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Search Results: 1 - 10 of 1953 matches for " Rossaint Rolf "
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Sudden cardiac death: Role of therapeutic hypothermia
Matthias Derwall,Michael Fries,Rolf Rossaint
Applied Cardiopulmonary Pathophysiology , 2012,
Abstract: Permanent neurocognitive deficits due to cerebral sequelae account for the majority of long-term morbidity and mortality in survivors of cardiac arrest today. Albeit therapeutic hypothermia had been used as effective measure to ameliorate cerebral ischemia-reperfusion injury during surgery for decades, it was not yet introduced into regular post-arrest care until 2003 due to significant side effects of profound hypothermia. These include shivering, higher infection rates, coagulopathy or cardiac arrhythmias, but are less frequently observed with mild therapeutic hypothermia. When body temperature is kept around 33°C, the beneficial effects of hypothermia clearly outweigh its adverse effects. Therefore, treatment of comatose survivors of out-of-hospital cardiac arrest using mild therapeutic hypothermia has now been widely adopted around the globe. Although it still remains controversial who, how, when, and for how long to cool, with only six patients requiring treatment to save one additional life, it is clear that therapeutic hypothermia is the single most effective intervention in brain resuscitation available today.
Time-dependency of improvements in arterial oxygenation during partial liquid ventilation in experimental acute respiratory distress syndrome
Martin Max, Ralf Kuhlen, Rolf Dembinski, Rolf Rossaint
Critical Care , 2000, DOI: 10.1186/cc665
Abstract: Application of four sequential doses of perfluorocarbon resulted in a dose-dependent increase in PaO2. Comparison of measurements 5 and 30 min after instillation of each dose revealed a time-dependent decrease in PaO2 for doses that approximated the functional residual capacity of the animals.Although oxygen dissolved in perfluorocarbon at the onset of PLV can cause a short-term improvement in arterial oxygenation, diffusion of oxygen through the liquid may not be sufficient to maintain the initially observed increase in PaO2.Partial liquid ventilation (PLV) is a novel technique to improve gas exchange in acute lung injury (ALI). It combines the intrapulmonary application of perfluorocarbons in volumes up to the functional residual capacity of the lungs with conventional gaseous ventilation [1], and has been shown to improve gas exchange and lung mechanics in a dose-dependent manner in experimental and clinical settings of severe respiratory failure [2,3,4,5]. Two different mechanisms are presently proposed to account for a persistent increase in arterial oxygenation during PLV. First, it is suggested that the low surface tension of perfluorocarbons(10-15 dyn/cm) can facilitate the recruitment of atelectatic lung segments for ventilation, indicated by an increase in lung compliance [6]. Second, it is hypothesized that pooling of the dense compounds (1.75-1.92 g/ml) along the gravitational gradient causes a redistribution of pulmonary blood flow from dependent to nondependent, better ventilated lung areas, due to a compression of the pulmonary vasculature in the dorsal lung regions [7,8]. Additionally, the high solubility of oxygen and carbon dioxide in perfluorocarbons (40-60 and 160-210 ml/100ml, respectively) suggests a potential role for these substances as transport media for the respiratory gases in nonventilated but perfluorocarbon-filled, dependent lung segments, depending on the diffusion of oxygen and carbon dioxide through the liquid. A persistent effect o
Propofol: neuroprotection in an in vitro model of traumatic brain injury
Jan Rossaint, Rolf Rossaint, Joachim Weis, Michael Fries, Steffen Rex, Mark Coburn
Critical Care , 2009, DOI: 10.1186/cc7795
Abstract: In this controlled laboratory study organotypic hippocampal brain-slice cultures were gained from six- to eight-day-old mice pups. After 14 days in culture, hippocampal brain slices were subjected to a focal mechanical trauma and subsequently treated with different molar concentrations of propofol under both normo- and hypothermic conditions. After 72 hours of incubation, tissue injury assessment was performed using propidium iodide (PI), a staining agent that becomes fluorescent only when it enters damaged cells via perforated cell membranes. Inside the cell, PI forms a fluorescent complex with nuclear DNA.A dose-dependent reduction of both total and secondary tissue injury could be observed in the presence of propofol under both normo- and hypothermic conditions. This effect was further amplified when the slices were incubated at 32°C after trauma.When used in combination, the dose-dependent neuroprotective effect of propofol is additive to the neuroprotective effect of hypothermia in an in vitro model of traumatic brain injury.Traumatic brain injury (TBI) is a common consequence of traffic-related accidents and incidents at work and at home. The