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The Landé or g-factors of charge carriers are decisive for the spin-dependent phenomena in solids and provide also information about the underlying electronic band structure. We present a comprehensive set of experimental data for values and anisotropies of the electron and hole Landé factors in hybrid organic-inorganic (MAPbI3, MAPb(Br0.5Cl0.5)3, MAPb(Br0.05Cl0.95)3, FAPbBr3, FA0.9Cs0.1PbI2.8Br0.2, MA=methylammonium and FA=formamidinium) and all-inorganic (CsPbBr3) lead halide perovskites, determined by pump-probe Kerr rotation and spin-flip Raman scattering in magnetic fields up to 10 T at cryogenic temperatures. Further, we use first-principles density functional theory (DFT) calculations in combination with tight-binding and k â p approaches to calculate microscopically the Landé factors. The results demonstrate their universal dependence on the band gap energy across the different perovskite material classes, which can be summarized in a universal semi-phenomenological expression, in good agreement with experiment.
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The complex structure and morphology of ultrathin praseodymia films deposited on a ruthenium(0001) single crystal substrate by reactive molecular beam epitaxy is analyzed by intensity-voltage low-energy electron microscopy in combination with theoretical calculations within an ab initio scattering theory. A rich coexistence of various nanoscale crystalline surface structures is identified for the as-grown samples, notably comprising two distinct oxygen-terminated hexagonal Pr2O3(0001) surface phases as well as a cubic Pr2O3(111) and a fluorite PrO2(111) surface component. Furthermore, scattering theory reveals a striking similarity between the electron reflectivity spectra of praseodymia and ceria due to very efficient screening of the nuclear charge by the extra 4f electron in the former case.
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To improve perioperative quality and patient safety, the German S3 guideline should be consistently implemented to avoid perioperative hypothermia. Perioperative normothermia is a quality indicator and should be achieved by anesthesiologists and surgeons. To detect hypothermia early during the perioperative process, measuring body temperature should be started 1-2 h preoperatively. Patients should be actively warmed for 20-30 min before starting anesthesia. Prewarming is most effective and should be included in the preoperative process. Patients should be informed about the risks of perioperative hypothermia and members of the perioperative team should be educated. A standard operating procedure (SOP) to avoid hypothermia should be introduced in every operative unit. The incidence of postoperative hypothermia should be evaluated in operative patients every 3-6 months. The goals should be to measure body temperature in >80% of patients undergoing surgery and for >70% to exhibit a core temperature >36 °C at the end of surgery.
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Adhesión a Directriz , Hipotermia/prevención & control , Complicaciones Intraoperatorias/prevención & control , Temperatura Corporal , Alemania , Humanos , Capacitación en Servicio , Grupo de Atención al Paciente , Seguridad del Paciente , Garantía de la Calidad de Atención de Salud , Indicadores de Calidad de la Atención de Salud , Valores de ReferenciaRESUMEN
Electron scattering by oxygen monolayers on the Ru(0 0 0 1) surface is studied both experimentally and theoretically. Sharp transmission resonances at low energies are revealed and established to originate from critical points of a special kind in the complex band structure of the substrate. Electron reflection from the clean and oxidized Ru(0 0 0 1) is measured for kinetic energies up to 40 eV at normal incidence for oxygen coverages of 1/4, 1/2, 3/4, and one monolayer. The reflection spectra R(E) are analyzed using a Bloch-waves based ab initio scattering theory. In addition to the substrate-induced resonances the reconstructed (2 × 1) and (2 × 2) surfaces show surface resonances due to pre-emergent secondary diffraction beams. The R(E) spectra are shown to give unambiguous evidence of the hcp stacking of the oxygen layer.
