Purpose: Although rocuronium bromide (Rb) is suitable for continuous administration use, determination of optimal continuous doses is difficult due to individual differences. This study examines the efficacy of a cont...Purpose: Although rocuronium bromide (Rb) is suitable for continuous administration use, determination of optimal continuous doses is difficult due to individual differences. This study examines the efficacy of a continuous Rb administration method based on effect-site concentrations calculated by a pharmacokinetic/pharmacodynamics model during propofol, sevoflurane, and desflurane anesthesia. Methods: The 36 enrolled patients were equally divided into three groups (P;propofol, S;sevoflurane, and D;desflurane groups). After induction and administration of Rb 0.6 mg/kg, we calculated the simulated effect-site concentration at the point which the first twitch (%T1) recovered to > 0% and defined this as the Rb recovery concentration (Rbr.c.) level appropriate for continuous rocuronium administration. The continuous administration doses of Rb were adjusted to maintain Rbr.c. during surgery. The Rbr.c. and the recovery time at %T1 > 25% were recorded for each type of anesthesia. Results: Rbr.c. (μg/mL) for the P, S, and D groups were 1.54 ± 0.2, 1.24 ± 0.2, and 1.09 ± 0.2, respectively. Continuous administration doses (μg/kg/min) in the P, S, and D group were 6.7 ± 0.9, 5.2 ± 1.0, and 4.5 ± 0.8, respectively. Rbr.c. and continuous doses in the S and D groups were lower than the P group. Neuromuscular relaxations during surgery in the S and D groups were more strongly maintained than for the P group. There was also a significantly prolonged recovery duration for the %T1 > 25% in the D versus the other two groups (P < 0.05). Conclusion: Results showed that our continuous administration method was effective for maintaining sufficient muscle relaxation without excessively prolonged recovery effects for both sevoflurane and desflurane as well as propofol anesthesia.展开更多
Background: General anesthesia using remifentanil may suppress the unwanted metabolic changes caused by surgical stress including hyperglycemia and ketogenesis. Surgery-related changes in catabolism can be attenuated ...Background: General anesthesia using remifentanil may suppress the unwanted metabolic changes caused by surgical stress including hyperglycemia and ketogenesis. Surgery-related changes in catabolism can be attenuated with low-dose glucose load, without causing hyperglycemia. However, the impact of glucose load in diabetic patients during surgery is unknown. In this study, we investigated the effect of glucose load on catabolism during remifentanil-based anesthesia in patients with diabetes mellitus. Methods: Twenty-nine patients with diabetes mellitus undergoing elective surgery were randomly assigned to receive a glucose load (1.5 mg/kg/min) or not. Plasma levels of glucose, insulin, cortisol, dopamine, adrenaline, noradrenaline, acetoacetic acid, free fatty acid, ketone bodies, 3-hydroxybutyric acid, and 3-methylhistidine/creatinine, a marker of protein catabolism were measured at the start of surgery and 3 h after the start of surgery. Results: Glucose and insulin levels were significantly higher in patients who received a glucose load than in those who did not. Cortisol levels decreased at 3 h after the start of surgery in both groups whereas the levels of catecholamines were unchanged. Acetoacetic acid and total ketone body levels were significantly lower in patients given a glucose load than in those who were not 3 h after the start of surgery. The difference in the 3 methylhistidine/creatinine ratio between the two groups was not significant. Conclusions: The infusion of glucose suppressed lipid catabolism in diabetic patients under remifentanil-based anesthesia during surgery. Our study also suggests that in patients with diabetes mellitus, protein sparing is inhibited by remifentanil-based anesthesia, regardless of the glucose load. Trial registration: the University Hospital Medical Information Network identifier: UMIN000010914.展开更多
