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
Background There are few studies to assess whether the effect-site concentration of propofol can predict anesthetic depth during the target-controlled infusion （TCI） induction in elderly patients. This study aimed t...Background There are few studies to assess whether the effect-site concentration of propofol can predict anesthetic depth during the target-controlled infusion （TCI） induction in elderly patients. This study aimed to evaluate the relationship between effect-site concentration of propofol and depth of anesthesia during the TCI induction in elderly patients. Methods Ninety patients （60-80 years） with an American Society of Anesthesiologists （ASA） physical status of 1-3, undergoing scheduled abdominal and thoracic surgery under general anesthesia were randomly allocated into one of three groups, Group S1, S2 and S3 （30 patients in each group）. The patients in Group S1 received propofol with a target plasma concentration of 4.0 pg/ml; patients in Group S2 received propofol with an initial target plasma concentrations of 2.0 IJg/ml that was raised to 4.0 pg/ml 3 minutes later; patients in Group S3 received an infused scheme of 3 steps; starting from a target plasma concentration of 2.0 pg/ml that was increased stepwised by 1 pg/ml until a target plasma concentration of 4.0 pg/ml was achieved, the interval between the two steps was 3 minutes. When an Observer＇s Assessment of Alertness/Sedation （OANS） score of 1 was achieved, remifentanil （effect-site concentration （Ce） of 4.0 ng/ml） and rocuronium 0.9 mg/kg were administered. Tracheal intubation was started 2 minutes after rocuronium injection. Changes of propofol Ce, blood pressure （BP）, heart rate （HR）, and bispectral index （BIS） were recorded. Results When an OAA/S score of 1 was achieved, Ce of propofol were （1.7±0.4） pg/ml, （1.9±0.3） pg/ml, （1.9±0.4） pg/ml and the BIS values were 64±5, 65±8, and 62±8 in Groups S1, S2 and S3. Before intubation, Ce of propofol was （2.8±0.2） pg/ml, （2.8±0.3） pg/ml, （2.7±0.3） pg/ml, and the BIS values were 48±7, 51±7, and 47±5 in Groups S1, S2 and S3. By linear regression analysis, a significant correlation between Ce of propofol and BIS values was found （r=-0.580, P 〈0.01）. Systolic blood pressure （SBP） before intubation was significantly lower in Group S1 than in Groups S2 and S3. SBP and HR after intubation in the three groups were significantly increased when compared with pre-intubation values, but they did not exceed baseline values Conclusions During the TCI induction, Ce of propofol with （1.9±0.3） pg/ml may make the elderly patients unconscious. When remifentanil with a Ce of 4.0 ng/ml is added a Ce of propofol with （2.8±0.3） pg/ml is suitable for intubation. The Ce of propofol has a close correlation with the BIS values. Also, a two-step TCI technique seems to be a more suitable method of anesthesia induction in elderly patients compared with the no-stepwise TCI technique and three-step TCI technique.展开更多
Background：In this prospective randomized study,we compared the predicted blood and effect-site C50 for propofol and remifentanil target-controlled infusion （TCI） and the bispectral index （BIS） values at loss of ...Background：In this prospective randomized study,we compared the predicted blood and effect-site C50 for propofol and remifentanil target-controlled infusion （TCI） and the bispectral index （BIS） values at loss of consciousness （LOC） and response to a standard noxious painful stimulus （LOS） in elderly and young patients,respectively.We hypothesized that the elderly patients will require lower target concentration of both propofol and remifentanil at above two clinical end-points.Methods：There were 80 American Society of Anesthesiologists （ASA） physical status Ⅰ Ⅱ unpremedicated patients enrolled in this study,they were divided into elderly group （age ≥65 years,n =40） and young group （aged 18-54 years,n =40）.Propofol was initially given to a predicted blood concentration of 1.2 μg/ml and thereafter increased by 0.3 μg/ml every 30 s until Observer＇s Assessment of Alertness and Sedation score was 1.The propofol level was kept constant,and remifentanil was given to provide a predict blood concentration of 2.0 ng/ml,and then increased by 0.3 ng/ml every 30 s until loss of response to a tetanic stimulus.BIS （version 3.22,BIS Quattro sensor） was also recorded.Results：In elderly group,the propofol effect-site C50 at LOC of was 1.5 （1.4-1.6） μg/ml,was significantly lower than that of young group,which was 2.2 （2.1-2.3） μg/ml,the remifentanil effect-site C50 at LOS was 3.5 （3.3-3.7） ng/ml in elderly patients,was similar with 3.7 （3.6-3.8） ng/ml in young patients.Fifty percent of patients lost consciousness at a BIS value of 57.3 （56.4-58.1）,was similar with that of young group,which was 55.2 （54.0-56.3）.Conclusion：In elderly patients,the predicted blood and effect-site concentrations of propofol at LOC were lower than that of young patients.At same sedation status,predicted blood and effect-site concentrations of remifentanil required at LOS were similar in elderly and young patients.BIS were not affected by age.Low-propofol/high-opioid may be optional TCI strategy for elderly patients.展开更多
