Arterial blood and end-tidal concentrations of sevoflurane during the emergence from anesthesia in gynecologic patients

OBJECTIVE: The end-tidal concentration of inhalation anesthetics is a clinical indicator for predicting the emergence from anesthesia. This study was conducted to assess the relationship between arterial blood and end-tidal sevoflurane concentrations during emergence. METHODS: Thirty-two female American Society of Anesthesiologists physical status I-II patients receiving general anesthesia for elective gynecologic surgery were included. A fixed dose of 3.5% inspiratory sevoflurane in 6 L min-1 oxygen was maintained until the end of surgery. At 20 and 10 minutes before and 0, 5, 10, 15, and 20 minutes after discontinuing sevoflurane, as well as at the time of eye opening by verbal command, defined as awakening, 1 ml arterial blood was obtained to measure its sevoflurane concentration by gas chromatography. Simultaneous inspiratory and end-tidal concentrations of sevoflurane were detected by an infrared analyzer and tested by Bland-Altman agreement analysis. RESULTS: The arterial blood concentrations of sevoflurane were similar to the simultaneous end-tidal concentrations during emergence: 0.36% (0.10) and 0.36% (0.08) sevoflurane at awakening, respectively. The mean time from discontinuing sevoflurane to eye opening was 15.8 minutes (SD 2.9, range 10-26) and was significantly correlated with the duration of anesthesia (52-192 minutes) (P = 0.006) but not with the body mass index or total fentanyl dose. CONCLUSION: The mean awakening arterial blood concentration of sevoflurane was 0.36%. The time to awakening was prolonged in accordance with the anesthetic duration within 3 hours. With well-assisted ventilation during emergence, the sevoflurane end-tidal concentration was nearly equal to its arterial blood concentration, which could be a feasible predictor for awakening. .

Effects of inhalation anesthesia with low-flow sevoflurane on renal function of neonates / 中华麻醉学杂志

Objective To evaluate the effects of inhalation anesthesia with low-flow sevoflurane on the renal function of neonates.Methods Forty ASA physical status Ⅰ or Ⅱ neonates undergoing abdominal surgery under general anesthesia,aged 6-28 days,weighing 1730-2928 g,were included in the study.After induction of anesthesia,anesthesia was maintained with sevoflurane inhalation using a semi-closed circuit system (FGF 1 L/min).The end-tidal concentration of sevoflurane was maintained at 2.5％-4.0％ according to the vital signs.Before induction of anesthesia,immediately after operation,and at 24,48 and 72 h after operation,blood samples from the peripheral vein and urine specimens were taken for determination of serum concentrations of creatinine (Cr),blood urea nitrogen (BUN),urinary retinol binding protein (RBP) and β-N-acetyl-glucosaminidase (NAG).A temperature probe was inserted to the center of soda lime canister.Results Compared with the baseline value at T0,no significant changes were found in the serum Cr and BUN concentrations at T1-4,urinary RBP concentrations were increased at T1,no significant changes were found in urinary RBP concentrations at T2-4,NAG concentrations were significantly increased at T2 and no significant changes were found in NAG concentrations at T1,3,4.The temperature of soda lime was (37 ± 3) ℃ at the end of operation.Conclusion Inhalation anesthesia with low-flow sevoflurane (FGF 1 L/min) produces no significant effect on the renal function of neonates.

The neuroprotective effect of combining sevoflurane and remote ischemic preconditioning in forebrain ischemia model

