Alexander Pichler

Introduction Nowadays, managing out-of-hospital cardiac arrest (OHCA) prioritises measures that achieve a good neurological outcome. Monitoring neurological function early is an essential step in identifying patients who could benefit from invasive techniques, such as extracorporeal membrane oxygenation, compared with patients suffering from irreversible hypoxic–ischaemic brain injury. Electroencephalography (EEG) has been used in the hospital; thus, its prehospital data are lacking. This study aimed to evaluate the feasibility of non-invasive EEG in the prehospital environment as a potential tool for neurological assessment. Methods and analysis This feasibility trial will recruit 45 OHCA patients aged 18 and over in the catchment area of the physician response unit at the University Hospital Graz, Austria. Two different measurement conditions will be assessed: (1) during the phase of cardiopulmonary resuscitation (CPR) and (2) after the return of spontaneous circulation for those who achieve this condition. EEG not only has the potential to provide an early neurological prognosis for immediate treatments or outcome-related decisions but can also aid in better managing CPR-induced consciousness. Ethics and dissemination The ethics committee of the Medical University of Graz (IRB00002556), decision number 35-352 ex 22/23, reviewed and approved this study protocol, registered at ClinicalTrials.gov (Identifier NCT06072092). The data generated from this research will be published openly alongside the study results. Trial registration number NCT06072092.

Fragestellung / Studienziel Die Behandlungspriorität von Herzstillständen konzentriert sich nicht mehr nur auf die Wiederherstellung des spontanen Kreislaufs (ROSC), sondern vorrangig auf Maßnahmen, die zu einem guten neurologischen Ergebnis führen. Es ist jedoch bisher nicht möglich Patient*innen mit solch einem Potential von denen zu unterscheiden, die bereits einen hypoxischen Hirnschaden haben. Weiters ist auch unklar, ob CPR-induziertes Bewusstsein (CPRIC) durch diese Methode festgestellt werden kann.In dieser Studie soll die Machbarkeit der präklinischen BIS-Messung während CPR und ROSC bis zur Krankenhausaufnahme überprüft werden um in weiterer Folge diese Fragen zuverlässig beantworten zu können. Methoden Eine prospektive Beobachtungsstudie zur BIS-Anwendung bei Patient*innen mit außerklinischem Kreislaufstillstand wird durch das Notarzteinsatzmittel des Universitätsklinikums Graz, Österreich durchgeführt. Insgesamt werden 45 Patient*innen eingeschlossen, wobei EEG-Aufzeichnungen während der Herz-Lungen-Wiederbelebung angebracht werden, um bei ROSC vom ersten Moment an Daten zu erfassen. Anhand von Qualitätsparametern (Signalqualitätsindex und Elektromyogramm) soll die Reliabilität der Messung in diesem Setting überprüft werden. Auch Patient*innencharakteristika, wiederbelebungs-spezifische Daten und innerklinische Verlaufswerte werden erhoben. Das neurologische Outcome wird explorativ durch den CPC-Score 1 Monat nach Wiederbelebung evaluiert. Diskussion / Schlussfolgerung Die Machbarkeit der frontalen EEG-Messung in der Präklinik stellt den ersten Schritt dar um potenziell Patient*innen filtern zu können, die durch die Möglichkeit eines guten neurologischen Outcomes auch von eventuellen invasiven Techniken wie der extrakorporalen Membranoxygenierung (ECMO) profitieren könnten. Weiters soll dadurch auch die Erforschung des CPR-induzierten Bewusstseins verbessert werden. Diese Pilotstudie soll erstmals die Anwendung dieser innerklinischen Routinemessung in der ressourcenarmen Präklinik überprüfen.

