Microstructure, physical and mechanical properties of dental polychromic multilayer zirconia of uniform composition.

The present study aimed to compare the microstructure, physical, and mechanical properties of three commercially available dental polychromatic multilayer zirconia materials of uniform composition: Dima Mill Zirconia ML, VITA YZ/ST Multicolor, and VITA YZ/XT Multicolor (with 3, 4, and 5 mol% Y2 O3 , respectively); thus, the influence of Y2 O3 content on the above properties of the produced materials was experimentally studied. Homogeneous zirconia ceramics with a dense micro- and nanostructure, without pores or defects, were produced after milling the blocks and sintering, which resulted in yttrium-stabilized tetragonal and cubic zirconia. Statistical analysis of the results of measurable magnitudes was performed by the one-way ANOVA test. The increase of Y2 O3 content (from 3 to 5 mol%) favored larger grain and crystallite sizes and a decrease of the values of the mechanical properties; yet, the differences were statistically insignificant. Clinically, these differences are expected to have no impact on their function in the oral cavity, both in terms of their fracture propensity and the damage that can be caused to the opposing teeth. Accordingly, the experimental results qualify the polychromic multilayer zirconia ceramics of uniform composition fabricated by milling technology for use in dental restorations.

Evaluation of bond strength between zirconia milled ceramic material and veneered dental porcelain.

This study aimed at examining the bond strength between zirconia and ceramic veneer, following the ISO 9693 guidelines. A total of fifty specimens of zirconia/ceramic-veneer system were produced using two commercial zirconias (VITA YZ-HTWhite and Zolid HT+ White, referred to as Group A and Group B, respectively) and a ceramic-veneering material (Zirkonia 750). The microstructure (via x-ray diffraction analysis, XRD and Secondary Electron mode, SEM) and the mechanical properties (via 3-point bending tests) of the two groups were assessed. Then, experiments were conducted according to the ISO 9693 and conventional protocols applied for producing zirconia/ceramic-veneer restorations. Bond strength values, measured by 3-point bending tests, were 34.42 ± 7.60 MPa for Group A and 31.92 ± 6.95 MPa for Group B. SEM observations of the cohesively fractured surfaces (on the porcelain side) and the examination for normality using the Shapiro-Wilk test suggested the use of Weibull statistical analysis. Median strength (σ50%) for Group A and Group B was 34.76 and 32.22 MPa, while the characteristic strength (σ63.2%) was 35.78 and 33.14 MPa, respectively. The Weibull modulus disparity between groups (12.69 and 13.07) was not significant. Bond strength exceeded the ISO 9693 minimum of 20 MPa, suggesting satisfactory strength for clinical use.

Development and validation of a new drug-focused predictive risk score for postoperative delirium in orthopaedic and trauma surgery patients.

BACKGROUND: Postoperative delirium (POD) is the most common complication following surgery in elderly patients. During pharmacist-led medication reconciliation (PhMR), a predictive risk score considering delirium risk-increasing drugs and other available risk factors could help to identify risk patients. METHODS: Orthopaedic and trauma surgery patients aged ≥ 18 years with PhMR were included in a retrospective observational single-centre study 03/2022-10/2022. The study cohort was randomly split into a development and a validation cohort (6:4 ratio). POD was assessed through the 4 A's test (4AT), delirium diagnosis, and chart review. Potential risk factors available at PhMR were tested via univariable analysis. Significant variables were added to a multivariable logistic regression model. Based on the regression coefficients, a risk score for POD including delirium risk-increasing drugs (DRD score) was established. RESULTS: POD occurred in 42/328 (12.8%) and 30/218 (13.8%) patients in the development and validation cohorts, respectively. Of the seven evaluated risk factors, four were ultimately tested in a multivariable logistic regression model. The final DRD score included age (66-75 years, 2 points; > 75 years, 3 points), renal impairment (eGFR < 60 ml/min/1.73m2, 1 point), anticholinergic burden (ACB-score ≥ 3, 1 point), and delirium risk-increasing drugs (n ≥ 2; 2 points). Patients with ≥ 4 points were classified as having a high risk for POD. The areas under the receiver operating characteristic curve of the risk score model were 0.89 and 0.81 for the development and the validation cohorts, respectively. CONCLUSION: The DRD score is a predictive risk score assessable during PhMR and can identify patients at risk for POD. Specific preventive measures concerning drug therapy safety and non-pharmacological actions should be implemented for identified risk patients.

