Effects of maternal enflurane exposure on NR2B expression in the hippocampus of their offspring

This work aims to study the pathogenesis of learning and memory impairment in offspring rats resulting from maternal enflurane anesthesia by focusing on the expression of the N-methyl-d-aspartic acid receptor subunit 2B (NR2B) in the hippocampus of the offspring. Thirty female Sprague-Dawley rats were randomly divided into three groups: control (C group), 4 h enflurane exposure (E1 group), and 8 h enflurane exposure (E2 group) groups. Eight to ten days after the initiation of pregnancy, rats from the E1 and E2 groups were allowed to inhale 1.7% enflurane in 2 L/min oxygen for 4 h and 8 h, respectively. Rats from the C group were allowed to inhale 2 L/min of oxygen only. The Morris water maze was used to assay the learning and memory function of the offspring on postnatal days 20 and 30. RT-PCR and immunohistochemistry assays were then used to measure the mRNA levels and protein expression of NR2B, respectively. Relative to offspring rats from the C group, those from the E1 and E2 groups exhibited longer escape latencies, lesser number of crossings over the platform, and less time spent in the target quadrant in the spatial exploration test (P < 0.05). In addition, the mRNA and protein expression levels of NR2B in the hippocampus of offspring rats in the E1 and E2 groups were down-regulated (P < 0.05). No significant differences between the E1 and E2 groups were observed (P > 0.05) in terms of mRNA levels and protein expression of NR2B. The cognitive function of the offspring is impaired when maternal rats are exposed to enflurane during early pregnancy. A possible mechanism of this effect is related to the down-regulation of NR2B expression.

Este trabalho objetiva o estudo da patogênese de deficiência no aprendizado e memória de prole de ratos resultante da anestesia maternal por enflurano, por meio da expressão da subunidade 2B do receptor do ácidoN-metil-D-aspártico (NR2B) no hipocampo dos filhotes. Dividiram-se, aleatoriamente, 30 fêmeas de ratos Sprague-Dawley em três grupos: controle (grupo C), exposição ao enflurano por 4 h (grupo E1) e por 8 h (grupo E2). De oito a 10 dias após o início da gravidez, os ratos dos grupos E1 e E2 inalaram enflurano 1,7% em 2 L/min de oxigênio, por 4 h e 8 h, respectivamente. Ratos do grupo C inalaram apenas 2 L/min de oxigênio. O labirinto de água de Morris foi empregado para analisar as funções de aprendizado e memória da cria em 20 e 30 dias após o nascimento. Utilizaram-se ensaios de RT-PCR e de imuno-histoquímica para medir os níveis de mRNA e expressão da proteína do NR2B, respectivamente. Em comparação com os ratos controle do grupo C, aqueles dos grupos E1 e E2 exibiram latências de escape mais longas, menor número de travessias na plataforma e menos tempo gasto no quadrante alvo no teste de exploração espacial (P < 0,05). Adicionalmente, os níveis de expressão de mRNA e de proteína do NR2B no hipocampo dos filhotes nos grupos E1 e E2 estavam reduzidos (P < 0,05). Não se observaram diferenças significativas entre os grupos E1 e E2 (P < 0,05) quanto aos níveis de mRNA e à expressão de proteína de NR2B. A função cognitiva dos filhotes é prejudicada quando as mães são expostas ao enflurano durante o início da gravidez. O mecanismo possível para esse efeito está relacionado à diminuição na expressão de NR2B.

Peripheral nerve injury caused by needle impalement: Synchrotron small-angle X-ray scattering study in ex-vivo rat sciatic nerve

