Indigo Carmine for the Selective Endoscopic Intervertebral Nuclectomy

This study was undertaken to prove that the selectively infiltrated parts of nucleus pulposus with indigo carmine was degenerated parts of nucleus pulposus. This study was done, between August and October 2002, in 5 patients, who received endoscopic discectomy, due to intervertebral disc herniation. Discogram was done with mixture of indigo carmine and radioactive dye. Blue discolored part was removed through endoscope, and small undiscolored part was removed together for the control. The two parts were stained with hematoxylin and eosin and compared under the microscope. Undiscolored part was normal nucleus pulposus, composed of chondrocytes with a matrix of type II collagen and proteoglycan, mainly aggrecan. However, in discolored part, slits with destruction of collagen fiber array and ingrowth of vessel and nerve were observed. Using indigo carmine in endoscopic discectomy gives us selective removal of degenerated disc.

Altered Glutamate Receptor Subtype mRNA Expressions after Transient Spinal Ischemia in the Rat / 대한마취과학회지

BACKGROUND: Massive increases in glutamate concentration in the spinal cord have been known to cause neurologic injury after spinal ischemia. However, changes in glutamate receptor subtype mRNA expression have not been evaluated. The purpose of this study was to elucidate changes of glutamate receptor subtype mRNA expressions after 15 minutes of transient spinal ischemia in the rat. METHODS: Rats were anesthetized with enflurane, and divided into 7 groups: Sham operation (S group), 1 hour reperfusion (H1 group), 3 hours reperfusion (H3 group), 1 day reperfusion (D1 group), 2 days reperfusion (D2 group), 1 week reperfusion (W1 group), and 2 weeks reperfusion (W2 group). Spinal ischemia was produced by inducing hypotension and by clamping the thoracic aorta. After spinal ischemia, neurologic scores were assessed and spinal cords were removed for glutamate receptor mRNA RT-PCR after various reperfusion times. RESULTS: No significant differences in the group were observed in physiologic variables and neurologic scores. mGluR2 and mGluR6 were up-regulated 1 day after ischemia and returned to baseline at 2 weeks. mGluR3 was up-regulated 1 week after reperfusion and returned at 2 week, and mGluR1 and mGluR4 were down- regulated 3 hours after reperfusion and returned to the control level at 1 2 weeks. NMDAR1 and 2A were down-regulated after reperfusion, but NMDAR2B was up-regulated 1 day after reperfusion and returned to the control level at 1 week. The GluR1, 2, 3, 4-flip were down-regulated 3 hours after reperfusion and returned to control level at 1 week. However, the GluR1, 2, 3-flop were up-regulated 2 days after reperfusion and returned to control level at 2 weeks. CONCLUSIONS: Changes in spinal cord glutamate receptor subtype mRNA expression after transient spinal ischemia were different for the receptor types and reperfusion times. The changes in glutamate receptor subtypes in the spinal cord differed from those in the brain.

Effects of Hypothermic Cardiopulmonary Bypass on Bispectral Analysis / 대한마취과학회지

BACKGROUND: Patient awareness is a particular problem in cardiac anesthesia with cardiopulmonary bypass (CPB). Transformed electroencephalogram monitors, such as the Bispectral index (BIS) monitor, has been advocated as a tool that may reduce the incidence of unexpected intraoperative recall. The authors studied the effects of hypothermia during CPB on the BIS score and the BIS can be a useful monitor to measure anesthetic depth and requirement during hypothermic CPB. METHODS: Eighteen consenting volunteers scheduled for an elective cardiac surgery were studied. Volunteers were randomly allocated to one of two groups. All patients were given propofol by a target controlled infusion system, Diprifusor, with fentanyl (0.6 ug/kg/min). In group A, before and during CPB propofol was infused at a predetermined target plasma concentration (2.0 ug/ml), the BIS score and temperature were monitored. In group B, before and during CPB, to maintain the BIS score at 30 40 units, changing propofol plasma concentrations and temperature were monitored. Then we asked patients about intraoperative awareness. RESULTS: In group A, compared with before the start of CPB, the BIS score was decreased by the temperature (P < 0.05) during CPB (5 min, 10 min, 20 min, 30 min after the start of CPB) and after the stop of CPB. In group B, compared with before the start of CPB, the required propofol plasma concentration was decreased by the temperature during CPB (P < 0.05). In addition, no one experienced awareness during surgery. CONCLUSIONS: The BIS score was decreased by a decline in temperature during the hypothermic CPB, and bispectral analysis can be a relative indicator of anesthetic requirement and the hypnotic state under this conception.

