• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.139-144
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• 2013

Objective : Transient anterograde amnesia is occasionally observed in a number of conditions, including migraine, focal ischemia, venous flow abnormalities, and after general anesthesia. The inhalation anesthetic, isoflurane, is known to induce transient anterograde amnesia. We examined the involvement of brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB) in the underlying mechanisms of the isoflurane-induced transient anterograde amnesia. Methods : Adult male Sprague-Dawley rats were divided into three groups : the control group, the 10 minutes after recovery from isoflurane anesthesia group, and the 2 hours after recovery from isoflurane anesthesia group (n=8 in each group). The rats in the isoflurane-exposed groups were anesthetized with 1.2% isoflurane in 75% nitrous oxide and 25% oxygen for 2 hours in a Plexiglas anesthetizing chamber. Short-term memory was determined using the step-down avoidance task. BDNF and TrkB expressions in the hippocampus were evaluated by immunofluorescence staining and western blot analysis. Results : Latency in the step-down avoidance task was decreased 10 minutes after recovery from isoflurane anesthesia, whereas it recovered to the control level 2 hours after isoflurane anesthesia. The expressions of BDNF and TrkB in the hippocampus were decreased immediately after isoflurane anesthesia but were increased 2 hours after isoflurane anesthesia. Conclusion : In this study, isoflurane anesthesia induced transient anterograde amnesia, and the expressions of BDNF and TrkB in the hippocampus might be involved in the underlying mechanisms of this transient anterograde amnesia.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.4
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• pp.344-348
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• 2001

Isoflurane and enflurane are currently used on orthognathic surgery in Korea. Since starting to use enflurane and isoflurane in orthognathic surgery, we have questioned their effect on liver function. Many studies have reported liver function after enflurane and isoflurane anesthesia. Although both enflurane and isoflurane are less hepatotoxic than halothane, some cases of liver dysfunction have been reported after enflurane and isoflurane anesthesia. And, we know that isoflurane is less hepatotoxic than its predecessors, enflurane. But, fulminant liver failure and necrosis were also reported after isoflurane anesthesia. The purpose of this study was to compare immediate liver function in healthy orthognathic surgical patients receiving enflurane or isoflurane anesthesia. To assess the effect of enflurane and isoflurane on liver function, we measured pre-and post-operative serum concentrations of aspartate aminotransferase(AST), and alanine aminotransferase(ALT), alkaline phosphatase(ALP), total bilirubin(Tbil).

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.291-297
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• 2010

The sleep homeostatic response significantly affects the state of anesthesia. In addition, sleep recovery may occur during anesthesia, either via a natural sleep-like process to occur or via a direct restorative effect. Little is known about the effects of isoflurane anesthesia on sleep homeostasis. We investigated whether 1) isoflurane anesthesia could provide a sleep-like process, and 2) the depth of anesthesia could differently affect the post-anesthesia sleep response. Nine rats were treated for 2 hours with $ad$ $libitum$ sleep (Control), sleep deprivation (SD), and isoflurane anesthesia with delta-wave- predominant state (ISO-1) or burst suppression pattern-predominant state (ISO-2) with at least a 1-week interval. Electroencephalogram and electromyogram were recorded and sleep-wake architecture was evaluated for 4 hours after each treatment. In the post-treatment period, the duration of transition to slow-wave-sleep decreased but slow wave sleep (SWS) increased in the SD group, but no sleep stages were significantly changed in ISO-1 and ISO-2 groups compared to Control. Different levels of anesthesia did not significantly affect the post-anesthesia sleep responses, but the deep level of anesthesia significantly delayed the latency to sleep compared to Control. The present results indicate that a natural sleep-like process likely occurs during isoflurane anesthesia and that the post-anesthesia sleep response occurs irrespective to the level of anesthesia.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.148-153
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• 2015

This study was performed to compare two opioid drugs with isoflurane and to determine the difference between isoflurane/remifentanil anesthesia and isoflurane/fentanyl anesthesia in terms of the anesthetic effects in beagle dogs. Isoflurane was maintained at 0.5 MAC, and the opioid drug was administered as a constant rate infusion. The anesthesia was maintained for 2 hours, and isoflurane and opioid drugs were discontinued 2 hours later. After discontinuing the anesthetics, the extremity movement time, eye global positioning time, gag reflex time, head up time, sternal recumbency time, standing time, walking time and complete recovery times were recorded for each dog. Both of the studied anesthetic protocols were suitable in beagle dogs because the anesthetic status was well maintained until the end of the procedure, and rapid recovery times were demonstrated in this experiment. And this study shows that the isoflurane/remifentanil group was more reliable than the isoflurane/fentanyl group because the recovery time CV was lower. Therefore, isoflurane/remifentanil combination anesthesia could be a better choice than isoflurane/fentanyl anesthesia if the patient is severely ill and stable recovery time is needed.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.119-123
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• 2012