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The growth of cerium oxide on Ru(0001) by reactive molecular beam epitaxy has been investigated using low-energy electron microscopy (LEEM) and diffraction as well as local valence band photoemission. The oxide islands are found to adopt a carpet-like growth mode, which depending on the local substrate morphology and misorientation leads to deviations from the otherwise almost perfect equilateral shape at a growth temperature of 850 °C. Furthermore, although even at this high growth temperature the micron-sized CeO2(111) islands are found to exhibit different lattice registries with respect to the hexagonal substrate, the combination of dark-field LEEM and local intensity-voltage analysis reveals that the oxidation state of the islands is homogeneous down to the 10 nm scale.
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BACKGROUND: Measurement of the balance between nociception and anti-nociception during anaesthesia is challenging and not yet clinically established. The Surgical pleth index (SPI), derived from photoplethysmography, was proposed as a surrogate measure of nociception. Recently, the analgesia nociception index (ANI) derived by heart rate (HR) variability was developed. The aim of the present study was to challenge the ability of ANI compared with SPI to detect standardized noxious stimulation during propofol-remifentanil anaesthesia. METHODS: After Ethics approval and informed consent, 25 patients were anaesthetized with propofol [bispectral index (BIS) 30-60]. A laryngeal mask (LMA) was inserted and remifentanil stepwise increased to effect-site concentrations (Ce(remi)) of 0, 2, and 4 ng ml(-1). At each step, tetanic stimulation (STIM) was applied. ANI, SPI, BIS, HR, and mean arterial pressure (MAP) were obtained before and after LMA insertion and each STIM. Analysis was performed using Wilcoxon rank tests and calculation of prediction probabilities (P(K)). RESULTS: ANI and SPI, but not BIS, HR, or MAP, were significantly (P<0.05) changed at all examined steps. ANI response to STIM was (median [IQR]) -24 [-12-35], -30 [-20 - -40] and -13 [-5 - -27] at 0, 2 and 4 ng ml(-1) Ce(remi). However, prediction of movement to STIM was not better than by chance, as P(K) values were 0.41 (0.08) for ANI and 0.62 (0.08) for SPI. CONCLUSIONS: The two variables, ANI and SPI, enabled consistent reflection of stimulation during propofol-remifentanil anaesthesia. Nevertheless, ANI and SPI may improve detection but not prediction of a possible inadequate nociception-anti-nociception balance. Clinicaltrials.gov Identifier. NCT01522508.
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Analgesia , Anestesia , Anestésicos Intravenosos/administración & dosificación , Nocicepción/fisiología , Piperidinas/administración & dosificación , Propofol/administración & dosificación , Adulto , Anciano , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , RemifentaniloRESUMEN
BACKGROUND: Xenon seems to be an ideal anesthetic drug. To explore if next to the antagonism at the NMDA-receptor other molecular targets are involved, we tested the xenon requirement in short sleeping Drosophila shaker mutants and in na[har(38)]. METHODS: The Drosophila melanogaster strains wildtype Canton-S, na[har(38)], sh(102) and sh(mns), were raised and sleep was measured. Based on the response of the flies at different xenon concentrations, logEC50 values were calculated. RESULTS: The logEC50-values for WT Canton-S were 1.671 (1.601-1.742 95%-confidence intervall; n = 238; P versus sh(102) > 0,05), for sh(mns) 1.711 (1.650-1.773; n = 242; P versus WT Canton-S > 0,05). The logEC50-value for sh(102) was 1.594 (1.493-1.694; n = 261; P versus sh(mns) > 0.05). The logEC-value of na[har(38)] was 2.076 (1.619-2.532; n = 207; P versus sh(mns) < 0.05, versus sh(102) < 0.05, versus WT Canton-S < 0.05). P values for all shaker mutants were P > 0.05, while na[har(38)] was found to be hyposensitive compared to wildtype (P < 0.05). CONCLUSIONS: The xenon requirement in Drosophila melanogaster is not influenced by a single gene mutation at the shaker locus, whereas a reduced expression of a nonselective cation channel leads to an increased xenon requirement. This supports the thesis that xenon mediates its effects not only via an antagonism at the NMDA-receptor.