Introduction: Increased inflammatory processes after non-cardiac surgery are very common. The association between postoperative inflammation and the occurrence of cardiovascular complications after non-cardiac surgery are still not entirely clear. Therefore, we will evaluate the association between postoperative inflammation and the occurrence of major cardiovascular complications in patients at-risk for cardiovascular complications undergoing non-cardiac surgery. We will further evaluate the association of postoperative inflammation and days-at-home within 30 days after surgery (DAH ₃₀ ), the incidence of acute kidney injury, postoperative N-terminal probrain natriuretic peptide (NT-proBNP) concentrations and neurocognitive decline. Methods and analysis: In this multicentre study, we will include 1400 patients at-risk for cardiovascular complications undergoing non-cardiac surgery. Our primary aim is to evaluate the association of postoperative maximum C-reactive protein concentration and the occurrence of a composite of five major cardiovascular complications (myocardial infarction, myocardial injury after non-cardiac surgery, new onset of atrial fibrillation, stroke and death) within 30 days after surgery using a Mann-Whitney-U test as well as a logistic regression model. As our secondary aim, we will evaluate the association of a composite of three inflammatory biomarkers (interleukin 6, procalcitonin and copeptin) on the occurrence of our composite of five cardiovascular complications within 30 days and 1 year after surgery, acute kidney injury, DAH ₃₀ and NT-proBNP concentrations using linear or logistic regression models. We will measure inflammatory biomarkers before surgery, and on the first, second, third and fifth postoperative day. We will check medical records and conduct a telephone survey 30 days and 1 year after surgery. We evaluate neurocognitive function, using a Montreal Cognitive Assessment, before and 1 year after surgery. Ethics and dissemination: This study was approved by the ethics committees at the Medical University of Vienna (2458/2020) and at the Medical University of Graz (33-274 ex 20/21). Trial registration number: NCT04753307 .

Background and purpose: Serum neurofilament light chain (sNfL) is a promising biomarker of neuroaxonal damage in persons with multiple sclerosis (pwMS). In cross‐sectional studies, sNfL has been associated with disease activity and brain magnetic resonance imaging (MRI) changes; however, it is still unclear to what extent in particular high sNfL levels impact on subsequent disease evolution.Methods: sNfL was quantified by an ultrasensitive single molecule array (Simoa) in 199 pwMS (median age = 34.2 years, 64.3% female) and 49 controls. All pwMS underwent 3‐T MRI to assess global and compartmental normalized brain volumes, T2‐lesion load, and cortical mean thickness. Follow‐up data and serum samples were available in 144 pwMS (median follow‐up time = 3.8 years). Linear and binary logistic models were used to estimate the independent contribution of sNfL for changes in MRI and Expanded Disability Status Scale (EDSS). Age‐corrected sNfL z‐scores from a normative database of healthy controls were used for sensitivity analyses.Results: High sNfL levels at baseline were associated with atrophy measures of the whole brain (standardized beta coefficient βj = −0.352, p < 0.001), white matter (βj = −0.229, p = 0.007), thalamus (βj = −0.372, p = 0.004), and putamen (βj = −1.687, p = 0.012). pwMS with high levels of sNfL at baseline and follow‐up had a greater risk of EDSS worsening (p = 0.007).Conclusions: Already single time point elevation of sNfL has a distinct effect on brain volume changes over a short‐term period, and repeated high levels of sNfL indicate accumulating physical disability. Serial assessment of sNfL may provide added value in the clinical management of pwMS.

The maximal oxygen uptake (VO2max) and maximal power output (Pmax) are commonly used parameters to evaluate the endurance fitness status. A connection between exercise and the kynurenine pathway (KP), which describes the metabolism of unused tryptophan, has already been reported. However, a potential association of the KP with endurance fitness levels remains unknown. In this study, adolescent competitive athletes performed an exhaustive incremental exercise test. Blood samples were taken before, directly after, and 30 minutes after the end of exercise. Tryptophan (Trp), kynurenine (Kyn) and kynurenic acid (KA) serum levels were determined by high-performance liquid chromatography (HPLC). Forty-four male and 27 female athletes (median age: 16 years) were recruited. During exhaustive exercise tests, Trp initially declined and then increased 30 minutes after discontinuing exercise. Similar findings were observed for Kyn, whereas KA levels behaved inversely. After incremental exhaustive exercise the relative increase of Trp concentrations, termed the tryptophan-recovery-index (TRI), showed a highly significant positive correlation with VO2max and Pmax (r=0.468 and 0.491, p-values <0.001). There was a significant gender-difference with higher levels of all metabolites at all measured time points in male participants. In the present study, a highly significant correlation was found between the TRI and the maximal oxygen uptake in well-trained athletes. The implementation of TRI can therefore be suggested as a biomarker for physical fitness.