BACKGROUND: Direct puncture by a needle is a risk factor for nerve damage. This study was designed to demonstrate nerve damage caused by a needle using the synchrotron small-angle X-ray scattering (SAXS) technique. METHODS: A 15 mm section of rat (Male Spargue-Dawley, about 250 grams) sciatic nerves were involved in this study. The nerve specimen for the experiment (N = 5) was punctured 5 times by a needle (25 G, 100 beveled) under general anesthesia with enflurane. The needle was placed perpendicular to the nerve and the needle bevel was placed parallel to the nerve. The SAXS patterns of the punctured nerves, extracted about 15 min prior to the experiment, were acquired after 1 week. The SAXS patterns of a normal sciatic nerve (N = 5), extracted about 15 min prior to the experiment, were measured in order to provide a comparison. Experiments were carried out at 4C1 beamline at Pohang Accelerator Laboratory in Korea. Incoming X-rays were monochromatized at 11 keV using a double multilayer (WB4C) monochromator; the beam size was around 0.5 (V) x 0.8 (H) mm2. The exposure time was 60 sec, and 8 to 12 images were acquired per sample with a 0.5 mm interval. RESULTS: In the punctured group, the periodic peaks of myelin sheath and collagen fiber were not changed. However, the periodic peaks of interfibrillar distance of collagen were greatly changed. CONCLUSIONS: Direct needle-nerve impalement did not cause damages in myelin sheath and collagen fibers when the needle was placed perpendicular and the needle bevel paralleled to the nerve fiber. This result can imply that the needle slipped into the interfibrillar packing of collagen fibrils.

Comparação entre o enflurano e o propofol na eletroconvulsoterapia: um estudo preliminar, aleatório, aberto e cruzado sobre a duração de convulsões e a recuperação anestésica / Comparison of enflurane and propofol in electroconvulsive therapy, a randomized crossover open preliminary study on seizure duration and anaesthetic recovery

JUSTIFICATIVA E OBJETIVOS: A eletroconvulsoterapia (ECT) é comumente utilizada para o tratamento de depressão, mania e transtornos do humor. Anestésicos para anestesia geral durante a ECT devem ter início e despertar rápidos, não interferir com a atividade da convulsão e não encurtar a duração das crises. O objetivo deste estudo é comparar os efeitos do enflurano, um agente anestésico pró-convulsivo, e o propofol na duração das ocnvulsões, no índice de supressão pós-ictal e nos tempos de recuperação durante a eletroconvulsoterapia. MÉTODO: Pacientes sem uso de medicação pré-anestésica foram alocados em dois grupos de acordo com a indução da anestesia. Os pacientes foram induzidos para a ECT com 5 por cento de enflurano no grupo E e 1,2 mg.kg-1 de propofol no grupo P, até perda de consciência. A duração das crises motora e no eletroencefalograma (EEG), o índice de supressão pós-ictal, o tempo para respiração espontânea, para duração da abertura dos olhos e obedecer aos comandos foram registrados. RESULTADOS: Não houve diferença estatisticamente significativa entre os grupos quanto aos tempos das crises motora e no EEG e índice de supressão pós-ictal nos registros de EEG. Tempos de recuperação (tempo de início de respiração espontânea, de abertura dos olhos e para obedecer aos comandos) foram significativamente menores no grupo E em relação ao grupo P. Não foram observados náuseas ou vômitos e nenhuma anormalidade no ECG, exceto bradicardia sinusal transitória e taquicardia sinusal. CONCLUSÕES: Embora convulsões suficientes para o tratamento tenham ocorrido durante a anestesia com enflurano, nenhum benefício adicional foi observado sobre os tempos de convulsão ou índice de supressão pós-ictal quando comparado à anestesia com propofol. Por outro lado, o tempo de recuperação após anestesia com enflurano foi mais curto que com propofol. No entanto, ainda há necessidade de mais estudos em diferentes níveis de ETCO2.

BACKGROUND AND OBJECTIVES: Electroconvulsive therapy (ECT) is commonly used for treatment of depression, mania and affective disorders. Anaesthetics for general anaesthesia during ECT should have rapid onset, rapid emerge, not interfere with seizure activity and not shorten seizure duration. The aim of this study is to compare effects of enflurane, a pro-convulsive anaesthetic agent, and propofol on seizure durations, postictal suppression index and recovery times during electroconvulsive therapy. METHODS: Unpremedicated subjects were divided into two groups according to induction of anaesthesia. Patients were induced for ECT with 5 percent enflurane in group E and 1.2 mg.kg-1 propofol in group P until loss of consciousness. The durations of electroencephalogram (EEG) and motor seizures, postictal suppression index, time to spontaneous breathing, duration of eye opening, and obeying commands were recorded. RESULTS: There was no statistically significant difference between the groups regarding motor and EEG seizure times and postictal suppression index on the EEG records. Recovery times (times of starting spontaneous breathing, eye opening, and obeying command) were significantly shorter in group E compared to group P. No nausea or vomiting were observed and no ECG abnormality was noted except transient sinus bradycardia and sinus tachycardia. CONCLUSIONS: Although sufficient seizure for the treatment was provided during enflurane anaesthesia, any additional benefit was not revealed regarding seizure times or postictal suppression index when compared to propofol anaesthesia. On the other hand, recovery times after enflurane anaesthesia were shorter than propofol anaesthesia. However, there is still a need for further study in different ETCO2 levels.