Fit for Service: Preparing Residents for Neurointensive Care with Entrustable Professional Activities: A Delphi Study.

BACKGROUND: Although the relevance of neurointensive medicine and high-quality training of corresponding physicians is increasingly recognized, there is high heterogeneity in the nature, duration, and quality of neurointensive care curricula around the world. Thus, we aimed to identify, define, and establish validity evidence for entrustable professional activities (EPAs) for postgraduate training in neurointensive care to determine trainees' readiness for being on-call. METHODS: After defining EPAs through an iterative process by an expert group, we used a modified Delphi approach with a single-center development process followed by a national consensus and a single-center validation step. EPAs were evaluated by using the EQual rubric (Queen's EPA Quality Rubric). Interrater reliability was measured with Krippendorff's α. RESULTS: The expert group defined seven preliminary EPAs for neurointensive care. In two consecutive Delphi rounds, EPAs were adapted, and consensus was reached for level of entrustment and time of expiration. Ultimately, EPAs reached a high EQual score of 4.5 of 5 and above. Interrater reliability for the EQual scoring was 0.8. CONCLUSIONS: Using a multistep Delphi process, we defined and established validity evidence for seven EPAs for neurointensive medicine with a high degree of consensus to objectively describe readiness for on-call duty in neurointensive care. This operationalization of pivotal clinical tasks may help to better train clinical residents in neurointensive care across sites and health care systems and has the potential to serve as a blueprint for training in general intensive care medicine. It also represents a starting point for further research and development of medical curricula.

Simulating porcelain firing effect on the structure, corrosion and mechanical properties of Co-Cr-Mo dental alloy fabricated by soft milling.

This study aims at evaluating the effect of simulating porcelain firing on the microstructure, corrosion behavior and mechanical properties of a Co-Cr-Mo alloy fabricated by Metal Soft Milling (MSM). Two groups of Co-28Cr-5Mo specimens (25 × 20 × 3 mm) were prepared by MSM: The as-sintered (AS) specimens and the post-fired (PF) specimens that were subjected to 5 simulating porcelain firing cycles without applying the ceramic mass onto their surface. Phase identification by X-ray Diffraction (XRD), microstructure examination by optical microscopy and Scanning Electron Microscopy combined with Energy-Dispersive X-ray Spectroscopy (SEM/EDX), corrosion testing by cyclic polarization and chronoamperometry in simulated body fluid (SBF), the latter test accompanied by Cr3+ and Cr6+ detection in the electrolyte through the 1.5-diphenylcarbazide (DPC) method and UV/visible spectrophotometry, and mechanical testing by micro-/nano-indentation were conducted to evaluate the effect of the post-firing cycles on the properties of Co-Cr-Mo. The results were statistically analyzed by the t test (p < 0.05: statistically significant). All specimens had a mixed γ-fcc and ε-hcp cobalt-based microstructure with a dispersion of pores filled with SiO2 and a fine M23C6 intergranular presence. PF led to an increase in the ε-Co content and slight grain coarsening. Both AS and PF alloys showed high resistance to general and localized corrosion, whereas neither Cr6+ nor Cr3+ were detected during the passivity-breakdown stage. PF improved the mechanical properties of the AS-alloy, especially the indentation modulus and true hardness (statistically significant differences: p = 0.0009 and 0.006, respectively). MSM and MSM/simulating-porcelain firing have been proven trustworthy fabrication methods of Co-Cr-Mo substrates for metal-ceramic prostheses. Moreover, the post-firing cycles improve the mechanical behavior of Co-Cr-Mo, which is vital under the dynamically changing loads in the oral cavity, whereas they do not degrade the corrosion performance.

Microstructural and mechanical characterization of six Co-Cr alloys made by conventional casting and selective laser melting.