The Effects of Moderate Hypothermia on the Formation of Apoptosis in Transient F degrees Cal Cerebral Ischemia Model in Rats / 대한구급학회지

BACKGROUND: Delayed neuronal injury after cerebral ischemia came major neurologic complication after stroke or cardiac arrest. Apoptosis formation after ischemia may be one of a mechanism of delayed neuronal injury. This study was conducted to evaluate the effect of moderate hypothermia on apoptosis formation after one hour of middle cerebral artery degrees Cclusion in rats. METHODS: Ten Sprague-Dawley rats (300 g) were freely fed till just before operation. Anesthesia was induced with 4 vol% isoflurane in oxygen and then maintained with 2 vol% isoflurane in oxygen. Middle cerebral artery degrees Cclusion (MCAO) was induced by intraluminal monofilament nylon with blunted tip. All rats were divided randomly into two groups. In group 1 (n=5), rectal temperature was maintained at 38 degrees C. In group 2 (n=5), rectal temperature was maintained at 32 degrees C. Rectal temperature was monitored during experiment. After 60 minutes of MCAO, intraluminal monofilament was removed and all rats were returned to cages. Brain were quickly removed and cerebral hemispheres were separated after 23 hours reperfusion. Apoptosis formation were counted with TUNEL stain. RESULTS: In group 1, after 60 minutes of MCAO and 23 hours reperfusion, 51 3.6% of hipp degrees Campal neurons were TUNEL-positive stained apoptotic cells. In group 2, TUNEL-positve neurons were 26.1 6.5% and significantly less than those of group 1 (p<0.05). CONCLUSIONS: Sixty minutes of MCAO and 23 hours reperfusion induce hipp degrees Campal neuronal apoptosis. Moderate hypothermia of 32 degrees C reduces apoptosis of hipp degrees Campal neurons after 60 minutes of MCAO and 23 hours reperfusion.

Neuroprotective Effects of Propofol, Ketamine and Propofol-ketamine after Transient Forebrain Ischemia in the Rat / 대한마취과학회지

BACKGROUND: Intravenous anesthetics such as propofol and ketamine have been known to have neuroprotective effects. However, the combination of these drug is not known. This study was conducted to determine the neuroprotective effects of propofol, ketamine or both after transient forebrain ischemia. METHODS: Twenty Sprague-Dawley rats (250-300 gm) were used. Anesthesia was induced with 4% isoflurane in oxygen and then maintained with 1 - 2% isoflurane in oxygen. Ischemic injury was induced by 10 minutes of both common carotid artery ligation and hypotension (MAP < 50 mmHg). All rats were randomly divided into four groups: group I; control group; group II; ketamine 10 mg/kg was administered 10 minutes before injury; group III; propofol (1 mg/kg/min) was administered until EEG isoelectricity; and group IV; ketamine 10 mg/kg and propofol 1 mg/kg/min was administered. The Rectal temperature was maintained at 38oC. After forebrain ischemia, neurologic scores were estimated at 1 hr, 2 hrs, 1 day and 2 days after recovery. The brain was removed 3 days after and stained with H-E stain. RESULTS: Neurologic and histologic scores of group II, III, IV were significantly lower than that of group I. However, there were no significant difference between group II, III and IV. CONCLUSIONS: Ketamine and propofol have neuroprotective effects in transient forebrain ischemia in rats. However, the combination of propofol and ketamine did not show any synergistic or additive effects.