JUSTIFICATIVA Y OBJETIVOS: La electroconvulsoterapia (ECT), se usa a menudo para el tratamiento de la depresión, manía y transtornos del humor. Los anestésicos para la anestesia general durante la ECT deben tener un inicio y un despertar rápidos, no interferir en la actividad de la convulsión y no acortar la duración de las crises. El objetivo de este estudio, es comparar los efectos del enflurano, un agente anestésico pro convulsivo, y el propofol, en la duración de las convulsiones, en el índice de supresión postictal y en los tiempos de recuperación durante la electroconvulsoterapia. MÉTODO: Pacientes sin uso de medicación preanestésica que fueron colocados en dos grupos de acuerdo con la inducción de la anestesia. Los pacientes fueron inducidos para la ECT con 5 por ciento de enflurano en el grupo E y 1,2 mg.kg-1 de propofol en el grupo P, hasta la pérdida de la conciencia. También fueron registrados la duración de las crises motora y en el electroencefalograma (EEG), el índice de supresión postictal, el tiempo para la respiración espontánea, para la duración de la abertura de los ojos y obedecer a los comandos. RESULTADOS: No hubo diferencia estadísticamente significativa entre los grupos en cuanto a los tiempos de las crises motora y en el EEG e índice de supresión postictal en los registros de EEG. Los tiempos de recuperación (tiempo de inicio de la respiración espontánea, de abertura de los ojos, y para obedecer a los comandos), fueron significativamente menores en el grupo E con relación al grupo P. No se observaron náuseas o vómitos, ni ninguna anormalidad en el ECG tampoco fue notada, excepto bradicardia sinusal transitoria y taquicardia sinusal. CONCLUSIONES: Aunque las convulsiones suficientes para el tratamiento hayan sucedido durante la anestesia con enflurano, ningún beneficio adicional fue observado sobre los tiempos de convulsión o sobre el índice de supresión postictal cuando se le comparó con la anestesia con propofol. Por otro lado, el ti...

Participation of KATP Channels in the Antinociceptive Effect of Pregabalin in Rat Formalin Test

BACKGROUND: Pregabalin is an anticonvulsant and analgesic agent that interacts selectively with the voltage-sensitive-Ca(2+)-channel alpha-2-delta subunit. The aim of this study was to evaluate whether the analgesic action of intrathecal (IT) pregabalin is associated with KATP channels in the rat formalin test. METHODS: IT PE-10 catheters were implanted in male Sprague-Dawley rats (250-300 g) under inhalation anesthesia using enflurane. Nociceptive behavior was defined as the number of hind paw flinches during 60 min after formalin injection. Ten min before formalin injection, IT drug treatments were divided into 3 groups: normal saline (NS) 20 microl (CON group); pregabalin 0.3, 1, 3 and 10 microg in NS 10 microl (PGB group); glibenclamide 100 microg in DMSO 5 microl with pregabalin 0.3, 1, 3 and 10 microg in NS 5 microl (GBC group). All the drugs were flushed with NS 10 microl. Immunohistochemistry for the KATP channel was done with a different set of rats divided into naive, NS and PGB groups. RESULTS: IT pregabalin dose-dependently decreased the flinching number only in phase 2 of formalin test. The log dose response curve of the GBC group shifted to the right with respect to that of the PGB group. Immunohistochemistry for the KATP channel expression on the spinal cord dorsal horn showed no difference among the groups 1 hr after the formalin test. CONCLUSIONS: The antinociceptive effect of pregabalin in the rat formalin test was associated with the activation of the KATP channel. However, pregabalin did not induce KATP channel expression in the spinal cord dorsal horn.

