BACKGROUND Many studies have addressed safety and effectiveness of non-anaesthesiologist propofol sedation(NAPS)for gastrointestinal(GI)endoscopy Target controlled infusion(TCI)is claimed to provide an optimal sedatio...BACKGROUND Many studies have addressed safety and effectiveness of non-anaesthesiologist propofol sedation(NAPS)for gastrointestinal(GI)endoscopy Target controlled infusion(TCI)is claimed to provide an optimal sedation regimen by avoiding under-or oversedation.AIM To assess safety and performance of propofol TCI sedation in comparison with nurse-administered bolus-sedation.METHODS Fouty-five patients undergoing endoscopy under TCI propofol sedation were prospectively included from November 2016 to May 2017 and compared to 87 patients retrospectively included that underwent endoscopy with NAPS.Patients were matched for age and endoscopic procedure.We recorded time of sedation and endoscopy,dosage of medication and adverse events.RESULTS There was a significant reduction in dose per time of propofol administered in the TCI group,compared to the NAPS group(8.2±2.7 mg/min vs 9.3±3.4 mg/min;P=0.046).The time needed to provide adequate sedation levels was slightly but significantly lower in the control group(5.3±2.7 min vs 7.7±3.3 min;P<0.001),nonetheless the total endoscopy time was similar in both groups.No differences between TCI and bolus-sedation was observed for mean total-dosage of propofol rate as well as adverse events.CONCLUSION This study indicates that sedation using TCI for GI endoscopy reduces the dose of propofol necessary per minute of endoscopy.This may translate into less adverse events.However,further and randomized trials need to confirm this trend.展开更多
This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and ...This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.展开更多
Instability of a wake controlled by a streamwise Lorentz force is investigated through a Floquet stability analysis. The streamwise Lorentz force, which is a two-dimensional control input created by an electromagnetic...Instability of a wake controlled by a streamwise Lorentz force is investigated through a Floquet stability analysis. The streamwise Lorentz force, which is a two-dimensional control input created by an electromagnetic actuator located on the cylinder surface,adjusts the base flow to affect the three-dimensional wake instability and achieve wake stabilization and transition delay. The instability mode at a Reynolds number Re = 300 can be transformed from B to A with N = 1.0, where N is an interaction number representing the strength of the Lorentz force relative to the inertial force in the fluid. The wake flow is Floquet stable when N increases to 1.3. The spanwise perturbation wavelengths are 3.926 D and 0.822 D in the modes A and B, respectively, where D is the cylinder diameter. In addition, the oscillating amplitudes of drag and lift are reduced with the increase in the interaction number. Particle tracing is used to explore the essential physical mechanism for mode transformation. The path lines show that suppression of flow separation hinders the fluid deformation and rotation, leading to the decrease in elliptic and hyperbolic instability regions, which is the material cause of mode transformation.All of the results indicate that wake stabilization and transition delay can be achieved under open-loop active control via the streamwise Lorentz force.展开更多
A physically accurate and computationally effective pure finite element method （FEM） was developed to simulate the isothermal resin infusing process. The FEM was based on conservation of resin muss at and instant of...A physically accurate and computationally effective pure finite element method （FEM） was developed to simulate the isothermal resin infusing process. The FEM was based on conservation of resin muss at and instant of time and was objective of resin film infusion （RFI） fiber impregnation and mold filling . The developed computer code was able to simulate the resin infusing visually. A numerical example presented here demonstrated that compared with traditional finite element/ control-volume （FE/CV）, and FEM was physically accurate and computationally efficient.展开更多
