• 제목/요약/키워드: Target concentration

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Pharmacodynamic principles and target concentration intervention

  • Holford, Nick
    • Translational and Clinical Pharmacology
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    • 제26권4호
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    • pp.150-154
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    • 2018
  • This tutorial reviews the principles of dose individualisation with an emphasis on target concentration intervention (TCI). Once a target effect is chosen then pharmacodynamics can predict the target concentration and pharmacokinetics can predict the target dose to achieve the required response. Dose individualisation can be considered at three levels: population, group and individual. Population dosing, also known as fixed dosing or "one size fits all" is often used but is poor clinical pharmacology; group dosing uses patient features such as weight, organ function and comedication to adjust the dose for a typical patient; individual dosing uses observations of patient response to inform about pharmacokinetic and pharmacodynamics in the individual and use these individual differences to individualise dose.

혈중 목표 농도 자동 조절기(TCI) 개발 PART2: 시스템 구현 및 평가 (Development of Target-Controlled Infusion system in Plasma Concentration. PART2: Design and Evaluation)

  • 안재목
    • 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.

Monitoring of Mycophenolic Acid Trough Concentration in Kidney Transplant under Cyclosporine Is Beneficial in Reducing Acute Rejection within 1 Year

  • Rhu, Jinsoo;Lee, Kyo Won;Park, Jae Berm;Kim, Sung Joo
    • 대한이식학회지
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    • 제32권4호
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    • pp.75-83
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    • 2018
  • Background: This study was designed to analyze the clinical usefulness of mycophenolic acid trough concentration monitoring in kidney transplantation patients who were maintained with cyclosporine. Methods: The data of patients who underwent mycophenolic acid trough concentration monitoring after their first kidney transplant between November 2006 and August 2013 and were prescribed with cyclosporine, mycophenolate, and methylprednisolone were reviewed retrospectively. Cox analysis was used to analyze the risk factors for acute rejection within 1 year post-transplantation. Results: Among 90 patients, 41 (45.6%) achieved both the target levels of cyclosporine and mycophenolic acid, while three patients (3.3%) failed to achieve the target level of either cyclosporine or mycophenolic acid. Nine patients (10.0%) only achieved the mycophenolic acid target level and 37 patients (41.1%) only achieved the cyclosporine target level. While patients who achieved only the mycophenolic acid target concentration had no statistically increased risk compared to patients who achieved both target levels (hazard ratio [HR], 1.569; 95% confidence interval [CI], 0.316 to 7.778; P=0.581), patients who only achieved the cyclosporine target concentration showed an increased risk of rejection compared to the both achievement group (HR, 4.112; 95% CI, 1.583 to 10.683; P=0.004). Patients who had no achievement in the target levels showed significantly increased rejection risk compared to the patients who achieved both target levels (HR, 17.811; 95% CI, 3.072 to 103.28; P=0.001). Conclusions: Mycophenolic acid trough concentration monitoring combined with cyclosporine trough concentration monitoring is useful for avoiding acute cellular rejection if the first 1 year post-transplantation.

Comparison of Efficacy of Propofol When Used with or without Remifentanil during Conscious Sedation with a Target-Controlled Infuser for Impacted Teeth Extraction

  • Sung, Juhan;Kim, Hyun-Jeong;Choi, Yoon Ji;Lee, Soo Eon;Seo, Kwang-Suk
    • 대한치과마취과학회지
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    • 제14권4호
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    • pp.213-219
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    • 2014
  • Background: Clinical use of propofol along with remifentanil for intravenous sedation is increasing in these days, but there are not enough researches to evaluate proper target concentration when these drugs are infused by using target controlled infusion (TCI) pump in dental treatment cases. In this study, we compared efficacy of TCI conscious sedation and target concentration of propofol when it used with or without remifentanil during conscious sedation with the help of a TCI for the surgical extraction of impacted teeth. Methods: After IRB approval, all the charts of patients who had undergone surgical extraction of impacted teeth under propofol TCI sedation for 6 months were selected and reviewed for this study. After reviewal of charts, we could divide patients in two groups. In one group (group 1), only propofol was selected for sedation and initial effect site concentration of propofol was $1{\mu}g/ml$ (n = 33), and in another group (group 2), both propofol and remifentanil was infused and initial effect site concentration of each drug was $0.6{\mu}g/ml$ and 1 ng/ml respectively (n = 25). For each group, average propofol target concentration was measured. In addition, we compared heart rate, respiratory rate, and systolic and diastolic blood pressure as well as oxygen saturation. Besides, BIS, sedation scores (OAAS/S), and subjective satisfaction scores were compared. Results: Between group 1 and 2, there were no significant differences in demographics (age, weight and height), and total sedation time. However, total infused dose and the effect site target concentration of propofol was $163.8{\pm}74.5mg$ and $1.13{\pm}0.21{\mu}g/ml$ in group 1, and $104.3{\pm}46.5mg$ and $0.72{\pm}0.26{\mu}g/ml$ in the group 2 with $1.02{\pm}0.21ng/l$ of the effect site target concentration of remifentanil, respectively. During sedation, there were no differences between overall vital sign, BIS and OAAS/S in 2 groups (P > 0.05). However, we figured out patients in group 2 had decreased pain sensation during sedation. Conclusions: Co-administration of propofol along with remifentanil via a TCI for the surgical extraction of impacted teeth may be safe and effective compared to propofol only administration.