A Case Report of Takotsubo Cardiomyopathy During Breast Augmentation

PURPOSE: Takotsubo cardiomyopathy is a relatively uncommon type of stress-induced cardiomyopathy characterized by transient left ventricular regional wall motion abnormalities. Emotional and physical stresses play a key role in this type of cardiomyopathy in postmenopausal women. The current hypothesis is that the syndrome represents a form of catecholamine surge due to stress or epinephrine-mediated acute myocardial stunning. METHODS: A 44-year-old woman had suffered premature ventricular contraction following a cardiogenic shock during a breast augmentation surgery under enflurane anesthesia and tumescent solution infiltration. She was treated with cardiopulmonary resuscitation at a local clinic. Then she was brought to the Emergency Department of the authors' hospital. RESULTS: The woman's echocardiogram showed an ejection fraction of 20~25% with associated basal hyperkinesis and left ventricular apical ballooning. The patient was admitted to the ICU and required inotropic support for two weeks. The patient's condition dramatically improved, and her ejection fraction returned to 70%. CONCLUSION: It is believed that there were multiple triggering factors of the onset of Takotsubo cardiomyopathy in the woman's social and family history, including infiltration of a large volume of the tumescent solution and VPCs induced by enflurane anesthesia without premedication. The importance of careful history-taking, careful pre-operative consultation on psychological suffering especially for breast surgery, premedication before surgery, patient reassurance, and post-operative psychosocial and emotional assistance was again seen in this case.

Development of three Drosophila melanogaster strains with different sensitivity to volatile anesthetics / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The mechanisms of action for volatile anesthetics remain unknown for centuries partly owing to the insufficient or ineffective research models. We designed this study to develop three strains derived from a wild-type Drosophila melanogaster with different sensitivities to volatile anesthetics, which may ultimately facilitate molecular and genetic studies of the mechanism involved.</p><p><b>METHODS</b>Median effective doses (ED(50)) of sevoflurane in seven-day-old virgin female and male wild-type Drosophila melanogaster were determined. The sensitive males and females of percentile 6 - 10 were cultured for breeding sensitive offspring (S(1)). So did median ones of percentile 48 - 52 for breeding median offspring (M(1)), resistant ones of percentile 91 - 95 for breeding resistant offspring (R(1)). Process was repeated through 31 generations, in the 37th generation, S(37), M(37) and R(37) were used to determine ED(50) for enflurane, isoflurane, sevoflurane, desflurane, halothane, methoxyflurane, chloroform and trichloroethylene, then ED(50) values were correlated with minimum alveolar concentration (MAC) values in human.</p><p><b>RESULTS</b>From a wild-type Drosophila melanogaster we were able to breed three strains with high, median and low sevoflurane requirements. The ratio of sevoflurane requirements of three strains were 1.20:1.00:0.53 for females and 1.22:1.00:0.72 for males. Strains sensitive, median and resistant to sevoflurane were also sensitive, median and resistant to other volatile anesthetics. For eight anesthetics, ED(50) values in three strains correlated directly with MAC values in human.</p><p><b>CONCLUSIONS</b>Three Drosophila melanogaster strains with high, median and low sensitivity to volatile anesthetics, but with same hereditary background were developed. The ED(50) are directly correlated with MAC in human for eight volatile anesthetics.</p>

Effect of fentanyl on hemodynamic changes connected with a thigh tourniquet during knee arthroscopic surgery / 대한마취과학회지

BACKGROUND: The use of a tourniquet can produce pain and increase in blood pressure. It is known that fentanyl reduces central sensitization, however its effect on blood pressure increase due to tourniquet is unknown. So we investigated the effect of fentanyl on tourniquet-induced changes of mean arterial blood pressure (MBP), heart rate (HR), and cardiac index (CI). METHODS: ASA physical status I and II, who were scheduled for knee arthroscopic surgery using a tourniquet, were assigned into control (n = 30) and fentanyl group (n = 30). Anesthesia was maintained with enflurane, N2O and O2. Fentanyl was injected 1.5 ug/kg at 10 min before inflation of the tourniquet in the fentanyl group. Changes of the MBP, HR, CI were measured before and 10, 20, 30, 40, 50, 60 min after inflation of the tourniquet. RESULTS: There were no differences in the baseline values. MBP was increased at 40, 50, 60 min in the control group. At 60 min, MBP was lower in the fentanyl than the control group. HR was decreased at 10 min in the fentanyl group. CI was decreased in all groups after tourniquet inflation. At 60 min, CI was more decreased in the control than the fentanyl group. CONCLUSIONS: Fentanyl injection prior to tourniquet inflation can attenuate the tourniquet induced hemodynamic changes in the knee arthroscopic surgery patients.

