Articles: closed-circuit-anesthesia.
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Large quantities of water condensation occur in the anaesthesia circuit during low-flow anaesthesia. We hypothesized that cooling of the CO2 absorbent would prevent water condensation. ⋯ TGR of CO2 absorbent with cooling is a useful and simple method to reduce water condensation in the anaesthesia circuit in low-flow anaesthesia, with a little increase in the longevity of the CO2 absorbent.
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Anesthesia and analgesia · Dec 2007
Estimation of optimal modeling weights for a Bayesian-based closed-loop system for propofol administration using the bispectral index as a controlled variable: a simulation study.
Implementing Bayesian methods in a model-based closed-loop system requires the integration of a standard response model with a patient-specific response model. This process makes use of specific modeling weights, called Bayesian variances, which determine how the specific model can deviate from the standard model. In this study we applied simulations to select the Bayesian variances yielding the optimal controller for a Bayesian-based closed-loop system for propofol administration using the Bispectral Index (BIS) as a controlled variable. ⋯ We believe this system can be introduced safely into clinical testing for both induction and maintenance of anesthesia under direct observation of an anesthesiologist.
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Acta Anaesthesiol Taiwan · Sep 2007
Randomized Controlled TrialClosed-circuit isoflurane-based anesthesia provides better fast-tracking anesthesia than fentanyl/propofol-based anesthesia for off-pump coronary artery bypass graft surgery.
In recent years, low-dose fentanyl combined with short-acting hypnotic drug has been thought to be better than traditional high-dose fentanyl in cardiac anesthesia. On the other hand, the practice of closed-circuit inhaled anesthesia offers many advantages, including hemodynamic stability, maintenance of adequate anesthesia depth and early recovery. This study sought to evaluate the effect of closed-circuit isoflurane-based anesthesia (CIA) and fentanyl/propofol-based anesthesia (FPA) on off-pump coronary artery bypass graft (OPCABG) surgery. ⋯ These results suggest that CIA, as compared with FPA, provides a significant reduction in the time to extubation after OPCABG surgery with less use of inotropic agents.
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Anaesth Intensive Care · Jun 2007
Randomized Controlled TrialClosed-loop anaesthesia delivery system (CLADS) using bispectral index: a performance assessment study.
The development of electroencephalographic indices of anaesthetic depth has in turn generated interest in automated anaesthesia delivery systems using these as the input variable. In this paper, one patented closed loop anaesthesia delivery system (CLADS) (502/DEL/2003) is compared to manual control of propofol delivery titrated to the bispectral index (BIS). Forty ASA I-II patients undergoing elective surgery under general anaesthesia were enrolled in the study. ⋯ Smaller amounts of anaesthetic agent were required (P < 0.01) and there was faster postoperative recovery (P < 0.05). Manual delivery of propofol required the infusion rate to be changed a median of 30 times (IQR 12-45), which required considerable time and attention by the anaesthetist. In conclusion, automated delivery of propofol adjusted to the bispectral index using our CLADS was both effective and efficient as compared to manual control.