Articles: closed-circuit-anesthesia.
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J Clin Monit Comput · Feb 2014
An enriched simulation environment for evaluation of closed-loop anesthesia.
To simulate and evaluate the administration of anesthetic agents in the clinical setting, many pharmacology models have been proposed and validated, which play important roles for in silico testing of closed-loop control methods. However, to the authors' best knowledge, there is no anesthesia simulator incorporating closed-loop feedback control of anesthetic agent administration freely available and accessible to the public. Consequently, many necessary but time consuming procedures, such as selecting models from the available literatures and establishing new simulator algorithms, will be repeated by different researchers who intend to explore a novel control algorithm for closed-loop anesthesia. ⋯ This simulator could be a benchmark-testing platform for closed-loop control of anesthesia, which is of great value and has significant development potential. For convenience, this simulator is termed as Wang's Simulator, which can be downloaded from http://www. AutomMed.org .
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Anaesth Intensive Care · Jan 2014
Comparative StudyA ten-year audit of fresh gas flows in a New Zealand hospital: the influence of the introduction of automated agent delivery and comparisons with other hospitals.
Reducing fresh gas flow (FGF) rates with volatile anaesthetics reduces waste, with positive financial and environmental consequences. We have audited FGF since 2001 by analysis of data collected from anaesthetic machines. We recently introduced Aisys(®) (GE Healthcare, Madison, WI, USA) machines that allow automated control of end-tidal levels of volatile anaesthetics. ⋯ The proportion of time spent in automated delivery mode has increased from 35% to 63%. Users valued the workload reduction with end-tidal control. Our findings suggest that in daily practice, with a wide range of practitioners at different levels of training and a broad patient mix, mean flow rates of around 1.3 l/minute with median flows in the range 0.5 to 1.0 l/minute are achievable targets.
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Clinical Trial
Agent consumption with the Zeus® in the automated closed circuit anesthesia mode with O2/air mixtures.
Earlier software versions of the Zeus® (Lübeck, Dräger, Germany) failed to provide true closed circuit anesthesia (CCA) conditions. We examined whether the latest software (SW 4.03 MK 04672-00) achieves this goal. ⋯ Under the conditions specified, the Zeus® approaches CCA conditions so closely that further reductions in agent usage would have minimal economic significance.
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Paediatric anaesthesia · Dec 2013
Randomized Controlled TrialEvaluation of closed-loop anesthesia delivery for propofol anesthesia in pediatric cardiac surgery.
The objective of this study was to compare the feasibility of closed-loop anesthesia delivery with manual control of propofol in pediatric patients during cardiac surgery. ⋯ This study demonstrated the feasibility of closed-loop controlled propofol anesthesia in children, even in challenging procedures such as cardiac surgery. Closed-loop system needs further and larger evaluation to establish its safety and efficacy.
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Anesthesia and analgesia · Dec 2013
Apparent Dead Space with the Anesthetic Conserving Device, AnaConDa®: A Clinical and Laboratory Investigation.
The anesthetic conserving device (ACD) reduces consumption of volatile anesthetic drug by a conserving medium adsorbing exhaled drug during expiration and releasing it during inspiration. Elevated arterial CO2 tension (PaCO2) has been observed in patients using the ACD, despite tidal volume increase to compensate for larger apparatus dead space. In a test lung using room temperature dry gas, this was shown to be due to adsorption of CO2 in the ACD during expiration and release of CO2 during the following inspiration. The effect in the test lung was higher than in patients. We tested the hypothesis that a lesser dead space effect in patients is due to higher temperature and/or moisture attenuating rebreathing of CO2. ⋯ The use of an ACD increases apparent dead space to a greater extent than can be explained by its internal volume. This is caused by adsorption of CO2 in the ACD during expiration and release of CO2 during inspiration. Rebreathing of CO2 was attenuated by moisture. The dead space effect of the ACD could be clinically relevant in acute respiratory distress syndrome and other diseases associated with ventilation difficulties, but investigations with larger sample sizes would be needed to determine the clinical importance.