The Effect of Preemptive Local Infiltration of Lidocaine and Gabapentin on Postoperative Pain in Rats / 대한마취과학회지

BACKGROUND: Preemptive analgesia may improve postoperative antinociceptive treatment that prevents the development of central sensitization which contributes to post-injury pain hypersensitivity. However, beneficial effects of preemptive analgesia appear controversial. The purpose of this study was to examine the effect of pre- and post-incisional local infiltration of lidocaine and gabapentin on incisional pain in rats. METHODS: Thirty five male rats were divided into 7 groups; control group (n = 5), pre-lidocaine infiltration group (n = 5), post-lidocaine infiltration group (n = 5), pre-gabapentin 10 mg infiltration group (n = 5), post-gabapentin 10 mg infiltration group (n = 5), pre-gabapentin 30 mg infiltration group (n = 5), and post-gabapentin 30 mg infiltration group (n = 5). To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal thresholds were measured by calibrated von Frey filaments at 2 hrs, 1, 2, 3, 4, and 5 days after an incision. RESULTS: The pre-lidocaine infiltration group shows better analgesic effects than post-lidocaine infiltration group until postoperative day 1 (P < 0.05). The gabapentin infiltration groups were effective in postoperative pain management but there were no significant differences between pre- and post- incisional treatment. CONCLUSIONS: A preemptive lidocaine injection has a good analgesic effect on incisional pain. Gabapentin also has a good analgesic effect on incisional pain.

Monitoring of Anesthetic Depth by BIS & Anemon Monitor / 대한마취과학회지

BACKGROUND: Monitoring of "Depth of anesthesia" is an ongoing problem in anaesthesia. In this study, the author has compared the bispectral index (BIS) and Anemon monitor for monitoring depth of anesthesia in propofol or isoflurane anesthesia. METHODS: Anemon-1 and BIS index were obtained from 24 patients (ASA I, II) during general anesthesia with propofol or isoflurane. For patients in the propofol group, anesthesia was induced with fentanyl 100ng followed by propofol 2 mg/Kg. For patients in the isoflurane group, anesthesia was induced with thiopental 5 mg/Kg. The author observed changes of these values at 5 major times: before induction, during induction, after induction, at sKin incision, before extubation, after extubation. RESULTS: The anemon index showed a significant increase during induction (propofol group: 86.9 +/- 26.4, isoflurane group: 106.0 +/- 18.6) and at sKin incision (propofol group: 89.9 +/- 22.7, isoflurane group: 92.0 +/- 23.1), but this did not correlate with the level of consciousness. The BIS index showed a significant decrease in the score after induction (propofol group: 55.0 +/- 9.6, isoflurane group: 61.0 +/- 17.2), but no response to surgical stimuli. CONCLUSIONS: BIS had a good correlation with level of consciousness. The Anemon-1 index was recognized to reflect invasive stimulus. As the BIS and Anemon-1 had no correlation, it was not possible to assume changes of each index from the other. Both the anemon-1 index and BIS are useful to monitor the anesthesia level during surgery.

The Role of the Glutamate Receptor in the Transient Focal Cerebral Ischemia in Rats / 대한마취과학회지

BACKGROUND: To investigate the role of glutamate in the transient focal cerebral ischemia, a reversible middle cerebral artery occlusion model was induced in 25 male Sprague-Dawley rats. METHODS: Triphenyltetrazolium chloride (TTC) stain was used for evaluation of the changes of infarction ratio in MK-801 (0.3, 1.0, 3.0 mg/kg) or pentylenetetrazole (50 mg/kg) treated groups. RESULT: The infarction ratio at 48 hours after 2 hour transient focal brain ischemia was 39.2 +/- 13.2% in control group and 23.8 +/- 4.2, 27.0 +/- 8.9, and 12.8 +/- 4.4% in MK-801 (0.3, 1.0, 3.0 mg/kg) groups. In the pentylenetetrazole (PTZ) group, the infarction ratio was 32.6 +/- 6.7%. CONCLUSIONS: The non-specific glutamate receptor antagonist, MK-801, showed a trend toward dose-dependent improvement, but the PTZ group showed no improvement. From these results, it suggested that glutamate might be partly involved in the mechanisms of ischemia-induced neuronal damage.

