No abstract available.
Anesthetics, Inhalation* ; Inhalation*

No abstract available.
Anesthetics, Inhalation* ; Inhalation*

BACKGROUND: The bispectral index (BIS) has been designed to objectively measure the degree of sedation and hypnosis for anesthesia. Although it has been well-known that BIS correlates highly with the concentration of inhalation anesthetics, it is not clear whether analgesic potency expressed as MAC is comparable to hypnotic potency described as BIS50 in inhaled anesthetics. This study was conducted to examine the degree of correspondence by correlating the changes of BIS according to the different MAC of commonly used inhalation anesthetics. METHODS: One hundred ASA class 1 or 2 patients, scheduled for laparoscopic knee surgery were included. Patients were equally divided into 4 groups (n = 25 each) according to the inhalational agent enflurane, isoflurane, desflurane, or sevoflurane. Anesthetic depth for each individual agent was controlled to 2.0, 1.75, 1.5, 1.25, 1.0, 0.75 and 0.5 MAC, respectively. After equilibration for each concentration, BIS values were measured three times at 30 second intervals and an average was obtained. In addition, MAC values for each agent were measured when the bispectral index showed 50. RESULTS: The concentrations of inhaled agents vs. BIS showed high negative correlations (enflurane; -0.91, isoflurane; -0.94, desflurane; -0.84, and sevoflurane; -0.86). BIS50 for each agent was enflurane, 0.93 (1.6 vol%); isoflurane, 0.71 (0.9 vol%); desflurane, 0.95 (5.7 vol%); and sevoflurane, 0.84 MAC (1.7 vol%). Isoflurane-BIS50 showed a significant difference to the others (P<0.05). CONCLUSIONS: We concluded that the MAC of inhalation anesthetics showed poor correlation with BIS, suggesting a difference between the hypnotic and analgesic potency of individual inhaled anesthetic agents.
Anesthesia ; Anesthetics ; Anesthetics, Inhalation* ; Enflurane ; Humans ; Hypnosis ; Inhalation* ; Isoflurane ; Knee

One of the most popular types of vaporizer mounting sytems is Selectatec, as it possesses a simple detachment mechanism. Detachable units can loosen between the vaporizer and anesthetic machine, which can cause vapor leakage. A locking system was subsequently developed to prevent this issue; however, we report a case of an unexpected vapor leakage from a locked vaporizer.
Anesthesia ; Anesthetics ; Inhalation ; Nebulizers and Vaporizers

To evaluate the second gas effect and the effect of solubility of volatile anesthetics on the alveolar concentration, the ratio of the end-tidal to the inspired concentration(FET/F1) of enflurane and isoflurane with or without N2O were measured in 40 adult patients in ASA class I or Il. The patients were devided into four groups ; group 1 received 100% O2-1 vol% enflurane, group 2 received 50% O2-50% N2O-1 vol % enflurane, group 3 received 100 % O2-1 vo1% isoflurane and group 4 received 50% 0 50% N2O-1 vo1% isoflurane. The ratio of FET/F1 were measured at 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 30 minute after administration of inhalation anesthetics in each group. The results were as follows. 1) The increase in FET/F1, compared with previous value in each group was significant at 2 minute in group 1 and 2(p<0.05), and at 2 minute and 3 minute in group 3 and 4(p< 0.05), respectively. 2) To compare between group 1 and 2, the significant differance of FET/F1 was noticed during entire observation period and between group 3 and 4, too(p<0.05). This is the result of the second gas effect. 3) The FET/F1 ratio of isoflurane which has lower blood solubility rised more rapidly than the FET/F1 ratio of enflurane. When given without NO, the FET/F1 ratio of group 3 rised significantly more rapidly than the FET/F1 ratio of group 1(p<0.05). But, when given with N2O, changes of the FET/F1 ratio were not significantly different between group 2 and 4. In this study, the alveolar concentration of enflurane and isoflurane rised more rapidly when given with 50% N2O than when given without N2O, it might be the second gas effect by the uptake of NO. And, to the exclusion of the second gas effect, the FET/F1 ratio of less soluble isoflurane rised more rapidly than the more soluble enflurane. But, under the presence of the second gas effect, the difference of the alveolar concentration which depends on the anesthetic solubility between enflurane and isoflurane was not significant.
Adult ; Anesthetics* ; Anesthetics, Inhalation ; Enflurane ; Humans ; Isoflurane ; Solubility*

