanding intervention was higher in group II than that of group I. No severe cardiovascular emergency was noted in two groups. Conclusion Dexmedetomidine can reduce the dose of anaesthetic drugs, improve the cardiovascular stability during the perioperative period, accelerate the time of recovery of consciousness, and is safe and effective in assisting controlled hypotension during endoscopic sinus surgery.%目的 探讨鼻内窥镜手术中应用右旋美托咪啶辅助控制性降压的可行性.方法 择期行鼻内窥镜手术患者48例,ASA Ⅰ或Ⅱ级,随机均分为2组(n=24):对照组(Ⅰ组)和右旋美托咪啶组(Ⅱ组).两组均采用静脉注射咪达唑仑、丙泊酚、芬太尼和顺苯磺阿曲库铵麻醉诱导,麻醉维持采用丙泊酚、芬太尼、顺苯磺阿曲库铵辅以七氟烷吸入.桡动脉穿刺置管监测有创平均动脉压(MAP).Ⅰ组通过调整七氟烷的浓度施行控制性降压,Ⅱ组于麻醉诱导前15～30min内静脉泵注右旋美托咪啶0.8μg/kg,以0.4μg/(kg·h)维持,诱导后手术开始时调整七氟烷的吸人浓度,直到降至靶目标血压,维持MAP在65 ～ 75mmHg至手术结束.分别记录麻醉诱导前(T0)、控制性降压开始时(T1)、30min(T2)和拔管时(T3)的心率(HR)、MAP、血浆肾上腺素(E)和去甲肾上腺素(NE)浓度,术中抽取桡动脉血行血气分析和乳酸浓度测定.用Fromme术野质量评分法评定术野质量,同时记录丙泊酚、芬太尼和七氟烷的用量和MAC值,观察麻醉恢复情况和不良反应发生率.结果 与Ⅰ组比较,Ⅱ组丙泊酚、芬太尼、七氟烷用量和MAC值均明显减少(p＜0.01),术野质量提高,术野质量评定(SSFQ)评分明显降低(p＜0.05)；与Ⅰ组比较,Ⅱ组T0-T3时点HR明显减慢；T0、T3时点MAP、E、NE明显降低(P＜0.05)；两组术中的血气分析和乳酸测定结果以及苏醒时间、拔管时间均无统计学差异(p＞0.05)；与Ⅰ组比较,Ⅱ组术后鼻部胀痛头痛、谵妄躁动、寒战的发生率也明显降低(p＜0.05),但Ⅱ组需要干预的心动过缓发生率较Ⅰ组高(P＜0.05),两组均无严重心血管不良事件发生.结论 右旋美托咪啶可以减少麻醉药用量,增强围术期心血管稳定性,改善麻醉恢复过程,用于辅助鼻内窥镜手术控制性降压安全、有效.
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