BACKGROUND: The aim of this study was to investigate the combining effects of sevoflurane and remote ischemic preconditioning (RIPC) on cell death of pyramidal neurons in the CA1 hippocampus induced by transient global cerebral ischemia in rats. METHODS: Twenty rats were assigned to one of two groups; sevoflurane group and combination of sevoflurane and RIPC group. RIPC was performed by occluding the bilateral femoral arteries for 10 min 3 times in an interval of 10 min. Ischemia was induced by a bilateral common carotid artery occlusion plus hemorrhagic hypotension (26-30 mmHg) and was maintained for 8 min. Histologic outcomes were measured at 7 days after ischemia in CA1 pyramidal cells of the rat hippocampus. RESULTS: The combination group contained significantly more viable cells in the hippocampal CA1 area than sevoflurane group (71% vs. 46%, P = 0.03). The mean percentage of apoptotic cells was significantly reduced in the combination group compared to sevoflurane group (11% vs. 41%, P = 0.014). CONCLUSIONS: A combination of sevoflurane and RIPC can offer additional neuroprotective effects after transient global cerebral ischemia in rats.

Age-related requisite concentration of sevoflurane for adequate sedation with combined epidural-general anesthesia / 대한마취과학회지

BACKGROUND: The requisite anesthetic concentration of sevoflurane required to obtain adequate sedation when sufficient analgesics are supplied has not been determined. The purpose of this study was to determine the requisite age-associated concentration of sevoflurane to obtain an adequate level of anesthesia during combined epidural-general anesthesia by bispectral index (BIS) monitoring. METHODS: Twenty-seven elective abdominal surgery patients (American Society of Anesthesiologists physical status I-II) were enrolled. The patients were divided into two groups of more or less than 60 years of age. We investigated the concentration of sevoflurane required to obtain an adequate sedation level during combined epidural-general anesthesia, maintaining the BIS value between 40 and 60. RESULTS: The requisite sevoflurane concentration required to keep the BIS value at 40-60 was not stable during surgery. In the younger group, the maximum concentration of sevoflurane needed during surgery was 1.95 +/- 0.14 (95% confidence interval: 1.87-2.10) vol%, while it was 1.54 +/- 0.44 (95% confidence interval: 1.27-1.80) vol% in the older group (P < 0.01). CONCLUSIONS: The requisite concentration of sevoflurane required with combined epidural-general anesthesia was 2.5 vol% for the younger group and 2.0 vol% for the older group as determined by BIS monitoring. We believe that these percentages are sufficient to avoid awareness during surgery with adequate analgesia.

Effects of sevoflurane on neuronal cell damage after severe cerebral ischemia in rats / 대한마취과학회지

BACKGROUND: The aim of this study was to investigate the neuroprotective effects of sevoflurane after severe forebrain ischemic injury. We also examined the relationship between the duration of ischemia and neuronal cell death. METHODS: Male Sprague-Dawley rats (300-380 g) were subjected to 6 (each n = 6) or 10 min (each n = 10) of near-complete forebrain ischemia while anesthetized with either 50 mg/kg of zoletil given intraperitoneally or inhaled sevoflurane (2.3%). Ischemia was induced by bilateral common carotid artery occlusion plus hemorrhagic hypotension (26-30 mmHg). Histologic outcomes were measured 7 days after ischemia in CA1 pyramidal cells of the rat hippocampus. RESULTS: The mean percentage of necrotic cells in the hippocampal CA1 area decreased in the sevoflurane group compared to the zoletil group (25% vs. 40% after 6 min ischemia, respectively: P = 0.004 and 44% vs. 54% after 10 min of ischemia, respectively P = 0.03). The percentage of apoptotic cells was similar in all groups. The percentage of necrotic cells in each anesthetic groups was significantly higher in the 10 min ischemia group compared to the 6 min ischemia group (P = 0.004 in the sevoflurane group, P = 0.03 in the zoletil group). CONCLUSIONS: The present data show that sevoflurane has neuroprotective effects in rats subjected to near-complete cerebral ischemia. Longer duration of ischemia is associated with more neuronal injury when compared to ischemia of shorter duration.