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Proteínas de Drosophila/genética , Drosophila melanogaster/fisiología , Receptores de N-Metil-D-Aspartato/metabolismo , Canales de Potasio de la Superfamilia Shaker/genética , Sueño/efectos de los fármacos , Sueño/genética , Xenón/farmacología , Anestésicos por Inhalación/farmacología , Animales , Mutación/genéticaRESUMEN
The aim of our study was to evaluate the performance of different durations of active pre-operative skin-surface warming (pre-warming) to prevent peri-operative hypothermia and postoperative shivering. We randomly assigned 200 patients, scheduled for surgery of 30-90 min under general anaesthesia, to receive passive insulation or forced-air skin surface warming for 10, 20 or 30 min. Body temperature was measured at the tympanic membrane. Shivering was graded by visual inspection. There were significant differences in changes of core temperature between the non-pre-warmed group and all the pre-warmed groups (p < 0.00001), but none between the three pre-warmed groups (p = 0.54). Without pre-warming, 38/55 (69%) patients became hypothermic (< 36 °C) at the end of anaesthesia, whereas only 7/52 (13%), 3/43 (7%) and 3/50 (6%) patients following 10, 20 or 30 min pre-warming, respectively, became hypothermic (p < 0.001 vs no pre-warming). Shivering was observed in 10 patients without, and in three, three and one patients with pre-warming in the respective groups (p = 0.02). Pre-warming of patients for only 10 or 20 min before general anaesthesia mostly prevents hypothermia and reduces shivering.
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Hipotermia/prevención & control , Complicaciones Intraoperatorias/prevención & control , Atención Perioperativa/métodos , Complicaciones Posoperatorias/prevención & control , Adulto , Anciano , Anestesia General , Temperatura Corporal/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medicación Preanestésica , Tiritona/fisiologíaRESUMEN
Deaf citizens are confronted with barriers in a health-care system shaped by hearing people. Therefore the German legislature provides a supply with sign language interpreters at the expense of the health insurances. The present study initially examines in how far the deaf are informed about this and use said interpreters. Traditional surveys are based on spoken and written language and therefore are unsuitable for the target audience. Because of this, a cross-sectional online study was performed using sign language videos and visually oriented answers to allow a barrier-free participation. With a multivariate analysis, factors increasing deaf people's risks not to be informed of the supply with interpreters were identified: Of 841 deaf participants, 31.4% were not informed of their rights. 41.3% have experience with an interpreter at the doctor's and report a mainly trouble-free reimbursement of costs. Young and modestly educated deaf have a higher risk of not being informed of the interpreter supply. Further information is necessary to provide equality of opportunities to deaf patients utilising medical benefits.
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Equipos de Comunicación para Personas con Discapacidad/estadística & datos numéricos , Sordera/epidemiología , Sordera/rehabilitación , Revelación/legislación & jurisprudencia , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Derechos del Paciente/legislación & jurisprudencia , Lengua de Signos , Adulto , Anciano , Estudios Transversales , Femenino , Alemania/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud/legislación & jurisprudencia , Humanos , Masculino , Persona de Mediana Edad , PrevalenciaRESUMEN
INTRODUCTION: Regarding therapy and prognosis of acute ischemic stroke the identification of ischemic penumbra is pivotal. A promising candidate is BOLD-imaging using qT2'-maps. For valid interpretation of experimental studies in animals normal values for qT2' are needed. Normal values in humans at 1.5T already exist. Normal values for cortical and subcortical structures in a spontaneously hypertensive stroke prone rat stem (SHR-SP) at a fieldstrength of 3T are reported. MATERIALS AND METHODS: 39 (20 males and 19 females) spontaneously hypertensive stroke prone (SHRSP) rats were examined in a 3T scanner using a dedicated small animal coil. Mean weight was 144.1 ± 8.2g and mean age was 60.2 ± 2.7 days. For the calculation of qT2' multiple echo T2w and T2 w images were acquired. ROIs were placed into deep and cortical grey matter in five different brain regions to obtain values for qT2', qT2 and qT2. RESULTS: Mean qT2' for cortical grey matter was 74.76 ± 33.27 ms and 67.73 ± 17.86 ms for deep grey matter. The 99% confidence interval for cortical grey matter was 69.91-79.61 ms. For qT2 it was 79.02 ± 2.9 ms and 70.45 ± 1.89 ms, respectively. For qT2 it was 34.65 ± 5.25 ms and 31.9 ± 2.9 ms. CONCLUSION: The values for qT2' presented here can serve as reference values for further studies examining the ischemic penumbra in a rat model.
