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.
We studied nociception-associated arousal following laryngoscopy and intubation in patients scheduled for elective open heart surgery, using EEG power spectra and hemodynamics. Either fentanyl (7 micrograms/kg; n = 30) or sufentanil (1 microgram/kg; n = 30) were given in a randomized fashion to induce anesthesia in heavily premedicated patients, followed by pancuronium bromide (100 micrograms/kg).
The results of any study of the relative importance of anesthetic depth versus intensity of neuromuscular block on conditions for endotracheal intubation can be manipulated by the investigator. Several independent factors, such as the depth of hypnosis induced, the interval between drug administration and laryngoscopy, the onset profile of the muscle relaxant, and the multiple of the 95% effective dose given, must be controlled.
The growing interest in combining local and general anesthesia has led to studies investigating possible interactions between general anesthesia and local anesthetics administered via spinal, epidural, IV, or IM routes. However, no study has evaluated the effect of local anesthetics on all three components of balanced anesthesia, i.e., hypnosis, analgesia, and muscle relaxation.
BACKGROUND: Bispectral index (BIS) and state entropy (SE) monitor hypnosis. We evaluated the correlation and the agreement between those parameters during propofol anaesthesia and laryngoscopy with and without muscle relaxation. METHODS: A total of 25 patients were anaesthetized with propofol. At steady state (SS: BIS 40-50), they randomly received rocuronium (R) or saline (S); 3 min thereafter, a 20 s laryngoscopy was performed.
BACKGROUND: The spectral entropy of the electroencephalogram has been proposed to monitor the depth of anaesthesia. State Entropy (SE) reflects the level of hypnosis. Response Entropy (RE), computed from electroencephalogram and facial muscle activity, reflects the response to nociceptive stimulation. We evaluated the effect of rocuronium on Bispectral Index (BIS) and entropy responses to laryngoscopy. METHODS: A total of 25 patients were anaesthetized with propofol using a target-controlled infusion. At steady state, they randomly received 0.6 mg kg(-1) rocuronium (R) or saline (S).
BACKGROUND: There are conflicting results on the influence of neuromuscular block (NMB) on the bispectral index (BIS). We investigated the influence of two degrees of NMB on BIS, Alaris auditory-evoked potential index (AAI), and the electromyogram (EMG) obtained with needle electrodes from the frontal and temporal muscles, immediately adjacent to the BIS-sensor. METHODS: Twenty patients were anesthetized with sevoflurane, titrated for 30 min to an end-tidal concentration of 1.2% (baseline).