BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of low-flow anesthesia with a semi-closed circle anesthesia system in infants. METHODS: Twenty, ASA physical status 1 or 2, infants were randomly assigned into two groups: high-flow anesthesia (HFA) or low-flow anesthesia (LFA). An identical semi-closed Dr ger circle anesthesia system (Cato) was used to all patients. Initial fresh gas flow (FGF) was N2O 1.5 L/min and O2 1.5 L/min in both groups. This FGF of 3 L/min was maintained in the HFA group. After 10 min of HFA, the FGF was reduced to 500 ml/min (N2O 250 ml/min and O2 250 ml/min) in the LFA group. RESULTS: Hypoxic or hypercarbic gas concentrations were not observed in all patients. Enflurane consumption during LFA was about 1/3 of that during HFA (6.8 +/- 1.3 ml vs. 19.5 +/- 5.8 ml). The mean highest esophageal temperature was similar in both groups. The mean highest inspiratory gas and soda lime temperatures were significantly higher in the LFA group than in the HFA group. CONCLUSIONS: Low-flow anesthesia in a circle system with a fresh gas flow of N2O 250 ml/min and O2 250 ml/min could be performed safely and economically for infants.
Anesthesia* ; Enflurane* ; Humans ; Infant*

Enflurane* ; Metabolism* ; Methoxyflurane* ; Panax*

We chose enflurane as the primary anesthetic agent for the surgical removal of a pheochromocytoma (23 year old male) with the satisfactory results. A review of the literature on the anesthetic management of pheochromocytoma discloses no general agreement regarding choice of an anesthetic agent. Almost all agents have at some time been both praised and rejected. It would suggest that selection of an anesthetic agent is not as important as the adequate management of that agent.
Anesthesia* ; Enflurane* ; Pheochromocytoma*

Plasma inorganic fluoride concentrations were measured in adult patients without hepatic or renal disease following sevoflurane-N2O anesthesia (n=7) or enflurane-N2O anesthesia (n=6). The anesthetic dosage of sevoflurane and enflurane was 6.48+/-2,15%-hour and 6.57+/-2.05%-hour, respectively. The mean peak plasma inorganic fluoride concentration in the sevoflurane group was 19.5+/-13.4 umol/L 1hour after anesthesia, which decreased to preanesthetic levels 24 hours after anesthesia. In the enflurane group the values were 13.2+/-5.8 umol/L at the end of anesthesia and decreased, but remained, still twice as high as the preanesthetic level 24 hours after anesthesia. The relationship of plasma inorganic fluoride concentration and anesthetic dosage was more pronounced in the sevoflurane group (r=0.68, slope=4.2) than in the enflurane group (r=0.39, slope=1.2). In conclusian, sevoflurane-N2O anesthesia results in similar subnephrotoxic levels of plasma inorganic fluoride as enflurane-N2O. anesthesia, and although the fluoride concentration had a better correlation to anesthetic dosage in the sevoflurane group than in the enflurane group, its excretion was faster in the sevoflurane group than in the enflurane group.
Adult ; Anesthesia* ; Enflurane ; Fluorides* ; Humans ; Plasma*

BACKGROUND: Various aspects of immunological homeostasis are affected by anesthesia and surgery, including the function of immunocompetent cells and the modulation of stress responses. To evaluate immunologic changes that occurred following propofol and enflurane anesthesia, we evaluated the proliferative responsiveness of peripheral blood mononuclear cells (PBMC) in patients undergoing laparoscopic gynecologic surgery. METHODS: PBMC were isolated from patients prior to anesthesia and on the first postoperative day (n = 10). The proliferative response was then evaluated based on the level of 5-bromo-2-deoxyunridine (BrdU) incorporation that occurred during DNA synthesisafter the induction of mitogenic stimulation by treatment with 1 microgram/ml lipopolysaccharides (LPS). To accomplish this, cell proliferation was assayed by enzyme-linked immuno-sorbent assay (ELISA), after which a stimulation index was calculated. RESULTS: Although the calculated stimulation index decreased in response to both propofol and enflurane anesthesia, the stimulation index did not differ significantly between groups. However, following stimulation with LPS, the stimulation index was significantly higher in the enflurane group than in the propofol group (P < 0.05). CONCLUSIONS: Propofol and enflurane anesthesia inhibit the PBMC proliferation. However, the decrease in proliferation that occurred in response to enflurane was attenuated by LPS.
Anesthesia ; Bromodeoxyuridine ; Cell Proliferation ; DNA ; Enflurane ; Homeostasis ; Humans ; Lipopolysaccharides ; Propofol

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*

Various complications may arise during and after the general anesthesia. The anesthetic agents and techniques of anesthetic administration employed have the power to impair or abolish a variety of essential functions of body, in addition to bearing potentially serious risks to the major organ systems. Four pediatric patients, who were 2, 3, 6 and 8 years old in 1993, had received repeated general anesthesia 8, 19, 31 and 25 times respectively for laryngeal microsurgery since their infaneies. The mean intervals between anesthesia were 45, 103, 37 and 91 days and the mean durations of anesthetia were 79, 86, 73 and 78 minuites respectively. Enflurane was used most frequently without any remarkable complication except one episode of pneumonia. The hepatic enzymes increased transiently in two patiens but none was eonfirmed as hepatitis.
Anesthesia ; Anesthesia, General* ; Anesthetics ; Child ; Enflurane ; Hepatitis ; Humans ; Microsurgery ; Pneumonia

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

To evaluate the depth of enflurane anesthesia, spectrum analysis of rat EEG was used. Bipolar EEG was recorded through one lead form rat scalp during inhalation with 1,2,3 and 4% of enflurane, and analysed to produce the spectrum from which the density of each band(delta 1-3.25Hz, theta 3.5-7.75Hz, alpha 8-12.75Hz, beta2 18-20.75Hz, and beta3 21-31.75Hz)and total density, and medican power frequency were calculated. Differences among the EEG patterns, which were represented by F values through discriminant analysis of those 8 variables, in each level of anesthesia were significant among all concentrations except between 1% and 2% enflurane administration. The results suggest that the discriminat anlysis for the EEG parameters derived from power spectrum analysis can apply to determine the level of enflurane anesthesia.
Anesthesia ; Anesthetics* ; Animals ; Electroencephalography* ; Enflurane* ; Inhalation ; Rats* ; Scalp ; Spectrum Analysis*

Change in heart rate, mean arterial pressure, PaO2 and PaCO2 Caused by enflurane and halothane anesthesia were investigated in patients premedicated with diazepam and glycop-yrrolate. Enflurane caused a slightly(10.1%) increase in heart rate and not change in mean arter-ial pressure(0.1%), Halothane depressed heart slightly(10.16%) and arterial pressure was also (12.2%). The authors conclude that enflurane possesses a positive chronotropic effect.
Anesthesia* ; Arterial Pressure* ; Diazepam ; Enflurane* ; Halothane* ; Heart Rate* ; Heart* ; Humans