DEVELOPMENT OF A METHOD FOR CONTROLLING GAS CONCENTRATION FOR USE IN C.A EXPERIMENTS

  • Yun, H.S.
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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    • pp.662-669
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    • 2000
  • Based on the viscous flow characteristics of gas through capillary tube, a simple and low cost system was developed for controlling gas concentration for use in C.A experiments. The gas flow rate through capillary tube had a linear relationship with pressure, $(length)^{-1}$ and $(radius)^4$ of capillary tube, which agreed well with Hagen-Poiseuille's law. The developed system could control the gas concentration in storage chamber within ${\pm}0.3%$ deviation compared to the preset concentration. The required time for producing target gas concentration in storage chamber was exactly predicted by the model used in this study, and it required much longer time than the calculated time which divided the volume of chamber by flow rate. Therefore, for producing target gas concentration as quickly as possible, it needs to supply higher flow rate of gas during the initial stage of experiment when gas concentration in storage chamber has not reached at target value. It appeared that the developed system was very useful for C.A experiments. Because one could decide a desired flow rate by the prediction model, control flow rate freely and easily by changing pressure in the pressure-regulating chamber and the accuracy was high.

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Specific Detection of DNA Using Quantum Dots and Magnetic Beads for Large Volume Samples

  • Kim, Yeon-Seok;Kim, Byoung-Chan;Lee, Jin-Hyung;Kim, Jung-Bae;Gu, Man-Bock
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권5호
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    • pp.449-454
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    • 2006
  • Here we present a sensitive DNA detection protocol using quantum dots (QDs) and magnetic beads (MBs) for large volume samples. In this study, QDs, conjugated with streptavidin, were used to produce fluorescent signals while magnetic beads (MBs) were used to isolate and concentrate the signals. The presence of target DNAs leads to the sandwich hybridization between the functionalized QDs, the target DNAs and the MBs. In fact, the QDs-MBs complex, which is bound using the target DNA, can be isolated and then concentrated. The binding of the QDs to the surface of the MBs was confirmed by confocal microscopy and Cd elemental analysis. It was found that the fluorescent intensity was proportional to concentration of the target DNA, while the presence of non-complementary DNA produced no significant fluorescent signal. In addition, the presence of low copies of target DNAs such as 0.5 pM in large volume samples up to 40mL was successfully detected by using a magnet-assisted concentration protocol which consequently results in the enhancement of the sensitivity more than 100-fold.

휘발성 유기물질에 대한 차량 탑승시 노출 (In-Vehicle Exposure to Volatile Organic Compounds)

  • 조완근
    • 한국대기환경학회지
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    • 제12권2호
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    • pp.151-157
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    • 1996
  • Vehicle occupant exposure to volatile organic compounds (VOCs) continues to be the subject of active research because of higher levels of VOCs in vehicles than in the surrounding ambient atmosphere and because of potential health risk. This study identified in-auto and in-bus exposures to 6 selected aromatic VOCs during rush-hour driving. A bus service route was selected to include an urban route (Taegu) and a suburban route (Hayang-Up) to satisfy the specified criteria of this study. The most abundant VOC concentration measured in this study was toluene. In-vehicle target Voc concentrations of the urban route were significantly different from those of the suburban segment. On the sum of average of the target VOCs, in-auto VOC concentration was about 1.5 times higher than in-bus VOC concentration. Based on the sum of average, in-automobile target VOC concentrations of this study were within the range of previous studies conducted in several cities of the United States, while in-bus VOC concentrations of this study were much lower than those of Taipei in Taiwan. In-vehicle VOC concentrations of present study significantly varied with sampling days, while they did not varied with driving period.