Effect of sevoflurane preconditioning on TREK-1 channel expression in hippocampus after focal cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

Objective To investigate the effect of sevoflurane preconditioning on TREK-1 channel expression in hippocampus after focal cerebral ischemia-reperfusion (I/R)in rats and the mechanism.Methods Thirty-six male SD rats weighing 240-280 g were randomly divided into 3 groups(n=12 each):group Ⅰ sham operation (group S),group Ⅱ I/R and group Ⅲ sevoflurane preconditioning (group Sevo).Focal cerebral ischemia was produced by inserting a 4-0 nylon thread with rounded tip into right internal jugular vein.The nylon thread was the nylon thread Wag about 18-20 Innl.The right middle cerebral artery(MCA)Wag occluded for 2 h and then released for 24 h reperfusion.The Sevo group inhaled 2.4% sevoflurane for 30 min at l h before ischemia.Neurological deftcits were assessed and scored at the end of 24 h reperfusion (the higher was the score,the severer was the deficit).The cerebral infarct size was determined by TTC staining and the TREK-1 mRNA in hippocampus by RT-PCR.Results The cerebral infarct size was significantly smaller and the neurological deficit scores were significantly lower in Sevo group than in I/R group.The TREK-1 mBNA expression was significantly up-regulated in Sevo group as compared with I/R group.Conclusion Sevoflurane preconditioning Can protect the brain against I/R injury by activating TREK-1 in hippocampus.

Efeito da umidificação dos gases anestésicos nas propriedades físicas e transportabilidade do muco respiratório durante anestesia geral / Effects of inspired gases humidity on respiratory mucus in patients under general anesthesia

Introdução: Em pacientes sob intubação endotraqueal os mecanismos fisiológicos de climatização do ar inspirado são anulados. Durante anestesia geral, quando os gases inspiratórios são ofertados secos e frios, a manutenção da umidade das vias aéreas é condição importante para prevenção de lesões da mucosa respiratória e ressecamento das secreções. Os sistemas de anestesia possuem propriedades de umidicação inerentes, decorrentes do sistema respiratório circular e a presença do absorvedor de CO2. Entretanto, os níveis de umidificação, durante a anestesia, dependem de vários fatores incluindo o tipo de ventilador anestésico, montagem do sistema respiratório e o fluxo de gás fresco utilizado. Porém não há dados na literatura que tenham investigado o efeito nos níveis de umidade do gás inspirado nas propriedades físicas e de transportabilidade do muco respiratório. Objetivo: Avaliar os níveis de Temperatura (T), umidade absoluta (UA) e umidade relativa (UR) do ar inspirado durante anestesia geral oferecidos pelo sistema circular valvular com absorção de CO2 e com a adição do HME em dois tipos de ventiladores (Drãger e Takaoka). Avaliar os efeitos do HME sobre os níveis de Temperatura e Umidade dos gases inspirados ofertados pelos dois equipamentos. Avaliar o impacto da umidade sobre as propriedades físicas e de transportabilidade do muco respiratório. Método: Foram selecionados 44 pacientes da Clínica Cirúrgica II do Departamento de Gastroenterologia do HCFMUSP com indicação de cirurgia abdominal eletiva e anestesia geral com duração superior a 4 horas. Os pacientes foram alocados em 4 grupos conforme o tipo do ventilador utilizado (Drãger ou Takaoka) e a presença ou ausência do HME. O muco respiratório e os dados de temperatura, UR e UA do gás ofertado foram coletados logo após a intubação endotraqueal, e a cada duas horas até o final da cirurgia. A análise do muco respiratório foi realizada através dos seguintes métodos: Transportabilidade mucociliar (MCT)...