Molecular Biologic Study on the Changes of Glutamate Receptor (mGluR5) in Rat Hippocampus after Brain Ischemia / 대한구급학회지

BACKGROUND: Metabotropic glutamate receptors (mGluRs) participate in the induction of synaptic plasticity phenomena, such as long-term potentiation and long-term depression that are thought to be at the origin of learning and memory. They are also likely to play a role in modulating glutamate-induced neurotoxicity. It will become apparent that mGluRs are excellent targets for the development of drugs that modulate excitatory synaptic transmission. But there were several controversies about the exact role of group 1 mGluRs subtype 5 (mGluR5). This study was designed for evaluation of the neuroprotective role of mGluR5. METHODS: Fifty male Sprague-Dawley rats were divided into three groups, control, MK-801 and lamotrigine. The hippocampus and basal ganglia were removed at 6 hours and 3 days after the one hour transient middle cerebral artery occlusion. The gene expression of mRNA of the brain samples were evaluated by using reverse transcriptase polymerase chain reaction technique. RESULTS: The gene expression of mGluR5 mRNA in hippocampus was increased by 101.96 +/- 18.45% at 6 hours after ischemia and decreased by 50.70 +/- 15.73% at 3 days after ischemia (p<0.01). MK-801 and lamotrigine attenuated the ischemia-induced increases of gene expression of mGluR5 mRNA. In MK-801 group, the expression in basal ganglia was increased by only 0.23 +/- 5.41% at 6 hours after ischemia and decreased by 9.82 +/- 4.35% at 3 days after ischemia. In MK-801 group, the expression in hippocampus was decreased by 3.45 +/- 8.24% and 9.35 5.69% at 6 hours and 3 days after ischemia. In lamotrigine group, the expressions in hippocampus and basal ganglia were decreased by 26.66 +/- 9.85% and 9.45 +/- 5.22% at 6 hours after ischemia. CONCLUSIONS: From these results, the role of mGluR5 was defined as a mediator for neuronal damage after transient focal cerebral ischemia in hippocampus and basal ganglia.

The Assessment of Midazolam Effect as Premedication by Bispectral Index System / 대한마취과학회지

BACKGROUND: Midazolam is often used as an anxiolytic premedication before surgery, but it is difficult and complex to assess its effect. This study evaluated the bispectral index as an objective indicator of midazolam premedication and the relation of cardiovascular response to anesthetic induction. METHODS: Forty patients (aged 20 to 60 and in ASA class I or II) to undergo simple elective surgery under general anesthesia entered the study. The patients were divided into the midazolam group (n = 20) that received midazolam (0.08 mg/kg IM) and glycopyrrolate (0.2 mg IM) premedication, and the control group (n = 20) that received glycopyrrolate (0.2 mg IM) only. Then, anesthetic induction (fentanyl 1 microgram/kg, propofol 2 mg/kg, succinylcholine 1 mg/kg) was done. The bispectral index of the electroencephalogram, blood pressure, and heart rate were measured under unanesthetized conditions, after fentanyl, propofol injection, and intubation. RESULTS: The bispectral index was significantly lower in the midazolam group as compared with the control group before anesthetic induction, after fentanyl injection, and intubation. Blood pressure was not significantly different in the two groups. Heart rate was significantly lower in the midazolam group compared with the control group before anesthetic induction and after fentanyl injection. CONCLUSIONS: Midazolam-premedicated patients appear to maintain stable hemodynamics during anesthetic induction and intubation. The bispectral index can be objectively used in midazolam-premedicated patients when evaluating the degree of sedation. (Korean J Anesthesiol 2000; 38: 947~953)