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Isquemia Encefálica/patología , Imagen por Resonancia Magnética/métodos , Animales , Femenino , Masculino , Ratas , Ratas Endogámicas SHR , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Dynamic variables reliably predict fluid responsiveness (FR) in adults, but no data are available regarding their performance in infants. The aim of this prospective study was to assess whether pulse pressure variation (PPV) and stroke volume variation (SVV), in contrast to central venous pressure (CVP) and global end-diastolic volume (GEDV), are applicable in infants undergoing congenital heart surgery and to assess threshold values that may help to guide fluid administration in these patients. METHODS: Twenty-six anaesthetized infants, mean (sd) weight 9.7 (4.3) kg, were studied during closed-chest conditions and changing loading conditions before and after repair of congenital heart disease. Stroke volume index was measured by transoesophageal echocardiography (SVI(TOE)), CVP was measured via a central venous line, GEDV index (GEDVI) was measured by transpulmonary thermodilution, and PPV and SVV were monitored using the PiCCO monitoring system. RESULTS: Fifteen infants had increased SVI(TOE) with fluid loading ≥15% (responders); 11 infants were defined as non-responders. Analysing the relationship between CVP, GEDVI, SVV, and PPV at baseline with volume-induced percentage change in SVI(TOE), only PPV was significantly correlated with ΔSVI(TOE) both before (r=0.54, P=0.004) and after (r=0.73, P>0.0001). As assessed by receiver-operating characteristic curve analysis, only PPV accurately predicted FR before surgical repair [area under the curve (AUC): 0.79, P=0.01] and after surgical repair (AUC: 0.86, P=0.002). CONCLUSIONS: PPV, in contrast to SVV, CVP, and GEDVI, predicted FR in infants undergoing congenital heart surgery both before and after repair of congenital heart disease.
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Procedimientos Quirúrgicos Cardíacos/métodos , Fluidoterapia/métodos , Cardiopatías Congénitas/cirugía , Algoritmos , Anestesia General , Aorta/diagnóstico por imagen , Área Bajo la Curva , Presión Sanguínea/fisiología , Cateterismo Venoso Central , Presión Venosa Central/fisiología , Ecocardiografía Transesofágica , Femenino , Hemodinámica , Humanos , Lactante , Masculino , Valor Predictivo de las Pruebas , Pulso Arterial , Curva ROC , Volumen Sistólico/fisiología , Termodilución , Resultado del TratamientoRESUMEN
BACKGROUND: Respiratory variations in plethysmographic waveform amplitudes derived from pulse oximetry are believed to predict fluid responsiveness. The non-invasive pleth variability index (PVI) is a variable based on the calculation of changes in the perfusion index (PI). The aim of the following study was to examine whether the predictive power of PVI depends on different values of PI. METHODS: Eighty-one patients undergoing elective coronary artery surgery were studied before operation: at baseline after induction of anaesthesia and during passive leg raising (PLR). Each patient was monitored with central venous pressure (CVP), the PiCCO monitor and the non-invasive Masimo monitoring system. Stroke volume index by transpulmonary thermodilution (SVI(TPTD)), pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance index (SVRI) were measured using the PiCCO monitoring system. PI and PVI were obtained by pulse oximetry. RESULTS: Responders were defined to increase their SVI(TPTD) >15% after PLR. The highest area under the curve (AUC) was found for PPV (AUC: 0.83, P<0.0001) and SVV (AUC: 0.72, P=0.002), in contrast to PVI (AUC: 0.60, P=0.11) and CVP (AUC: 0.60, P=0.13). The accuracy of PVI to predict fluid responsiveness was improved on analysing patients with higher PI values. PI of about 4% (n=45) achieved statistical significance (AUC: 0.72, P=0.01). CONCLUSION: The PVI was not able to predict fluid responsiveness with sufficient accuracy. In patients with higher perfusion states, the PVI improved its ability to predict haemodynamic changes, strongly suggesting a relevant influence of the PI on the PVI.
