Simon T Schäfer

Simon T Schäfer
Ludwig-Maximilians-University of Munich | LMU · Department of Anesthesiology

Professor M.D. MHBA

About

70
Publications
7,968
Reads
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830
Citations
Introduction
Simon T Schäfer currently works at the Department of Anesthesiology, Ludwig-Maximilians-University of Munich. Simon does research in Anaesthetics, Immunology and Molecular Biology. Their current project is 'DOAK detection with ROTEM'.
Additional affiliations
May 2021 - present
Ludwig-Maximilians-University of Munich
Position
  • Leitender Oberarzt
October 2015 - July 2020
Ludwig-Maximilians-University of Munich
Position
  • Geschäftsführender Oberarzt
December 2014 - September 2015
University Hospital Essen
Position
  • Geschäftsführender Oberarzt

Publications

Publications (70)
Article
BACKGROUND: Recent guidelines suggest that benzodiazepine premedication should be avoided in elderly patients, though with limited supporting evidence. OBJECTIVE: We conducted a secondary analysis of the POSE data to explore the association of premedication in patients aged 80 years or older with 30-day mortality. DESIGN: We used propensity score m...
Article
Full-text available
OBJECTIVES: The aim of this study was to describe the 30-day mortality rate of patients aged 80 years and older undergoing surgical and nonsurgical procedures under anaesthesia in Europe and to identify risk factors associated with mortality. DESIGN: A prospective cohort study. SETTING: European multicentre study, performed from October 2017 to Dec...
Article
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Background DOAC detection is challenging in emergency situations. Here, we demonstrated recently, that modified thromboelastometric tests can reliably detect and differentiate dabigatran and rivaroxaban. However, whether all DOACs can be detected and differentiated to other coagulopathies is unclear. Therefore, we now tested the hypothesis that a d...
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Tranexamic acid (TXA) can reduce blood loss and transfusion rates in orthopaedic surgery. In this regard, a new viscoelastometric test (TPA-test, ClotPro), enables the monitoring of TXA effects. This prospective observational study evaluated and correlated TXA plasma concentrations (cTXA) following intravenous and oral administration in patients un...
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Abstract Background Determination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device. Methods This prospective, observational stud...
Article
Introduction: While previous studies have shown a significant impact of extreme hypo- and hyperthermia on coagulation, effects of much more frequently occurring perioperative mild hypothermia are largely unknown. This study therefore aimed to analyze the effects of mild hypothermia using rotational thromboelastometry in vitro. Materials and metho...
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Introduction: Tranexamic acid (TXA) is the standard medication to prevent or treat hyperfibrinolysis. However, prolonged inhibition of lysis (so-called "fibrinolytic shutdown") correlates with increased mortality. A new viscoelastometric test enables bedside quantification of the antifibrinolytic activity of TXA using tissue plasminogen activator...
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Introduction Tranexamic acid (TXA) is considered gold standard for treatment and prophylaxis of hyperfibrinolysis in trauma patients and cardiac surgery [1,2]. However, prolonged inhibition of lysis (so-called “fibrinolytic shutdown”) correlates with increased mortality in critical ill patients [3]. Additionally, there is still an ongoing discussio...
Article
Background COVID-19 is a novel viral disease. Severe courses may present as ARDS. Several publications report a high incidence of coagulation abnormalities in these patients. We aimed to compare coagulation and inflammation parameters in patients with ARDS due to SARS-CoV-2 infection versus patients with ARDS due to other causes. Methods This retr...
Article
Purpose: Mitochondrial dysfunction has long been considered in the pathogenesis of Parkinson's disease (PD). This is evident from the presence of mitochondrial DNA deletions in substantia nigra neurons and respiratory chain abnormalities in the skeletal muscle of PD patients. However, the contributing factors that potentially cause oxidative stress...
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Induction of hypoxia-inducible-factor-1α (HIF-1α) pathway and HIF-target genes allow adaptation to hypoxia and are associated with reduced incidence of acute mountain sickness (AMS). Little is known about HIF-pathways in conjunction with inflammation or exercise stimuli under acute hypobaric hypoxia in non-acclimatized individuals. We therefore tes...
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Travel of unacclimatized subjects to high altitude has been growing in popularity. Changes of endothelial shedding (circulating endothelial cells, ECs) and hematopoietic stem and progenitor cells (CPCs) during physical exercise in hypobaric hypoxia, however, are not well understood. We investigated the change of ECs and CPCs when exposed to high al...