STATEMENT OF PROBLEM: Three Co-Cr alloy types (Co-Cr-Mo, Co-Cr-W, and Co-Cr-Mo-W) have been commonly used in the fabrication of dental prostheses. These alloys can be manufactured using either conventional casting or selective laser melting (SLM) techniques. Nevertheless, research that directly compares these materials and/or manufacturing processes in terms of their microstructural and mechanical characteristics is sparse. PURPOSE: The purpose of this in vitro study was to conduct microstructural and mechanical analysis via X-ray interpretation, optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), image analysis, X-ray diffraction (XRD), instrumented indentation testing (IIT), and 3-point bending testing to characterize Co-Cr-Mo, Co-Cr-W, and Co-Cr-Mo-W alloys produced through conventional casting and SLM. MATERIAL AND METHODS: Six Co-Cr-based alloys were analyzed and divided into 3 types based on their elemental composition (Co-Cr-Mo, Co-Cr-W, and Co-Cr-Mo-W). Additionally, each group was categorized based on the manufacturing process used (casting or SLM). X-ray scans were used to assess porosity. The microstructures of the specimens were assessed through SEM/EDS examination and XRD analysis. IIT was used to determine the Martens hardness (HM) and elastic index (ηIT), while the elastic modulus (E) was estimated through the 3-point bending test. The mechanical properties were statistically analyzed using 2-way analysis of variance (ANOVA) and the Tukey multiple comparison post hoc test, with alloy type and manufacturing process as discriminating variables (α=.05). RESULTS: All cast groups exhibited gross porosity, while no pores or other flaws were found in the SLM groups. Based on the XRD results, the crystalline structure of all Co-Cr specimens consisted of the face-centered cubic γ phase (γ-fcc), along with the hexagonal close-packed ε phase (ε-hcp) and Cr23C6 carbide. Different microstructures were identified between the cast and SLM alloys. Significant differences were identified for the mean standard deviation HM (ranging from 2601 ±94 N/mm2 to 3633 ±61 N/mm2) and mean ±standard deviation ηIT (ranging from 16.8 ±0.3% to 20.9 ±0.3%) among alloys prepared by the same manufacturing process, while all SLM alloys had statistically higher HM and ηIT results than their cast counterparts (P<.05). No statistically significant differences were identified for the mean ±standard deviation Eb (ranging from 170 ±25 GPa to 244 ±36 GPa) among the groups prepared with the same manufacturing process (P>.05), but the SLM alloys had significantly higher results (P<.05) than the cast alloys. CONCLUSIONS: In general, the manufacturing procedure significantly affected the porosity, microstructure, and mechanical properties of the tested Co-Cr alloys. SLM decreased the internal porosity, provided a uniform microstructure, and improved the mechanical properties for all the tested alloy types.

Plasma and Cerebrospinal Fluid Population Pharmacokinetics of Vancomycin in Patients with External Ventricular Drain.

Vancomycin is a commonly used antibacterial agent in patients with primary central nervous system (CNS) infection. This study aims to examine predictors of vancomycin penetration into cerebrospinal fluid (CSF) in patients with external ventricular drainage and the feasibility of CSF sampling from the distal drainage port for therapeutic drug monitoring. Fourteen adult patients (9 with primary CNS infection) were treated with vancomycin intravenously. The vancomycin concentrations in blood and CSF (from proximal [CSF_P] and distal [CSF_D] drainage ports) were evaluated by population pharmacokinetics. Model-based simulations were conducted to compare various infusion modes. A three-compartment model with first-order elimination best described the vancomycin data. Estimated parameters included clearance (CL, 4.53 L/h), central compartment volume (Vc, 24.0 L), apparent CSF compartment volume (VCSF, 0.445 L), and clearance between central and CSF compartments (QCSF, 0.00322 L/h and 0.00135 L/h for patients with and without primary CNS infection, respectively). Creatinine clearance was a significant covariate on vancomycin CL. CSF protein was the primary covariate to explain the variability of QCSF. There was no detectable difference between the data for sampling from the proximal and the distal port. Intermittent infusion and continuous infusion with a loading dose reached the CSF target concentration faster than continuous infusion only. All infusion schedules reached similar CSF trough concentrations. Beyond adjusting doses according to renal function, starting treatment with a loading dose in patients with primary CSF infection is recommended. Occasionally, very high and possibly toxic doses would be required to achieve adequate CSF concentrations, which calls for more investigation of direct intraventricular administration of vancomycin. (This study has been registered at ClinicalTrials.gov under registration no. NCT04426383).

Circadian rhythm of ischaemic core progression in human stroke.

