• Title/Summary/Keyword: Local Anesthetics

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Characteristic Intracelluar Response to Lidocaine And MK-801 of Hippocampal Neurons: An In Vivo Intracellular Neuron Recording Study

  • Choi, Byung-Ju;Cho, Jin-Hwa
    • 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.

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Effectiveness Evaluation of Displacement Accommodatable Pressure Measuring Jig for Quality Assessment of Pressure Application Device (압력 인가 장치의 품질관리를 위한 변위 수용이 가능한 압력 측정용 지그의 유효성 평가)

  • Mun, Chang-Su;Jun, Sung-Chul;Noh, Si-Cheol
    • 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.

Efficacy of sucrose application in minimizing pain perception related to dental injection in children aged 3 to 9 years: a randomized control trial

  • Ishani Ratnaparkhi;Jasmin Winnier;Divya Shetty;Sanjana R. Kodical;Reema Manoj;Shilpa S Naik
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.24 no.2
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    • pp.109-117
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    • 2024
  • Background: Dental fear and anxiety are significant challenges in managing behavior in children. Oral administration of sucrose or sweet-tasting solutions has shown effectiveness in reducing procedural pain in infants and neonates. This study aimed to investigate whether pre-application of sucrose solution had an effect on minimizing pain perception during injection and to assess the potential impact of the child's age and sweet preference. Methods: A randomized control clinical trial was conducted on 60 children aged 3-9 years requiring buccal infiltration injections. Following parental consent, demographic data of the children were recorded. Sweet preferences was assessed using a modified forced-choice test. Children were equally and randomly allocated into study (sucrose) and control groups using a lottery method. Sucrose solution or distilled water, respectively, was applied to the lateral surface of the tongue for 2 min. Topical anesthetic was applied at the site of injection, followed by local anesthesia administration. The children rinsed their mouths thrice with water immediately after anesthetic injection. A video was recorded during injection which was then scored by three blinded examiners on the Sound Eye Motor (SEM) scale. The children also self-evaluated using Wong-Baker Faces Pain Rating Scale (WBFPS). Results: The mean SEM scores and WBFPS scores were analyzed using the Kruskall-Wallis test. The mean SEM score in the study group was 1.37 ± 0.61, compared to 3.17 ± 0.87 in the control group, showing a statistically significant difference (P < 0.001). Mean pain scores assessed by WBFPS in the study group were 0.60 ± 1.4, while in the control group, they were 6.27 ± 2.33, also showing a statistically significant difference (P < 0.001). Children with a sweet preference demonstrated a subjective reduction in pain perception. Conclusion: Application of sucrose before dental injections in children helps to minimize pain upon injection across all age groups.

Effect of Inferior Alveolar Nerve Block Anesthesia on Taste Threshold (하치조신경 전달마취가 미각역치에 미치는 영향)

  • Ahn, Young-Joon;Kim, Seung-Whan;Kim, Mee-Eun;Kim, Ki-Suk
    • Journal of Oral Medicine and Pain
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    • v.32 no.2
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    • pp.177-185
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    • 2007
  • Iatrogenic injury following dental treatments and the use of local anesthetics may cause taste disorders. The aims of this study were to investigate quantitative and qualitative changes of taste due to unilateral inferior alveolar nerve block anesthesia and further to evaluate potential effects on taste function related to anesthesia or hypoesthesia of inferior alveolar nerve, possibly occurring after dental procedure. 30 healthy volunteers in their twenties participated in this study (male to female = 1:1, mean age of $24.0{\pm}1.8$ years). Each subject received inferior alveolar nerve block anesthesia on his or her right side with 2% lidocaine HCl containing 1:100,000 epinephrine. Before and after anesthesia, electrogustometric test and chemical localized test for salty, sweet, sour and bitter tastes were performed on the eight sites in the oral cavity; right and left anterior and lateral tongue and circumvallate papilla of the tongue and soft palate. Unilateral inferior alveolar nerve anesthesia produced elevation of electrical taste threshold and reduction of intensity ratings for all 4 tastes (salty, sweet, sour and bitter) over anterior and lateral tongue and circumvallate papilla on the ipsilateral side (p<0.05). Contralateral sides exhibited decreased intensity ratings for salty and sweet taste (p<0.05) on anterior and lateral tongue while there was no significant difference in electrogustometric testing. Based on the results of this study, it is assumed that unilateral local anesthesia on inferior alveolar nerve can affect chorda tympani and glossopharyngeal nerves on the same side, leading to taste deficits. Taste intensity on the contralateral side may, in part, be deteriorated as well.

