Neural Networks Modeling for Prediction of Required Resources for Personalized Endourologic Treatment of Urolithiasis.

When scheduling surgeries for urolithiasis, the lack of information about the complexity of procedures and required instruments can lead to mismanagement, cancellations of elective surgeries and financial risk for the hospital. The aim of this study was to develop, train, and test prediction models for ureterorenoscopy. Routinely acquired Computer Tomography (CT) imaging data and patient data were used as data sources. Machine learning models were trained and tested to predict the need for laser lithotripsy and to forecast the expected duration of ureterorenoscopy on the bases of 474 patients over a period from May 2016 to December 2019. Negative predictive value for use of laser lithotripsy was 92%, and positive predictive value 91% before application of the reject option, increasing to 97% and 94% after application of the reject option. Similar results were found for duration of surgery at ≤30 min. This combined prediction is possible for 54% of patients. Factors influencing prediction of laser application and duration ≤30 min are age, sex, height, weight, Body Mass Index (BMI), stone size, stone volume, stone density, and presence of a ureteral stent. Neuronal networks for prediction help to identify patients with an operative time ≤30 min who did not require laser lithotripsy. Thus, surgical planning and resource allocation can be optimised to increase efficiency in the Operating Room (OR).

Isavuconazole therapeutic drug monitoring in critically ill ICU patients: A monocentric retrospective analysis.

BACKGROUND: The broad-spectrum triazole isavuconazole is used for the treatment of invasive aspergillosis and mucormycosis. Data regarding human plasma concentrations in clinical routine of the drug are rare. OBJECTIVES: Plasma concentrations of isavuconazole were determined in critically ill ICU patients while considering different patients' characteristics. METHODS: Retrospective analysis of isavuconazole plasma concentrations were obtained as part of routine therapeutic drug monitoring (TDM) of ICU patients with invasive aspergillosis or other fungal infections treated with isavuconazole. Plasma levels 0-4 h after last dosing were defined as peak levels (Cmax ), those 20-28 h after last dosing as trough levels (Cmin ). RESULTS: Overall, 223 isavuconazole levels of 41 patients were analysed, divided into 141 peak levels and 82 trough levels. The overall median Cmax was 2.36 µg/ml (mean 2.43 µg/ml, range 0.41-7.79 µg/ml) and the overall median Cmin was 1.74 µg/ml (mean 1.77 µg/ml, range 0.24-4.96 µg/ml). In total, 31.7% of the Cmin values of the total cohort were below the plasma target concentrations of 1 µg/ml, defined as EUCAST antifungal clinical breakpoint for Aspergillus fumigatus. Both peak and trough plasma levels of isavuconazole were significantly lower among patients with a body mass index (BMI) ≥25. In addition, a significant correlation was observed between isavuconazole trough levels and sepsis-related organ failure assessment (SOFA) score. CONCLUSIONS: This study shows that isavuconazole plasma concentrations vary in critical ill ICU patients. Significantly lower isavuconazole levels were associated with elevated BMI and higher SOFA score indicating a need of isavuconazole TDM in this specific patient population.

Right ventricular and pulmonary artery pulse pressure variation and systolic pressure variation for the prediction of fluid responsiveness: an interventional study in coronary artery bypass surgery patients.