The present study evaluated the effects of different anesthesia techniques on oxidative stress in beagle dogs. Ten dogs were randomly assigned to either total intramuscular anesthesia with medetomidine-tiletamine/zolazepam (MTZ) combination (group T, 40 ${\mu}g/kg$ medetomidine and 2 mg/kg tiletamine/zolazepam) or volatile anesthesia with isoflurane (group I, 2% isoflurane and 100% oxygen). Heart rate, respiratory rate, and rectal temperature for vital signs and the concentration of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) for oxidative stress were measured. SOD activity decreased significantly from baseline anesthesia in both groups ($p$ < 0.05). CAT and GPx activities were also decreased significantly after anesthesia between both groups ($p$ < 0.05). CAT activity decreased significantly from baseline after anesthesia in both groups, but activities of group I were significantly higher compared with group T after anesthesia ($p$ < 0.05). GPx activity in group T decreased significantly from baseline after anesthesia, but activities of group I were significantly higher compare with that of group T 1 hour after the conclusion of anesthesia ($p$ < 0.05). In conclusion, general anesthesia seems to induce oxidative stress, and volatile anesthesia with isoflurane attenuates oxidative injuries in beagle dogs.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.259-263
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• 2005

To compare cardiopulmonary effects and recovery between total intravenous anesthesia (TIVA) with propofol (PRO group, n=5) and volatile induction/maintenance anesthesia (VIMA) with isoflurane (ISO group, n=5), we investigated changes of heart rate, $SpO_2$, arterial pressure, rectal temperature and respiratory rate during 60 minute anesthesia and 40 minute recovery period in beagle dogs, and investigated recovery (extubation, head lift, sternal position and righting) after 60 minute anesthesia. Rectal temperature was significantly low in ISO group (p<0.05) from 10 to 100 minute. Heart rate was significantly low in ISO group (p<0.05) at 40, 50, 60 minute. Respiratory rate was significantly low in PRO group (p<0.05) at induction and 70 minute. $SpO_2$ tendency was similar. Systolic arterial pressure (SAP) was significantly low in ISO group (p<0.05) at induction and during anesthesia. Recovery was similar in two groups. We concluded that TIVA with propofol is useful in stabilizing rectal temperature and arterial pressure during anesthesia and provide fast and stable recovery.

• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.460-463
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• 2012

The present study was aimed to evaluate and compare the oxidative stress status of isoflurane and propofol in pigs undergoing surgery with measuring the activities of antioxidant enzymes. The pigs were divided into 2 groups according to the type of anesthesia used for the surgical procedure. In the isoflurane group (group 1), anesthesia was induced and maintained with 2-2.5% isoflurane under 100% oxygen. The propofol group (group 2) received 8 mg/kg/h of IV propofol with 0.5-1% isoflurane under 100% oxygen. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities of isoflurane group were significantly lower at the end of surgery than at induction of anesthesia, while that of the propofol group maintained their baseline values. There were significant differences in all enzymes activities between groups at the end of surgery. These results indicate that propofol is capable of preserving the antioxidant capacity in pigs anesthetized with the combination of isoflurane and propofol infusion.

• Korean Journal of Veterinary Research
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• v.52 no.3
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• pp.153-155
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• 2012

This study investigated the effects of vitamin C on oxidative stress induced by volatile anesthetics in pigs. One group of pigs was used as an anesthesia control group (group 1), and they were anesthetized with isoflurane in oxygen and saline (0.9% NaCl) was injected intravenously. The other group (group 2) was anesthetized with isoflurane and injected intravenously with vitamin C. Total oxidant status, total antioxidant status, and the oxidative stress index in group 2 were significantly different compared with those in group 1. The results showed that intravenous administration of vitamin C decreased oxidative stress during isoflurane anesthesia in pigs.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.260-267
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• 2023

Specialized hearing tests for pets are currently in demand. A brainstem auditory evoked response (BAER) test is an objective, non-invasive, and practical electrophysiological method that records electric signals from the peripheral auditory system to the brainstem when an auditory stimulation is provided. In veterinary medicine, sedation or anesthesia is essential for a successful examination. In human medicine, research has established the indications for various sedatives, anesthetics, and drugs according to the depth of anesthesia required. However, in veterinary medicine, there are very few comparative studies on propofol or isoflurane, which are the most common anesthetics used. Therefore, the present study aimed to analyze the difference in BAER test results between sedation with medetomidine, anesthesia using propofol, and inhalation anesthesia with isoflurane after propofol administration. The test was conducted on four healthy adult dogs. There was no statistically significant difference in latency, interpeak latency, or amplitude between the various drugs. The results suggest that a sedative or anesthetic for the administration of a BAER test can be selected according to the patient's needs.

• Current Optics and Photonics
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• v.6 no.5
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• pp.489-496
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• 2022

Our previous study on monitoring cerebral oxygenation with a variation of isoflurane concentration in a rat model showed that near-infrared spectroscopy (NIRS) signals have potential as a new depth of anesthesia (DOA) index. However, that study obtained results from the brain in a completely invasive way, which is inappropriate for clinical application. Therefore, in this follow-up study, it was investigated whether the NIRS signals measured in a minimally invasive model including the skull and cerebrospinal fluid layer (CSFL) are similar to the previous study used as a gold standard. The experimental method was the same as the previous study, and only the subject model was different. We continuously collected NIRS signals before, during, and after isoflurane anesthesia. The isoflurane concentration started at 2.5% (v/v) and decreased to 1.0% by 0.5% every 5 min. The results showed a positive linear correlation between isoflurane concentration and ratio of reflectance intensity (RRI) increase, which is based on NIRS signals. This indicates that the quality of NIRS signals passed through the skull and CSFL in the minimally invasive model is as good as the signal obtained directly from the brain. Therefore, we believe that the results of this study can be easily applied to clinics as a potential indicator to monitor DOA.