• 대한의용생체공학회:의공학회지
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• 제24권1호
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• pp.45-53
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• 2003

Based on the 4-compartmental pharmacokinetic model developed in PART1, target-controlled infusion(TCI) pump system was designed and evaluated. The TCI system consists of digital board including microcontroller and digital signal process(DSP), analog board, motor-driven actuator, user friendly interface, power management and controller. It provides two modes according to the drugs: plasma target concentration and effect target concentration. Anaesthetist controls the depth of anaesthesia for patients by adjusting the required concentration to maintain both plasma and effect site in drug concentration. The data estimated in DSP include infusion rate, initial load dose, and rotation number of motor encoder. During TCI operation, plasma concentration. effect site concentration, awaken concentration, context-sensitive decrement time and system error information are displayed in real time. Li-ion battery guarantees above 2 hours without power line failure. For high reliability of the system, two microprocessors were used to perform independent functions for both pharmacokinetic algorithm and motor control strategy.

• 대한치과마취과학회지
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• 제12권3호
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• pp.177-181
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• 2012

Amyotrophic lateral sclerosis (ALS) is one of the major neurodegenerative diseases that involves degeneration at all levels of the motor system- from the cortex to the anterior horn of the spinal cord. Patients with ALS often have difficulty of ambulation for dental treatment though they have poor oral hygiene state. General anesthesia may cause respiratory problem due to its high sensitivity to muscle relaxant and weakened upper airway. In this case report, 38-year-old female patient with ALS required many dental treatments. Conscious sedation with intravenous target controlled infusion method was successfully employed and patient was discharged without any complications.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권3호
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• pp.165-173
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• 2016

Dentists often sedate patients in order to reduce their dental phobia and stress during dental treatment. Sedatives are administered through various routes such as oral, inhalation, and intravenous routes. Intravenous administration has the advantage of rapid onset of action, predictable duration of action, and easy titration. Typically, midazolam, propofol or dexmedetomidine are used as intravenous sedatives. Administration of these sedatives via infusion by using a syringe pump is more effective and successful than infusing them as a bolus. However, during intravenous infusion of sedatives or opioids using a syringe pump, fatal accidents may occur due to the clinician's carelessness. To prevent such risks, smart syringe pumps have been introduced clinically. They allow clinicians to perform effective sedation by using a computer to control the dose of the drug being infused. To ensure patient safety, various alarm features along with a drug library, which provides drug information and prevents excessive infusion by limiting the dose, have been added to smart pumps. In addition, programmed infusion systems and target-controlled infusion systems have also been developed to enable effective administration of sedatives. Patient-controlled infusion, which allows a patient to control his/her level of sedation through self-infusion, has also been developed. Safer and more successful sedation may be achieved by fully utilizing these new features of the smart pump.

• 대한치과마취과학회지
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• 제10권2호
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• pp.209-213
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• 2010

Anxiety and fear is two main factors that keep patients from going to dental clinic. Especially, patients may feel implants operations are more traumatic. Intravenous conscious sedation for dental treatment can make patient comfortable and relaxable. Midazolam is more popular for sedation for dental treatment, but target-controlled infusion (TCI) of propofol and remifentanil is gaining wide popularity. A 54-year-old female patient who had severe dental phobia was referred to our dental hospital. She had past history of 2 times of hyperventilation and syncope during dental treatment. The patient showed a lot of dental anxiety and fear to dental treatments and stress reduction protocol was needed. We administered intravenous conscious sedation using target controlled infusion system with remifentanil and propofol. During sedation, we monitored the status of consciousness with bispectral index and vital signs. Dental treatment could be finished successfully without any problems.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권3호
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• pp.169-175
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• 2018