PURPOSE: Predicting fluid responsiveness is essential when treating surgical or critically ill patients. When using a pulmonary artery catheter, pulse pressure variation and systolic pressure variation can be calculated from right ventricular and pulmonary artery pressure waveforms. METHODS: We conducted a prospective interventional study investigating the ability of right ventricular pulse pressure variation (PPVRV) and systolic pressure variation (SPVRV) as well as pulmonary artery pulse pressure variation (PPVPA) and systolic pressure variation (SPVPA) to predict fluid responsiveness in coronary artery bypass (CABG) surgery patients. Additionally, radial artery pulse pressure variation (PPVART) and systolic pressure variation (SPVART) were calculated. The area under the receiver operating characteristics (AUROC) curve with 95%-confidence interval (95%-CI) was used to assess the capability to predict fluid responsiveness (defined as an increase in cardiac index of > 15%) after a 500 mL crystalloid fluid challenge. RESULTS: Thirty-three patients were included in the final analysis. Thirteen patients (39%) were fluid-responders with a mean increase in cardiac index of 25.3%. The AUROC was 0.60 (95%-CI 0.38 to 0.81) for PPVRV, 0.63 (95%-CI 0.43 to 0.83) for SPVRV, 0.58 (95%-CI 0.38 to 0.78) for PPVPA, and 0.71 (95%-CI 0.52 to 0.89) for SPVPA. The AUROC for PPVART was 0.71 (95%-CI 0.53 to 0.89) and for SPVART 0.78 (95%-CI 0.62 to 0.94). The correlation between pulse pressure variation and systolic pressure variation measurements derived from the different waveforms was weak. CONCLUSIONS: Right ventricular and pulmonary artery pulse pressure variation and systolic pressure variation seem to be weak predictors of fluid responsiveness in CABG surgery patients.

Factors which influence the complications of external ventricular cerebrospinal fluid drainage.

BACKGROUND: External ventricular drainage (EVD) is one of the most common neurosurgical procedures in emergencies. This study aims to find out which factors influence the occurrence of EVD-related complications in a comparative investigation of metal needles and polyurethane catheters. This is the first clinical study comparing these two systems. METHODS: Adult patients undergoing pre-coronal EVD placement via freehand burr hole trepanation were included in this prospective study. The exclusion criteria were the open EVD insertion and/or a pre-existing infectious disease of the central nervous system. RESULTS: Two hundred consecutive patients were enrolled. Of these, 100 patients were treated by using metal EVD (group 1) and 100 patients with polyurethane catheters (group 2). The overall complication rate was 26% (misplacement 13.5%, hemorrhage 12.5%, infection 2.5%, and dislocation 1%) without statistically significant differences between both groups. Generalized brain edema and midline shift had a significant influence on misplacements (generalized brain edema: p = 0.0002, Cramer-V: 0.307, OR = 7.364, 95% CI: 2.691-20.148; all patients: p = 0.001, Cramer-V: 0.48, OR = 43.5, 95% CI: 4.327-437.295; group 1: p = 0.047, Cramer-V: 0.216, OR = 3.75, 95% CI: 1.064-13.221; group 2: midline shift: p = 0.038, Cramer-V: 0.195, OR = 3.626, 95% CI: 1.389-9.464) all patients: p = 0.053, Cramer-V: 0.231, OR = 5.533, 95% CI 1.131-27.081; group 1: p = 0.138, Cramer-V: 0.168, OR = 2.769, 95% CI: 0.813-9.429 group 2. Hemorrhages were associated with the use of oral anticoagulants or antiplatelet therapy (p = 0.002; Cramer-V: 0.220, OR = 3.798, 95% CI: 1.572-9.175) with a statistically similar influence in both groups. CONCLUSION: Generalized brain edema has a significant influence on misplacements in both groups. Midline shift lost its significance when considering only the patients in group 2. Patients under oral anticoagulation and antiplatelet therapy have increased odds of EVD-associated hemorrhage. Metal needles and polyurethane catheters are equivalent in terms of patient safety when there are no midline shift and generalized brain edema.

Understanding how the motivational dimension of learning is influenced by clinical teaching in medical education: A prospective cohort study.