The Effect of Hypertonic Saline and Mannitol against Edema Formation after Cryogenic Brain Injury in Rats / 대한마취과학회지

BACKGROUND: After experimental cryogenic cerebral injury, severe focal brain contusion develops due to blood-brain barrier breakdown and vasogenic cerebral edema formation. This study has been conducted to find out the effects of hypertonic saline against cryogenic brain edema in rats. METHODS: Thirty rats of either sex weighing 250 to 300 g underwent a 60 seconds of cryogenic brain injury. All rats were randomly divided into one of three groups; control group (n = 10), 7.5% saline group (n = 10), and 10% mannitol group (n = 10). The water contents were measured 60 minutes after cryogenic injury by using the dry-weight method. RESULTS: The water contents in the 7.5% saline and 10% mannitol groups were significantly decreased compared with the control group. The levels of edema in the 7.5% saline and 10% mannitol groups were also significantly decreased compared with the control group. Although it appeared as if that 10% mannitol might decrease edema formation more than 7.5% saline, there were no statistical differences between the 7.5% saline and 10% mannitol groups. CONCLUSIONS: Hypertonic saline (7.5%) may be as effective agent to reduce edema formation after brain trauma to the same degree as mannitol.

Different effects of dopamine on differential rotational mobility between inner and outer monolayer of synaptosomal plasma membrane vesicles isolated from bovine brain

Fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) was used to evaluate the effects of dopamine cntdot HCl on the range of the rotatioanl mobility of bulk bilayer structure of the synaptosomal plasma membrane vesicles (SPMV) isolated from whole bovine brain. In a dose-dependent manner, dopamine decreased the anisotropy (gamma), limiting anisotropy (gammainfin) and order parameter (S) of DPH in the membranes. These indicate that dopamine increased the rotational mobility of the probe in the neuronal membranes. Cationic 1-(4-(trimethylammonio)-phenyl)-6-phenylhexa-1,3,5-hexatriene (TMA-DPH) and anionic 3-(p-(6-phenyl)-1,3,5-hexatrienyl)-phenylpropionic acid (PRO-DPH) were utilized to examine the range of transbilayer asymmetric rotational mobility of the neuronal membranes. Dopamine had a greater increasing effect on the mobility of the inner monolayer as compared to the outer monolayer of the neuronal membranes. It has been proven that dopamine exhibits a selective rather than nonselective fluidizing effect within the transbilayer domains of the SPMV.

Effect of lidocaine cntdot HCl on microviscosity of phosphatidylcholine model membrane

In order to provide a basis for studying the molecular mechanism of pharmacological action of local anesthetics and to develop a fluorescence spectroscopic method which can detect the microviscosity of native and model membranes using intramolecular excimerization of 1,3-di(l-pyrenyl)propane (Py-3-Py), we examined the effect of lidocaine cntdot HCl on the microviscosity of model membranes of phosphatidylcholine fraction extracted from synaptosomal plasma membrane vesicles (SPMVPC). The excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in liquid paraffin was a simple linear function of T/eta. Based on this calibration curve, the microviscosity values of the direct probe environment in SPMVPC model membranes ranged from 234.97 +/- 48.85 cP at 4degreeC to 19.21 +/- 1.11 cP at 45degreeC. At 37degreeC, a value of 27.25 +/- 0.44 cP was obtained. The lidocaine cntdot HCl decreased the microviscosity of SPMVPC model membranes in a concentration-dependent manner, with a significant decrease in microviscosity value by injecting the local anesthetic even at the concentration of 0.5 mM. These results indicate that the direct environment by Py-3-Py in the SPMVPC model membranes is significantly fluidized by the lidocaine cntdot HCl. Also, the present study explicitly shows that an interaction between local anesthetics and membrane lipids is of importance in the molecular mechanism of pharmacological action of lidocaine cntdot HCl.

