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Objectives: Electroencephalographic burst activity characteristic of burst-suppression pattern (BSP) in sedated patients and of burst-interburst pattern (BIP) in the quiet sleep of healthy neonates have similar linear and non-linear signal properties. Strong interrelations between a slow frequency component and rhythmic, spindle-like activities with higher frequencies have been identified in previous studies. Time-varying characteristics of BSP and BIP prevent a definite patternrelated analysis. A continuous estimation of the bispectrum is essential to analyze these patterns. Parametric bispectral approaches provide this opportunity.Methods: The adaptation of an AR model leads to a parametric bispectrum by using the transfer function of the estimated AR filter. Time-variant parametric bispectral approaches require an estimation of AR parameters which consider higher order moments to preserve phase information. Accordingly, a time-variant parametric estimation of the bispectrum was introduced. Data driven simulations were performed to provide optimal parameters. BSP (12 patients) and BIP (6 neonates) were analyzed using this novel approach.Results: Significant differences in the time course of burst pattern during BSP and burst-like pattern before the onset of BSP could be shown. A rhythmic quadratic phase coupling (period 10 sec) was identified during BIP in all neonates.Conclusion: Quadratic phase couplings during BSP increases in the time course depending on depth of sedation. The visually detected burst activity in BIP is only the temporarily observable EEG correlate of a hidden neural process. Time-variant bispectral approaches offer the possibility of a better characterization of underlying neural processes leading to improved diagnostic tools used in clinical routine. [ABSTRACT FROM AUTHOR]

An automatic EEG pattern detection unit was developed and tested for the recognition of burst-suppression periods and for the separation of burst from suppression patterns. The median, standard deviation and the 95% edge frequency were computed from single channels of the EEG within a moving window and completed by the continuous computation of frequency band power via an adapted Hilbert resonance filter. These parameters were given to the inputs of two hierarchically arranged artificial neural networks (NNs). The output signals of NNs indicate the suppression and burst phases. The burst recognition was focused on the precise recognition of the burst onset. In subsequent processing steps the time course of percentages of burst patterns within their corresponding burst-suppression-phases was calculated and the time locations of burst onsets can be used to trigger an averaging for a burst-related analysis. The data for our investigations were derived from the routine EEG derivations of 12 patients with various neurosurgical diseases. A group-related training of the NNs was realized. For the group-related trained NNs EEG data for 6 patients were used for training and the data of 6 other patients for testing the classification performance of the pattern recognition units. Additionally, the reliability of the detection algorithm was tested with data of two patients with convulsive state, resistant to treatment, and burst-suppression like pattern EEC. [ABSTRACT FROM AUTHOR]

Aortic arch aneurysms can be treated with hybrid procedures by endovascular exclusion and prior debranching of supra-aortic arteries. We report on a case of symptomatic arch aneurysm following previous supracoronary ascending aorta and hemiarch replacement with a very short proximal landing zone. A successful reconstruction was performed by retrograde revascularization of supra-aortic vessels from the descending aorta and subsequent endovascular repair deploying a proximal stent graft directly above the sinotubular junction with good results in the 4-year follow-up. Retrograde supra-aortic debranching may constitute a suitable approach for hybrid endovascular repair of aneurysms of the aortic arch and the ascending aorta in selected cases., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Management of cardiac surgery patients is a very standardized procedure in respective local institutions. Yet only very limited evidence exists concerning optimal indication, safety and efficacy of hemodynamic monitoring catecholamine and fluid therapy., Methods: Between April and May 2013, all 81 German anaesthesia departments involved in cardiac surgery care were asked to participate in a questionnaire addressing the institutional specific current practice in hemodynamic monitoring, catecholamine and volume therapy., Results: 51 (63%) questionnaires were completed and returned. All participating centers used basic hemodynamic monitoring (i.e. invasive arterial blood pressure and central venous pressure), supplemented by transesophageal echocardiography. Pulmonary arterial catheter and calibrated trend monitoring devices were also routinely available. In contrast, non-calibrated trend monitoring and esophageal doppler ultrasound devices were not commonly in use. Cerebral oximetry is increasingly emerging, but lacks clear indications. The majority of patients undergoing cardiac surgery, especially in university hospitals, required catecholamines during perioperative care, In case of low cardiac output syndrome, dobutamine (32%), epinephrine (30%) or phosphodiesterase inhibitors (8%) were first choice. In case of hypotension following vasoplegia, norepinephrine (96%) represented the most common catecholamine. 88% of the participating centers reported regular use of colloid fluids, with hydroxyethyl starches (HES) being first choice (64%)., Conclusions: Choice of hemodynamic monitoring is homogenous throughout German centers treating cardiac surgery patients. Norepinephrine is the first line catecholamine in cases of decrease in peripheral vascular resistance. However, catecholamine choice for low cardiac output syndrome varies considerably. HES was the primary colloid used for fluid resuscitation. After conduct of this survey, HES use was restricted by European regulatory authorities in critically ill patients and should only be considered as second-line fluid in surgical patients without renal impairment or severe coagulopathy. Large clinical studies addressing catecholamine and fluid therapy in cardiac surgery patients are lacking.