INTRODUCTION: Many changes of medical curricula have been conducted in the past years. Based on learning psychology, three dimensions of learning have to be covered, in order to create the best possible curricula: Cognitive, metacognitive and motivational. The metacognitive and cognitive dimension (what/how to teach) have always been considered and the motivational dimension has been neglected, although the importance and benefits of motivation in learning have been emphasized repeatedly. One way to influence motivation in medical curricula are the teaching formats, as it has been shown that the construction of a curriculum can influence students' motivation. So far, evidence about the motivational effects of teaching formats are scarce. METHODS: In a prospective interventional cohort study, 145 3rd year medical students were sampled. The effects of a 3-day bedside teaching in the operating theatre and two simulation-based trainings on students' motivation (outcome measure) were analysed. It was hypothesized, that the simulation training and the bedside teaching enhance autonomous motivation and decrease controlled motivation. RESULTS: The bedside-teaching decreased external (controlled) motivation (-0.14, p = .013, 95% CI [-0.24, -0.03]), alongside with identified (autonomous) motivation (-0.22, p < .001, 95% CI [-0.34, -0.10]). The simulation-based trainings did not change students' motivation. CONCLUSION: To prevent the unintended decrease of identified (autonomous) motivation, undergraduates should be supervised and introduced carefully, when attending bedside teaching in unknown medical fields. Simulation-based medical education certainly has plenty of benefits in medical education but its effects on the motivational dimension of learning needs further investigations.

Economic impact of enhanced recovery after surgery protocol in minimally invasive cardiac surgery.

BACKGROUND: ERAS (Enhanced Recovery After Surgery) is a multidisciplinary and integrative approach with the goal of optimizing the postoperative recovery. We aimed to analyze the economic impact of a newly established ERAS protocol in minimally invasive heart valve surgery at our institution. METHODS: ERAS protocol was implemented in 61 consecutive patients who were referred for elective minimally-invasive aortic or mitral valve surgery, between February 1, 2018 and March 31, 2019 (ERAS-group). Another 69 patients who underwent elective minimally-invasive heart valve surgery during the same time period were managed according to the hospital standards (Control-group). A detailed cost comparison analysis was carried out from a hospital perspective using a micro-costing approach. RESULTS: The total in-hospital stay was significantly shorter in the ERAS-group compared to the Control-group (6.1 ± 2.6 vs 7.7 ± 3.8 days; p = 0.008) resulting in significant cost savings of €1087.2 per patient (p = 0.003). Due to the intensified physiotherapy in the ERAS protocol, the costs for physiotherapy were €94.3 higher compared to the Control-group (p < 0.001). The total costs in the ERAS cohort were €11,200.0 ± 3029.6/patient compared to € 13,109.8 ± 4527.5/patient in the Control-Group resulting in cost savings of €1909.8 patient due to the implementation of the ERAS protocol (p = 0.006). CONCLUSION: Implementation of an ERAS-protocol in minimally-invasive cardiac surgery can be carried out safely with a fast postoperative recovery of the patient. ERAS results in a financial benefit of up to €1909 per patient and therefore will play a key role in modern cardiac surgery in the near future.

Virtual reality as a teaching method for resuscitation training in undergraduate first year medical students: a randomized controlled trial.

BACKGROUND: Virtual reality is an innovative technology for medical education associated with high empirical realism. Therefore, this study compares a conventional cardiopulmonary resuscitation (CPR) training with a Virtual Reality (VR) training aiming to demonstrate: (a) non-inferiority of the VR intervention in respect of no flow time and (b) superiority in respect of subjective learning gain. METHODS: In this controlled randomized study first year, undergraduate students were allocated in the intervention group and the control group. Fifty-six participants were randomized to the intervention group and 104 participants to the control group. The intervention group received an individual 35-min VR Basic Life Support (BLS) course and a basic skill training. The control group took part in a "classic" BLS-course with a seminar and a basic skill training. The groups were compared in respect of no flow time in a final 3-min BLS examination (primary outcome) and their learning gain (secondary outcome) assessed with a comparative self-assessment (CSA) using a questionnaire at the beginning and the end of the course. Data analysis was performed with a general linear fixed effects model. RESULTS: The no flow time was significantly shorter in the control group (Mean values: control group 82 s vs. intervention group 93 s; p = 0.000). In the CSA participants of the intervention group had a higher learning gain in 6 out of 11 items of the questionnaire (p < 0.05). CONCLUSION: A "classic" BLS-course with a seminar and training seems superior to VR in teaching technical skills. However, overall learning gain was higher with VR. Future BLS course-formats should consider the integration of VR technique into the classic CPR training or vice versa, to use the advantage of both teaching techniques.