annual incidence of TBI in the UK is estimated to be approximately 400 per 100,000 patients per year [1]. The treatment of patients with traumatic injury to the brain accounts for a considerable proportion of the budget spent annually on health care and the subsequent costs for rehabilitation, post-hospital long-term care and disability are a significant burden for the economy and society. It should be noted that all currently available therapy approaches for TBI are symptomatic in nature. To date, no clinically established therapy exists that specifically counteracts the actual pathological mechanisms leading to traumatic brain tissue injury.Propofol (2,6-diisopropylphenol) is a short-acting, intravenous hypnotic agent widely used for the induction and maintenance of general anaesthesia in the perioperative setting, for
Neuroprotective properties of levosimendan in an in vitro model of traumatic brain injury
Anna B Roehl, Marc Hein, Philipp D Loetscher, Jan Rossaint, Joachim Weis, Rolf Rossaint, Mark Coburn
BMC Neurology , 2010, DOI: 10.1186/1471-2377-10-97
Abstract: Organotypic hippocampal brain slices from mouse pups were subjected to a focal mechanical trauma. Slices were treated after the injury with three different concentrations of levosimendan (0.001, 0.01 and 0.1 μM) and compared to vehicle-treated slices. After 72 hrs, the trauma was quantified using propidium iodide to mark the injured cells.A significant dose-dependent reduction of both total and secondary tissue injury was observed in cells treated with either 0.01 or 0.1 μM levosimendan compared to vehicle-treated slices.Levosimendan represents a promising new pharmacological tool for neuroprotection after brain injury and warrants further investigation in an in vivo model.Traumatic brain injury (TBI) is common, carries high rates of morbidity and mortality and lacks specific treatment. In our study of TBI, the initial lesion results from direct mechanical damage at the impact site. Subsequently, several cellular and molecular processes expand the local injury. This so-called secondary injury is due to several factors: excitotoxicity; mitochondrial dysfunction resulting in the up-regulation of cell-death genes and the formation of free radicals; and proapoptotic mediator pathway activation [1]. At present, medical intervention cannot rescue directly traumatised, dying cells. Therefore, current neuroprotective drugs target the surviving cells near the impact site [2]. Hypotension, hypoxia, hyper- and hypocapnia, and hyper- and hypoglycemia remain potentially avoidable insults, all of which aggravate the outcomes of TBI [3]. Levosimendan is a novel inodilator that enhances myocardial performance without leading to substantial changes in oxygen consumption. Levosimendan's positive inotropic and vasodilator effects are tied to its abilities to increase calcium sensitivity and open ATP-sensitive K+ channels (mitoKATPchannels) [4]. In a swine model of cardiac arrest, levosimendan significantly improved the initial resuscitation success, increased coronary perfusion pressu
Cardiovascular Agents Affect the Tone of Pulmonary Arteries and Veins in Precision-Cut Lung Slices
Annette D. Rieg, Rolf Rossaint, Stefan Uhlig, Christian Martin
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0029698
Abstract: Introduction Cardiovascular agents are pivotal in the therapy of heart failure. Apart from their action on ventricular contractility and systemic afterload, they affect pulmonary arteries and veins. Although these effects are crucial in heart failure with coexisting pulmonary hypertension or lung oedema, they are poorly defined, especially in pulmonary veins. Therefore, we investigated the pulmonary vascular effects of adrenoceptor agonists, vasopressin and angiotensin II in the model of precision-cut lung slices that allows simultaneous studies of pulmonary arteries and veins. Materials and Methods Precision-cut lung slices were prepared from guinea pigs and imaged by videomicroscopy. Concentration-response curves of cardiovascular drugs were analysed in pulmonary arteries and veins. Results Pulmonary veins responded stronger than arteries to α1-agonists (contraction) and β2-agonists (relaxation). Notably, inhibition of β2-adrenoceptors unmasked the α1-mimetic effect of norepinephrine and epinephrine in pulmonary veins. Vasopressin and angiotensin II contracted pulmonary veins via V1a and AT1 receptors, respectively, without affecting pulmonary arteries. Discussion Vasopressin and (nor)epinephrine in combination with β2-inhibition caused pulmonary venoconstriction. If applicable in humans, these treatments would enhance capillary hydrostatic pressures and lung oedema, suggesting their cautious use in left heart failure. Vice versa, the prevention of pulmonary venoconstriction by AT1 receptor antagonists might contribute to their beneficial effects seen in left heart failure. Further, α1-mimetic agents might exacerbate pulmonary hypertension and right ventricular failure by contracting pulmonary arteries, whereas vasopressin might not.