Background: Real-time ultrasound (US) in central venous catheterization is superior to pre-procedure US. However, moving real-time US into routine practice is impeded by its perceived expense and difficulty. Currently, pre-procedure US and landmark (LM) methods are most widely used. We investigated these techniques in internal jugular vein (IJV) catheterization in respect of operator experience, complications, and risk factors., Methods: In an observational non-randomized study, we investigated 606 of ∼1300 procedures, that is, 200 patients were treated under pre-procedure US and 406 under LM [pathfinder (PF) n=202, direct cannulation (DC) n=204]. We recorded first needle pass success rate, success rate after the third attempt, and the cannulation time. Procedures were performed by inexperienced (<100) or experienced (>100 catheterizations) operators., Results: Pre-procedure US was associated with more successful attempts and shorter cannulation times. Under pre-procedure US, 88% of first attempts were successful and 100% of third attempts. The median (range) cannulation time was 39 (10-330) s. Under PF, only 56% of first, and 87% of third, attempts were successful with a median (range) cannulation time of 100 (25-3600) s. Under DC, 61% of first and 89% of third attempts were successful; the median (range) cannulation time was 70 (10-3600) s. Remarkably, inexperienced operators using pre-procedure US (n=38) were significantly faster than experienced operators using PF or DC (n=343) (cannulation time: median 60 s, range 12-330, for inexperienced; 60 s, range 10-3600, for experienced). First puncture success rates were higher (pre-procedure US, inexperienced 84%, PF or DC, experienced 57%)., Conclusions: Pre-procedure US for IJV catheterization is safe, quick, and superior to LM., (© The Author [2014]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objectives: To determine clinical outcomes of synthetic colloids, tetrastarch, and gelatin, used before and after cardiac surgery., Design: Prospective observational cohort study., Setting: Fifty-bed cardiac ICU., Patients: Six thousand four hundred seventy-eight consecutive patients with cardiopulmonary bypass surgery., Interventions: Fluid therapy in the operating room and on the ICU directed at preset hemodynamic goals: 1) hydroxyethyl starch (predominantly 6% hydroxyethyl starch 130/0.4) in 2004-2006, n = 2,137; 2) 4% gelatin in 2006-2008, n = 2,324; and 3) only crystalloids in 2008-2010, n = 2,017., Measurements and Main Results: Renal replacement therapy was more common during periods when patients received synthetic colloids compared to only crystalloids. Risk of renal replacement therapy was greater after hydroxyethyl starch (odds ratio, 2.29; 95% CI, 1.47-3.60) and gelatin (odds ratio, 2.75; 95% CI, 1.84-4.16; both p < 0.001) compared to crystalloid. Propensity score stratification confirmed greater use of renal replacement therapy in the hydroxyethyl starch and gelatin periods compared to the crystalloid period (odds ratio, 1.46 [1.08, 1.97]; p = 0.013 and odds ratio, 1.72 [1.33, 2.24]; p < 0.001, respectively). Time to vasopressor cessation, normalization of serum lactate, and mean arterial pressure did not differ among groups. Total fluid requirement was 163 mL/kg in the hydroxyethyl starch period, 207 mL/kg in the gelatin period, and 224 mL/kg in the crystalloid period. Fluid intake was higher in the crystalloid group only during the first 20 hours., Conclusions: In cardiac surgery patients, fluid therapy with perioperative administration of synthetic colloids carries a high risk of renal replacement therapy and is not more effective than treating with only crystalloids.