The Effect of Lidocaine Dose and Pretreated Diazepam on Cardiovascular System and Plasma Concentration of Lidocaine in Dogs Ansthetized with Halothane-Nitrous Oxide (Diazepam 전투여와 Lidocaine 투여용량이 혈중농도 및 심혈역학적 변화에 미치는 영향)

  • Lee, Kyeong-Sook;Kim, Sae-Yeon;Park, Dae-Pal;Kim, Jin-Mo;Chung, Chung-Gil
    • Journal of Yeungnam Medical Science
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    • v.10 no.2
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    • pp.451-474
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    • 1993
  • Lidocaline if frequently administered as a component of an anesthetic : for local or regional nerve blocks, to mitigate the autonomic response to laryngoscopy and tracheal intubation, to suppress the cough reflex, and for antiarrythmic therapy. Diazepam dectease the potential central nervous system (CNS) toxicity of local anesthetic agents but may modify the sitmulant action of lidocaine in addition to their own cardiovascular depressant. The potential cardiovascular toxicity of local anesthetics may be enhanced by the concomitant administration of diazepam. This study was designed to investigate the effects of lidocaine dose and pretreated diazepam to cardiovascular system and plasma concentration of lidocaine. Lidocaine in 100 mcg/kg/min, 200 mcg/kg/min, and 300 mcg/kg/min was given by sequential infusion to dogs anesthetized with halothane-nitrous oxide (Group I). And in group II, after diazepam pretreatment, lidocaine was infused by same way when lidocaine was administered in 100 mcg/kg/min, the low plasma levels ($3.97{\pm}0.22-4.48{\pm}0.36$ mcg/ml) caused a little reduction in cardiovascular hemodynamics. As administered in 200 mcg/kg/min, 300 mcg/kg/min, the higher plasma levels ($7.50{\pm}0.66-11.83{\pm}0.59$ mcg/ml) reduced mean arterial pressure (MAP), cardiac index (CI), stroke index (SI), left ventricular stroke work index (LVSWI), and right ventricular stroke work index (PVSWI) and increased pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), systemic vascular resistance index (SVRI), but was associated with little changes of heart rate (HR), mean pulmonary artery pressure (MPAP), and pulmonary vascular resistance index (PVRI). When lidocaine with pretreated diazepam was administered in 100 mcg/kg/min, the low plasma level, the lower level than when only lidocaine administered, reduced MAP, but was not changed other cardiovascular hemodynamics. While lidocaine was infused in 200 mcg/kg/min, 300 mcg/kg/min in dogs pretreated diazepam, the higher plasma level ($7.64{\pm}0.79-13.79{\pm}0.82$ mcg/ml) was maintained and was associated with reduced CI, SI, LVSWI and incresed PAWP, CVP, SVRI but was a little changes of HR, MPAP, PVRI. After $CaCl_2$ administeration, CI, SI, SVRI, LVSWI was recovered but PAWP, CVP was rather increased than recovered. The foregoing results demonstrate that pretreated diazepam imposes no additional burden on cardiovascular system when a infusion of large dose of lidocaine is given to dogs anesthetized with halothanenitrous oxide. But caution may be advised if the addition of lidocaine is indicated in subjects who have impared autonomic nervous system and who are in hypercarbic, hypoxic, or acidotic states.