Background: Perioperative exacerbation of hyperglycemia and insulin resistance is associated with increased complications in patients with diabetes mellitus. We recently reported that glucose load during anesthesia wi...Background: Perioperative exacerbation of hyperglycemia and insulin resistance is associated with increased complications in patients with diabetes mellitus. We recently reported that glucose load during anesthesia with sevoflurane suppressed lipid catabolism in diabetic patients. In contrast to inhaled anesthetics, propofol solution contains triglycerides, which can be an energy source during surgery. However, the clinical relevance of glucose load under propofol-based anesthesia in diabetic patients is unknown. Therefore, we investigated the effect of intraoperative glucose load on catabolism during propofol-based anesthesia in patients with diabetes mellitus. Methods: Twenty-three patients with diabetes mellitus undergoing elective surgery with propofol-remifentanil-based anesthesia were randomly assigned to receive a glucose load (1.5 mg/kg/ min) or not. Plasma levels of glucose, insulin, cortisol, catecholamines, acetoacetic acid, free fatty acids, ketone bodies, 3-hydroxybutyric acid, and 3-methylhistidine/creatinine, used as a marker for protein catabolism, were measured at the start of surgery and 3 h later. Results: Glucose and insulin levels were significantly higher in patients who received a glucose load than in those who did not. Nonetheless, the levels of cortisol and catecholamines were unchanged during surgery. Similarly, the difference in the levels of markers for lipid as well as protein catabolism was not significant between the groups at 3 h after the start of surgery. Conclusions: Changes in lipid as well as protein catabolism were not altered by glucose load in diabetic patients under propofol-based anesthesia with remifentanil. Our study suggested that continuous infusion of propofol at a clinical dose is sufficient to reduce the requirement for glucose infusion during surgery in patients with diabetes.展开更多
It is known that the transonic resonance takes place, in divergent section of supersonic nozzle, similarly to the longitudinal acoustic resonance of a conical section with one end closed and the other end open. And t...It is known that the transonic resonance takes place, in divergent section of supersonic nozzle, similarly to the longitudinal acoustic resonance of a conical section with one end closed and the other end open. And the “conical section” is similar to the separation zone between shock wave and nozzle exit in divergent part of supersonic nozzle. The present paper describes an experimental work to investigate a reduction of transonic resonance by change the lip length of 2-Dimensional converging-diverging nozzle. In this study, the nozzle pressure ratio varied in the range between 1.4 and 2.2 as shock-containing flow conditions. And a Schlieren optical system was used to visualize the flow fields. Especially, by using a high-speed video camera, we obtained the shock position at that moment. And acoustic measurements were employed to compare the sound spectra level of each experimental case. And it was found that the transonic resonance was decreased when a large separation zone located at the side, where a nozzle-lip attached to nozzle exit additionally. In this case, the amplitude of shock oscillation and wall static pressure oscillation were also decreased.展开更多
文摘Purpose: Although rocuronium bromide (Rb) is suitable for continuous administration use, determination of optimal continuous doses is difficult due to individual differences. This study examines the efficacy of a continuous Rb administration method based on effect-site concentrations calculated by a pharmacokinetic/pharmacodynamics model during propofol, sevoflurane, and desflurane anesthesia. Methods: The 36 enrolled patients were equally divided into three groups (P;propofol, S;sevoflurane, and D;desflurane groups). After induction and administration of Rb 0.6 mg/kg, we calculated the simulated effect-site concentration at the point which the first twitch (%T1) recovered to > 0% and defined this as the Rb recovery concentration (Rbr.c.) level appropriate for continuous rocuronium administration. The continuous administration doses of Rb were adjusted to maintain Rbr.c. during surgery. The Rbr.c. and the recovery time at %T1 > 25% were recorded for each type of anesthesia. Results: Rbr.c. (μg/mL) for the P, S, and D groups were 1.54 ± 0.2, 1.24 ± 0.2, and 1.09 ± 0.2, respectively. Continuous administration doses (μg/kg/min) in the P, S, and D group were 6.7 ± 0.9, 5.2 ± 1.0, and 4.5 ± 0.8, respectively. Rbr.c. and continuous doses in the S and D groups were lower than the P group. Neuromuscular relaxations during surgery in the S and D groups were more strongly maintained than for the P group. There was also a significantly prolonged recovery duration for the %T1 > 25% in the D versus the other two groups (P < 0.05). Conclusion: Results showed that our continuous administration method was effective for maintaining sufficient muscle relaxation without excessively prolonged recovery effects for both sevoflurane and desflurane as well as propofol anesthesia.