Since Steven(1971) introduced the cardiovascular effects of isoflurane many characteristics of isoflurane were reported. Among many advantages of isoflurane its limited metabolism in the body results least effect on the liver. In order to compare the effects isoflurane and halothane on liver function in five each gynecologic patient with normal liver function test(LFT), we checked liver function preoperatively as control and postoperative 7th day as experiment. We also studied the effects of isoflurane on liver function in patients with abnormal LFT. The results were as follows: First, there were no difference on the effect of LFT between halothane and isoflurane in patient with preoperatively normal LFT. Second, inhalation of isoflurane in patient with abnormal LFT does not seem to worsen liver function furthermore.
Anesthetics ; Halothane ; Humans ; Inhalation ; Isoflurane* ; Liver* ; Metabolism

A male patient of 26 years old was received with multiple fracture by tranffic accident. Anesthesia was maintained with inhalation of isoflurance. Malignant hyperthermia (MH) was appeared after operation. The patient rehabilited after physical cooling, bedside persistence hematodialysis, hormone application and so on.
Anesthetics, Inhalation ; Humans ; Male ; Malignant Hyperthermia

Objective To study the influence of halogenated hydroxyl-alkanes inhalation anesthetic on the determination of ethanol content in blood. Methods Halogenated hydroxyl-alkanes were analyzed by headspace gas chromatography with double column confirmatory detection method. The influence of halogenated hydroxyl-alkanes on determination of ethanol content in blood sample by headspace gas chromatography was explored under the different detection conditions of KB-BAC1/ KB-BAC2 and J&W DB-ALC1/DB-ALC2 gas chromatographic column. Results The retention time of sevoflurane and enflurane was similar to that of ethanol and tert butanol respectively when using the J&W DB-ALC1/DB-ALC2 gas chromatographic column, and interfered with the detection of ethanol content in blood; only J&W DB-ALC1 gas chromatographic column can separate the sevoflurane and ethanol components, so as to eliminate their influence on the detection of ethanol content in blood. When using KB-BAC1/KB-BAC2 gas chromatographic column, the retention time of sevoflurane, isoflurane and ethanol is similar, especially that of sevoflurane and ethanol, and sevoflurane obviously interferes with the determination of ethanol content in blood. Conclusion Halogenated hydroxy-alkanes interfere with determination of ethanol content in blood by headspace gas chromatography. The interference can be discriminated effectively by choosing the suitable chromatographic column and double column confirmatory detection.
Alkanes ; Anesthetics, Inhalation ; Ethanol ; Isoflurane ; Sevoflurane

There is some controversy regarding the effect of general inhalation anesthesia on platelet function. In 20 patients undergoing long operations over 3 hours, and anesthetized with either nitrous oxide-oxygen and enflurane (A group) or nitrous oxide-oxygen and halothane (B group), we could not find any clinically significant impairment of coagulation. Platelet functions were consecutively evaluated on the samples collected at preinduction, during anesthesia (3 hours) and at postoperation (24 hours) using an aggregometer and several aggregating agents including ADP, epinephrine, collagen and ristocetin. There were no statistically significant changes between the maximum aggregation rate of preinduction and that duirng anesthesia in either group.
Adenosine Diphosphate ; Anesthesia ; Anesthesia, Inhalation ; Anesthetics, Inhalation* ; Blood Platelets* ; Collagen ; Enflurane ; Epinephrine ; Halothane ; Humans ; Inhalation* ; Ristocetin

Any factor which increases rebreathing (such as a decrease in inflow rate or an increase in ventilation) or increase uptake (such as an increase in solubility or in cardiac output) will lower the inspired anesthetic concentration. This in turn, will be reflected in an slower rate of anesthesia induction. In a circle absorption system, the inspired anesthetic concentration may be reduced from the inflowing concentration by rebreathing of anesthetic depleted gas. Semiclosed system, most widely used modern anesthetic system was tested to determine what effect the inflow rate had on the rate of rise of anesthetizing alveolar concentration of halothane and enflurane. The results were as follows: 1) High fresh gas inflow rate put the inspired anesthetic concentration close to that of inflow more rapidly. 2) In halothane anesthesia with 4 and 6 L/min of fresh gas flow, the anesthesia induction time was about 20 and 15 minutes respectively. But there was marked delay of the development of anesthesia by 2 L/min of fresh gas fiow. 3) In enflurane anesthesia, the anesthesia induction time was within about 10 minutes without respect to inflow rate. With these results, in general inhalation anesthesia with halothane or enflurane when a semiclosed technique and 100% oxygen are employed, a total gas flow at 4 to 6L per minute is recommended to establish a satisfactory induction and maintenance level of anesthesia.
Absorption ; Anesthesia ; Anesthesia, Inhalation ; Anesthetics, Inhalation* ; Enflurane ; Halothane ; Inhalation* ; Oxygen ; Solubility