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Fluidoterapia/métodos , Hemodinámica , Respiración , Adulto , Anciano , Anciano de 80 o más Años , Puente de Arteria Coronaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oximetría , Pletismografía , Curva ROCRESUMEN
BACKGROUND: The PiCCO system provides different variables of cardiac function: the cardiac function index (CFI), the global ejection fraction (GEF) and the maximal pressure developed by the left ventricle (dP/dtMax). The purpose of this study was to investigate the ability of these variables to predict impaired left ventricular ejection fraction (LVEF) derived by transesophageal echocardiography during acute myocardial ischemia. METHODS: In this prospective experimental study, fifteen pigs (28-34 kg) were anesthetized, mechanically ventilated and subjected to left anterior descending (LAD) coronary artery occlusion. PiCCO-derived variables and LVEF were obtained 5, 10, 15, and 20 minutes after LAD occlusion. Receiver operating characteristics analysis was performed to assess the ability of PiCCO-derived parameters to estimate LVEF ≤40% and ≤50%. RESULTS: LAD occlusion induced a decrease in PiCCO-derived variables and LVEF (P<0.001 for each). Significant correlations were found between LVEF and CFI (r=0.59, P<0.001), GEF (r=0.64, P<0.001), dP/dtMax (r=0.36, P<0.001), and cardiac output (r=0.25, P=0.028). The area under the receiver operating characteristics curve for the estimation of LVEF ≤40% and ≤50% was 0.80 and 0.79 for CFI (P=0.009, P<0.001), 0.86 and 0.78 for GEF (P=0.002, P<0.001), 0.76 and 0.68 for dP/dtMax (P=0.033, P=0.012), and 0.57 and 0.58 for cardiac output (P=0.554, P=0.259). CONCLUSION: Cardiac function indices permit the bedside quantification of left ventricular systolic function during acute myocardial ischemia in pigs. Therefore, the PiCCO system may represent a valuable technique for cardiovascular monitoring, particularly for detecting acute left ventricular systolic dysfunction due to myocardial ischemia.
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Ecocardiografía Transesofágica/métodos , Isquemia Miocárdica/diagnóstico , Termodilución/métodos , Función Ventricular Izquierda/fisiología , Algoritmos , Animales , Hemodinámica/fisiología , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Curva ROC , Volumen Sistólico/fisiología , PorcinosRESUMEN
Combined morphological, immunocytochemical, biochemical and molecular genetic studies were performed on skeletal muscle, heart muscle and liver tissue of a 16-months boy with fatal liver failure. The pathological characterization of the tissues revealed a severe depletion of mtDNA (mitochondrial DNA) that was most pronounced in liver, followed by a less severe, but still significant depletion in skeletal muscle and the heart. The primary cause of the disease was linked to compound heterozygous mutations in the polymerase γ (POLG) gene (DNA polymerase γ; A467T, K1191N). We present evidence, that compound heterozygous POLG mutations lead to tissue selective impairment of mtDNA replication and thus to a mosaic defect pattern even in the severely affected liver. A variable defect pattern was found in liver, muscle and heart tissue as revealed by biochemical, cytochemical, immunocytochemical and in situ hybridization analysis. Functionally, a severe deficiency of cytochrome-c-oxidase (cox) activity was seen in the liver. Although mtDNA depletion was detected in heart and skeletal muscle, there was no cox deficiency in these tissues. Depletion of mtDNA and microdissection of cox-positive or negative areas correlated with the histological pattern in the liver. Interestingly, the mosaic pattern detected for cox-activity and mtDNA copy number fully aligned with the immunohistologically revealed defect pattern using Pol γ, mtSSB- and mtTFA-antibodies, thus substantiating the hypothesis that nuclear encoded proteins located within mitochondria become unstable and are degraded when they are not actively bound to mtDNA. Their disappearance could also aggravate the mtDNA depletion and contribute to the non-homogenous defect pattern.