Comparing Midazolam and Morphine as Premedication by Bispectral Index System / 대한마취과학회지

BACKGROUND: The bispectral index (BIS) has been used as an indicator of a sedative state and has been considered to be related to anesthetic agents and noxious stimulus. In this study, we measured the BIS, blood pressure (BP) and heart rate (HR) during induction of anesthesia after premedication with or without midazolam or morphine and evaluated the bispectral index as an indicator of an objective evaluation of midazolam premedication and relation to the cardiovascular response to the anesthetic induction. METHODS: Seventy five patients scheduled to undergo elective surgery under general anesthesia were divided into 3 groups. Each group received midazolam and glycopyrrolate (midazolam group, n = 25), or morphine and glycopyrrolate (morphine group, n = 25), or glycopyrrolate only (control group, n = 25) as premedication (midazolam 0.08 mg/kg IM, morphine 0.05 mg/kg IM, glycopyrrorate 0.2 mg IM). Then, anesthetic induction (propofol 2 mg/kg, succynylcholine 1 mg/kg) was done. The bispectral index, blood pressure, and heart rate were measured at before induction, after propofol injection, and intubation. RESULTS: The Bispectral index was significantly lower in the midazolam group and the morphine group compared with the control group before anesthetic induction. Blood pressure was not significantly different among the three groups. Heart rate was significantly lower in the midazolam group compared with the control group before anesthetic induction. CONCLSIONS: Midazolam or morphine premedicated patients appear to maintain a stable heart rate and have a low BIS at before induction. The Bispectral index could be objectively used in midazolam-premedicated patients when evaluating the degree of sedation and predicting hemodynamic changes, and probably in morphine-premedicated patients also.

The Effects of Dexamethasone and MK-801 on Edema Formation in Middle Cerebral Artery Occlusion Model of the Rat / 대한마취과학회지

BACKGROUND: This study was conducted to determine the effects of dexamethasone and MK-801 on the formation of brain edema resulting from a focal ischemic injury by middle cerebral artery occlusion in rats. METHODS: Fifteen Sprague-Dawley rats (220 280 g) were freely allowed to drink and eat until just before surgery. Anesthesia was induced with 4% isoflurane in oxygen and then maintained with 2% isoflurane in oxygen. Ischemic injury was induced by an intraluminal suture with a blunted tip inserted into the internal carotid artery and occlusion of the middle cerebral artery. All rats were divided randomly into three groups. In group I (n = 5), normal saline 1 ml was injected intravenously 10 minutes before MCA occlusion. In group II (n = 5), dexamethasone 3 mg/kg was administered 10 minutes before injury. In group III (n = 5), a N-methyl-D-aspartate receptor antagonist, MK-801 1 mg/kg was injected 30 minutes before injury. Rectal temperatures were monitored during the experiment. After 60 minutes of MCA occlusion, the intraluminal sutures were removed and all the rats were returned to their cages. Their brain were quickly removed and the cerebral hemispheres were sepaerated into ischemic cores and penumbra zones after 1 hour of reperfusion. The separated cerebral hemispheres were dried 7 days at 60oC dry oven. The cerebral water content was assessed by the dry-weight method. RESULTS: In the dexamethasone group, there were no significant changes in cerebral edema formation in both ischemic core and the penumbra. In the MK-801 group, there were significant reductions in the brain edema formation in the penumbra (P< 0.05), but not in the core. CONCLUSIONS: Dexamethasone has no effect on ischemic brain edema; however, MK-801 is effective in the ischemic penumbra zone by reducing of edema formation.

