Intraoperative Period

Publication Title: 
L'Encéphale

Diazepam, clorazepate and flunitrazepam are used to premedicate , to anesthetize and after the intervention. Anxiolysis , sedation, hypnosis, muscle relaxation, amnesia and seizure prevention justified their employment. They have few side effects. Anesthesiologist just have to be careful of their long-acting effects as for ambulatory anaesthesia.

Author(s): 
Lepresle, E.
Debras, C.
Publication Title: 
Anaesthesia

Thirty patients scheduled for elective cardiopulmonary bypass surgery were interviewed pre-operatively and postoperatively to assess changes in their emotional state and recollections, both aware and unaware, of intra-operative events. A random selection of patients heard a prerecorded audio tape towards the end of bypass after they were rewarmed to 37 degrees C. The tape contained suggestions for patients to touch their chin during the postoperative interview, to remember three sentences and to recover quickly. The interviewers were blind to the experimental condition.

Author(s): 
Goldmann, L.
Shah, M. V.
Hebden, M. W.
Publication Title: 
Anesthesia and Analgesia

We studied 94 healthy ASA physical status I or II children to determine the end-expired concentration of halothane associated with eye opening on emergence from anesthesia, and to determine if parenteral opioid therapy or regional analgesia significantly altered this concentration. In our study, anesthesia was maintained with halothane in an air-oxygen mixture. After the surgical procedure was completed, the inspired concentration of halothane was adjusted to zero and the end-expired concentrations were permitted to decrease spontaneously.

Author(s): 
Watcha, M. F.
Lagueruela, R. G.
White, P. F.
Publication Title: 
British Journal of Anaesthesia

Using the isolated forearm technique (IFT), we wished to determine if patients known to be unresponsive to commands during general anaesthesia with nitrous oxide, halothane and neuromuscular blocking agents had any evidence of explicit or implicit recall. Two groups of women, studied in a single-blind sequential block design, heard different tapes, either a command and information tape (n = 34) or radio static (n = 34), throughout surgery.

Author(s): 
Russell, I. F.
Wang, M.
Publication Title: 
British Journal of Anaesthesia

BACKGROUND: The effect of cardiopulmonary bypass (CPB) on the level of anaesthetic depth has not been studied previously in a randomized way. METHODS: We assessed the effect of CPB on the propofol needed to maintain a fixed bispectral index score, and on the recovery from anaesthesia in 22 patients undergoing coronary artery bypass graft surgery with CPB (on-pump) compared with 18 patients operated on without CPB (off-pump). Anaesthesia was induced and maintained with propofol and alfentanil.

Author(s): 
Ahonen, J.
Sahlman, A.
Yli-Hankala, A.
Eriksson, H.
Nemlander, A.
Rämö, J.
Salmenperä, M.
Publication Title: 
The Annals of Otology, Rhinology, and Laryngology

Today cochlear implantation is a widely used means of treatment in deafness and severe hearing disorders in adults, children, and infants. Postoperative fitting of the externally worn speech processor is very important for successful use of the cochlear implant. However, especially in infants and young children, this fitting process can be difficult because of limited communication capabilities.

Author(s): 
Schultz, Arthur
Berger, Frank Andreas
Weber, Benno Paul
Grouven, Ulrich
Niclaus, Oliver
Lüllwitz, Ekkehard
Schultz, Barbara
Publication Title: 
Anesthesia and Analgesia

In this double-blinded randomized study, we sought to confirm that patients undergoing general anesthesia who were exposed to a hemispheric synchronization (Hemi-Sync) musical recording during surgery had a smaller analgesia requirement, as was suggested in a previous study. Bispectral index monitoring was used to adjust depth of hypnosis, and hemodynamic variables were used to determine analgesia administration. Consented patients underwent either laparoscopic bariatric or one-level lumbar disk surgery.

Author(s): 
Lewis, Ariane K.
Osborn, Irene P.
Roth, Ram
Publication Title: 
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference

Research has demonstrated the efficacy of closed-loop control of anesthesia using bispectral index (BIS) as the controlled variable, and the recent development of model-based, patient-adaptive systems has considerably improved anesthetic control. To further explore the use of model-based control in anesthesia, we investigated the application of fuzzy control in the delivery of patient-specific propofol-induced hypnosis. In simulated intraoperative patients, the fuzzy controller demonstrated clinically acceptable performance, suggesting that further study is warranted.

Author(s): 
Moore, Brett L.
Pyeatt, Larry D.
Doufas, Anthony G.
Publication Title: 
Anesthesia and Analgesia

BACKGROUND: Research has demonstrated the efficacy of closed-loop control of anesthesia using bispectral index (BIS) as the controlled variable. Model-based and proportional-integral-derivative (PID) controllers outperform manual control. We investigated the application of reinforcement learning (RL), an intelligent systems control method, to closed-loop BIS-guided, propofol-induced hypnosis in simulated intraoperative patients. We also compared the performance of the RL agent against that of a conventional PID controller.

Author(s): 
Moore, Brett L.
Quasny, Todd M.
Doufas, Anthony G.
Publication Title: 
Anesthesia and Analgesia

Reinforcement learning (RL) is an intelligent systems technique with a history of success in difficult robotic control problems. Similar machine learning techniques, such as artificial neural networks and fuzzy logic, have been successfully applied to clinical control problems. Although RL presents a mathematically robust method of achieving optimal control in systems challenged with noise, nonlinearity, time delay, and uncertainty, no application of RL in clinical anesthesia has been reported.

Author(s): 
Moore, Brett L.
Doufas, Anthony G.
Pyeatt, Larry D.

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