• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.25-34
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• 2005

A trigger point injection (TPI) has been reported to have an immediate analgesic effect, and to be one of the most widely employed treatment methods of myofascial pain. There are normal saline, local anesthetics, and steroids as the solutions frequently used in TPI. They can be used separately or in combination. Local anaesthetics have myotoxicity in proportion to its concentration. The purpose of this study was to evaluate microstructural changes in point of the myotoxic effects of the combined solution of lidocaine and dexamethasone (a local anesthetic and a steroid) after being injected into the muscle of BALB/c mice. And this study tested solutions with various concentration separately and in combination, to find out proper concentration of solution without muscular tissue damage. This study shows that lidocaine and dexamethasone combination is not histologically myotoxic in case of the concentration of lidocaine less than 1.5%. Also it is suggested from this study that this combined solution will have an analgesic and anti-inflammatory effect. Hereafter continuous study should be performed to reveal that these results can be applied to human when lidocaine and dexamethasone combination is used as an injection modality of TrP treatment.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.39-42
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• 2005

Background: Besides its general anesthetic effect, ketamine interacts with sodium channels in a local anesthetic-like fashion, including the sharing of binding sites with those commonly used by clinical local anesthetics. This study evaluated the dose related effects of ketamine during epidural anesthesia with 0.5% ropivacaine. Methods: Sixty ASA physical status I II patients, scheduled for minor elective surgery under epidural anesthesia using 0.5% ropivacaine, were randomly divided into three groups (n = 20 each). The patients initially received either 0.5% ropivacaine (group 1), ketamine (0.1 mg/kg) in addition to the epidural 0.5% ropivacaine (group 2) or ketamine (0.2 mg/kg) in addition to the epidural 0.5% ropivacaine (group 3). The regression of sensory block was assessed by transcutaneous electric stimulation (TES), equivalent to a surgical incision. Motor block was assessed using the Modified Bromage's scale. Episodes of bradycardia, hypotension and sedation were also recorded. Results: There were no significant differences among the three groups in the maximal levels of sensory block or the times taken for these levels to be reached. The mean times for the block to regress to two and four segments below the maximal level were significantly prolonged by epidural ketamine. Conclusions: Epidural ketamine prolongs the duration of ropivacaine epidural anesthesia. These results suggest that ketamine has local anesthetic-like actions.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.3
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• pp.297-305
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• 1998

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.413-422
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• 2012

The purpose of this study is to investigated the mechanism of pharmacological action of local anesthetic and provide the basic information about the development of new effective local anesthetics. Fluorescent probe techniques were used to evaluate the effect of lidocaine HCl on the physical properties (transbilayer asymmetric lateral and rotational mobility, annular lipid fluidity and protein distribution) of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex, and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) and 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups, and radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py. Lidocaine HCl increased the bulk lateral and rotational mobility of neuronal and model membrane lipid bilayes, and had a greater fluidizing effect on the inner monolayer than the outer monolayer. Lidocaine HCl increased annular lipid fluidity in SPMV lipid bilayers. It also caused membrane proteins to cluster. The most important finding of this study is that there is far greater increase in annular lipid fluidity than that in lateral and rotational mobilities by lidocaine HCl. Lidocaine HCl alters the stereo or dynamics of the proteins in the lipid bilayers by combining with lipids, especially with the annular lipids. In conclusion, the present data suggest that lidocaine, in addition to its direct interaction with proteins, concurrently interacts with membrane lipids, fluidizing the membrane, and thus inducing conformational changes of proteins known to be intimately associated with membrane lipid.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.18-23
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• 2007

