scholarly journals The relationship between the effect-site concentration of propofol and sedation scale in children: a pharmacodynamic modeling study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Young-Eun Jang ◽  
Sang-Hwan Ji ◽  
Ji-Hyun Lee ◽  
Eun-Hee Kim ◽  
Jin-Tae Kim ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Pharmacodynamic Modeling ◽  
Sedation Scale ◽  
Mixed Effect ◽  
Link Type ◽  
Effect Site ◽  
Nonlinear Mixed Effect ◽  
Effect Site Concentration ◽  
The University ◽  
The Relationship

Abstract Background Continuous infusion of propofol has been used to achieve sedation in children. However, the relationship between the effect-site concentration (Ce) of propofol and sedation scale has not been previously examined. The objective of this study was to investigate the relationship between the Ce of propofol and the University of Michigan Sedation Scale (UMSS) score in children with population pharmacodynamic modeling. Methods A total of 30 patients (aged 3 to 6 years) who underwent surgery under general anesthesia with propofol and remifentanil lasting more than 1 h were enrolled in this study. Sedation levels were evaluated using the UMSS score every 20 s by a 1 μg/mL stepwise increase in the Ce of propofol during the induction of anesthesia. The pharmacodynamic relationship between the Ce of propofol and UMSS score was analyzed by logistic regression with nonlinear mixed-effect modeling. Results The estimated Ce50 (95% confidence interval) of propofol to yield UMSS scores equal to or greater than n were 1.84 (1.54–2.14), 2.64 (2.20–3.08), 3.98 (3.66–4.30), and 4.78 (4.53–5.03) μg/mL for n = 1, 2, 3, and 4, respectively. The slope steepness for the relationship of the Ce versus sedative response to propofol (95% confidence interval) was 5.76 (4.00–7.52). Conclusions We quantified the pharmacodynamic relationship between the Ce of propofol and UMSS score, and this finding may be helpful to predict the sedation score at the target Ce of propofol in children. Trial registration http://www.clinicaltrials.gov (No.: NCT03195686, Date of registration: 22/06/2017).

scholarly journals Pharmacokinetic-Pharmacodynamic Modeling of Propofol in Children

2010 ◽  
Vol 113 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Agnes Rigouzzo ◽  
Frederique Servin ◽  
Isabelle Constant
Keyword(s):  
Peak Effect ◽  
Concentration Effect ◽  
Pharmacodynamic Modeling ◽  
Maximal Effect ◽  
Time To Peak ◽  
Effect Site ◽  
Mixed Effects Modeling ◽  
Effect Site Concentration ◽  
Relationship Of ◽  
The Relationship

Background The aim of this study was to identify the best model to describe pharmacokinetics and pharmacodynamics in prepubertal children and therefore to calculate the corresponding pharmacodynamic parameters. In addition, and to confirm our method, a group of postpubertal subjects was also studied. Methods Sixteen children (9.5 yr, range 6-12) and 13 adults (22 yr, range 13-35) were included. Induction was performed by plasma target-controlled infusion of propofol (6 microg/ml) based on the Kataria model in children and on the Schnider model in adults. The relationship of bispectral index to predicted concentrations was studied during induction using the Kataria, pediatric Marsh, Schüttler, and Schnider models in children. Because the best performance was obtained, strangely enough, with the Schnider model, the two groups were pooled to investigate influence of puberty on pharmacodynamic parameters (kE0 [plasma effect-site equilibration rate constant] and Ce50 [effect-site concentration corresponding with 50% of the maximal effect]). The time-to-peak effect was calculated, and the kE0 was determined for the Kataria model (nonlinear mixed-effects modeling; pkpdtools). Results In children, the predicted concentration/effect relationship was best described using the Schnider model. When the whole population was considered, a significant improvement in this model was obtained using puberty as a covariate for kE0 and Ce50. The time to peak effect, Tpeak (median, 0.71 [range, 0.37-1.64] and 1.73 [1.4-2.68] min), and the Ce50 (3.71 [1.88-4.4] and 3.07 [2.95-5.21] microg/ml) were shorter and higher, respectively, in children than in adults. The kE0 linked to the Kataria model was 4.6 [1.4-11] min. Conclusions In children, the predicted concentration/effect relationships were best described using the Schnider model described for adults compared with classic pediatric models. The study suggests that the Schnider model might be useful for propofol target-control infusion in children.

