Correlation of Approximate entropy, bispectral index, and spectral edge frequency 95 (SEF95) with clinical signs of anesthetic depth during coadministration of propofol and remifentanil

• Published in: Anesthesiology (Philadelphia) 2003-03, Vol.98 (3), p.621-627
• Main Authors: BRUHN, Jörgen, BOUILLON, Thomas W, RADULESCU, Lucian, HOEFT, Andreas, BERTACCINI, Edward, SHAFER, Steven L
• Format: Article
• Language: English
• Subjects: Adult; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Intravenous - administration & dosage; Biological and medical sciences; Electrodiagnosis. Electric activity recording; Electroencephalography - drug effects; Entropy; Female; General anesthesia. Technics. Complications. Neuromuscular blocking. Premedication. Surgical preparation. Sedation; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Nervous system; Piperidines - administration & dosage; Propofol - administration & dosage; Prospective Studies; Remifentanil
• ISSN: 0003-3022; 1528-1175
• DOI: 10.1097/00000542-200303000-00008

Several studies relating electroencephalogram parameter values to clinical endpoints using a single (mostly hypnotic) drug at relatively low levels of central nervous system depression (sedation) have been published. However, the usefulness of a parameter derived from the electroencephalogram for clinical anesthesia largely depends on its ability to predict the response to stimuli of different intensity or painfulness under a combination of a hypnotic and an (opioid) analgesic. This study was designed to evaluate the predictive performance of spectral edge frequency 95 (SEF95), BIS, and approximate entropy for the response to increasingly intense stimuli under different concentrations of both propofol and remifentanil in the therapeutic range. Ten healthy male and ten healthy female volunteers were studied during coadministration of propofol and remifentanil. After having maintained a specific target concentration for 10 min, the depth of sedation-anesthesia was assessed using the responsiveness component of the Observer's Assessment of Alertness/Sedation (OAA/S) rating scale, which was modified by adding insertion of a laryngeal mask and laryngoscopy. The electroencephalogram derived parameters approximate entropy, bispectral index, and SEF95 were recorded just before sedation level was assessed. The prediction probability values for approximate entropy were slightly, but not significantly, better than those for bispectral index, SEF95, and the combination of drug concentrations. A much lower prediction ability was observed for tolerance of airway manipulation than for hypnotic endpoints. Approximate entropy revealed informations on hypnotic and analgesic endpoints using coadministration of propofol and remifentanil comparable to bispectral index, SEF95, and the combination of drug concentrations.