The effects of propofol and enflurane anesthesia on the proliferative responsiveness of peripheral blood mononuclear cells in culture as determined by the level of bromodeoxyuridine incorporation / 대한마취과학회지

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.

The Effects of Remifentanil on Hemodynamic Changes in Endotracheal Intubation during Rapid Sequence Induction using Thiopental-succinylcholine or Propofol-succinylcholine / 대한마취과학회지

BACKGROUND: This study evaluated the effects of remifentanil on hemodynamic changes in endotracheal intubation during rapid sequence induction using thiopental or propofol and succinylcholine. METHODS: One hundred and twenty patients were divided into 4 groups (30 patients in each group).Anesthesia was induced with propofol 2 mg/kg or thiopental 5 mg/kg and succinylcholine 1 mg/kg followed by remifetanil 0.5microgram/kg (group PR), remifentanil 1microgram/kg (group TR) or normal saline as control (group PC, group TC).An endotracheal intubation was performed 90 s later, and vecuronium 0.08 mg/kg was given for neuromuscular block.Anesthesia was maintained using 1-3 vol% enflurane with 2 L/min N2O and 2 L/min O2.Arterial blood pressure (ABP) and heart rate (HR) were recorded before induction, just before intubation, and at 1 min intervals for 5 min after intubation.The incidence of hypertension, hypotension, tachycardia, and bradycardia were recorded. RESULTS: ABP in group PR was lower than in group TR, but HR was not different.The incidence of hypotension in group PR was higher than group TR or group PC.ABP in groups using remifentanil was lower than in control groups.The incidence of hypertension and tachycardia in groups using remifentanil were lower than control groups. CONCLUSIONS: During administration of propofol or thiopental and succinylcholine, remifentanil as a bolus for rapid sequence induction attenuated cardiovascular responses to endotracheal intubation effectively, but with a higher incidence of hypotension following propofol.

Effects of Intra-articular Injection of Agmatine and Clonidine into the Knee Joint Cavity on the Induction and Maintenance of Arthritic Pain in Rats / 대한마취과학회지

BACKGROUND: Previous studies suggest that systemic administration of agmatine, endogenous ligand for imidazoline receptors has anti-hypernociceptive effects in experimental animal. However the peripheral effects of agmatine on inflammatory pain have not yet been elucidated. Here we examined the effects of intra-articular injection of agmatine in the induction and maintenance phase of arthritic pain. In addition, we sought to determine the potential contribution of imidazoline and alpha(2)-adrenergic receptors to the antinociceptive effects using clonidine which is mixed alpha(2)-adrenoceptor and imidazoline receptor agonist. METHODS: To induce arthritis in rats, 2% lambda-carrageenan (50microliter, in saline) was injected into the joint of the right hind limb under enflurane anesthesia. Either agmatine (10, 50, 100microgram/40microliter) or clonidine (10, 50, 100microgram/40microliter) was injected into the knee joint cavity immediately before or 4 hr after carrageenan injection. Weight load tests were performed to measure pain-related behavior in freely walking rats. RESULTS: The intraarticular injection of agmatine into the knee joint had no effects in the both phase of induction and maintenance of arthritic pain at any dose tested. However, injection of clonidine reversed arthritic pain, when injected 4 h after carrageenan injection. CONCLUSIONS: In rats, agmatine has no peripheral effect on inflammatory pain and imidazoline receptors in the periphery may not contribute to the anti-inflammatory pain.