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Background: There is little knowledge, whether in patients with sepsis neutrophil extracellular trap (NET) formation and NET degrading nuclease activity are altered. Thus, we tested the hypotheses that 1) NET formation from neutrophils of septic patients is increased compared to healthy volunteers, both without stimulation and following incubation...
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Altered aquaporin 5 (AQP5) expression in immune cells impacts on key mechanisms of inflammation and is associated with sepsis survival. Since epigenetic regulation via DNA methylation might contribute to a differential AQP5 expression in sepsis, we tested the hypotheses that DNA methylation of the AQP5 promotor (1) influences AQP5 expression, (2) i...
Article
Background: Intravenous fluids can impair coagulation and affect the endothelial glycocalyx, whereas glycocalyx shedding itself can cause an impairment of clot formation and firmness. We hypothesized that hydroxyethyl starch 6% (130/0.4) has a more distinct effect on coagulation and glycocalyx shedding than albumin 5%. Methods: Presented data de...
Preprint
Background: Critically ill patients are at risk for sepsis and immunosuppressive mechanisms may prevail. Whether functional tests are helpful to detect immune alterations is largely unknown. Therefore, we tested the hypotheses, that reactivity of peripheral blood mononuclear cells (PBMCs) to secrete interferon-g (IFNγ) following stimulation in vit...
Preprint
Background Postoperative delirium is associated with worse outcome. The aim of this study is to understand present strategies for delirium screening and therapy in German Post Anesthesia Caring Units (PACU) in hospitals and ambulatory anesthesia facilities. Methods We designed German-wide web-based survey of 922 leading anesthesiologists in hospita...
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Introduction: Fibrinogen concentrates are widely used to restore clot stability in situations of bleeding. Fibrinogen preparations are produced using different production methods, resulting in different compounds. Thus, different preparations might have a distinct impact on blood coagulation. We tested the effect of fibrinogen concentrates Haemoco...
Article
Postoperative delirium is common and has multiple adverse consequences. Guidelines recommend routine screening for postoperative delirium beginning in the post‐anaesthesia care unit. The 4 A's test (4AT) is a widely used assessment tool for delirium but there are no studies evaluating its use in the post‐anaesthesia care unit. We evaluated the perf...
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Objective Normobaric (NH) and hypobaric hypoxia (HH) are associated with acute mountain sickness (AMS) and cognitive dysfunction. Only few variables, like heart-rate-variability, are correlated with AMS. However, prediction of AMS remains difficult. We therefore designed an expedition-study with healthy volunteers in NH/HH to investigate additional...
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PURPOSE OF REVIEW: Neurocognitive dysfunction after surgery is highly relevant in the elderly. The multifactorial manner of this syndrome has made it hard to define an ideal biomarker to predict individual risk and assess diagnosis and severity of delirium [postoperative delirium (POD)] and subsequent postoperative cognitive decline (POCD). This re...
Article
Accidental severe hypothermia is a medical emergency in which symptoms may include coma, apnea, pulmonary edema, ventricular dysrhythmia or asystole. Despite optimal treatment, mortality remains high. This article reports a case of severe hypothermia in a geriatric hypothyroid patient, where despite a body core temperature of 23.1 °C the patient pr...
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Background: Sepsis is now operationally defined as life-threatening organ dysfunction caused by an infection, identified by an acute change in SOFA-Score of at least two points, including clinical chemistry such as creatinine or bilirubin concentrations. However, little knowledge exists about organ-specific microRNAs as potentially new biomarkers....
Data
Baseline characteristics of the control group (infection without sepsis) and patients with sepsis according sepsis-3 criteria. (DOCX)
Data
Cycle Threshold [CT] of cel-miR-54 expression in control patients, sepsis survivors, and sepsis non-survivors. Cel-miR-54 levels are presented in scatter plots. Data are shown as median with interquartile range. (PDF)
Article
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Epigenetik, die Wissenschaft, die sich mit der geänderten Ablesung des Genoms ohne Veränderung der Gene selbst beschäftigt, gelangt wissenschaftlich zunehmend in den Fokus. Unterschieden werden Veränderungen an der DNA von Modifikationen der Histone und nichtkodierenden RNA, die die messenger (m)RNA verändern. Epigenetische Modifikationen können du...