The Efficacy of Epinephrine Test Doses during Combined Spinal-Epidural Anesthesia in Adult Patients / 대한마취과학회지

BACKGROUND: Combined spinal-epidural anesthesia has been used to reduce the side effect of spinal or epidural anesthesia. The epinephrine test dose to prevent intravascular injection of local anesthetics after subarachnoid block has not been clearly understood. The purpose of present study is to see the efficacy of simulated intravenous test dose during subarachnoid block. METHODS: 20 ASA physical status 1 and 2 patients underwent subarachnoid block with tetracaine 10 mg in hyperbaric solution at the L3-4 interspace and were divided into two groups, Group 1 (n=10) and Group 2 (n=10). 3 ml of Normal saline was injected intravenously to group 1, while 1:200,000 epinephrine 3 ml (15 microgram) was injected intravenously to group 2 at regression of sensory block to T8-10. 1:200,000 epinephrine 3 ml (15 microgram) was given to each volunteer (Group 3, n=10). Heart rate (HR) was measured at 15 seconds intervals for 3 minutes and systolic blood pressure (SBP) was measured at 1 minute intervals for 5 minutes. RESULTS: SBP increased significantly in group 2 and group 3 at 1 minute after epinephrine test dose injection. Maximal HR changes was 39.7 3.7 beat per minute in group 2 and 25.8 5.2 beat per minute in group 3. There was 100% incidence of detection of intravascular injection of 15 microgram epinephrine in both group when HR increase > or = 20 beats per minute is regarded as positive response. CONCLUSIONS: This study demonstrates that the epinephrine test dose is useful method to detect intravascular injection of local anesthetics either in the combined spinal-epidural anesthesia or epidural anesthesia. The heart rate response after injection of epinephrine was greater than the blood pressure response.

The Cardiovascular Responses and Recovery Patterns According to the Anesthetic Methods during Suspension Laryngoscopic Procedures / 대한마취과학회지

BACKGROUND: Anesthetic techniques for laryngeal microsurgery aims on modulation of sympathetic stimulation, good relaxation and rapid recovery from deep anesthesia. This study was designed to compare the influence of the different anesthetic methods on the cardiovascular responses and the recovery patterns during suspension laryngoscopic surgery. METHOD: Sixty patients of ASA class 1 or 2 scheduled for suspension laryngoscopic surgery were divided into 4 groups randomly. Two groups were anesthetized with inhalational anesthetic, enflurane, and other two groups were anesthetized with intravenous anesthetic, propofol. In each groups, esmolol or fentanyl was used as an adjunctive during anesthesia. When blood pressures increased above 30% of baseline value each adjunctive was added. The changes of blood pressure and heart rate were compared with each others during operation. Postoperatively, the start of spontaneous respiration, consciousness, memory, and the frequencies of other complications were also compared with each others. RESULT: The results were as follows; 1) The blood pressures and heart rates during operations were not different among the groups. 2) The recovery of spontaneous respiration was early in propofol esmolol group. 3) 30 minutes after operation, the consciousness state was better and complications were less in propofol groups compared with enflurane groups. CONCLUSION: From this results, it seems that propofol with nitrous oxide and supplemental fentanyl or esmolol may be useful in laryngeal microsurgery. Especially, esmolol can be a good substitute for those who can't be treated with opioids.

The Effects of Repeated Toluene Exposure on Amino Acid Neurotransmitters in the Rat Brain / 대한구급학회지

Introduction: It was aimed to investigate the effect of chronic toluene exposure on amino acid neurotransmitters in the rat brain, corpus striatum. METHODS: Twenty four male Sprague-Dawley rats were divided into one of three groups, control, acute, and chronic. Each groups was for the microdialysis to estimate the changes of amino acid neurotransmitters, aspartate, glutamate, and citrulline before, during, and after 3,000 ppm toluene exposure for 2 hours. RESULTS: The results were as follows; 1) Aspartate and glutamate concentration were generally decreased in the toluene inhalation groups compared with the control group and more significantly decreased in chronic inhalation group than other groups. 2) Citrulline that expressed the activity of nitric oxide synthase and taurine as an inhibitory amino acid showed no significant differences between all groups. Based on these results, it is suggested that the decreasing excitatory amino acids, aspartate and glutamate, are partly contributed to the toxic mechanisms of toluene in rat brain.

