Zhang Ling, Yu Yang, Xue Juan, Lei Weiping, Huang Yaqin, Li Yong, Sun Jianliang
The Fourth Clinical Medical College, Zhejiang Chinese Medical University School of Medicine, Hangzhou, China.
Department of Anesthesia, Hangzhou First People's Hospital Affiliated to Zhejiang University School of Medicine, Hangzhou, China.
Front Surg. 2021 Sep 8;8:681471. doi: 10.3389/fsurg.2021.681471. eCollection 2021.
Deliberate hypotension can reduce bleeding and improve visualization of the surgical field during functional endoscopic sinus surgery (FESS). However, hypotension may cause brain hypoperfusion and subsequent ischemic injuries, such as delayed awakening, stroke, postoperative delirium, and postoperative cognitive dysfunction. Near-infrared spectroscopy (NIRS) can be used to monitor real-time regional cerebral oxygen saturation (rSO) levels to estimate brain perfusion. The present study aimed to evaluate the change in rSO induced by deliberate hypotension during FESS, and assess the impact of deliberate hypotension on the surgical process. A randomized controlled trial was registered with the Chinese clinical trial registry (ChiCTR2000039846). A total of 40 patients were enrolled and randomly divided into the control and intervention groups, and finally, 39 patients were analyzed. Deliberate hypotension was induced in the intervention group using nicardipine and esmolol, whereas the control group received general anesthesia without deliberate hypotension. We recorded mean arterial pressure (MAP), saturation of pulse oximetry (SpO), rSO, and heart rate (HR) before induction of anesthesia (T0), immediately after induction of anesthesia (T1), at the beginning of the operation (corresponding with the establishment of deliberate hypotension) (T2), 10 min (T3) and 20 min (T4) after the operation began, at the end of the operation (corresponding with the end of deliberate hypotension) (T5), and 5 min (T6) and 15 min (T7) after the operation. The partial pressure of end-tidal carbon dioxide (PetCO) was recorded at T1, T2, T3, T4, T5, and T6. The duration of surgery, intraoperative blood loss, tracheal extubation time, and the number of patients that experienced cerebral desaturation events (CDEs) were recorded. The surgical field was estimated postoperation based on the Fromme score. A 30% decrease from the baseline MAP resulted in a decrease of intraoperative bleeding, improvement in the quality of the surgical field, and the shortening of the duration of surgery during FESS in the intervention group compared with the control group. In addition, rSO was reduced and no CDEs were experienced in the intervention group. Linear regression analysis demonstrated a correlation between the decline in rSO and that in MAP. A decrease in MAP to a certain level will cause a decrease of rSO in patients undergoing FESS under general anesthesia. Based on our findings, we recommend that the deliberate hypotensive target indicated by MAP be reduced by 30%, while PetCO is maintained at 35-40 mmHg and HR is maintained at about 60 beats per minute during FESS.
控制性低血压可减少功能性鼻内镜鼻窦手术（FESS）期间的出血并改善手术视野的可视化。然而，低血压可能导致脑灌注不足及随后的缺血性损伤，如苏醒延迟、中风、术后谵妄和术后认知功能障碍。近红外光谱（NIRS）可用于监测实时局部脑氧饱和度（rSO）水平以评估脑灌注。本研究旨在评估FESS期间控制性低血压引起的rSO变化，并评估控制性低血压对手术过程的影响。一项随机对照试验已在中国临床试验注册中心注册（ChiCTR2000039846）。共纳入40例患者，随机分为对照组和干预组，最终分析了39例患者。干预组使用尼卡地平和艾司洛尔诱导控制性低血压，而对照组接受无控制性低血压的全身麻醉。我们记录了麻醉诱导前（T0）、麻醉诱导后即刻（T1）、手术开始时（对应控制性低血压建立）（T2）、手术开始后10分钟（T3）和20分钟（T4）、手术结束时（对应控制性低血压结束）（T5）以及手术后5分钟（T6）和15分钟（T7）的平均动脉压（MAP）、脉搏血氧饱和度（SpO）、rSO和心率（HR）。在T1、T2、T3、T4、T5和T6记录呼气末二氧化碳分压（PetCO）。记录手术时间、术中出血量、气管拔管时间以及发生脑去饱和事件（CDE）的患者数量。术后根据弗罗梅评分评估手术视野。与对照组相比，干预组中MAP较基线降低30%导致FESS期间术中出血减少、手术视野质量改善以及手术时间缩短。此外，干预组的rSO降低且未发生CDE。线性回归分析表明rSO的下降与MAP的下降之间存在相关性。在全身麻醉下进行FESS的患者中，MAP降至一定水平会导致rSO降低。基于我们的研究结果，我们建议在FESS期间将MAP指示的控制性低血压目标降低30%，同时将PetCO维持在35 - 40 mmHg，HR维持在约每分钟60次搏动。