Background: In patients who are intubated, the natural mechanism of gas climatization by the nose and the upper airway is bypassed. During anesthesia, when the inspiratory gases are cold and dry, humidification of gases is recommended to prevent drying of the mucosal epithelium and respiratory secretions. The anesthesia systems have inherent humidifying properties as a result of the valvular rebreathing of some of the expired humidity and of the production of water in the CO2 absorber. However, the level of moisture in anesthetic ventilation is critically dependent on several factors that include the equipment, the arrangement of the circle breathing system and the fresh gas flow. To date the effect of humidity on respiratory mucus properties and transportability was not investigated. Objectives: The objective of this study was to measure the humidity and temperature of the inspired gas from a circle absorber system in two different ventilators (Drãger and Takaoka) and the effect of a heat and moisture exchanger (HME) on the inspired gas. Furthermore, we also evaluated the impact of humidity on in vitro mucus transportability and physical properties. Methods: We studied 44 patients with no pulmonary disease scheduled for elective surgery that were randomly allocated in four groups according to the anesthetic equipment (Drãger or Takaoka) and the absence or presence of HME. Respiratory mucus was collected and Temperature (T), absolute humidity (AH), relative humidity (RH) of inspired gases were recorded immediately after intubation (T0) and every 2 hours. In vitro respiratory mucus was studied by mucociliary transportability (MCT) by the frog palate method; cough clearance (CC) by the cough equipment, and contact angle (CA) by direct observation. Results: Drãger equipment delivered significantly higher levels of RH and AH when compared to Takaoka. The addition of HME increased AH and T in both equipments. RH was improved only in the Takaoka equipment...

The Effects of Anesthetic Preconditioning on Neurologic Injury and Bcl-2 Family Protein mRNA Expression after Transient Spinal Ischemia in the Rat / 대한마취과학회지

BACKGROUND: Spinal cord ischemic injury occurring after surgical repair of thoracoabdominal aortic disease leaves a devastating complication. The purpose of this study was to evaluate the effects of anesthetic preconditioning on neurologic outcome and Bcl-2 family protein gene expression in transient spinal ischemia. METHODS: In first experiment rats were divided by 4 groups and anesthetized with intraperitoneal propofol, enflurane, sevoflurane, or isoflurane. In second experiment, all rats were anesthetized with intraperitoneal propofol and enflurane, sevoflurane, isoflurane were given during 30 minutes and 14 minutes of spinal ischemia was induced 30 minutes later. Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. Neurologic scores were assessed 1, 3, 24, 48 hours after transient spinal ischemia. After 48 hours, rats were killed under anesthesia and spinal cords were removed for the assay of Bcl-2 family protein mRNA expression. RESULTS: The neurologic injury of S and I group were significantly lesser than P group. 30 minutes of anesthetic preconditioning with enflurane, sevoflurane, and isoflurane showed significantly better neurologic outcome compared to propofol, enflurane, sevoflurane, or isoflurane anesthetized rats. Bcl-2 family protein mRNA expression of I group and IP group were lesser than the other groups. CONCLUSIONS: Anesthetic preconditioning with volatile anesthetics for 30 minutes could reduce ischemic injury during transient spinal ischemia. The degree of neurologic injury may not be related to the expression of pro-apoptotic protein Bax. Isoflurane may have different influence on apoptosis after spinal ischemia compared to enflurane or sevoflurane.

The Effects of Anesthetic Preconditioning on Neurologic Injury and Bcl-2 Family Protein mRNA Expression after Transient Spinal Ischemia in the Rat / 대한마취과학회지

BACKGROUND: Spinal cord ischemic injury occurring after surgical repair of thoracoabdominal aortic disease leaves a devastating complication. The purpose of this study was to evaluate the effects of anesthetic preconditioning on neurologic outcome and Bcl-2 family protein gene expression in transient spinal ischemia. METHODS: In first experiment rats were divided by 4 groups and anesthetized with intraperitoneal propofol, enflurane, sevoflurane, or isoflurane. In second experiment, all rats were anesthetized with intraperitoneal propofol and enflurane, sevoflurane, isoflurane were given during 30 minutes and 14 minutes of spinal ischemia was induced 30 minutes later. Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. Neurologic scores were assessed 1, 3, 24, 48 hours after transient spinal ischemia. After 48 hours, rats were killed under anesthesia and spinal cords were removed for the assay of Bcl-2 family protein mRNA expression. RESULTS: The neurologic injury of S and I group were significantly lesser than P group. 30 minutes of anesthetic preconditioning with enflurane, sevoflurane, and isoflurane showed significantly better neurologic outcome compared to propofol, enflurane, sevoflurane, or isoflurane anesthetized rats. Bcl-2 family protein mRNA expression of I group and IP group were lesser than the other groups. CONCLUSIONS: Anesthetic preconditioning with volatile anesthetics for 30 minutes could reduce ischemic injury during transient spinal ischemia. The degree of neurologic injury may not be related to the expression of pro-apoptotic protein Bax. Isoflurane may have different influence on apoptosis after spinal ischemia compared to enflurane or sevoflurane.