scholarly journals Comparison between Bispectral Index and Patient State Index as Measures of the Electroencephalographic Effects of Sevoflurane

2008 ◽  
Vol 109 (5) ◽  
pp. 799-805 ◽  
Author(s):  
Martin Soehle ◽  
Richard K. Ellerkmann ◽  
Matthias Grube ◽  
Matthias Kuech ◽  
Stefan Wirz ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Pharmacodynamic Modeling ◽  
Depth Of Anesthesia ◽  
Sevoflurane Anesthesia ◽  
Effect Site ◽  
Effect Site Concentration ◽  
Patient State ◽  
State Index ◽  
Patient State Index ◽  
End Tidal

Background The Bispectral Index (BIS) and the Patient State Index (PSI) quantify depth of anesthesia by analyzing the electroencephalogram. The authors examined the response of BIS and PSI to sevoflurane anesthesia. Methods In 22 patients, sevoflurane anesthesia was induced by inhalation with a tight-fitting facemask and was maintained via a laryngeal mask. Sevoflurane concentrations were increased until burst suppression occurred and subsequently decreased until BIS recovered to values above 60. This procedure was repeated twice until patients underwent intubation for subsequent surgery. End-tidal sevoflurane concentrations, BIS, and PSI were recorded simultaneously. The performance of PSI and BIS to predict the estimated sevoflurane effect site concentration, as derived from simultaneous pharmacokinetic and pharmacodynamic modeling, was compared by determination coefficients (rho(2)) and prediction probabilities (P(K)). Results A significant (P < 0.001) correlation between BIS and PSI was found (r(2) = 0.75), and a close sigmoid relation between sevoflurane effect site concentration and both BIS (rho(2) = 0.84 +/- 0.09) and PSI (rho(2) = 0.85 +/- 0.15) was observed. The maximum sevoflurane electroencephalographic effect resulted in PSI values (1.3 +/- 4.3) that were significantly (P = 0.019) lower than BIS values (7.9 +/- 12.1), and the effect site efflux constant k(e0) was significantly smaller (P = 0.001) for PSI (0.13 +/- 0.08 min(-1)) than for BIS (0.24 +/- 0.15 min(-1)). The probability of BIS (P(K) = 0.80 +/- 0.11) to predict sevoflurane effect site concentration did not differ (P = 0.76) from that of PSI (P(K) = 0.79 +/- 0.09). Conclusions The BIS reacted faster to changes in sevoflurane concentrations, whereas the PSI made better use of the predefined index range. However, despite major differences in their algorithms and minor differences in their dose-response relations, both PSI and BIS predicted depth of sevoflurane anesthesia equally well.

Using Permutation Entropy to Measure the Electroencephalographic Effects of Sevoflurane

2008 ◽  
Vol 109 (3) ◽  
pp. 448-456 ◽  
Author(s):  
Xiaoli Li ◽  
Suyuan Cui ◽  
Logan J. Voss
Keyword(s):  
Dose Response ◽  
Drug Effect ◽  
Brain Activity ◽  
Approximate Entropy ◽  
Permutation Entropy ◽  
Pharmacodynamic Modeling ◽  
Anesthetic Drug ◽  
Effect Site ◽  
Prediction Probability ◽  
Effect Site Concentration