INTRODUCTION: Experimental stroke studies suggest an influence of the time of day of stroke onset on infarct progression. Whether this holds true after human stroke is unknown, but would have implications for the design of randomised controlled trials, especially those on neuroprotection. METHODS: We pooled data from 583 patients with anterior large-vessel occlusion stroke from three prospectively recruited cohorts. Ischaemic core and penumbra volumes were determined with CT perfusion using automated thresholds. Core growth was calculated as the ratio of core volume and onset-to-imaging time. To determine circadian rhythmicity, we applied multivariable linear and sinusoidal regression analysis adjusting for potential baseline confounders. RESULTS: Patients with symptom onset at night showed larger ischaemic core volumes on admission compared with patients with onset during the day (median, 40.2 mL vs 33.8 mL), also in adjusted analyses (p=0.008). Sinusoidal analysis indicated a peak of core volumes with onset at 11pm. Core growth was faster at night compared with day onset (adjusted p=0.01), especially for shorter onset-to-imaging times. In contrast, penumbra volumes did not change across the 24-hour cycle. DISCUSSION: These results suggest that human infarct progression varies across the 24-hour cycle with potential implications for the design and interpretation of neuroprotection trials.

Phenobarbital in super-refractory status epilepticus (PIRATE): A retrospective, multicenter analysis.

OBJECTIVE: Super-refractory status epilepticus (SRSE) is an enduring or recurring SE after 24 h or more of general anesthesia. This study aimed to evaluate the efficacy and safety of phenobarbital (PB) for the treatment of SRSE. METHODS: This retrospective, multicenter study included neurointensive care unit (NICU) patients with SRSE treated with PB between September 2015 and September 2020 from six participating centers of the Initiative of German NeuroIntensive Trial Engagement (IGNITE) to evaluate the efficacy and safety of PB treatment for SRSE. The primary outcome measure was seizure termination. In addition, we evaluated maximum reached serum levels, treatment duration, and clinical complications using a multivariate generalized linear model. RESULTS: Ninety-one patients were included (45.1% female). Seizure termination was achieved in 54 patients (59.3%). Increasing serum levels of PB were associated with successful seizure control (per µg/mL: adjusted odds ratio [adj.OR] = 1.1, 95% confidence interval [CI] 1.0-1.2, p < .01). The median length of treatment in the NICU was 33.7 [23.2-56.6] days across groups. Clinical complications occurred in 89% (n = 81) of patients and included ICU-acquired infections, hypotension requiring catecholamine therapy, and anaphylactic shock. There was no association between clinical complications and treatment outcome or in-hospital mortality. The overall average modified Rankin scale (mRS) at discharge from the NICU was 5 ± 1. Six patients (6.6%) reached mRS ≤3, of whom five were successfully treated with PB. In-hospital mortality was significantly higher in patients in whom seizure control could not be achieved. SIGNIFICANCE: We observed a high rate in attainment of seizure control in patients treated with PB. Success of treatment correlated with higher dosing and serum levels. However, as one would expect in a cohort of critically ill patients with prolonged NICU treatment, the rate of favorable clinical outcome at discharge from the NICU remained extremely low. Further prospective studies evaluating long-term clinical outcome of PB treatment as well as an earlier use of PB at higher doses would be of value.

Liver Biopsy: To Do or Not to Do - A Single-Center Study.

INTRODUCTION: A variety of liver disorders are associated with characteristic histopathological findings that help in their diagnosis and treatment. However, percutaneous liver biopsy (PLB) is prone to limitations and complications. We evaluated all PLBs done in our hospital in a 13-year period, aiming to assess PLB's utility and complications. METHODS: All PLBs conducted in an internal medicine department of a tertiary university hospital in Athens, Greece, during a 13-year period were reviewed. Recorded data included demographic characteristics, laboratory results acquired on biopsy day, indication for liver biopsy, and occurrence of side effects. All patients were followed for 1 month post-hospital discharge for possible PLB-related complications. RESULTS: A total of 261 patients underwent PLB during the study period. The commonest indication of PLB was investigation of liver mass, followed by transaminasemia. PLB assisted in setting a diagnosis in 218 patients and was unhelpful in only 43, in 14 of them due to inadequate or inappropriate biopsy specimen. Complications attributable to PLB were rare, with 10 patients exhibiting pain, either at biopsy site or in the right shoulder, and 3 having bleeding episodes; no deaths were noted. CONCLUSIONS: Our study shows that PLB is still a powerful diagnostic tool in everyday practice, provided it is used when indicated.