Conference Paper
Full-text available
Fragestellung: Akklimatisierte Personen können auch arterielle Sauerstoffpartialdrücke unter 25 mmHg tolerieren [1], wohingegen die Hypoxietoleranz bei nicht-akklimatisierten Personen schlecht prognostiziert werden kann. Anpassungsmechanismen an Hypoxie und inflammatorische Stimuli werden maßgeblich durch die hypoxisch-inflammatorische Genregulatio...
Conference Paper
Full-text available
Introduction: Acute hypoxia in both high altitude and under normobaric conditions is associated with symptoms of acute mountain sickness (AMS) and cognitive dysfunction in humans. However, global or molecular predictors for the development of AMS are missing. Thus, the aim of this study was to investigate in non-acclimatized subjects associations b...
Article
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Hypoxia-inducible-factor-2α (HIF-2α) and HIF-2 degrading prolyl-hydroxylases (PHD) are key regulators of adaptive hypoxic responses i.e., in acute respiratory distress syndrome (ARDS). Specifically, functionally active genetic variants of HIF-2α (single nucleotide polymorphism (SNP) [ch2:46441523(hg18)]) and PHD2 (C/T; SNP rs516651 and T/C; SNP rs4...
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Randomized controlled trials (RCTs) are considered the gold standard for clinical research, thus having a high impact on clinical guidelines and our daily patients’ care. However, various treatment strategies which we consider “evidence based” have never been subject to a prospective RCT, as we would rate it unethical to withheld an established tre...
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Background The C-allele of the aquaporin (AQP5) -1364A/C polymorphism is associated with decreased AQP5 expression but increased 30-day survival in patients with severe sepsis. AQP5 expression might affect survival via an impact on cell migration. Consequently, we tested the hypothesis that (1) Aqp5 knockout (KO) compared to wild type (WT) mice sho...
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Unfortunately, the original version of this article [1] contained an error. Figure 2 and Figure 3 have been swapped with each other. Figure 2 is supposed to be the graph and figure 3 is supposed to be the boxplot. There will also be an update to correct this.
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Background: Acute kidney injury (AKI) is a common complication following transcatheter aortic valve implantation (TAVI) leading to increased mortality and morbidity. Urinary G1 cell cycle arrest proteins TIMP-2 and IGFBP7 have recently been suggested as sensitive biomarkers for early detection of AKI in critically ill patients. However, the precise...
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Background Hypoxia-inducible-factor-1α (HIF-1α) and HIF-1 degrading prolyl-hydroxylases (PHD) are key regulators of the hypoxic-inflammatory response. Functionally active genetic variants in the HIF-1α (C/T; Single Nucleotide Polymorphism (SNP) rs11549465) and the PHD2 gene (EGLN1; C/T; SNP rs516651 and T/C; SNP rs480902) are associated with altere...
Article
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Sepsis, with a persistently high 90-day mortality of about 46%, is the third most frequent cause of death in intensive care units worldwide. Further understanding of the inflammatory signaling pathways occurring in sepsis is important for new efficient treatment options. Key regulator of the inflammatory response is the transcription factor NFκB. A...
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Background Critically ill patients are at high risk to suffer from sepsis, even in the absence of an initial infectious source, but the molecular mechanisms for their increased sepsis susceptibility, including a suppressed immune system, remain unclear. Although microbes and pathogen-associated molecular pattern are accepted inducers of sepsis and...
Article
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Neutrophil extracellular trap (NET) formation is a significant innate immune defense mechanism against microbial infection that complements other neutrophil functions including phagocytosis and degranulation of antimicrobial peptides. NETs are decondensed chromatin structures in which antimicrobial components (histones, antimicrobial peptides and p...
Article
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Toll-like receptor (TLR) 13 and TLR2 are the major sensors of Gram-positive bacteria in mice. TLR13 recognizes Sa19, a specific 23S ribosomal (r) RNA-derived fragment and bacterial modification of Sa19 ablates binding to TLR13, and to antibiotics such as erythromycin. Similarly, RNase A-treated Staphylococcus aureus activate human peripheral blood...
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Background: Previous investigations and meta-analyses on the effect of glucocorticoids on mortality in septic shock revealed mixed results. This heterogeneity might be evoked by genetic variations. Such candidate is a promoter polymorphism (-94ins/delATTG) of the gene encoding the ubiquitous transcription-factor nuclear-factor-κB (NF-κB) which bin...