Purpose: Anthropometry can be divided into two methods, direct anthropometry and indirect anthropometry. The most ideal and accurate method is a direct anthropometry. However, it is difficult to measure in the case of children because of poor cooperation, and it lacks re-productivity. Cast model has advantages of three dimensional featuring, inexpensive and easy fabrication. This study is conducted to find out an accuracy of indirect anthropometry on cast model by comparing it with direct anthropometry. Methods: Total 48 cleft lip nasal deformity patients (unilateral, 40; bilateral, 8) were included in this study. Cast models were made before surgery under general anesthesia with alginate impression material and model plaster. Eleven linear measurements among 7 landmarks were taken as direct anthropometry before surgery with Castroviejo spreading caliper. At the same time, indirect anthropometry on cast model was done at the same linear distances as well. Results: Of the total 11 linear measurements, both ala lengths, both columella lengths, nose width, projective distance between facial insertion points of the ala, projective distance between the alar base points, right nostril floor width, and columella width were statistically correlated between indirect anthropometry on cast model and direct anthropometry. However, the nasal tip protrusion and the left nostril floor width were not statistically correlated. Conclusion: Accuracy of indirect anthropometry on cast model can be influenced by cast model fabrication techniques and correct identification of landmarks. Nasal tip protrusion could be reduced by compression of the nasal tip in the process of cast model fabrication and nostril floor width can be varied by muscle relaxation of anesthetics and incorrect identification of subalare in cleft lip nasal deformity. If sufficient care is taken to make cast model and to define landmarks exactly, indirect anthropometry on cast model can be a reliable method as direct anthropometry.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.283-289
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• 2002

The effects of electroacupuncture (EA) at SP-6 with different durations on the minimum alveolar concentration (MAC) and on the cardiovascular system were evaluated in dogs under isoflurane anesthesia. Eight healthy male beagles were randomly assigned to four study groups (n = 5/group) with washout period of 7 days for recovery and anesthetic withdrawal between experiments. Four study groups were control, nonacupoint electrical stimulation (NA), EA for 30 minutes (SP-6) and continuous EA for 70 or 90 minutes (SP-6C). For the nonacupoint electrical stimulation group, needles were inserted into the nonacupoint at the muscle bellies of left triceps brachii and right quadriceps femoris. MAC and cardiovascular parameters were determined after EA at SP-6 acupoint and at nonacupoint. Thirty minutes of EA and continuous EA until re-determination of MAC at SP-6 acupoint lowered the MAC of isoflurane by 21.3$\pm$8.0% and 16.1$\pm$4.6%, respectively (p<0.05). The decrements in MAC values were not significantly different between two EA groups. However, electrical stimulation of nonacupoint did not induce a significant change in MAC. In SP-6 and SP-6C groups, significant changes in cardiovascular parameters were not observed. These results indicate that EA at SP-6 have an advantage in isoflurane anesthesia in terms of reducing the requirement for anesthetics and minimizing cardiovascular side effects. EA for 30 minutes at maximum might be the sufficient time to produce acupuncture analgesia.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.104-108
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• 2007

The purpose of the study is to evaluate the clinical antagonistic effect of atipamezole(0.25 mg/kg, IM) in cats anesthetized with tiletamine-zolazepam ($Zoletil^{(R)}$, 10 mg/kg, IM) and medetomidine (0.05 mg/kg, IM). Twelve healthy 1 year old Korean mixed breed cats were used for this study. They were 4 males and 8 females. These cats were randomly assigned to two groups. One was control group ($Zoletil^{(R)}$ + medetomidine, ZM), and the other was treatment group ($Zoletil^{(R)}$ + medetomidine and antagonism by atipamezole, ZMA). All cats were examined 15 minutes before, 5, 25, 65 and 105 minutes after administration of tiletamine-zolazepam and medetomidine. Atipamezole was injected intramuscularly 20 minutes after ZM administation. Recovery time, heart rate, respiratory rate, total plasma protein and blood glucose were significantly different between ZM group and ZMA group (P<0.05). However, rectal temperature was not significantly different between ZM group and ZMA group. Two groups were able to induce sternal recumbency within 2 minutes and lateral recumbency within 4 minutes after the anesthetics injection. Mean sternal position time ($mean{\pm}SD$) was $174.0{\pm}44.6\;and\;116.2{\pm}27.3$ minutes, and mean standing position time was $210.8{\pm}45.6\;and\;154.2{\pm}21.1$ minutes in ZM and ZMA group, respectively. In these two groups, adverse effects during recovery time from anesthesia were not seen. As a result, the ZMA group had a faster recovery than the ZM group. Thus it was concluded that atipamezole could exert a useful reversal effect in cats anesthetized with medetomidine-tiletamine/zolazepam combination.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.15 no.1
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• pp.50-54
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• 2019