Customizing foam sclerotherapy of the great saphenous vein: A proposed algorithm to enhance technical efficacy.

OBJECTIVES: The catheter-directed foam sclerotherapy (FS) and the suggested perivenous tumescent application for great saphenous vein (GSV) diameter reduction are suggested to improve technical and clinical results; yet, their use is reported rather indiscriminately. Our aim is to introduce an algorithm categorising the use of technical modalities accompanying ultrasound-guided FS of the GSV and present the technical efficacy of FS through a 5 F × 11  cm sheath placed at the knee level. METHODS: Representative cases of GSV insufficiency were chosen to describe our methodology. RESULTS: Sole sheath-directed FS can achieve complete GSV occlusion proximally at a level comparable to the catheter-directed technique. We apply perivenous 4°C cold tumescent to GSV >6 mm even in the standing position to ensure diameter reduction of the proximal GSV as close to the saphenofemoral junction. We use long catheters only to overcome large varicosities above the knee level that could otherwise compromise the adequate foam infusion from the sheath tip. When GSV insufficiency extends along the entire limb and severe skin lesions preclude the antegrade distal catheterisation, the sheath-directed FS in the thigh can be concomitantly combined with retrograde FS from catheterisation just below the knee. CONCLUSIONS: A topology-oriented methodology with sheath-directed FS is technically feasible and avoids indiscriminate use of more complex modalities.

Characteristics and quality assessment of online mentoring profile texts in academic medical mentoring.

BACKGROUND: Mentoring is important for a successful career in academic medicine. In online matching processes, profile texts are decisive for the mentor-selection. We aimed to qualitatively characterize mentoring-profile-texts, identify differences in form and content and thus elements that promote selection. METHODS: In a mixed method study first, quality of texts in 150 selected mentoring profiles was evaluated (10-point Likert scale; 1 = insufficient to 10 = very good). Second, based on a thematic and content analysis approach of profile texts, categories and subcategories were defined. We compared the presence of the assigned categories between the 25% highest ranked profiles with the 25% lowest ranked ones. Finally, additional predefined categories (hot topics) were labelled on the selected texts and their impact on student evaluation was statistically examined. RESULTS: Students rated the quality of texts with a mean of 5.89 ± 1.45. 5 main thematic categories, 21 categories and a total of 74 subcategories were identified. Ten subcategories were significantly associated with high- and four with low-rated profiles. The presence of three or more hot topics in texts significantly correlated with a positive evaluation. CONCLUSION: The introduced classification system helps to understand how mentoring profile texts are composed and which aspects are important for choosing a suited mentor.

Microstructural features, physicο-mechanical properties, and wear behavior of dental translucent polychromic multilayer zirconia of hybrid composition prepared by milling technology.

OBJECTIVE: The present study determined the mechanical properties and the wear behavior, as results of the micro(nano)structure, of the enamel, transition, and dentine layers, which comprise the polychromic multilayer zirconia materials of hybrid composition fabricated by milling technology. MATERIALS AND METHODS: Prismatic blocks were fabricated from two commercial pre-sintered dental polychromic multilayer zirconia materials of hybrid composition, IPS e.max ZirCAD Prime (medium and high translucency, from the dentine to the incisal layer) and 3D Pro ML (translucency gradient, from the dentine to the incisal layer) by milling technique, and then, cut into 3 distinct parts to separate the enamel, transition, and dentine layers. The samples were sintered, thermally treated (similarly to the glazing procedure), and polished for characterization. Their microstructure, mechanical properties (determined by nanoindentation and microhardness), and wear behavior (evaluated by scratch test), were examined. RESULTS: The produced materials had a homogeneous and dense nanostructure, where the grain size decreased from the enamel to dentine layer. The mechanical properties decreased from the dentine to enamel layer. However, the three layers manifested similar dynamic friction coefficient. CONCLUSION: The differences in the above properties in the three layers negligibly influenced the wear behavior of the entire multilayer zirconia material. CLINICAL SIGNIFICANCE: The properties of dental restorations produced from polychromic multilayer zirconia of hybrid composition by milling technology (i.e., strong, non-fragile, and esthetic materials), anticipate good performance in oral cavity.

[Neurointensive care medicine and COVID-19]. / Neurointensivmedizin und COVID-19.