Effect of Ketorolac on Blood Pressure Changes Connected with a Thigh Tourniquet during Knee Arthroscopic Surgery / 대한마취과학회지

BACKGROUND: The use of a tourniquet can produce pain and cause increased blood pressure. Ketorolac is known to have analgesic effects at the peripheral and central levels, however, its effect on the increased blood pressure due to a tourniquet is unknown. Therefore, the effects of ketorolac on the tourniquet-induced changes in the systolic, and diastolic blood pressures (SBP & DBP), as well as the heart rate (HR), were investigated. METHODS: ASA physical status I and II patients, who were scheduled for knee arthroscopic surgery using a tourniquet, were assigned to control (n = 20), K30 (n = 20) and K60 groups (n = 20). Anesthesia was maintained with enflurane, N2O and O2. Either 30 or 60 mg ketorolac was injected 10 min prior to tourniquet inflation in both the K30 and K60 groups. The changes in the SBP, DBP and HR were measured before and 10, 20, 30, 40, 50, and 60 min after tourniquet inflation. RESULTS: There were no differences in the baseline SBP, DBP, and HR values. The SBP was higher than the baseline value at 10, 20, 30, 40, 50, and 60 min in the control and at 30, 40, 50, and 60 min in the K30 groups, but only at 60 min in the K60 group. At 60 min, the SBP was lower in the K60 than the control group. The DBP was higher than the baseline value at 50, and 60 min in the control, but not in the ketorolac groups. CONCLUSIONS: A 60 mg ketorolac injection prior to tourniquet inflation can attenuate the tourniquet induced increase in blood pressure in knee arthroscopic surgery patients.

Comparison between Remifentanil and Nicardipine with Esmolol Continuously Infused for Attenuation of Hemodynamic Changes during Total Knee Arthroplasty in Elderly Patient / 대한마취과학회지

BACKGROUND: The use of tourniquet is associated with severe hemodynamic changes, particularly in elderly patients. This study examined the effects of continuously infused remifentanil or nicardipine with esmolol on the attenuation of the hemodynamic changes with enflurane inhalation during total knee arthroplasty in elderly patients. METHODS: Thirty elderly female patients undergoing total knee arthroplasty were enrolled into this randomized, prospective study. Remifentanil (group R) or nicardipine with esmolol (group EN) was infused using a titration method to maintain a mean arterial pressure (MAP) of 90 mmHg to 70 mmHg during tourniquet inflation. In addition, the inhalation of enflurane was adjusted to guarantee a hypnotic state based on entropy. The hemodynamic variables, inhaled concentration of enflurane, recovery time, and postoperative pain characteristics were measured and compared. RESULTS: Following tourniquet inflation, the MAP was increased and maintained in the target since 20 min after that in both group. Following tourniquet deflation the MAP was decreased significantly in both groups and more patients in group R required a vasopressor. Group R inhaled a lower enflurane concentration and showed more rapid recovery than group EN. There were no significant differences in the level of postoperative pain between the two groups. CONCLUSIONS: These results suggest that remifentanil is more likely to be associated with hypotension after tourniquet deflation and require more attention than nicardipine with esmolol.

Effect of general anaesthesia with combination of acupuncture and enflurane applied in radical operation of laryngocarcinoma / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effect of general anaesthesia with combination of acupuncture [conducted with Han's acupoint nerve stimulator (HANS) applied] and enflurane in radical operation of laryngocarcinoma (LC).</p><p><b>METHODS</b>Sixty patients with LC of grade I - II , classified according to the standard of American Society of Anesthesiologists (ASA), were assigned by randomizing number table to the control group and the tested group, 30 patients in each group. The control group received anaesthesia with enflurane alone for inducing and maintaining; the tested group was anaesthetized with enflurane like that given to the control group but also received additionally needling stimulation conducted by HANS. The dosage of enflurane used, the minimum effective concentration of enflurane in alveolar air (MACEnf) and the changes of heart rate (HR) as well as blood pressure (BP) in patients at different time points in the operational process were observed.</p><p><b>RESULTS</b>As compared with those in the control group, in the tested group, both the MACEnf and the dosage of enflurane were reduced, with the difference between the two groups significant (P<0. 01). The changes of HR and BP among different time points in the tested group were slight, and as compared with those in the control group at the corresponding time points, the difference was significant ( P <0. 05 or P<0.01).</p><p><b>CONCLUSION</b>General anaesthesia with combination of enflurane and needling conducted by HANS applied in radical operation of LC has definite effect with less complication. Needling could be cooperated with narcotics, and so it could be taken as an auxiliary measure of anaesthesia for radical operation of LC.</p>