Muscular dystrophy (MD) is a heterogeneous group of inherited neuromuscular disorders, characterized by progressive muscle weakness. Severity of the disease ranges from mild to severe, and the disease is mostly caused by mutations in a number of genes. These genetic mutations cause lack of proteins which are essential for muscle cell stability. Muscle fibers are gradually replaced by fat and fibrous tissue. The muscles of the head and neck are affected in several types of MD that manifest as altered craniofacial morphology and dental malocclusion. A 3-year-10-month old, 15.0 kg boy with MD presented to Seoul National University Dental Hospital, Seoul, South Korea because of extensive carious teeth. A number of dental caries in primary dentition were identified during clinical oral examination. Due to dental anxiety and underlying systemic disease, general anesthesia was considered. General anesthesia was induced and maintained with intravenous anesthetics, propofol and remifentanil. Caries treatments - resin restoration, pulpectomy, zirconia crown restoration, stainless steel crown restoration - were performed. Under general anesthesia, successful dental procedure was done. Total intravenous anesthesia (TIVA) was performed instead of inhalation anesthesia in order to avoid risk of complications such as malignant hyperthermia and life-threatening rhabdomyolysis. With decreasing muscle function, plaque control becomes more difficult and leads to gingivitis. Especially, the open-mouth posture worsens gingivitis and can leads to malocclusions and problems in swallowing. Regular and periodic dental care is essential for maintaining oral health for patients with MD.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.61-66
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• 2020

Recently, a variety of electric anesthetics devices have been developed and used in clinical practice to reduce the fatigue of the operator during local anesthesia for dental procedures and to compensate for the disadvantages of manual anesthesia device. In this electric anesthesia injection device, the accurate and constant delivery of pressure for drug infusion is a very important performance factor. In order to evaluate the accuracy of the transfer pressure, a small pressure gauge using a load cell is often used, but since the elastic body inside the load cell may not be able to accommodate a sufficient displacement, an error may occur when evaluating pressure performance. For these reasons, in this study, we proposed and evaluated a silicon-chrome steel (Si-Cr steel) spring jig that can accommodate relatively large displacements that can be used when evaluating the performance of a pressure-controlled pressure application device using a load cell type pressure gauge. As a result of the pressure transmissibility test and repeated measurement results using a commercial dental anesthesia injection device, a more stable result was obtained when using a spring jig, and it was confirmed that the frequency of abnormally high measurement was reduced.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.145-153
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• 2022

Background: Postoperative analgesia (POA) is an important determinant of successful treatment. Dexmedetomidine (DEX) has recently gained attention as a promising adjuvant to local anesthetics (LA). The present study aimed to evaluate the efficacy and safety of levobupivacaine (LB) as an adjuvant during inferior alveolar nerve block (IANB) in the extraction of lower impacted third molars (LITM). Methods: A prospective, randomized, placebo-controlled, triple-blind, parallel-arm, and clinical study was performed on 50 systemically healthy participants who required removal of an asymptomatic LITM. Using a 1:1 distribution, the participants were randomized into two groups (n = 25). Group L (control group) received 1.8 mL of 0.5% LB and 0.2 mL normal saline (placebo) and Group D (study group) received a blend of 1.8 mL of 0.5% LB and 0.2 mL (20 ㎍) DEX. The primary outcome variable was the duration of POA and hemodynamic stability, and the secondary variable was the total number of analgesics required postoperatively for up to 72 h. The participants were requested to record the time of rescue analgesic use and the total number of rescue analgesics taken. The area under the curve was plotted for the total number of analgesics administered. The pain was evaluated using the visual analog scale. Data analysis was performed using paired students and unpaired t-test, Mann-Whitney U test, Chi-square test, and receiver operating characteristic analysis. Statistical significance was set at P < 0.05. Results: The latency, profoundness of anesthesia, and duration of POA were statistically significant (P < 0.05). The differences between mean pain scores at 6, 12, 24, 48, and 72 h were found to be significant (each P = 0.0001). Fewer analgesics were required by participants in group D (2.12 ± 0.33) than in L (4.04 ± 0.67), with a significant difference (P = 0.0001). Conclusion: Perineurally administered LA with DEX is a safe, effective, and therapeutic approach for improving latency, providing profound POA, and reducing the need for postoperative analgesia.