Background: The objective of this study was to compare hemodynamic and recovery characteristics of total intravenous anesthesia using propofol target-controlled infusion (TCI) versus sevoflurane for extraction of four third molar teeth. Methods: One hundred patients undergoing extraction of four third molar teeth under general anesthesia were randomized to one of two groups. Group 1 received propofol TCI-oxygen for induction and propofol TCI-oxygen-air for maintenance. Group II received a propofol bolus of 2 mg/kg for induction and sevoflurane-oxygen-air for maintenance. Heart rate, mean arterial pressure (MAP), operating time, time to emergence, nausea and vomiting, and sedation and pain scores were measured in each group. Results: Demographic data, including age, gender, weight, and height, were not significantly different between the two groups. The MAP was significantly higher after intubation (P = 0.007) and injection of anesthesia (P = 0.004) in the propofol group than in the sevoflurane group, with significant reflex bradycardia (P = 0.028). The mean time to emergence from anesthesia using propofol was 25 s shorter than that of sevoflurane (P = 0.02). Postoperatively, the propofol group was less sedated than the sevoflurane group at 30 min (0.02 versus 0.12), but this difference was not significant (P = 0.065). Conclusion: Both propofol TCI and sevoflurane are good alternatives for induction and maintenance of anesthesia for short day-case surgery. However, propofol TCI does not blunt the hemodynamic response to sudden, severe stimuli as strongly as sevoflurane, and this limitation may be a cause for concern in patients with cardiac comorbidities.

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권4호
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• pp.217-226
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• 2019

Background: We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects. Methods: We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1). Results: For all groups, the duration of dental treatments was $43{\pm}18$ minutes, total sedation time was $73{\pm}23$ minutes, and total BIS values was $57{\pm}12$. The propofol maintenance dosage values for each group were: mental retardation, $3{\pm}0.5(2-4){\mu}g/ml$; autism, $3.1{\pm}0.7(2-5){\mu}g/ml;$; brain lesion, $2.8{\pm}0.7(1.5-5){\mu}g/ml;$; genetic disease, $2.9{\pm}0.9(1-4){\mu}g/ml;$ and dementia $2.3{\pm}0.7(1-3.4){\mu}g/ml;$. Conclusions: The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

• 대한의용생체공학회:의공학회지
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• 제23권5호
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• pp.341-349
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• 2002

본 논문에서는 혈중 목표 농도 자동 조절기(Target-controlled infusion system. TCI)를 개발하는 것으로써, 마취의가 혈중 목표 농도를 설정하면 사용약제의 약동학적 모델링에 의해서 주입속도를 자동적으로 계산하여 마취의 깊이를 예측하는 약동학적 모델의 수립과 검증 방법을 설명한다. 정확한 약동학적 모델의 구축은 시스템의 성능에 큰 영향을 미치므로 먼저 PART 1에서는 약동학적 모델을 구축하되 3-콤파트먼트 모델과 4-콤파트먼트 모델로 해석하였다. 기존의 TCI에서 사용하고 있는 3-콤파트먼트 모델에 가상의 효과처 구획(Effect Site Compartment)을 만들고 이를 네 버내 구획으로 가정한 4-콤파트먼트 모델(Four-Compartment Model)을 수립하였고, matlab 5.0을 이용하여 비교 분석하였다. 모델은 혈중 목표 농도 주입(Plasma Targeting)과 효과처 목표 농도 주입(Effect Site Targeting), 혈중 농도 유지를 위한 주입율 계산과 기타 마취 상태를 추정하는 정보를 포함한다. 시뮬레이션의 결과를 바탕으로 4-콤파트먼트 모델을 디지털 z-변환을 거쳐 디지털시그널프로세서에 프로그램하고 TCI시스템의 적용가능성을 평가하였다. 정맥 마취용 TCI는 오동작에 대한 검증이 반드시 요구되므로 구축한 모델링에 대한 시뮬레이션의 평가 방법을 설정하였다. 기존의 TCI시스템과는 달리 약동학적 약물 전달 속도 상수(k-파라미터)를 독립적으로 조절할 수 있는 기능이 추가되어 다양한 약제의 사용이 가능할 뿐만 아니라 새로운 약동학적 모델의 개발과 평가에 기여하게 되고, 환자의 체형과 병명에 따른 약동학적 모델의 변화에 대응할 수 있게 하였다.