Background Approximate entropy (AE) has been proposed as a measure of anesthetic drug effect in electroencephalographic data. Recently, a new method called permutation entropy (PE) based on symbolic dynamics was also proposed to measure the complexity in an electroencephalographic series. In this study, the AE and PE were applied to electroencephalographic recordings for revealing the effect of sevoflurane on brain activity. The dose-response relation of PE during sevoflurane anesthesia was compared with that of AE. Methods Nineteen patients' electroencephalographic data were collected during the induction of general anesthesia with sevoflurane. PE and AE were applied to the electroencephalographic recordings, and the performance of both measures was assessed by pharmacokinetic-pharmacodynamic modeling and prediction probability. To ensure an accurate complexity measure of electroencephalographic recordings, a wavelet-based preprocessor was built in advance. Results Both PE and AE could distinguish between the awake and anesthetized states and were highly correlated to each other (r = 0.8, P = 0.004). The pharmacokinetic-pharmacodynamic model adequately described the dose-response relation between PE and AE and sevoflurane effect site concentration. The coefficient R between PE and effect site concentration was 0.89 +/- 0.07 for all patients, compared with 0.60 +/- 0.14 for AE. Prediction probabilities of 0.86 +/- 0.04 and 0.79 +/- 0.09 for PE and AE showed that PE has a stronger ability to differentiate between the awake and anesthetic states. Conclusion The results show that PE can estimate the sevoflurane drug effect more effectively than AE. This method could be applied to design a new electroencephalographic monitoring system to estimate sevoflurane anesthetic drug effect.

scholarly journals Induction Speed Is Not a Determinant of Propofol Pharmacodynamics

2004 ◽  
Vol 101 (5) ◽  
pp. 1112-1121 ◽  
Author(s):  
Anthony G. Doufas ◽  
Maryam Bakhshandeh ◽  
Andrew R. Bjorksten ◽  
Steven L. Shafer ◽  
Daniel I. Sessler
Keyword(s):  
Drug Effect ◽  
Peak Effect ◽  
Population Based ◽  
Pharmacodynamic Modeling ◽  
Time To Peak ◽  
Effect Site ◽  
Rate Of Increase ◽  
Effect Site Concentration ◽  
The Times ◽  
Plasma Effect

Background Evidence suggests that the rate at which intravenous anesthetics are infused may influence their plasma-effect site equilibration. The authors used five different rates of propofol administration to test the hypothesis that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate. The authors concurrently evaluated the automated responsiveness monitor (ARM) against other sedation measures and the propofol effect site concentration. Methods With Human Studies Committee approval, 18 healthy volunteers received five consecutive target-controlled propofol infusions. During each infusion, the effect site concentration was increased by a rate of 0.1, 0.3, 0.5, 0.7, or 0.9 microg . ml . min. The Bispectral Index and ARM were recorded at frequent intervals. The times of syringe drop and loss and recovery of responsiveness were noted. Pharmacokinetic and pharmacodynamic modeling was performed using NONMEM. Results When the correct rate of plasma-effect site equilibration was determined for each individual (plasma-effect site equilibration = 0.17 min, time to peak effect = 2.7 min), the effect site concentrations associated with each clinical measure were not affected by the rate of increase of effect site propofol concentration. ARM correlated with all clinical measures of drug effect. Subjects invariably stopped responding to ARM at lower effect site propofol concentrations than those associated with loss of responsiveness. Conclusions : Population-based pharmacokinetics, combined with real-time electroencephalographic measures of drug effect, may provide a means to individualize pharmacodynamic modeling during target-controlled drug delivery. ARM seems useful as an automated measure of sedation and may provide the basis for automated monitoring and titration of sedation for a propofol delivery system.

Thathir Quality Scholarship Program For Students At University level

2018 ◽  
Vol 2 (3) ◽  
pp. 206-219
Author(s):  
Louay Qais Abdullah ◽  
Duraid Faris Khayoun
Keyword(s):  
College Students ◽  
Life Sciences ◽  
Economic Feasibility ◽  
First Year ◽  
Grant Program ◽  
Scholarship Program ◽  
University Level ◽  
Faculty Of Education ◽  
The University ◽  
The Relationship

The study focused basically on measuring the relationship between the material cost of the students benefits program and the benefits which are earned by it, which was distributed on college students in the initial stages (matinee) and to show the extent of the benefits accruing from the grant program compared to the material burdens which matched and the extent of success or failure of the experience and its effect from o scientific and side on the Iraqi student through these tough economic circumstances experienced by the country in general, and also trying to find ways of proposed increase or expansion of distribution in the future in the event of proven economic feasibility from the program. An data has been taking from the data fro the Department of Financial Affairs and the Department of Studies and Planning at the University of Diyala with taking an data representing an actual and minimized pattern and questionnaires to a sample of students from the Department of Life Sciences in the Faculty of Education of the University of Diyala on the level of success and failure of students in the first year of the grant and the year before for the purpose of distribution comparison. The importance of the study to measure the extent of interest earned in comparision whit the material which is expenseon the program of grant (grant of students) to assist the competent authorities to continue or not in the program of student grants for the coming years.