Effects of intrathecal injection of NMDA on the analgesia of inhalation anesthetics / 中国药理学通报

0.05);in contrast, intrathecal NMDA 2.5,5,10 ng could significantly and dose dependently decrease the HPPT(P

The Comparison of Anesthetic Agents and Adjuvants between University Hospitals, General Hospitals and Hospitals / 대한마취과학회지

BACKGROUND: This study was performed to compare anesthetic agents and adjuvants for general anesthesia or regional anesthesia between university hospitals, resident-training general hospitals and hospitals without training program of residents. METHODS: We surveyed university hospitals, resident-training hospitals and hospitals without training program of residents and divided randomly each hospital groups to become twenty hospitals. We compared the use frequency of inhalation anesthetics, muscle relaxants, induction agents, reversing agents, local anesthetics, premedicants, cardiovascular drugs and plasma expanders. RESULTS: Enflurane was most commonly used inhalation anesthetic in all hospital groups. Isoflurane was less commonly used inhalation anesthetic in hospitals without training program of residents. Pancuronium was most commonly used muscle relaxant in university hospitals. Midazolam, ketamine, fentanyl, propofol were commonly used induction agents during induction in university hospitals and resident-training general hospitals. Differences of use frequency of local anesthetics among hospital groups were not significant, but epinephrine mixing with local anesthetics was more frequent in university hospitals and resident-training general hospitals. Midazolam as a premedicant and norepinephrine, phenylephrine, amrinone, esmolol, pentastarch were less used in hospitals without training program of residents. CONCLUSIONS: These results suggest that university hospitals and resident-training general hospitals didn't show difference in anesthestics or adjuvants but hospitals without training program of residents used less commonly isoflurane, atracurium, midazolam, ketamine, propofol, fentanyl, cardiovascular drugs and pentastarch.

Effects of Volatile Anesthetics on Isolated Rings of Thoracic Aorta in Rats / 대한마취과학회지

Halothane, enflurane, and isoflurane are generally regarded as vasodilators. This property has been attributed to a direct action on vascular smooth muscle or the inhibition of vasoconstricition by endogenous neurohumoral substances. Because of the importance of the endothelium in determining of modulating the vascular responses of a wide vareity of agents, vascular effects of halothane, enflurane and isoflaurane on isolated rings of thoracic aorta in Sprague-Dawley rats were studied in the presence and absence of intact endothelium. Halothane, enflurane and isoflurane induced relaxation on thoraeic aortic rings precan-tracted with 50mM KCl both with and without endothelium. Halothane also induced vasodilation in both aortic rings precontracted with 10-6 M phenylephrine. And enflurane and isoflurane induced vasodilation in denuded aortic rings precontracted with phenylephrine. But endothelium intact rings demonstrsted significant(p<0.05) vasoconstriction at low concentrations of both enflurane and isoflurane followed by vasodilation at higher concentra- tion precontracted with phenyephrine. These results suggest that at low concentration and intact rings, enflurane and isoflurane eause vasoconstriction through inhibition of basal EDRF production and /or stimulation of the release of an endothelium derived constricting factor. At higher concentration, a direct vasodilating effect of the anesthetic predominance.