目的探讨静脉输注右美托咪定(Dex)联合靶控输注瑞芬太尼在老年患者经内镜逆行胰胆管造影术(ERCP)麻醉中的安全性及可行性。方法选择2021年1月至8月择期监测麻醉(MAC)下行ERCP的老年患者(年龄≥65岁)98例,随机分为丙泊酚-瑞芬太尼(TRP)组...目的探讨静脉输注右美托咪定(Dex)联合靶控输注瑞芬太尼在老年患者经内镜逆行胰胆管造影术(ERCP)麻醉中的安全性及可行性。方法选择2021年1月至8月择期监测麻醉(MAC)下行ERCP的老年患者(年龄≥65岁)98例,随机分为丙泊酚-瑞芬太尼(TRP)组和Dex-瑞芬太尼(TRD)组。TRP组患者麻醉采用靶控输注丙泊酚-瑞芬太尼,TRD组患者麻醉采用静脉输注Dex联合靶控输注瑞芬太尼,2组均采用非气管插管的MAC麻醉。观察并记录患者在麻醉诱导前(T0)、麻醉诱导后即刻(T_(1))、进镜时(T_(2))、十二指肠乳头插管时(T_(3))、退镜时(T_(4))、留置鼻胆管结束时(T_(5))平均动脉压(MAP)、心率(HR)、脉博氧饱和度(SpO_(2))、呼吸频率(RR)、脑电双频指数(BIS)。于不同时点(术前、麻醉诱导后每隔15 min和苏醒即刻)采动脉血行血气分析,记录动脉血氧分压(PaO_(2))、动脉二氧化碳分压(PaCO_(2))、瑞芬太尼靶控输注浓度、手术时间、苏醒时间(停止输注瑞芬太尼至意识恢复时间)、麻醉恢复时间(意识恢复至离开手术室时间)、术中体动、离室Aldrete评分、术后60 min VAS评分、术后不良反应,以及麻醉医生、内镜医生和患者的满意度。结果2组患者的年龄、性别、BMI、ASA分级等一般资料均无统计学差异(P>0.05)。与TRP组比较,TRD组MAP在T_(1)和T_(3)时点增高(P<0.05),HR在T_(1)、T_(2)、T_(3)、T_(4)时点降低,SpO_(2)、RR在T_(1)、T_(2)、T_(3)、T_(4)时点增高,BIS在T_(2)、T_(3)、T_(4)、T_(5)时点增高,托下颌次数和低氧血症发生率降低,离室Aldrete评分增高,术后60 min VAS评分降低,麻醉医生、内镜医生及患者满意度增高,差异均有统计学意义(均P<0.05)。2组患者各时点PaO_(2)、PaCO_(2)、靶控输注瑞芬太尼浓度、手术时间、苏醒时间、麻醉恢复时间、术后不良反应发生率无统计学差异。结论与靶控输注丙泊酚-瑞芬太尼相比,静脉输注Dex联合靶控输注瑞芬太尼可降低老年患者在ERCP手术中低氧血症的发生率,麻醉方案能够满足ERCP手术的麻醉需求,安全可行。展开更多
文摘BACKGROUND Many studies have addressed safety and effectiveness of non-anaesthesiologist propofol sedation(NAPS)for gastrointestinal(GI)endoscopy Target controlled infusion(TCI)is claimed to provide an optimal sedation regimen by avoiding under-or oversedation.AIM To assess safety and performance of propofol TCI sedation in comparison with nurse-administered bolus-sedation.METHODS Fouty-five patients undergoing endoscopy under TCI propofol sedation were prospectively included from November 2016 to May 2017 and compared to 87 patients retrospectively included that underwent endoscopy with NAPS.Patients were matched for age and endoscopic procedure.We recorded time of sedation and endoscopy,dosage of medication and adverse events.RESULTS There was a significant reduction in dose per time of propofol administered in the TCI group,compared to the NAPS group(8.2±2.7 mg/min vs 9.3±3.4 mg/min;P=0.046).The time needed to provide adequate sedation levels was slightly but significantly lower in the control group(5.3±2.7 min vs 7.7±3.3 min;P<0.001),nonetheless the total endoscopy time was similar in both groups.No differences between TCI and bolus-sedation was observed for mean total-dosage of propofol rate as well as adverse events.CONCLUSION This study indicates that sedation using TCI for GI endoscopy reduces the dose of propofol necessary per minute of endoscopy.This may translate into less adverse events.However,further and randomized trials need to confirm this trend.
基金supported by a grant from Shenzhen Baoan Hospital Affiliated to Southern Medical University
文摘This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education(No.20133219110039)
文摘Instability of a wake controlled by a streamwise Lorentz force is investigated through a Floquet stability analysis. The streamwise Lorentz force, which is a two-dimensional control input created by an electromagnetic actuator located on the cylinder surface,adjusts the base flow to affect the three-dimensional wake instability and achieve wake stabilization and transition delay. The instability mode at a Reynolds number Re = 300 can be transformed from B to A with N = 1.0, where N is an interaction number representing the strength of the Lorentz force relative to the inertial force in the fluid. The wake flow is Floquet stable when N increases to 1.3. The spanwise perturbation wavelengths are 3.926 D and 0.822 D in the modes A and B, respectively, where D is the cylinder diameter. In addition, the oscillating amplitudes of drag and lift are reduced with the increase in the interaction number. Particle tracing is used to explore the essential physical mechanism for mode transformation. The path lines show that suppression of flow separation hinders the fluid deformation and rotation, leading to the decrease in elliptic and hyperbolic instability regions, which is the material cause of mode transformation.All of the results indicate that wake stabilization and transition delay can be achieved under open-loop active control via the streamwise Lorentz force.
基金Funded bythe National Natural Science Foundation of China(No50573060)
文摘A physically accurate and computationally effective pure finite element method （FEM） was developed to simulate the isothermal resin infusing process. The FEM was based on conservation of resin muss at and instant of time and was objective of resin film infusion （RFI） fiber impregnation and mold filling . The developed computer code was able to simulate the resin infusing visually. A numerical example presented here demonstrated that compared with traditional finite element/ control-volume （FE/CV）, and FEM was physically accurate and computationally efficient.