文摘Background: General anesthesia using remifentanil may suppress the unwanted metabolic changes caused by surgical stress including hyperglycemia and ketogenesis. Surgery-related changes in catabolism can be attenuated with low-dose glucose load, without causing hyperglycemia. However, the impact of glucose load in diabetic patients during surgery is unknown. In this study, we investigated the effect of glucose load on catabolism during remifentanil-based anesthesia in patients with diabetes mellitus. Methods: Twenty-nine patients with diabetes mellitus undergoing elective surgery were randomly assigned to receive a glucose load (1.5 mg/kg/min) or not. Plasma levels of glucose, insulin, cortisol, dopamine, adrenaline, noradrenaline, acetoacetic acid, free fatty acid, ketone bodies, 3-hydroxybutyric acid, and 3-methylhistidine/creatinine, a marker of protein catabolism were measured at the start of surgery and 3 h after the start of surgery. Results: Glucose and insulin levels were significantly higher in patients who received a glucose load than in those who did not. Cortisol levels decreased at 3 h after the start of surgery in both groups whereas the levels of catecholamines were unchanged. Acetoacetic acid and total ketone body levels were significantly lower in patients given a glucose load than in those who were not 3 h after the start of surgery. The difference in the 3 methylhistidine/creatinine ratio between the two groups was not significant. Conclusions: The infusion of glucose suppressed lipid catabolism in diabetic patients under remifentanil-based anesthesia during surgery. Our study also suggests that in patients with diabetes mellitus, protein sparing is inhibited by remifentanil-based anesthesia, regardless of the glucose load. Trial registration: the University Hospital Medical Information Network identifier: UMIN000010914.
文摘Background: Perioperative exacerbation of hyperglycemia and insulin resistance is associated with increased complications in patients with diabetes mellitus. We recently reported that glucose load during anesthesia with sevoflurane suppressed lipid catabolism in diabetic patients. In contrast to inhaled anesthetics, propofol solution contains triglycerides, which can be an energy source during surgery. However, the clinical relevance of glucose load under propofol-based anesthesia in diabetic patients is unknown. Therefore, we investigated the effect of intraoperative glucose load on catabolism during propofol-based anesthesia in patients with diabetes mellitus. Methods: Twenty-three patients with diabetes mellitus undergoing elective surgery with propofol-remifentanil-based anesthesia were randomly assigned to receive a glucose load (1.5 mg/kg/ min) or not. Plasma levels of glucose, insulin, cortisol, catecholamines, acetoacetic acid, free fatty acids, ketone bodies, 3-hydroxybutyric acid, and 3-methylhistidine/creatinine, used as a marker for protein catabolism, were measured at the start of surgery and 3 h later. Results: Glucose and insulin levels were significantly higher in patients who received a glucose load than in those who did not. Nonetheless, the levels of cortisol and catecholamines were unchanged during surgery. Similarly, the difference in the levels of markers for lipid as well as protein catabolism was not significant between the groups at 3 h after the start of surgery. Conclusions: Changes in lipid as well as protein catabolism were not altered by glucose load in diabetic patients under propofol-based anesthesia with remifentanil. Our study suggested that continuous infusion of propofol at a clinical dose is sufficient to reduce the requirement for glucose infusion during surgery in patients with diabetes.
文摘It is known that the transonic resonance takes place, in divergent section of supersonic nozzle, similarly to the longitudinal acoustic resonance of a conical section with one end closed and the other end open. And the “conical section” is similar to the separation zone between shock wave and nozzle exit in divergent part of supersonic nozzle. The present paper describes an experimental work to investigate a reduction of transonic resonance by change the lip length of 2-Dimensional converging-diverging nozzle. In this study, the nozzle pressure ratio varied in the range between 1.4 and 2.2 as shock-containing flow conditions. And a Schlieren optical system was used to visualize the flow fields. Especially, by using a high-speed video camera, we obtained the shock position at that moment. And acoustic measurements were employed to compare the sound spectra level of each experimental case. And it was found that the transonic resonance was decreased when a large separation zone located at the side, where a nozzle-lip attached to nozzle exit additionally. In this case, the amplitude of shock oscillation and wall static pressure oscillation were also decreased.