The Relationship Between The University Services Marketing And the Leading Orientation And Their Impact In Enhancing The University Reputation

2018 ◽  
Vol 2 (3) ◽  
pp. 110-140 ◽  
Author(s):  
Nusseibeh Ahmed Abdul Wahid
Keyword(s):  
Private Universities ◽  
Services Marketing ◽  
Correlation Relationship ◽  
Independent Variables ◽  
Marketing Orientation ◽  
University Reputation ◽  
Administrative Leaders ◽  
University Services ◽  
The University ◽  
The Relationship

The relationship between the university services marketing and the leading orientation and their impact in enhancing the university reputation: Field study on a sample of administrative leaders in       private universities in the Erbil city Objective - The current study try to find the role of marketing university services (educational services, research services, community services) and the leading orientation (research mobilization, distinction, cooperation, university policies, proactive) as independent variables in enhancing the university's reputation as dependent a variable (Social responsibility, innovation, quality of service, image of the organization) in a sample of private universities in the Erbil city. Methodology of the study - The problem of the study was determined in several questions related to the nature of the correlation relationship - the effect of independent study variables (marketing of university services and leadership orientation) and the dependent variable (the reputation of the university). For this purpose, the hypotheses were subjected to multiple tests. The study used the questionnaire as a means to obtain data from the administrative leaders of the investigated universities. - The study was used the analytical descriptive method. The main and sub-variables were described and correlation and effect relationships were analyzed between the variables using advanced statistical methods (arithmetic mean, standard deviation, percentages, Pearson correlation, multiple regression test) , And the implementation of the statistical program (SPSS-Ver.18). The study was conducted in the educational sector in the city of Erbil, in order to obtain the necessary information for the field through a questionnaire prepared for this purpose and distributed to six universities. The number of respondents was (73) (Presidents of universities, their assistants, deans, their assistants, heads of departments) at the universities in question. The value of the study: The main conclusions of the study are the existence of a significant relationship between the variables of the study and the existence of a significant effect of the independent variable marketing of university services and the leading trend in the dependent variable universities reputation and the existence of variation of the effect of independent variables in the dependent variable in the universities investigated, A set of recommendations, the most important of which is the establishment of a center for the marketing of services at the university level and at the level of each college. In order to conduct a continuous study of the labor market to determine market needs, the university should be aware of the importance of marketing orientation in university education

Teaching practicum and the development of professional and pedagogical knowledge

2020 ◽  
Vol 15 (1) ◽  
pp. 67-90
Author(s):  
Minerva Rosas ◽  
Verónica Ormeño ◽  
Cristian Ruiz-Aguilar
Keyword(s):  
Student Teachers ◽  
Qualitative Data ◽  
Thinking Skills ◽  
Pedagogical Knowledge ◽  
Critical Thinking Skills ◽  
Initial Teacher Education ◽  
Teaching Programme ◽  
Teaching Practicum ◽  
The University ◽  
The Relationship

To assess the progressive teaching practicums included in an English Teaching Programme at a Chilean university, 60 former student-teachers answered a questionnaire with both Likert-scale and open-ended questions. The issues assessed included the relationship between the progressive teaching practicums and the curriculum’s modules and sequence, and the skills developed while implementing innovation projects during the student-teachers’ two final practicums. Quantitative and qualitative data analyses allowed us to identify both strengths and weaknesses. The participants highlighted strengths in the areas of teaching strategies, critical thinking skills and professional and pedagogical knowledge. Among the weaknesses, they identified limited supervision and feedback, and diverging views on teaching education between the university and the schools as the most difficult to deal with. These findings may be useful for introducing improvements in Initial Teacher Education aimed at reducing problems and discrepancies and devising suitable induction processes.

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