Produktion von Lehrmedien im Qualifikationsprofil Neue Medien, Kommunikation, Didaktik in der Medizin“ im Modellstudiengang Humanmedizin Aachen: Ein Aufgabengebiet für die An sthesiologie? []
Beckers, Stefan,Sopka, Sasa,Ohnesorge-Radtke, Ulla,Rossaint, Rolf
GMS Zeitschrift für Medizinische Ausbildung , 2008,
Abstract:
The Hip Fracture Surgery in Elderly Patients (HIPELD) study: protocol for a randomized, multicenter controlled trial evaluating the effect of xenon on postoperative delirium in older patients undergoing hip fracture surgery
Coburn Mark,Sanders Robert D,Maze Mervyn,Rossaint Rolf
Trials , 2012, DOI: 10.1186/1745-6215-13-180
Abstract: Background Strategies to protect the brain from postoperative delirium (POD) after hip fracture are urgently needed. The development of delirium often is associated with the loss of independence, poor functional recovery, and increased morbidity, as well as increases in length of hospital stay, discharges to nursing facilities, and healthcare costs. We hypothesize that xenon may reduce the burden of POD, (i) by avoiding the need to provide anesthesia with a drug that targets the γ-amino-butyric acid (GABA)A receptor and (ii) through beneficial anesthetic and organ-protective effects. Methods and design An international, multicenter, phase 2, prospective, randomized, blinded, parallel group and controlled trial to evaluate the incidence of POD, diagnosed with the Confusion Assessment Method (CAM), in older patients undergoing hip fracture surgery under general anesthesia with xenon or sevoflurane, for a period of 4 days post surgery (primary outcome) is planned. Secondary objectives are to compare the incidence of POD between xenon and sevoflurane, to evaluate the incidence of POD from day 5 post surgery until discharge from hospital, to determine the time to first POD diagnosis, to evaluate the duration of POD, to evaluate the evolution of the physiological status of the patients in the postoperative period, to evaluate the recovery parameters, to collect preliminary data to evaluate the economical impact of POD in the postoperative period and to collect safety data. Patients are eligible if they are older aged (≥ 75 years) and assigned to a planned hip fracture surgery within 48 h after the hip fracture. Furthermore, patients need to be willing and able to complete the requirements of this study including the signature of the written informed consent. A total of 256 randomized patients in the 10 participating centers will be recruited, that is, 128 randomized patients in each of the 2 study groups (receiving either xenon or sevoflurane). Trial registration EudraCT Identifier: 2009-017153-35; ClinicalTrials.gov Identifier: NCT01199276
Prehospital digital photography and automated image transmission in an emergency medical service – an ancillary retrospective analysis of a prospective controlled trial
Bergrath Sebastian,Rossaint Rolf,Lenssen Niklas,Fitzner Christina
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2013, DOI: 10.1186/1757-7241-21-3
Abstract: Background Still picture transmission was performed using a telemedicine system in an Emergency Medical Service (EMS) during a prospective, controlled trial. In this ancillary, retrospective study the quality and content of the transmitted pictures and the possible influences of this application on prehospital time requirements were investigated. Methods A digital camera was used with a telemedicine system enabling encrypted audio and data transmission between an ambulance and a remotely located physician. By default, images were compressed (jpeg, 640 x 480 pixels). On occasion, this compression was deactivated (3648 x 2736 pixels). Two independent investigators assessed all transmitted pictures according to predefined criteria. In cases of different ratings, a third investigator had final decision competence. Patient characteristics and time intervals were extracted from the EMS protocol sheets and dispatch centre reports. Results Overall 314 pictures (mean 2.77 ± 2.42 pictures/mission) were transmitted during 113 missions (group 1). Pictures were not taken for 151 missions (group 2). Regarding picture quality, the content of 240 (76.4%) pictures was clearly identifiable; 45 (14.3%) pictures were considered “limited quality” and 29 (9.2%) pictures were deemed “not useful” due to not/hardly identifiable content. For pictures with file compression (n = 84 missions) and without (n = 17 missions), the content was clearly identifiable in 74% and 97% of the pictures, respectively (p = 0.003). Medical reports (n = 98, 32.8%), medication lists (n = 49, 16.4%) and 12-lead ECGs (n = 28, 9.4%) were most frequently photographed. The patient characteristics of group 1 vs. 2 were as follows: median age – 72.5 vs. 56.5 years, p = 0.001; frequency of acute coronary syndrome – 24/113 vs. 15/151, p = 0.014. The NACA scores and gender distribution were comparable. Median on-scene times were longer with picture transmission (26 vs. 22 min, p = 0.011), but ambulance arrival to hospital arrival intervals did not differ significantly (35 vs. 33 min, p = 0.054). Conclusions Picture transmission was used frequently and resulted in an acceptable picture quality, even with compressed files. In most cases, previously existing “paper data” was transmitted electronically. This application may offer an alternative to other modes of ECG transmission. Due to different patient characteristics no conclusions for a prolonged on-scene time can be drawn. Mobile picture transmission holds important opportunities for clinical handover procedures and teleconsultation.