Liver Function and Inhaled Anesthetics

The liver is the major site of endogenous and exogenous drug metabolism. The primary result of drug metabolism is the production of more water-soluble and therefore more easily excreted drug metabolites. Drugs are sometimes biotransformed into more reactive metabolites, which may lead to toxicity. Volatile anesthetics, like most drugs, undergo metabolism in the body and are sometimes associated with toxic reactions. Here, author will discuss the metabolism and hepatic toxicity of inhaled anesthetics. Toxicity and liver injury have been reported after repeated exposure on subsequent occasions to different fluorinated anesthetics. This phenomenon of cross-sensitization has also been reported with the chlorofluorocarbon(CFC) replacement agents, the hydrochlorofluorocarbons(HCFCs). Halothane, enflurane, sevoflurane, isoflurane, desflurane are all metabolized to trifluoroacetic acid, which have been reported to induce liver injury in susceptible patients. The propensity to produce liver injury appears to parrel metabolism of the parent drug: halothane(20%) >>>> enflurane(2.5%) >> sevoflurane(1%) > isoflurane(0.2%) > desflurane(0.02%). The use of any anesthetic must be based on its benefits and risks, how it may produce toxicity, and in which patients it may be most safely administered. Nonhalogenated inhaled anesthetics (nitrous oxide, xenon) chemically inert and not metabolized in human tissue. The perfect anesthetic agents dose not exist. But ongoing research attempts to uncover emerging toxicities. Xenon is not currently approved for clinical use. Other than the expense associated with its use, it may be the most ideal anesthetic agent. In general, surgical manipulation or disturbance of the surgical site appears to be more important in decreasing hepatic blood flow than current anesthetic agents such as isoflurane, sevoflurane, and desflurane or technique. However, the clinician is challenged to balance new information with current clinical practices and choice the safest, most effective agents for each patient.

Anesthetic Management in a Patient with Charcot-Marie-Tooth Disease: A case report / 대한마취과학회지

A 35-year old woman was scheduled to undergo a total hystectomy due to uterine myoma. She had been diagnosed with Charcot-Marie-Tooth disease 2 years ago. In addition, she had previously received a Cesarean section under epidural anesthesia 10 years ago and reported a prolonged motor blockade at that time. General anesthesia was induced with propofol 120 mg in a divided dose and the intubating condition was achieved with vecuronium 3 mg. Anesthesia was maintained with 1.5-2.5% enflurane with air and O2. During surgery, the body temperature and end tidal concentration of CO2 were maintained within the normal range. Despite the continuous monitoring of the train-of-four (TOF) response, no more muscle relaxants were required during surgery and the patient recovered without a delay in awakening. In the management of patients with Charcot-Marie-Tooth disease, it is desirable to evaluate the patient carefully, select the appropriate anesthetics and adjust the dosage of the drug according to the patients requirements.

Hemodynamic Response of Young Smokers to Induction and Intubation / 대한마취과학회지

BACKGROUND: To test whether smokers have exaggerated hemodynamic responses to induction and intubation, we investigated the changes in blood pressure (BP) and heart rate (HR) on induction and intubation in smokers and nonsmokers. METHODS: Healthy male patients (25 smokers and 25 nonsmokers, aged 20 to 29 yrs) for elective surgery were studied. Anesthesia was induced with thiopental 3 mg/kg, fentanyl 1.5 microgram/kg, vecuronium 0.1 mg/kg and maintained with enflurane 1 % in N2O and O2 for the period of observation. After three minutes, orotracheal intubation was performed. Noninvasive BP and HR were recorded one minute before induction (baseline), immediately before intubation, and then every minute until five minutes after intubation. RESULTS: Systolic BP of smokers decreased significantly immediately before intubation, and at 4 and 5 min after intubation as compared to that of nonsmokers (Mean +/- SEM, 120.8 +/- 3.0 vs. 109.9 +/- 2.8, 116.7 +/- 2.4 vs. 108.9 +/- 2.3, and 114.8 +/- 2.2 vs. 106.7 +/- 2.3 mmHg, respectively, P < 0.05). Diastolic BP of smokers decreased only immediately before intubation compared with that of nonsmokers (Mean +/- SEM, nonsmoker 64.6 +/- 2.4 vs. smoker 58.6 +/- 1.8 mmHg, P < 0.05). However, there was no significant difference of HR between smokers and nonsmokers during the observational period. CONCLUSIONS: Hemodynamic response is different in smokers compared with nonsmokers. Our results indicate that smoking affects the hemodynamic response to induction and intubation.