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Objectives and Contents of Basic Medical Sciences in Nursing Education (간호학 교육에서 기초의과학 교과목별 목표와 내용에 대한 연구)

  • 최명애;신기수
    • Journal of Korean Academy of Nursing
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    • v.29 no.6
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    • pp.1455-1468
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    • 1999
  • The purpose of this study was to investigate the objectives and contents of basic medical sciences at department of nursing in college of nursing, and junior college of nursing, thus ultimately providing the basic data to standardize the curriculum of the basic medical sciences in nursing education. Seventy eight professors who were in charge of teaching basic medical sciences to at 22 colleges of nursing/ department of nursing, and 20 junior colleges of nursing responded to the questionnaires that consisted of the questions regarding objectives and contents, of basic medical sciences. Based on the description of objectives, the description related to nursing, nurse, nursing science was cathegorized as on objective applicable to nursing science, the description related to medicine or clinical medicine as medical model, the description without description related to medicine was cathegorized as knowledge acquisition. The number of schools corresponding to each category were summerized in descending order. The objectives of basic medical sciences were categorized by concepts and number of schools corresponding to the categorized concept. The findings of the study are as follows ; 1. The subjects of basic medical science identified were physiology, anatomy, biochemistry, pathology, microbiology, and pharmacology in most colleges of nursing and junior colleges. Two colleges of nursing/department of nursing (9.1%) and 19 junior colleges of nursing(95%) did not offer biochemistry, 1 college of nursing /department of nursing(5%) did not offer pathology & pharmacology. 2 junior colleges of nursing (10%) did not offer pharmacology, 1 junior college of nursing(5%) did not offer pathology. The other 1 junior college of nursing did not offer microbiology. 2. Objectives of physiology were to acquire knowledge and understanding on human function in both 6 (50%) colleges and 5 junior colleges. Objectives of anatomy were to acquire knowledge on human structure in both 4 (57%) colleges and 2 (50%) junior colleges; knowledge applicable to nursing sciences in both 3 (42.8%) colleges and 2 (50%) junior colleges. Objectives of biochemistry was to obtain knowledge and understanding on biochemistry, and understanding of basic concepts about biochemistry. Objectives of pathology were to obtain knowledge and understanding on pathology in both 4 (57.1%) colleges and 5(62.5%) junior colleges. Objectives of microbiology were to acquire knowledge and understanding on microbiology in both 5(83.8%) colleges and 6(85.7%) junior colleges. Objectives of pharmacology were to acquire knowledge on pharmacology in both 7(100%) colleges and 8(100%) junior colleges. 3. Contents of physiology in 19 (100%) schools were membrane transport, digestion, circulation, nervous system and respiration. In 16(84.2%) were kidney and muscle, that in 13(68.4%) were endocrine physiology. In 11(57.9%) were introduction and that in 9(47.4%) were structure and function of cells. Contents of anatomy in 11(100%) schools were skeletal system, muscle system, digestive system, circulatory system, concepts regarding human structure. In 10(90.9%) schools were endocrine system and nervous system, and in 5(45.5%) schools were blood, urinary system and cell. Contents of biochemistry in 6(100%) schools were history of biochemistry, body regulating factor, bioenergy, health and nutrition, nutrition of cell, energy production system. In 5(83.3%) schools were metabolism of protein and carbohydrate and enzyme, and in 3(50%) schools were metabolism of energy and fat. Contents of microbiology in 13(100%) schools were environment and influenc of bacteria, virus, G(-) rods, purulent cocci, G(+) rods. In 10 (76.9%) were immunity, diphtheria, enterobacteria, and in 9(69.2%) were spirochete, rickettsia and clamydia, and that in 6(46.2%) were sterilization and disinfection. Contents of pathology in 14(100%) schools were cell injury and adaptation, inflammation, respiratory diseases, circulatory diseases. In 10(71.4%) were neurological disorders, in 8(57.1%) were immunity and disease, and in 7 (50%) were tumor and progressive changes. Contents of pharmacology in 15(100%) were cardivascular drugs, introduction to pharmacology, hypnotics, analgesics, local anesthetics, an ticonvulsants. In 12(80%) were drugs activity on sympathetic and parasympathetic nervous system, and in 11(73%) were sulfa drugs, antibiotics, drug abuse and addiction.

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