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ADN Mitocondrial/metabolismo , ADN Polimerasa Dirigida por ADN/genética , Fallo Hepático , ADN Polimerasa gamma , Replicación del ADN , Resultado Fatal , Humanos , Lactante , Hígado/metabolismo , Hígado/ultraestructura , Fallo Hepático/genética , Fallo Hepático/metabolismo , Fallo Hepático/patología , Masculino , Mitocondrias/enzimología , Mitocondrias/ultraestructura , Enfermedades Mitocondriales/genética , Enfermedades Mitocondriales/metabolismo , Enfermedades Mitocondriales/patología , Músculo Esquelético/metabolismo , Músculo Esquelético/ultraestructura , Mutación , Miocardio/metabolismo , Miocardio/ultraestructuraRESUMEN
BACKGROUND: Although in modern anaesthesia, monitoring depth of anaesthesia and quality of neuromuscular block are routine, monitoring of analgesia still remains challenging. Recently, the surgical stress index (SSI), derived from finger photoplethysmographic signal, was introduced as a surrogate variable reflecting the nociception-antinociception balance. This study aimed at evaluating the SSI in patients undergoing regional anaesthesia either alone or combined with sedation compared with patients undergoing general anaesthesia (GA). METHODS: Seventy-one patients undergoing general (n=24) or spinal anaesthesia with (n=24) or without sedation (n=23) were included. SSI was measured the day before surgery and at defined time points during anaesthesia and surgery and also in the recovery room. SSI was compared with haemodynamic variables like heart rate and systolic arterial pressure. RESULTS: The SSI was higher in patients undergoing spinal anaesthesia [mean 65, CI (59.3-70.5)] compared with GA [48 (39.9-56.4), P<0.01], and baseline [41 (37.3-44.2), P<0.001]. During spinal anaesthesia with sedation [44 (36.2-50.9)], it was comparable with the baseline level (P>0.05). In comparison with baseline, SSI in the recovery room was higher in patients after GA [59 (48.4-67.9), P<0.025] but not after spinal anaesthesia [53 (47.6-60.1), P>0.05] or after spinal anaesthesia with sedation [54 (45.8-65.1), P>0.05]. Changes of the SSI were not reflected by changes of haemodynamic variables. CONCLUSIONS: In fully awake patients under spinal anaesthesia, the SSI does not reflect the nociception-antinociception balance. This may be due to the influence of mental stress on the sympathetic nervous system. Even light sedation attenuates these influences.
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Anestesia General/métodos , Anestesia Raquidea/métodos , Monitoreo Intraoperatorio/métodos , Estrés Fisiológico/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Presión Sanguínea/fisiología , Sedación Consciente , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Ortopédicos , Estudios Prospectivos , Sistema Nervioso Simpático/fisiología , Procedimientos Quirúrgicos Urológicos , Adulto JovenRESUMEN
BACKGROUND: The surgical stress index (SSI) is a new monitoring tool for the assessment of nociception during general anaesthesia. It is calculated based on the heart beat interval and the pulse wave amplitude. Correlation of SSI with nociceptive stimuli and opioid effect-site concentrations has been demonstrated, but the influence of isolated modulation of heart rate (HR) on SSI is still unclear. The aim of this study was to evaluate the effect on SSI of atropine administration and cardiac pacing. METHODS: In 18 anaesthetized ASA III ICU patients, either repetitive cardiac pacemaker stimulation or administration of atropine (10 microg kg(-1)) was performed, and the effect on SSI, arterial pressure, spectral entropy, and bispectral index was analysed. RESULTS: Cardiac pacing at 100 beats min(-1) was followed by an increase in SSI from 26 [17-35 (10-41)] to 59 [53-72 (48-78)] {median [inter-quartile range (range)]} (P=0.0006), whereas other variables remained unaffected. Also, atropine administration increased SSI from 27 [20-34 (16-39)] to 58 [48-70 (41-81)] (P=0.007) without significant effect on other variables except HR. A recalibration of SSI during cardiac pacing leads to a significant decrease in SSI to 49 [40-52 (36-57)] (P=0.03), whereas recalibration after atropine administration had no effect. CONCLUSIONS: SSI values measured in patients receiving atropine or in patients with pacemakers should be interpreted cautiously.