Postoperative Pain Control in Low Abdominal Surgery; Comparison of Subarachnoid Block with Morphine or Morphine and Clonidine and Continuous Epidural Block with Morphine and Bupivacaine / 대한마취과학회지

BACKGROUND: Although epidural block has been widely used to control post operative pain, still there are many problems to be solved such as inadequate pain control and difficulty in its techniques. Subarachnoid morphine and clonidine injection also has been used to control postoperative pain and as adjuvant to spinal anesthesia. We compared subarachnoid morphine or morphine and clonidine injection with epidural morphine and bupivacaine injection for postoperative pain control. METHOD: The effect of the different types of postoperative pain control method in low abdominal surgery were investigated. 30 patients were randomly divided into one of three groups; single intrathecal morphine injection (group M), single intrathecal morphine and clonidine injection (group M/C) and continuous epidural morphine and bupivacaine injection (group M/B) prior to induction of general anesthesia. Visual analogue scale (VAS), Prince-Henry Hospital score (PHS), patient satisfaction score and the side effects were investigated at emergence, 1, 2, 4, 8, 12, 24 and 48 hours after emergence of anesthesia. The blood pressure and heart rate were monitored 0, 5, 10 and 30 min, 1, 2, 24 and 48 hours after block for monitor the hemodynamic changes. RESULT: In group M/C, the VAS showed statistically significant decrease till first 24 hours after block and in group M/B after then (p<0.05). PHS and patient satisfaction scores were similar in all groups. The side effects, pruritis and nausea, by the opioids were more frequent in subarachnoid groups versus epidural group but that were tolerable without medication in most cases. In spite that systolic and diastolic blood pressures and heart rate were significantly low (p<0.05) in group M/C, there were no severe hypotension or bradycardia that need treatment. CONCLUSION: From these results, it seems that intrathecal morphine and clonidine combination therapy can be used as an another choice for postoperative pain control in low abdominal surgery.

The Effect of Nitric Oxide on Edema Formation in Cryogenic Brain Injury Model of the Rat / 대한마취과학회지

BACKGROUND: Nitric oxide (NO) is a simple molecule with a complex involvement in a wide variety of biologic functions. However, whether NO protects or aggravates brain injury is still controversial. This study was conducted to determine the effect of nitric oxide on the formation of brain edema resulting from a focal cryogenic injury in rats. METHODS: Thirty nine Sprague-Dawley rats (200~250 gm) were allowed food and water ad libitum. Anesthesia was induced in a specially designed plastic box with 5% halothane in oxygen. In experiment I (24 rats), animals were divided randomly into eight group (3 rats in each group) according to the decapitation time in control, 15, 30, 45, 60, 90, 120, and 180 min. Cryogenic injury was made by pouring liquid nitrogen to exposed temporo-parietal area through metal funnel for 60 seconds. After cryogenic injury, brain was quickly removed and cerebral hemispheres were seperated. Separated cerebral hemispheres were dried in a drying oven for 7 days at 60 degrees C. Cerebral water content was assessed by dry-weight method. In experiment II (15 rats), one subgroup (n=8) was control group, normal saline 0.5 ml was injected intraperitoneally 30 minutes before injury. the other (n=7) was experimental group, and a competitive nitiric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME), was given intraperitoneally 30 minutes before injury in a dose of 20 mg/kg. Body temperature was monitored during whole experiment. Ninety minutes after injury, brain was quickly removed and cerebral hemispheres were seperated. The cerebral water content of separated cerebral hemisphere was assessed by dry-weight method. RESULTS: In time courses of cryogenic brain edema of experiment I, the amount of brain edema was increased till 90 minutes after cryogenic brain injury and then decreased. In L-NAME group of ex-periment II, the amount of cerebral edema was not changed significantly (p<0.05). But, there was a tendency of decrease in brain edema formation in L-NAME group than control group. CONCLUSION: It was not proved that nitric oxide had a major role in the edema formation aftercryogenic brain injury, but it still seems that nitric oxide has at least partly involved in the pathogenesis of cerebral edema resulting from traumatic brain injury.