This review article summarizes important findings on the interfaces between the coronavirus disease 2019 (COVID-19) pandemic and neurology with an emphasis of the implications for neurointensive care medicine. More specifically, the prevalence, pathomechanisms and impact of neurological manifestations are reported. The most common neurological manifestations of critically ill COVID-19 patients are cerebrovascular complications, encephalopathies and intensive care unit-acquired weakness (ICUAW). A relevant direct pathophysiological effect by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) itself has not yet been established with certainty. In fact, indirect systemic inflammatory processes triggered by the viral infection and side effects of intensive care treatment are much more likely to cause the reported sequelae. The impact of the pandemic on patients with neurological disorders and neurointensive care medicine is far-reaching but not yet sufficiently studied.

Electroencephalography in delirium assessment: a scoping review.

BACKGROUND: Delirium is a common disorder affecting around 31% of patients in the intensive care unit (ICU). Delirium assessment scores such as the Confusion Assessment Method (CAM) are time-consuming, they cannot differentiate between different types of delirium and their etiologies, and they may have low sensitivities in the clinical setting. While today, electroencephalography (EEG) is increasingly being applied to delirious patients in the ICU, a lack of clear cut EEG signs, leads to inconsistent assessments. METHODS: We therefore conducted a scoping review on EEG findings in delirium. One thousand two hundred thirty-six articles identified through database search on PubMed and Embase were reviewed. Finally, 33 original articles were included in the synthesis. RESULTS: EEG seems to offer manifold possibilities in diagnosing delirium. All 33 studies showed a certain degree of qualitative or quantitative EEG alterations in delirium. Thus, normal routine (rEEG) and continuous EEG (cEEG) make presence of delirium very unlikely. All 33 studies used different research protocols to at least some extent. These include differences in time points, duration, conditions, and recording methods of EEG, as well as different patient populations, and diagnostic methods for delirium. Thus, a quantitative synthesis and common recommendations are so far elusive. CONCLUSION: Future studies should compare the different methods of EEG recording and evaluation to identify robust parameters for everyday use. Evidence for quantitative bi-electrode delirium detection based on increased relative delta power and decreased beta power is growing and should be further pursued. Additionally, EEG studies on the evolution of a delirium including patient outcomes are needed.

Neurologic manifestations of COVID-19 in critically ill patients: results of the prospective multicenter registry PANDEMIC.

BACKGROUND: Neurologic manifestations are increasingly reported in patients with coronavirus disease 2019 (COVID-19). Yet, data on prevalence, predictors and relevance for outcome of neurological manifestations in patients requiring intensive care are scarce. We aimed to characterize prevalence, risk factors and impact on outcome of neurologic manifestations in critically ill COVID-19 patients. METHODS: In the prospective, multicenter, observational registry study PANDEMIC (Pooled Analysis of Neurologic DisordErs Manifesting in Intensive care of COVID-19), we enrolled COVID-19 patients with neurologic manifestations admitted to 19 German intensive care units (ICU) between April 2020 and September 2021. We performed descriptive and explorative statistical analyses. Multivariable models were used to investigate factors associated with disorder categories and their underlying diagnoses as well as to identify predictors of outcome. RESULTS: Of the 392 patients included in the analysis, 70.7% (277/392) were male and the mean age was 65.3 (SD ± 3.1) years. During the study period, a total of 2681 patients with COVID-19 were treated at the ICUs of 15 participating centers. New neurologic disorders were identified in 350 patients, reported by these centers, suggesting a prevalence of COVID-19-associated neurologic disorders of 12.7% among COVID-19 ICU patients. Encephalopathy (46.2%; 181/392), cerebrovascular (41.0%; 161/392) and neuromuscular disorders (20.4%; 80/392) were the most frequent categories identified. Out of 35 cerebrospinal fluid analyses with reverse transcriptase PCR for SARS-COV-2, only 3 were positive. In-hospital mortality was 36.0% (140/389), and functional outcome (mRS 3 to 5) of surviving patients was poor at hospital discharge in 70.9% (161/227). Intracerebral hemorrhage (OR 6.2, 95% CI 2.5-14.9, p < 0.001) and acute ischemic stroke (OR 3.9, 95% CI 1.9-8.2, p < 0.001) were the strongest predictors of poor outcome among the included patients. CONCLUSIONS: Based on this well-characterized COVID-19 ICU cohort, that comprised 12.7% of all severe ill COVID-19 patients, neurologic manifestations increase mortality and morbidity. Since no reliable evidence of direct viral affection of the nervous system by COVID-19 could be found, these neurologic manifestations may for a great part be indirect para- or postinfectious sequelae of the infection or severe critical illness. Neurologic ICU complications should be actively searched for and treated.