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Effect Site Concentrations of Propofol for Dental Treatment under Deep Sedation in Intellectually Disabled Patients

  • Lee, Brian Seonghwa;Shin, Teo Jeon;Kim, Hyun-Jeong;Choi, Yoon Ji;Lee, Soo Eon;Chang, Juhea;Seo, Kwang-Suk
    • 대한치과마취과학회지
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    • 제14권3호
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    • pp.167-172
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    • 2014
  • Background: Propofol is the most commonly used anesthetic for sedation and target-controlled infusion (TCI) is useful for dental treatment. However, it is important to assess and maintain an adequate depth of sedation in patients with severe intellectual disabilities Therefore, in this study we aimed to evaluate the adequate propofol target concentration for dental treatment in severely intellectually disabled patients. Methods: We undertook retrospective review of the sedation records of severely intellectually disabled patients who underwent dental treatment under TCI propofol sedation from September 2011 to April 2012. We evaluated the initial target concentration, stabilized concentration of propofol and monitored vital signs, including BIS score using sedation records. Results: Total 20 patients (10 male and 10 female patients) were included in the study. Every participant was severely intellectually disabled. The mean sedation duration was $70{\pm}16$ (45-100) minutes. The initial propofol target concentration infusion amount was $2.7{\pm}0.45$ (2.0-3.0) mcg/ml. The propofol effect site concentration (Ce) was $2.6{\pm}0.7$ (1.0-4.0) mcg/ml. The average value of BIS was $52.6{\pm}13$ (28-81). During the treatment period, there were no severe complications. Conclusions: The average propofol Ce for deep sedation without any complications in intellectually disabled patients was 2.6 mcg/ml.

Vancomycin 초기 투여 용량 개선 방안 (Development of Vancomycin Initial Dosage Guidelines to Achieve New Target Ranges)

  • 유재영;김정현;이용원;김은영;손기호
    • 한국임상약학회지
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    • 제20권3호
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    • pp.221-228
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    • 2010
  • In 2009, American Journal of Health-System Pharmacy (AJHP) recommended that targeting vancomycin trough concentrations of 10 mg/L or more because of therapeutic failure and potential risk of developing vancomycin resistance. Therefore, new dosage guidelines that could achieve to these higher target were needed. The aims of this study were to develop dosage guidelines targeting new vancomycin trough concentration and to evaluate the performance of these new guidelines. All data analysis were performed using NONMEM(R). Population pharmacokinetic model was first developed from vancomycin dosage and concentration data collected retrospectively during routine therapeutic drug monitoring in 441 patients, then new vancomycin dosage guidelines were developed by using the model to predict vancomycin trough and peak concentrations in a simulated dataset. The estimates, such as, vancomycin concentration trough level, time to achieve target level, mean error were performed to evaluate and compare difference between conventional dosage and new dosage guidelines. The proposed dosage guidelines were predicted to achieve 43.5% of vancomycin trough level within 10~20 mg/L, which is significantly higher than current guidelines (26.3%). Time to achieve target trough level was 19.4 hours in new guidelines comparing to 93.1 hours in the conventional dosage. Thus, new vancomycin dosage guidelines have been developed to achieve new target trough concentrations earlier and more consistently than conventional guidelines.

대기오염물질 저감을 위한 농도분석에 관한 연구 (A Study on Concentration Analysis for Decreasing Air Pollutants)

  • 김윤선
    • 한국안전학회지
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    • 제22권3호
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    • pp.28-33
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    • 2007
  • Often Regular Measurement Target 32 Spots which are distributed at Seo-gu in Incheon Metropolitan and Odour Emission Target 100 Factories based on the task instruction of Ministry of Environment in Korea were selected by considering to atmosphere phenomena and regional characteristics etc. This paper aims at building the Decreasing Prediction System of Odour which is capable of comparing and examining the concentration distribution by odour compounds, the distribution maps of odour diffusion and the contribution degree of sphere of influence, which is discharged from these above spots and factories.