Article
Aquaporin 1 (AQP1) and 5 (AQP5) expression may impact on key mechanisms in sepsis. However, it is unclear whether these aquaporins are expressed to an equal extent or regulated differentially. Accordingly, we investigated the time-dependent expression of AQP 1 and 5 following stimulation with LPS in cultured human THP-1 cells and in the lungs of mi...
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Angiogenesis is compromised under conditions of hypercholesterolemia. Since disturbed angiogenesis predisposes to ischemic injuries, efforts have been made to promote angiogenesis by delivery of growth factors. How stromal cell-derived growth factor (SDF)-1 influences angiogenesis under conditions reflecting hypercholesterolemia was unknown. We inv...
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Background: Hypoxia-inducible factor-1 (HIF-1) is a molecular key player in response to hypoxemic/inflammatory conditions prevailing in sepsis. In a prospective observational study, we tested the hypotheses that sepsis affects HIF-1α messenger ribonucleic acid (mRNA) expression (primary hypothesis) and also (secondary hypotheses) the expression of...
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Considerable efforts have been made to amplify angiogenesis under conditions of hypoxia and ischemia by vascular endothelial growth factor (VEGF) delivery, so far with limited success. Ischemic vascular diseases are often associated with hypercholesterolemia. To elucidate whether the exposure to blood lipids influences VEGF responses of microvessel...
Article
Background: Because the nuclear factor-κB (NF-κB) coupled pathway is believed to amplify inflammation prevailing in sepsis, the authors tested the hypotheses that the insertion-deletion polymorphism (-94ins/delATTG) (1) alters nuclear translocation of nuclear factor-κB and activator protein-1 (NF-κB1) in monocytes after lipopolysaccharide stimulat...
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ABSTRACT: ATP-binding cassette transporters at the blood-brain barrier are actively regulated upon ischemic stroke in a way that impedes the access of pharmacological compounds to the brain tissue. The luminal endothelial transporter ABCB1 was recently shown to be increased, whereas the abluminal transporter ABCC1 was decreased on ischemic brain ca...
Article
Venous air embolism activates platelets in vitro and can evoke platelet dysfunction in swine. We tested the hypothesis that venous air embolism during semi-sitting craniotomy induces thrombocytopenia in humans. We analysed the charts of 799 patients who had an elective craniotomy in the semi-sitting position between 1990 and June 2009. Venous air e...
Article
Anemia is common in patients with sepsis but its mechanism is unknown. We tested the hypothesis that effects on erythropoiesis evoked by darbepoetin alfa (DA), a long-acting erythropoietin analog, are diminished by lipopolysaccharide (LPS). We performed a prospective, controlled, randomized animal study (male Lewis rats n = 44). The interventions w...
Article
Using intra-cardiac echocardiography in anaesthetised swine we tested the hypotheses that embolised air (i) passes immediately through the right atrium into the ventricle; (ii) persists in the right ventricle for a long time; (iii) is detectable for longer within the right ventricle or main pulmonary artery than the right atrium, and (iv) right ven...
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In vitro, air bubbles can induce platelet activation and platelet to air bubble binding. We therefore tested in vivo the hypothesis that venous air embolism (VAE) induces (1) platelet dysfunction and (2) thrombocytopenia. Adult swine (60.8+/-3.9 kg; n=8) were anaesthetized, mechanically ventilated, and placed in a semi-upright position. Air boli (0...
Article
Darbepoetin alpha (DA), a long-acting erythropoietin derivative stimulating erythropoiesis, can, by antiapoptotic effects, mitigate myocardial I/R injury. We tested the hypothesis that DA treatment improves left ventricular function (LV) in LPS evoked cardiomyopathy and alters gene expression of apoptosis-regulating proteins (Bcl-XL, Bcl-2, Bax, an...
Article
Venous air embolism (VAE) is a potentially fatal complication during surgical procedures with patients in the sitting position. Since methods for detection of persistent low-volume VAE and targeted air aspiration are limited, we tested the hypotheses that transvenous intracardiac echocardiography (ICE) 1) improves detection of small air emboli in c...
Article
We reported recently that celecoxib inhibits the metabolism of the cytochrome P450 (CYP)2D6 substrate metoprolol in volunteers. Valdecoxib, the active metabolite of parecoxib, has also been claimed to interfere with the metabolism of CYP2D6 substrates. However, little support for this contention is available despite the intensive use of parecoxib i...