British journal of anaesthesia
-
Automated indices derived from mid-latency auditory evoked potentials (MLAEP) have been proposed for monitoring the state of anaesthesia. The A-Line ARX index (AAI) has been implemented in the A-Line monitor (Danmeter, V1.4). Several studies have reported variable and, in awake patients, sometimes surprisingly low AAI values. The purpose of this study was to reproduce these findings under steady-state conditions and to investigate their causes. ⋯ The version of the A-Line monitor used in this study does not exclude contaminated MLAEP signals. Previous publications involving this version of the A-Line monitor (as opposed to the newer A-Line/2 monitor series) should be reassessed in the light of these findings. Before exclusively MLAEP-based monitors can be evaluated as suitable monitors of depth of anaesthesia, it is essential to ensure that inbuilt validity tests eliminate contaminated MLAEP signals.
-
The goal of the study was to compare stroke volume (SV) and respiratory stroke volume variation (SVV) measured by pulse-contour analysis and aortic Doppler. ⋯ There is a fair correlation between pulse-contour analysis and aortic Doppler for beat-by-beat measurement of SV but not for calculation of SV respiratory ventilation.
-
Bispectral index is a topographically dependent variable in patients receiving propofol anaesthesia.
As very strong agreement has been reported between bispectral index (BIS) values measured from the occipital and frontal skull areas, we compared BIS values measured from central and parietal areas with those from frontal area to investigate whether BIS is really a topographically dependent or topographically independent variable. ⋯ The present results provide evidence that BIS index is a topographically dependent variable in patients receiving propofol anaesthesia.
-
To assess the adequacy of the position of the tracheal tube cuff and tracheal tube tip in the recently introduced preformed oral Microcuff paediatric endotracheal tube (PET) using the manufacturers recommendations for Microcuff tracheal tube size selection. ⋯ The new oral preformed cuffed tracheal tubes allow safe placement in almost all patients when inserted according to the tube bend. The critically low tube tip and the high cuff positions in a few tubes when placed according to the tube bend requires clinical alertness.
-
Reversal of neuromuscular block can be accomplished by chemical encapsulation of rocuronium by sugammadex (Org 25969), a synthetic gamma-cyclodextrin derivative. The present study determined the time course of the reversal action of sugammadex on rocuronium-induced block in the anaesthetized Rhesus monkey using train-of-four stimulation. ⋯ The half-life of sugammadex (Org 25969), a new fast and efficient reversal agent for rocuronium-induced block, is relatively short in the Rhesus monkey, implying the possibility to perform neuromuscular block by rocuronium shortly after reversal of a prior block. In translation to the human situation differences in rocuronium sensitivity and kinetics should be taken into account.