Auditory event-related potentials, bispectral index, and entropy for the discrimination of different levels of sedation in intensive care unit patients

BACKGROUND: Sedation protocols, including the use of sedation scales and regular sedation stops, help to reduce the length of mechanical ventilation and intensive care unit stay. Because clinical assessment of depth of sedation is labor-intensive, performed only intermittently, and interferes with sedation and sleep, processed electrophysiological signals from the brain have gained interest as surrogates. We hypothesized that auditory event-related potentials (ERPs), Bispectral Index (BIS), and Entropy can discriminate among clinically relevant sedation levels. METHODS: We studied 10 patients after elective thoracic or abdominal surgery with general anesthesia. Electroencephalogram, BIS, state entropy (SE), response entropy (RE), and ERPs were recorded immediately after surgery in the intensive care unit at Richmond Agitation-Sedation Scale (RASS) scores of -5 (very deep sedation), -4 (deep sedation), -3 to -1 (moderate sedation), and 0 (awake) during decreasing target-controlled sedation with propofol and remifentanil. Reference measurements for baseline levels were performed before or several days after the operation. RESULTS: At baseline, RASS -5, RASS -4, RASS -3 to -1, and RASS 0, BIS was 94 [4] (median, IQR), 47 [15], 68 [9], 75 [10], and 88 [6]; SE was 87 [3], 46 [10], 60 [22], 74 [21], and 87 [5]; and RE was 97 [4], 48 [9], 71 [25], 81 [18], and 96 [3], respectively (all P < 0.05, Friedman Test). Both BIS and Entropy had high variabilities. When ERP N100 amplitudes were considered alone, ERPs did not differ significantly among sedation levels. Nevertheless, discriminant ERP analysis including two parameters of principal component analysis revealed a prediction probability PK value of 0.89 for differentiating deep sedation, moderate sedation, and awake state. The corresponding PK for RE, SE, and BIS was 0.88, 0.89, and 0.85, respectively. CONCLUSIONS: Neither ERPs nor BIS or Entropy can replace clinical sedation assessment with standard scoring systems. Discrimination among very deep, deep to moderate, and no sedation after general anesthesia can be provided by ERPs and processed electroencephalograms, with similar P(K)s. The high inter- and intraindividual variability of Entropy and BIS precludes defining a target range of values to predict the sedation level in critically ill patients using these parameters. The variability of ERPs is unknown.

Classic and overlap chronic graft-versus-host disease (cGVHD) is associated with superior outcome after extracorporeal photopheresis (ECP)

The National Institutes of Health (NIH) classification of graft-versus-host disease (GVHD) is a significant improvement over prior classifications, and has prognostic implications. We hypothesized that the NIH classification of GVHD would predict the survival of patients with GVHD treated with extracorporeal photopheresis (ECP). Sixty-four patients with steroid refractory/dependent GVHD treated with ECP were studied. The 3-year overall survival (OS) was 36% (95% confidence interval [CI] 13-59). Progressive GVHD was seen in 39% of patients with any acute GVHD (aGVHD) (classic acute, recurrent acute, overlap) compared to 3% of patients with classic chronic GVHD (cGVHD) (P=.002). OS was superior for patients with classic cGVHD (median survival, not reached) compared to overlap GVHD (median survival, 395 days, 95% CI 101 to not reached) and aGVHD (delayed, recurrent or persistent) (median survival, 72 days, 95% CI 39-152). In univariate analyses, significant predictors of survival after ECP included GVHD subtype, bilirubin, platelet count, and steroid dose. In multivariate analyses overlap plus classic cGVHD was an independent prognostic feature predictive of superior survival (hazard ratio [HR] 0.34, 95% CI 0.14-0.8, p=.014). This study suggests that NIH classification can predict outcome after ECP for steroid refractory/dependent GVHD.

Intra- and inter-individual variation of BIS-index and Entropy during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers: an interventional study

INTRODUCTION: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS and Entropy, in volunteers under sedation. METHODS: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS and Entropy (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered. RESULTS: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy values showed greater variability than BIS(R) values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation. CONCLUSIONS: The large intra-individual and inter-individual variability of BIS and Entropy values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability. TRIAL REGISTRATION: clinicaltrials.gov Nr. NCT00641563.

Freiheitsheld und Symbolfigur: Der Pilsudski-Kult als Mittel nationaler Identitäts- und Bewusstseinsbildung

Der Pilsudski-Kult ist ein typischer politischer Kult, der durch die Komponenten Mythos, Ritual und Symbole sowie durch eine damit einhergehende Institutionalisierung definiert wird. In den Ausdrucks- und Vermittlungsformen ähneln sich politische Kulte, während die inhaltlichen Aspekte Bezug auf die jeweiligen Traditionen und den historischen Kontext nehmen müssen. Da der Totenkult um Pilsudski auf dem Personenkult aufbaut, wird dieser seit dem Ersten Weltkrieg bis 1935 skizziert und im Folgenden die Begräbnisfeierlichkeiten als Katalysator und Auftakt des Totenkultes, der Totenkult selbst bis 1939 und die Ausdrucksformen und Funktionen des Kultes bis 1939 dargestellt. Anschließend wird dessen Entwicklung im Zweiten Weltkrieg, in der Pilsudski-nahen Emigration, während der Volksrepublik Polen und in der Dritten Republik untersucht. Es soll verdeutlicht werden, dass man den Pilsudski-Kult jederzeit politisch instrumentalisierte, wobei der Mythos als inhaltlicher Bestandteil jeweils nuanciert wurde. Er erhielt legitimatorische und über die Zeit der Zweiten Republik hinausführend identitätsstiftende Funktionen und beeinflusste das historische Gedächtnis.

Godzilla trifft Poelzig

Die Verwendung europäischer Architektursettings in japanischen "Trick"-Filmen (anime) ist mehr als die bloße Adaption einer – aus asiatischer Perspektive – exotischen Kulisse. Populäre Medien vertreten keine kritische Positionen; sie sind bemüht, an Vorstellungswelten und Seherfahrungen ihrer Betrachter anzuknüpfen. Auf diese Weise gelesen, sagen Kopien und bewusste (Re-)Kombinationen europäischer Motive im japanischen Film eine Menge über die Assoziationen, die asiatische Betrachter mit bestimmten Phasen europäischer Geschichte verbinden. Doch auch Eigengesetzlichkeiten des "Trick"-Films als Medium dürfen nicht vernachlässigt werden. Wenig bekannte Motive aus der expressionistischen Architektur können beispielsweise dazu eingesetzt werden, einen bloßen Verfremdungseffekt zu erzielen. In subtileren Beispielen kann der Umweg über europäische Kulissen aber auch dazu dienen, Spannungen der jüngeren Geschichte Japans in einem verfremdeten Gewand zu verarbeiten.