Respiratory compliance but not gas exchange correlates with changes in lung aeration after a recruitment maneuver: an experimental study in pigs with saline lavage lung injury
Dietrich Henzler, Paolo Pelosi, Rolf Dembinski, Annette Ullmann, Andreas H Mahnken, Rolf Rossaint, Ralf Kuhlen
Critical Care , 2005, DOI: 10.1186/cc3772
Abstract: In eight anesthetized and mechanically ventilated pigs, acute lung injury was induced by saline lavage and a recruitment maneuver was performed by inflating the lungs three times with a pressure of 45 cmH2O for 40 s with a constant positive end-expiratory pressure of 10 cmH2O. The association of gas exchange and lung mechanics parameters with the amount and the changes in aerated and nonaerated lung volumes induced by this specific recruitment maneuver was investigated by multi slice CT scan analysis of the whole lung.Nonaerated lung correlated with shunt fraction (r = 0.68) and respiratory system compliance (r = 0.59). The arterial partial oxygen pressure (PaO2) and the respiratory system compliance correlated with poorly aerated lung volume (r = 0.57 and 0.72, respectively). The recruitment maneuver caused a decrease in nonaerated lung volume, an increase in normally and poorly aerated lung, but no change in the distribution of a tidal breath to differently aerated lung volumes. The fractional changes in PaO2, arterial partial carbon dioxide pressure (PaCO2) and venous admixture after the recruitment maneuver did not correlate with the changes in lung volumes. Alveolar recruitment correlated only with changes in the plateau pressure (r = 0.89), respiratory system compliance (r = 0.82) and parameters obtained from the pressure-volume curve.A recruitment maneuver by repeatedly hyperinflating the lungs led to an increase of poorly aerated and a decrease of nonaerated lung mainly. Changes in aerated and nonaerated lung volumes were adequately represented by respiratory compliance but not by changes in oxygenation or shunt.Severe impairment of oxygenation in acute lung injury and in the acute respiratory distress syndrome (ARDS) is caused by an inhomogenous ventilation-perfusion distribution () and an increase in shunt fraction. The amount of aerated lung is markedly reduced due to alveolar collapse and flooding [1,2]. Mechanical ventilation has been shown to further a
Acute Pain Therapy in Postanesthesia Care Unit Directed by Skin Conductance: A Randomized Controlled Trial
Michael Czaplik, Christa Hübner, Markus K?ny, Julia Kaliciak, Fatima Kezze, Steffen Leonhardt, Rolf Rossaint
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041758
Abstract: Background After surgery, effective and well-directed acute pain therapy is a necessary and integral part of the overall treatment plan. Generally, the assessment of pain intensity depends on a patient’s self-evaluation using scoring systems such as numeric rating scales (NRS, 0 to 10). Recently, a “Pain Monitor” was commercially provided which is based on measurements of fluctuations of skin conductance (NFSC). In this randomized, controlled, single-blind trial, possible benefits of this certain device were studied. Methods Postoperative patients (n = 44) were randomly assigned to a test or a control group during their stay in the postanesthesia care unit (PACU). All patients were treated and monitored according to internal hospital standards. Whereas all patients systematically evaluated their pain each 15 min, test group patients were additionally addressed when NFSC exceeded a predefined level. In cases of NRS≥5 during a routine elevation or in between, pain relief was achieved by standard procedures irrespective of group allocation. Results During their stay in PACU, both test and control groups experienced a significant decrease in NRS as a consequence of pain therapy. No significant differences in mean NRS or in NFSC values were found between the test and control groups. No correlation was observed between NRS and NFSC. Conclusion Postoperative patients experience diverse stressors, such as anxiety, disorientation, shivering, sickness and pain. Although the application of continuous pain monitoring would be meaningful in this clinical setting, the tested device failed to distinguish pain from other stressors in postoperative adult patients. Trial Registration German Clinical Trials Register DRKS00000755.
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