Factors Predicting Prolongation of the Prothrombin Time after Liver Donor Hepatectomy / 대한마취과학회지

BACKGROUND: The increasing shortage of liver donors has resulted in exponential growth of living donor liver transplantation (LDLT). There are obvious concerns about the increased risk to the donors. There has been study on the impact of donation as a function of the degree of resection. However, the effect of inhaled anesthetics combined with the degree of parenchymal loss on the liver function has not been quantified. We analyzed the prothrombin time (PT), as hepatic synthetic function, after donor hepatectomy (DH) with the recipient undergoing general anesthesia with different types of inhaled anesthetics. METHODS: One-hundred thirty-four patients who underwent DH were enrolled. The patients were randomly divided into four groups: enflurane (group E), isoflurane (group I), sevoflurane (group S), and desflurane (group D). Anesthesia was performed according to institutional standards. The PT was measured for 7 days before and daily after DH (POD). Total liver volume and resected liver volume were measured and fraction of the graft volume was calculated. RESULTS: The PT peaked on POD 1 in all groups. A significantly lower PT was observed in group D compared to the other groups until POD 3. The fraction of the graft volume showed significant correlation with the PT change. PT abnormalities were affected by the preoperative PT, the graft fraction and inhaled anesthetics. CONCLUSIONS: Desflurane induced lesser elevation of the PT than did the other inhaled anesthetics until POD 3. The preoperative PT, the graft fraction and the inhaled anesthetics may be key factors for inducing postoperative PT abnormalities.

The Effects of Lidocaine, Bupivacaine or Combined with Enflurane on the Contraction of Tracheal Smooth Muscle in Guinea Pig / 대한마취과학회지

BACKGROUND: The effects of local and inhalation anesthesia on the contraction of the tracheal smooth muscle have been reported. However, when inhalation and local anesthesia are administered simultaneously, their effects on the contraction of the airway smooth muscle are not well known. Therefore, this study evaluated the effects of lidocaine, bupivacaine, with or without enflurane, on the histamine induced tracheal smooth muscle contraction in guinea pigs. METHODS: Isolated tracheal rings of guinea pigs were suspended in Krebs solution. The contractions were recorded isometrically using a transducer. A contraction was induced by histamine (10(-5) M). Enflurane (1 MAC) was administered for 15 min after administering the histamine. The cumulative dose responses of the lidocaine and bupivacaine (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M, 10(-4) M, and 10(-3) M), enflurane-lidocaine and enflurane-bupivacaine groups were checked. RESULTS: The contraction by histamine were inhibited by lidocaine (10(-4) M and 10(-3) M) and bupivacaine (10(-5) M, 10(-4) M and 10(-3) M). In addition, the contractions were inhibited more significantly in the bupivacaine group (10(-7) M, 10(-6) M, 10(-5) M, 10(-4) M and 10(-3) M) after administering enflurane. CONCLUSIONS: Lidocaine and bupivacaine inhibited the contractions induced by histamine. The contractions by bupivacaine were further inhibited after administering enflurane.

High Grade Atrioventricular Block during Cesarean Section under General Anesthesia in a Parturient with Mobitz Type I Atrioventricular Block: A case report / 대한마취과학회지

This report is presented in which an asymptomatic parturient with Mobitz I second degree heart block developed high grade heart block during cesarean section under general anesthesia with enflurane. Progression of the block might be associated with vagal reflex. The event in this case suggests that the patients with pre-existing heart block may be a risk factor for development of high grade atrioventricular block during general anesthesia and surgery.