Survey of German medical students during the COVID-19 pandemic: attitudes toward volunteering versus compulsory service and associated factors.

Due to the spread of COVID-19, a key challenge was to reduce potential staff shortages in the healthcare sector. Besides recruiting retired healthcare workers, medical students were considered to support this task. Commitment of medical students in Germany during the COVID-19 pandemic was evaluated using an online survey, with particular focus on their burdens and anxieties. This survey was distributed to students within a 2-week period in April and May 2020. Ultimately, 1241 participants were included in the analysis. During the pandemic, 67.9% (65.3% to 70.5%) of the participants reported that they had volunteered. Furthermore, 88.9% (86.9% to 90.5%) stated that they were against compulsory recruitment in this context. Students who volunteered (committed students) had a significantly lower anxiety index than non-committed students. Additionally, students were more concerned about infecting other patients and relatives than themselves. Higher levels of anxiety were related to lower levels of commitment. A mandatory assignment during the pandemic was rejected by the students and does not seem to be necessary due to the large number of volunteers.

Guessing the sequence of multiple relinings with AFX and nitinol-based cuff: "A riddle, wrapped in a mystery, inside an enigma".

OBJECTIVE: Knowing the structural and technical features of both the older and newer aortic endografts is an essential tool to understand off-the-shelf combinations of different devices used to treat challenging abdominal aortic aneurysm (AAA) anatomies or failures of previous endovascular aneurysm repairs (EVAR). METHODS: We present a case of a 72-year-old male with history of AAA and evidence of multiple past EVAR interventions who presented with abdominal pain. With no reliable surgical history, we attempted to delineate the types of different endograft parts implanted and the sequence of relining procedure based on plain X-ray projections and combined computed tomography along with intraoperative angiography. RESULTS: A tubular endograft was presented with a distal fracture of its endoskeleton, and relined with the same type unibody bifurcate. The latter was extended proximally with an AFX extension of a characteristic radiopaque continuous rim. Angiographic findings intraoperatively excluded the latter as part of the initial procedure. Moreover, an extra nitinol-based cuff was identified centrally. CONCLUSION: In diagnostic challenges involving multiple relining attempts of different endograft parts, careful analysis of the imaging findings, based on knowledge of the structural and technical features of both the older and newer endografts is necessary for proper diagnosis, identification of potential problems and complications and intervention planning, if needed.

First case of relining an aortic bifurcated bypass graft with the Altura endograft to treat anastomotic aneurysms.

OBJECTIVE: Use of classic bifurcated endografts for relining of bifurcated aortic bypass grafts with aneurysms is usually precluded by the short distance between the lowermost renal artery and the aneurysmatic bifurcation, rendering their management challenging. METHODS: We present the use of the Altura endograft in a case of a 75-year old male with large anastomotic aneurysms in the proximal and the left iliac amastomosis of a bifurcated aortic bypass graft. The Altura endograft consists of two separate components with a proximal D-shaped design. Its braided nitinol endoskeleton is attached only at the proximal and distal ends of the inner surface of the polyester fabric and results in adjustable lengths of the components according to the vessel diameters where they are deployed. RESULTS: A 24 mm Altura sealed successfully at the native infarenal aortic segment covering the entire distance between the lowermost renal artery and the upper end of external iliac artery, providing successful exclusion of the aneurysms. No iliac extensions were used. The completion angiography showed no endoleaks. CONCLUSIONS: The unique design of Altura makes it ideal for treatment of anastomotic aneurysms of bifurcated bypass grafts, overcoming anatomic limitations. To the best of our knowledge, this is the first report addressing this crucial issue.

Foam sclerotherapy of great saphenous vein: The need for further improvement and ill-defined issues.

Foam sclerotherapy is considered an acceptable method to treat great saphenous vein (GSV) insufficiency, promoting occlusion of its trunk and eradicating reflux. Yet, certain technical points have not been standardized while issues regarding the ultrasonographic appearance of successful or acceptable GSV obliteration or the end-points of the method are not clearly defined. This article comments on the aforementioned using examples based on personal experience.