Introduction Closed loop total intravenous anesthesia is a technique in which the patient's hemodynamic and anesthetic depth variables are monitored, and based on this information, a computer ...controls the infusion rate of drugs to keep them within pre-established clinical parameters. Objective To describe the technical and clinical performance of a closed loop system for total intravenous anesthesia with propofol and remifentanil, using the SEDLine.sup.TM monitor Design Multicentric prospective cohort study Setting Surgery room Patients ASA I-II undergoing elective surgery Measurements The authors designed a closed loop system that implements a control algorithm based on anesthetic depth monitoring and the Patient State Index (PSI.sup.TM) of the SEDLine monitor for propofol, and on hemodynamic variables for remifentanil. The measurement of clinical performance was made based on the percentage of PSI.sup.TM maintenance time in the range 20-50. Precision analysis was evaluated by measuring median performance error (MDPE) can be defined as the median difference between actual and desired values, which refers to the degree of precision in which the controller is able to maintain the control variable within the objective set by the anesthesiologist; it represents the direction (over-prediction or under-prediction) of performance error (PE) rather than size of errors, which is represented by MDAPE, median absolute percentage error, Wobble index, which is used for measuring the intrasubject variability in performance error. Results Data were obtained from 93 patients in three healthcare centers. The percentage of PSI.sup.TM maintenance time in the 20-50 range was 92% (80.7-97.0). MDPE was 10.7 (- 11.0-18.0), MDAPE 21.0 (14.2-26.8) and wobble 10.7 (7.0-16.9). No adverse surgical or anesthetic events were found. Conclusions The closed loop total intravenous anesthesia system with SEDLine developed by the authors was used without major complication and appear to be feasible its use in clinical performance. Keywords: Closed loop, Total intravenous anesthesia, Propofol, Remifentanil, SEDline, Spectral density
Resumen La anestesia en lazo cerrado busca incrementar la exactitud con que se administran los fármacos, dando la cantidad necesaria de acuerdo con las condiciones del paciente y las necesidades del ...cirujano, al integrar el monitoreo a los sistemas de perfusión. Objetivo: Evaluar el desempeño de un sistema de administración de anestesia intravenosa en lazo cerrado con propofol y remifentanilo, utilizando el monitor de profundidad anestésica PatientStateIndex). Métodos: Estudio observacional prospectivo multicéntrico en pacientes ASA I-II sometidos a cirugía electivacon un sistema de anestesia en lazo cerradocapaz de retroalimentarse en tiempo real de las variables hemodinámicas y la profundidad anestésica del paciente.La medición del desempeño clínico se realizó a partir del porcentaje de tiempo de permanencia del ÍNDICE en el rango 20-50. El análisis de precisión se evaluó midiendo error medio de desempeño, error medio absoluto de desempeño y Wobble. Resultados: Se obtuvieron datos de 76 pacientes, recogidos en dos instituciones. El porcentaje de tiempo de permanencia del PSI en el rango 20-50 fue de 96% (89-99) en una institución y del 84,8% (70,8-94) en otra. El ERROR MEDIO de DESEMPEÑO fue de 11 y 10,7, el ERROR MEDIO ABSOLUTO de 21 y 21,4 y el Wobble de 7 y 14,2 respectivamente para cada institución. No se reportó ningún evento quirúrgico o anestésico adverso. Conclusiones: El sistema de administración de anestesia total intravenosa en lazo cerrado guiado por un nuevo monitor de profundidad anestésica mostró en esta serie de casos un buen desempeño clínico y técnico.
Closed loop total intravenous anesthesia is a technique in which the patient's hemodynamic and anesthetic depth variables are monitored, and based on this information, a computer controls the ...infusion rate of drugs to keep them within pre-established clinical parameters.
To describe the technical and clinical performance of a closed loop system for total intravenous anesthesia with propofol and remifentanil, using the SEDLine
monitor.
Multicentric prospective cohort study.
Surgery room.
ASA I-II undergoing elective surgery.
The authors designed a closed loop system that implements a control algorithm based on anesthetic depth monitoring and the Patient State Index (PSI
) of the SEDLine monitor for propofol, and on hemodynamic variables for remifentanil. The measurement of clinical performance was made based on the percentage of PSI
maintenance time in the range 20-50. Precision analysis was evaluated by measuring median performance error (MDPE) can be defined as the median difference between actual and desired values, which refers to the degree of precision in which the controller is able to maintain the control variable within the objective set by the anesthesiologist; it represents the direction (over-prediction or under-prediction) of performance error (PE) rather than size of errors, which is represented by MDAPE, median absolute percentage error, Wobble index, which is used for measuring the intrasubject variability in performance error.
Data were obtained from 93 patients in three healthcare centers. The percentage of PSI
maintenance time in the 20-50 range was 92% (80.7-97.0). MDPE was 10.7 (- 11.0-18.0), MDAPE 21.0 (14.2-26.8) and wobble 10.7 (7.0-16.9). No adverse surgical or anesthetic events were found.
The closed loop total intravenous anesthesia system with SEDLine developed by the authors was used without major complication and appear to be feasible its use in clinical performance.
Energy-driven biorefineries can be designed considering biotechnological and thermochemical conversion pathways. Nevertheless, energy and environmental comparisons are necessary to establish the best ...way to upgrade lignocellulosic biomass and set the requirements of these processes in different scenarios. This paper aims to evaluate experimentally a biorefinery producing energy vectors using coffee-cut stems (CCS) as feedstock. The obtained yields were the basis for energy and environmental analysis, in two different biorefinery scenarios: (i) production of bioethanol and biogas and (ii) production of syngas and electricity. The energy results indicated that the overall energy efficiency calculated in the first scenario was only 9.15%. Meanwhile, the second biorefinery configuration based on thermochemical routes presented an energy efficiency value of 70.89%. This difference was attributed to the higher consumption of utilities in the biorefinery based on biotechnological routes. The environmental results showed that the impact category of climate change for the first biorefinery (i.e., 0.0193 kg CO
2
eq./MJ) had a lower value than that of the second process (i.e., 0.2377 kg CO
2
eq./MJ). Thus, the biorefinery based on the biotechnological route presented a better environmental performance. Additionally, the results for both biorefineries allowed concluding that the inclusion of by-products and co-products in the calculation of the environmental analysis can dramatically affect the results.
This work assesses the economic and social performance of energy production through two biorefineries based on Coffee Cut-Stems (CCS). The economic assessment was carried out to determine the effect ...of the processing scale on the Net Present Value (NPV). The social analysis was performed to evaluate the social effects of the possible biorefineries implementation. Thus, a set of indicators were calculated as metrics of the social impact. The economic assessment shows that the base case biorefinery is infeasible in any processing scale. Meanwhile, the alternative solution I presents a positive economic behavior at scales higher than 17 ton h−1, this configuration presents a positive economic behavior. The social assessment indicates that the first biorefinery is infeasible because the astronomic resources requirements to reach economic feasibility. Meanwhile, the second biorefinery does not have high social risk in most of the social indicators being best configuration from the economic and social perspectives.
•A biorefinery analysis involving the Colombian socio-economic conditions is done.•The high demand of feedstock in base case contributes to its negative performance.•Alternative solution I is social and economically competitive at pilot scale.•Analysis of scale is determinant to find the economic feasibility of biorefineries.
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