The Effects of Inhalation Anesthetics on the Memory of Rats / 대한마취과학회지

The effect of inhalation anesthetics on memory was studied using 26 male Sprague-Dawley rats. In the control group the trained rats were tested the first performance time of T-maze and left them to anesthetic chamber for 120min. and checked second performance time 24hours later (Group A). For the experimental group the first performance time was tested and animals were exposed to the anesthetics (1% Halothane with N20:02=2:1) for 120min. and checked second performance time 24hours after cessation of exposure to evaluate retrograde amnesia (Group B). For the test of anterograde amnesia (Group C) rats were anesthetized before test the first performance time and checked second performance time 24hours later. The mean perfor- mance ratio (II/I) (i.e., I is the score in the first performance time and II is the score in the second performance time) was compared between anesthetized and non-anesthetized control group. In the group A the ratio was 102.8+/-19 but in group B it was 96.4+/-13 during anesthesia, 79.+/-19 after anesthesia and 92.3+/-11 in overaU anesthetized group, and was 100.2+/-17 in group C. All data of group B were significantly different with group A (p<0.01). But no statistical difference between group C and A was observed (p=0.174). These results suggest that post- training exposure to volatile anesthetics facilitates memory and no anterograde amnesia observed by pretraining exposure. These may be volatile anesthetics facilitate memory by enhancement of memory consolidation and/or retention or interference reduction.

The Neuromuscular Effects of Isoflurane and Enflurane on the Vecuronium - induced Neuromuscular Blockade / 대한마취과학회지

Enflurane, and isoflurane potentiated for the vecuronium-induced neuromuscular blokade in a study of 30 patients anesthetized with 1.0 or 1.5 MAC enflurane, and isoflurane or ketaminefentanyl. In the patients anesthetized with 1.0 MAC isoflurane or enflurane, 50% nitous oxide was administrated simultaneously. The median effective dose of vecuronium m the ketamine-fentanyl anesthesia patients(34,0+/-1.2 ug/kg) was higher than that in the 1.0 and 1.5 MAC enflurane or isoflurane patients(2l.2+/-3.2 and 19.4+/-2.7, or 17.8+/-4.5 and 20.0+/-5.3 ug/kg, respectively). There is no significant difference in ED 50 and ED 95 between 1.0 and 1.5 MAC with enflurane or isoflurane. The duration in patients with enflurane was longer than that in the other groups. But, there is no difference in recovery indices among all the groups. The authors conclude that enflurane or isoflurane potentiantes the vecuronium-induced neuromuscular blockade comparing with ketamine-fentanyl anesthesia. Enflurane prolongs the duration of vecuronium in contrast to isoflurane. But, there is no significant difference between 1.0 and 1.5 MAC in same anesthetic considered usually as clinical anesthetic depth.

The Effect of Enflurane Anesthesia on HBsAg Positive Patient / 대한마취과학회지

It is well known that halogenated anesthetics have been mainly used for inhalation anesthesia these days. However many controversies still exist concerning hepatic cellular damage after halothane anesthesia. Although several articles have been issued concerning the effects of halogenated anesthetics for hepatitis B surface antigen positive patients, a study of frequent research and strict case collections is meaningful. The authors observed the effects of enflurane anesthesia on 15 HBsAg positive patients who had not recognized themselves whether they had hepatitis symptoms or were carriers. During the period of study, all groups(enflurane study group and enflurane and halothane control groups) did not experience any difficulty with the anesthesia, blood transfusion, and jaundice, etc. The comparative data of liver function tests did not show great differences during the convalescent period. According to this and other recent studies, we can positively conclude that halogenated anesthetics, especially enflurane, may favorably be used to administer HBsAg positive patients, unless any undesirable problems related to anesthesia exist.

Effects of strychnine-sensitive glycine receptor on the hypnotic and analgesic effects of inhalation anesthetics / 中国药理学通报

0.05); in hot-plate test , strychnine at 0.1,0.2,0.4 ?g (it) can significantly and dose dependently decrease the HPPI of the mice treated with aether,enflurane and sevoflurane (P0.05), but at 0.2,0.4 ?g (it) could significantly decrease the HPPI of mice treated with isoflurane(P