文摘目的探讨静脉输注右美托咪定(Dex)联合靶控输注瑞芬太尼在老年患者经内镜逆行胰胆管造影术(ERCP)麻醉中的安全性及可行性。方法选择2021年1月至8月择期监测麻醉(MAC)下行ERCP的老年患者(年龄≥65岁)98例,随机分为丙泊酚-瑞芬太尼(TRP)组和Dex-瑞芬太尼(TRD)组。TRP组患者麻醉采用靶控输注丙泊酚-瑞芬太尼,TRD组患者麻醉采用静脉输注Dex联合靶控输注瑞芬太尼,2组均采用非气管插管的MAC麻醉。观察并记录患者在麻醉诱导前(T0)、麻醉诱导后即刻(T_(1))、进镜时(T_(2))、十二指肠乳头插管时(T_(3))、退镜时(T_(4))、留置鼻胆管结束时(T_(5))平均动脉压(MAP)、心率(HR)、脉博氧饱和度(SpO_(2))、呼吸频率(RR)、脑电双频指数(BIS)。于不同时点(术前、麻醉诱导后每隔15 min和苏醒即刻)采动脉血行血气分析,记录动脉血氧分压(PaO_(2))、动脉二氧化碳分压(PaCO_(2))、瑞芬太尼靶控输注浓度、手术时间、苏醒时间(停止输注瑞芬太尼至意识恢复时间)、麻醉恢复时间(意识恢复至离开手术室时间)、术中体动、离室Aldrete评分、术后60 min VAS评分、术后不良反应,以及麻醉医生、内镜医生和患者的满意度。结果2组患者的年龄、性别、BMI、ASA分级等一般资料均无统计学差异(P>0.05)。与TRP组比较,TRD组MAP在T_(1)和T_(3)时点增高(P<0.05),HR在T_(1)、T_(2)、T_(3)、T_(4)时点降低,SpO_(2)、RR在T_(1)、T_(2)、T_(3)、T_(4)时点增高,BIS在T_(2)、T_(3)、T_(4)、T_(5)时点增高,托下颌次数和低氧血症发生率降低,离室Aldrete评分增高,术后60 min VAS评分降低,麻醉医生、内镜医生及患者满意度增高,差异均有统计学意义(均P<0.05)。2组患者各时点PaO_(2)、PaCO_(2)、靶控输注瑞芬太尼浓度、手术时间、苏醒时间、麻醉恢复时间、术后不良反应发生率无统计学差异。结论与靶控输注丙泊酚-瑞芬太尼相比,静脉输注Dex联合靶控输注瑞芬太尼可降低老年患者在ERCP手术中低氧血症的发生率,麻醉方案能够满足ERCP手术的麻醉需求,安全可行。
文摘目的 探讨CONCERT-CL闭环靶控输注系统在腹腔镜胃肠手术患者中的应用效果及对患者术后胃肠功能和免疫功能的影响。方法 选取2022年8月至2023年5月上海市徐汇区中心医院收治的80例腹腔镜胃肠手术患者作为研究对象,按随机数表法分为观察组和对照组各40例。两组患者均采用相同的麻醉方案,但观察组患者采用CONCERT-CL闭环靶控输注系统进行麻醉管理,而对照组患者则采用开放式麻醉维持。比较两组患者的围术期相关指标、胃肠功能和围术期白细胞分化抗原(CD) TT细胞数量和自然杀伤细胞(NK)细胞数量,同时比较两组患者术后不良反应发生情况。结果 观察组患者的手术时间、麻醉时间分别为(183.60±30.15) min、(206.69±10.54) min,对照组分别为(189.12±43.85) min、(211.65±16.83) min,差异均无统计学意义(P>0.05);观察组患者术中丙泊酚用量和顺式阿曲库铵用量分别为(13.34±2.00) mg/kg、(0.26±0.09) mg/kg,明显低于对照组的(15.96±1.41) mg/kg、(0.35±0.11) mg/kg,拔管即刻警觉-镇静(OAA/S)评分和术中BIS时间为40~60的占比分别为(3.46±0.25)分、(82.60±4.22)%,明显高于对照组的(3.12±0.46)分、(64.02±3.65)%,差异均有统计学意义(P<0.05);观察组和对照组患者的肠鸣音恢复[(22.60±4.52) h vs (30.57±6.84) h]、腹痛缓解[(26.88±4.11) h vs (30.17±2.94) h]、术后首次排气时间[(32.69±4.25) h vs (44.35±1.68) h]比较,观察组明显短于对照组,差异均有统计学意义(P<0.05);术后12 h,观察组和对照组患者的CD4+TT数量[(35.69±1.54)%vs (32.01±6.21)%]、NK细胞数量[(20.36±2.41)%vs (18.73±2.65)%]比较,观察组明显高于对照组,CD8+TT数量[(27.01±1.79)%vs (29.28±3.87)%]比较,观察组明显低于对照组,差异均有统计学意义(P<0.05);观察组患者的不良反应总发生率为5.00%,略低于对照组的10.00%,但差异无统计学意义(P>0.05)。结论 CONCERT-CL闭环靶控输注系统在腹腔镜胃肠手术患者中的应用能够降低术中麻醉维持药物用量,患者苏醒速度更快。同时还能够促进患者术后胃肠功能的恢复,并且对免疫功能起到一定改善作用。