Background Although the performance of target-controlled infusion (TCI) have been studied extensively, the accuracy and safety of a TCI system that targets the effect site remains to be demonstrated. This study was to...Background Although the performance of target-controlled infusion (TCI) have been studied extensively, the accuracy and safety of a TCI system that targets the effect site remains to be demonstrated. This study was to investigate the relations of TCI of propofol to its concentrations in cerebral spinal fluid (CSF), the effect-site concentrations and bispectral index (BIS).Methods Twelve mongrel dogs were used for investigations. The target effect-site concentration was set at 3μg/ml and the infusion was lasted for 15 minutes. CSF and blood samples were then collected and propofol concentrations were determined by using high performance liquid chromatography with fluorescence detection. BIS and hemodynamic data were monitored continuously.Results The predicted plasma concentrations were generally overestimated. Median performance error (MDPE) and absolute median performance error (MDAPE) were -10.0% and 29.9% respectively. Propofol CSF concentrations were much lower than its effect-site concentrations. Changes in BIS were consistent with propofol concentrations in CSF, both of which changed direction at 5 minutes while the effect-site concentrations relatively lagged behind. Better correlation ( r2 = 0. 9195) was found between BIS and CSF concentrations, when compared with that between BIS and effect-site concentrations (r2=0. 554).Conclusion With 1% enflurane inhaled, the inconsistency of drug effect to the effect-site concentrations may result from inaccuracy of pharmacokinetic parameters. CSF may show effect-site concentrations more accurately than plasma when using target effect-site concentration infusion.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.
文摘Background There are few studies to assess whether the effect-site concentration of propofol can predict anesthetic depth during the target-controlled infusion （TCI） induction in elderly patients. This study aimed to evaluate the relationship between effect-site concentration of propofol and depth of anesthesia during the TCI induction in elderly patients. Methods Ninety patients （60-80 years） with an American Society of Anesthesiologists （ASA） physical status of 1-3, undergoing scheduled abdominal and thoracic surgery under general anesthesia were randomly allocated into one of three groups, Group S1, S2 and S3 （30 patients in each group）. The patients in Group S1 received propofol with a target plasma concentration of 4.0 pg/ml; patients in Group S2 received propofol with an initial target plasma concentrations of 2.0 IJg/ml that was raised to 4.0 pg/ml 3 minutes later; patients in Group S3 received an infused scheme of 3 steps; starting from a target plasma concentration of 2.0 pg/ml that was increased stepwised by 1 pg/ml until a target plasma concentration of 4.0 pg/ml was achieved, the interval between the two steps was 3 minutes. When an Observer＇s Assessment of Alertness/Sedation （OANS） score of 1 was achieved, remifentanil （effect-site concentration （Ce） of 4.0 ng/ml） and rocuronium 0.9 mg/kg were administered. Tracheal intubation was started 2 minutes after rocuronium injection. Changes of propofol Ce, blood pressure （BP）, heart rate （HR）, and bispectral index （BIS） were recorded. Results When an OAA/S score of 1 was achieved, Ce of propofol were （1.7±0.4） pg/ml, （1.9±0.3） pg/ml, （1.9±0.4） pg/ml and the BIS values were 64±5, 65±8, and 62±8 in Groups S1, S2 and S3. Before intubation, Ce of propofol was （2.8±0.2） pg/ml, （2.8±0.3） pg/ml, （2.7±0.3） pg/ml, and the BIS values were 48±7, 51±7, and 47±5 in Groups S1, S2 and S3. By linear regression analysis, a significant correlation between Ce of propofol and BIS values was found （r=-0.580, P 〈0.01）. Systolic blood pressure （SBP） before intubation was significantly lower in Group S1 than in Groups S2 and S3. SBP and HR after intubation in the three groups were significantly increased when compared with pre-intubation values, but they did not exceed baseline values Conclusions During the TCI induction, Ce of propofol with （1.9±0.3） pg/ml may make the elderly patients unconscious. When remifentanil with a Ce of 4.0 ng/ml is added a Ce of propofol with （2.8±0.3） pg/ml is suitable for intubation. The Ce of propofol has a close correlation with the BIS values. Also, a two-step TCI technique seems to be a more suitable method of anesthesia induction in elderly patients compared with the no-stepwise TCI technique and three-step TCI technique.