• The Korean Journal of Pain
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• 제22권1호
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• pp.39-46
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• 2009

Background: Ketamine has an indirect sympathetic stimulation effect. We investigated heart rate variability (HRV) as a marker of cardiac autonomic function after a target controlled infusion (TCI) of ketamine with a plasma concentration of 30 or 60 ng/ml. Methods: In 20 adult volunteers, the mean of the R wave to the adjacent R wave interval (RRI), the range of RRI, the root mean square successive difference of intervals (RMSSD), the total power, the low frequency (LF, 0.04-0.15 Hz) power, the high frequency (HF, 0.15-0.4 Hz) power, the normal unit HF (nuHF), the normal unit LF (nuLF), the LF/HF ratio and the SD1 and the SD2 in the Poincare plot were measured before and after a TCI of ketamine. We observed for any psychedelic symptoms or sedation. Results: There were no differences in the mean and range of the RRI, RMSSD, total power, LF power, HF power, nuHF, nuLF, LF/HF ratio, SD1 and SD2 between before and after ketamine administration. The OAA/S score was higher and there were more psychedelic symptoms with a 60 ng/ml plasma concentration than with a 30 ng/ml plasma concentration. Conclusions: This study did not show any effect of a low plasma concentration of ketamine on the autonomic nervous system.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권2호
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• pp.117-128
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• 2022

Background: Moderate sedation is an integral part of dental care delivery. Target-controlled infusion (TCI) has the potential to improve patient safety and outcome. We compared the effects of using TCI to administer remifentanil/manual bolus midazolam with manual bolus fentanyl/midazolam administration on patient safety parameters, drug administration times, and patient recovery times. Methods: In this retrospective chart review, records of patients who underwent moderate intravenous sedation over 12 months in a private dental clinic were assessed. Patient indicators (pre-, intra-, and post-procedure noninvasive systolic and diastolic blood pressure, respiration, and heart rate) were compared using independent t-test analysis. Patient recovery time, procedure length, and midazolam dosage required were also compared between the two groups. Results: Eighty-five patient charts were included in the final analysis: 47 received TCI-remifentanil/midazolam sedation, and 38 received manual fentanyl/midazolam sedation. Among the physiological parameters, diastolic blood pressure showed slightly higher changes in the fentanyl group (P = 0.049), respiratory rate changes showed higher changes in the fentanyl group (P = 0.032), and the average EtCO₂ was slightly higher in the remifentanil group (P = 0.041). There was no significant difference in the minimum SpO₂ levels and average procedure length between the fentanyl and remifentanil TCI pump groups (P > 0.05). However, a significant difference was observed in the time required for discharge from the chair (P = 0.048), indicating that patients who received remifentanil required less time for discharge from the chair than those who received fentanyl. The dosage of midazolam used in the fentanyl group was 0.487 mg more than that in the remifentanil group; however, the difference was not significant (P > 0.05). Conclusion: The combination of TCI administered remifentanil combined with manual administered midazolam has the potential to shorten the recovery time and reduce respiration rate changes when compared to manual administration of fentanyl/midazolam. This is possibly due to either the lower midazolam dosage required with TCI remifentanil administration or achieving a stable, steady-state low dose remifentanil concentration for the duration of the procedure.

• International Journal of Contents
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• 제11권2호
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• pp.69-73
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• 2015

This study was performed to determine the optimal doses of alfentanil or remifentanil (effect-site concentrations) required to prevent pain and other suffering after abdominal general surgery in ICU patients. A total of 52 general abdominal surgical patients (ASA IIIII) requiring artificial ventilatory care in the ICU were provided with either alfentanil (24 patients) or remifentanil (28 patients) through target controlled infusion (TCI). Alfentanil and remifentanil concentrations were titrated up and down until the pain score became less than 3 (VAS; Visual Analogue Score < 3). The effect-site concentrations (ng/ml) of alfentanil or remifentanil required to adequately control postoperative pain in the ICU were 64 +/- 12 and 1.9 +/- 0.5 for intubation with artificial ventilation, 57 +/- 9 and 1.7 +/- 0.7 for intubation with spontaneous ventilation, and 41 +/- 10 and 1.2 +/- 0.5 after extubation, respectively. Pain scores and the corresponding opioid concentrations were independent from respiratory condition. The three effect-site concentrations of alfentanil and remifentanil obtained from this clinical trial using the TCI technique can be a guideline in the administration of the same opioids to relieve the discomfort of ICU patients who have undergone abdominal general surgery.