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Antiarrítmicos/farmacología , Atropina/farmacología , Marcapaso Artificial , Estrés Fisiológico/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Presión Sanguínea/efectos de los fármacos , Puente de Arteria Coronaria , Cuidados Críticos/métodos , Electroencefalografía/efectos de los fármacos , Entropía , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Monitoreo Fisiológico/métodos , Cuidados Posoperatorios/métodosRESUMEN
We enrolled 114 patients, aged 65-83 years, undergoing elective surgery (duration > 2h) into a randomised, controlled study to evaluate the performance of bispectral index and spectral entropy for monitoring depth of xenon versus propofol anaesthesia. In the propofol group, bispectral index and state entropy values were comparable. In the xenon group, bispectral index values resembled those in the propofol group, but spectral entropy levels were significantly lower. Mean arterial blood pressure was higher and heart rate was lower in the xenon group than in the propofol group. Bispectral index and spectral entropy considerably diverged during xenon but not during propofol anaesthesia. We therefore conclude that these measures are not interchangeable for the assessment of depth of hypnosis and that bispectral index is likely to reflect actual depth of anaesthesia more precisely compared with spectral entropy.
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Anestésicos por Inhalación/farmacología , Anestésicos Intravenosos/farmacología , Electroencefalografía/efectos de los fármacos , Propofol/farmacología , Xenón/farmacología , Anciano , Anciano de 80 o más Años , Presión Sanguínea/efectos de los fármacos , Entropía , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Monitoreo Intraoperatorio/métodos , Estudios Prospectivos , Procesamiento de Señales Asistido por ComputadorRESUMEN
BACKGROUND: The bispectral index (BIS) and spectral entropy enable monitoring the depth of anaesthesia. Mild hypothermia has been shown to affect the ability of electroencephalography monitors to reflect the anaesthetic drug effect. The purpose of this study was to investigate the effect of hypothermia during a cardio-pulmonary bypass on the correlation and agreement between the BIS and entropy variables compared with normothermic conditions. METHODS: This prospective clinical study included coronary artery bypass grafting patients (n=25) evaluating correlation and agreement (Bland-Altman analysis) between the BIS and both spectral and response entropy during a hypothermic cardio-pulmonary bypass (31-34 degrees C) compared with nomothermic conditions (34-37.5 degrees C). Anaesthesia was maintained with propofol and sufentanil and adjusted clinically, while the anaesthetist was blinded to the monitors. RESULTS: The BIS and entropy values decreased during cooling (P<0.05), but the decrease was more pronounced for entropy variables compared with BIS (P<0.05). The correlation coefficients (bias+/-SD; percentage error) between the BIS vs. spectral state entropy and response entropy were r(2)=0.56 (1+/-11; 42%) and r(2)=0.58 (-2+/-11; 43%) under normothermic conditions, and r(2)=0.17 (10+/-12; 77%) and r(2)=0.18 (9+/-11; 68%) under hypothermic conditions, respectively. Bias was significantly increased under hypothermic conditions (P<0.001 vs. normothermia). CONCLUSION: Acceptable agreement was observed between the BIS and entropy variables under normothermic but not under hypothermic conditions. The BIS and entropy variables may therefore not be interchangeable during a hypothermic cardio-pulmonary bypass.