文摘Background：In this prospective randomized study,we compared the predicted blood and effect-site C50 for propofol and remifentanil target-controlled infusion （TCI） and the bispectral index （BIS） values at loss of consciousness （LOC） and response to a standard noxious painful stimulus （LOS） in elderly and young patients,respectively.We hypothesized that the elderly patients will require lower target concentration of both propofol and remifentanil at above two clinical end-points.Methods：There were 80 American Society of Anesthesiologists （ASA） physical status Ⅰ Ⅱ unpremedicated patients enrolled in this study,they were divided into elderly group （age ≥65 years,n =40） and young group （aged 18-54 years,n =40）.Propofol was initially given to a predicted blood concentration of 1.2 μg/ml and thereafter increased by 0.3 μg/ml every 30 s until Observer＇s Assessment of Alertness and Sedation score was 1.The propofol level was kept constant,and remifentanil was given to provide a predict blood concentration of 2.0 ng/ml,and then increased by 0.3 ng/ml every 30 s until loss of response to a tetanic stimulus.BIS （version 3.22,BIS Quattro sensor） was also recorded.Results：In elderly group,the propofol effect-site C50 at LOC of was 1.5 （1.4-1.6） μg/ml,was significantly lower than that of young group,which was 2.2 （2.1-2.3） μg/ml,the remifentanil effect-site C50 at LOS was 3.5 （3.3-3.7） ng/ml in elderly patients,was similar with 3.7 （3.6-3.8） ng/ml in young patients.Fifty percent of patients lost consciousness at a BIS value of 57.3 （56.4-58.1）,was similar with that of young group,which was 55.2 （54.0-56.3）.Conclusion：In elderly patients,the predicted blood and effect-site concentrations of propofol at LOC were lower than that of young patients.At same sedation status,predicted blood and effect-site concentrations of remifentanil required at LOS were similar in elderly and young patients.BIS were not affected by age.Low-propofol/high-opioid may be optional TCI strategy for elderly patients.
基金This study was supported by a grant from the Chinese Ministry of Education (No. 9805).
文摘Background Although the performance of target-controlled infusion (TCI) have been studied extensively, the accuracy and safety of a TCI system that targets the effect site remains to be demonstrated. This study was to investigate the relations of TCI of propofol to its concentrations in cerebral spinal fluid (CSF), the effect-site concentrations and bispectral index (BIS).Methods Twelve mongrel dogs were used for investigations. The target effect-site concentration was set at 3μg/ml and the infusion was lasted for 15 minutes. CSF and blood samples were then collected and propofol concentrations were determined by using high performance liquid chromatography with fluorescence detection. BIS and hemodynamic data were monitored continuously.Results The predicted plasma concentrations were generally overestimated. Median performance error (MDPE) and absolute median performance error (MDAPE) were -10.0% and 29.9% respectively. Propofol CSF concentrations were much lower than its effect-site concentrations. Changes in BIS were consistent with propofol concentrations in CSF, both of which changed direction at 5 minutes while the effect-site concentrations relatively lagged behind. Better correlation ( r2 = 0. 9195) was found between BIS and CSF concentrations, when compared with that between BIS and effect-site concentrations (r2=0. 554).Conclusion With 1% enflurane inhaled, the inconsistency of drug effect to the effect-site concentrations may result from inaccuracy of pharmacokinetic parameters. CSF may show effect-site concentrations more accurately than plasma when using target effect-site concentration infusion.