Asunto(s)
Puente Cardiopulmonar , Electroencefalografía/estadística & datos numéricos , Hipotermia Inducida , Monitoreo Intraoperatorio/estadística & datos numéricos , Anciano , Anestésicos Generales/administración & dosificación , Anestésicos Intravenosos/administración & dosificación , Monitoreo de Gas Sanguíneo Transcutáneo , Presión Sanguínea/fisiología , Temperatura Corporal/fisiología , Puente de Arteria Coronaria , Electrocardiografía , Electromiografía , Entropía , Femenino , Humanos , Ventilación con Presión Positiva Intermitente , Masculino , Oximetría , Propofol/administración & dosificación , Estudios Prospectivos , Método Simple Ciego , Sufentanilo/administración & dosificaciónRESUMEN
BACKGROUND: Although measurement of cerebral hypnotic drug effect and muscle relaxation is common clinical routine during anaesthesia, a reliable measurement of the neurophysiological effects evoked by a painful stimulus is still missing. Recently, the surgical stress index (SSI) has been introduced as a surrogate measure of 'nociception'. The present study aimed to examine the influence of increasing remifentanil concentrations on the ability of SSI to detect a standardized painful stimulus during sevoflurane anaesthesia. METHODS: Twenty-four patients received incremental or decremental doses of 0, 2, and 4 ng ml(-1) remifentanil effect-site concentration (Ce(remi)) during 0.7 MAC sevoflurane. Painful tetanic stimulation was applied at least 5 min after changing Ce(remi). SSI, heart rate (HR), response entropy (RE), state entropy (SE), RE-SE difference, and bispectral index (BIS) were obtained in each patient before and after stimulation. Further prediction of an author-defined response to painful stimulus was analysed. RESULTS: SSI and BIS, but not HR, SE, RE, or RE-SE difference were significantly altered after stimulation. Change in SSI (Delta SSI) was significantly dependent on Ce(remi), as Delta SSI was [median (inter-quartile range)] 20 (15-31), 10 (1-19), and 3 (1-10) at 0, 2, and 4 ng ml(-1) Ce(remi). In 10 out of 63 cases, SSI detected response to stimulation, not detected by another variable. SSI was unable to predict movement after stimulation as P(K) value is 0.59 (0.09). CONCLUSIONS: The SSI response to tetanic stimulation was dependent on the remifentanil concentration.
Asunto(s)
Analgésicos Opioides/administración & dosificación , Anestésicos por Inhalación , Éteres Metílicos , Piperidinas/administración & dosificación , Adolescente , Adulto , Anciano , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Electroencefalografía/efectos de los fármacos , Entropía , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Laparoscopía , Persona de Mediana Edad , Dimensión del Dolor/métodos , Estudios Prospectivos , Remifentanilo , Sevoflurano , Adulto JovenRESUMEN
Renal cell carcinoma (RCC) is a rare tumor in the pediatric population. Recently, a phenotypically and genetically distinct kidney carcinoma, mainly prevalent in children and associated with an Xp11.2 translocation or TFE3 gene fusion, has been described. It has been advanced that in this subtype of RCC, there is an accumulation of cyclin D1, cyclin D3, and p21 ((wafl/cip1)). The aim of the present study was to figure out in two pediatric RCC recently diagnosed in our department (one clear cell-type RCC and one TFE3-positive RCC) whether those features are indeed specific of the latter tumor or occur in pediatric RCC irrespective of the tumor type. The following immunostains were performed in both cases: Ki67, p16(ink4a), p21 ((wafl/cip1)), p27(kip1), p53, p63, mdm2, cyclin D1, cyclin D3, TFE3, CD10, vimentin, E-cadherin, and RCC-antigen. We observed in the TFE3-positive carcinoma an intense immunoreaction for p21 ((wafl/cip1)), cyclin D1, and cyclin D3, without expression for p53, p16, p27(kip1), and mdm2, whereas the immunoexpression profile observed in the classic RCC was similar to that of clear cell, adult-type RCC. Our study confirms that TFE3-positive RCC exhibits a deregulation of the cell cycle apparently unrelated to the young age of the patients.