Correlation of medical students' situational motivation and performance of non-technical skills during simulation-based emergency training.

BACKGROUND: Non-technical skills (NTS) are an indispensable element of emergency care and need to be prevalent alongside with good technical skills. Though, questions of how to teach (instructional design) and improve NTS effectively remain unresolved. One adjustment screw to enhance performance of NTS, which is detached from instructional designs and learning efforts might be motivation. Theoretical models and observational studies suggest that high levels of intrinsic (situational) motivation result in better performance and better learning. Therefore, this study analyzed the influence of motivation on performance of NTS, by exploring if high levels of intrinsic motivation lead to better performance of NTS in medical students. METHODS: In this prospective cross-sectional cohort study, the authors assessed the correlation of situational motivation and performance of NTS within a cohort of 449 undergraduates in their 1st to 4th year of medical studies, in a total of 101 emergency simulation trainings. Situational motivation was measured with the validated Situational Motivation Scale (SIMS), which was completed by every undergraduate directly before each simulation training. The NTS were evaluated with the Anesthesiology Students´ Non-Technical skills (AS-NTS) rating tool, a validated taxonomy, especially developed to rate NTS of undergraduates. RESULTS: Student situational motivation was weakly correlated with their performance of NTS in simulation-based emergency trainings. CONCLUSION: Although motivation has been emphasized as a determining factor, enhancing performance in different fields and in medicine in particular, in our study, student situational motivation was independent from their performance of NTS in simulation-based emergency trainings (SBET).

Implementation of basic life support training for school children: Online education for potential instructors? Results of a cluster randomised, controlled, non-inferiority trial.

AIM OF THE STUDY: Comprehensive training of the population in basic life support (BLS) increases the chance of survival in cardiac arrest. To implement BLS trainings at schools a high number of instructors will be needed. This non-inferiority study investigated, if online education is effective to prepare instructors to teach BLS compared to face-to-face education. METHODS: A cluster randomised, controlled, single blinded study was performed in 2018 in Hamburg, Germany. A mixed group of potential instructors were allocated alternately to either the intervention or control group and participated in a four-hour instructor training. The instructor training of the control group was realised by trained educators. The intervention group participated in a self-regulated online training with hands-on training supported by peers. Instructors provided BLS training for high school students. The primary endpoint was a mean score in the BLS skills assessment of the students. The secondary endpoint was teaching effectiveness of the instructors. RESULTS: BLS assessments of 808 students of 46 classes, who were taught by 74 instructors could be analysed. The students trained by interventional instructors achieved 0.14 points less (95% CI: -0.27 to 0.56) compared to students trained by control instructors (9.34 vs. 9.48). The non-inferiority could not be confirmed. The teaching performance in the intervention group was better in some aspects compared to the control group. CONCLUSION: Integrating all results of this study, online education may be an effective alternative to prepare potential BLS instructors. Using free online courses, motivated persons can independently acquire necessary skills to become instructors and autonomously realise low cost BLS trainings at schools.

Establishment of an enhanced recovery after surgery protocol in minimally invasive heart valve surgery.

Protocols for "Enhanced recovery after surgery (ERAS)" are on the rise in different surgical disciplines and represent one of the most important recent advancements in perioperative medical care. In cardiac surgery, only few ERAS protocols have been described in the past. At University Heart Center Hamburg, Germany, we invented an ERAS protocol for patients undergoing minimally invasive cardiac valve surgery. In this retrospective single center study, we aimed to describe the implementation of our ERAS program and to evaluate the results of the first 50 consecutive patients. Our ERAS protocol was developed according to a modified Kern cycle by an expert group, literature search, protocol creation and pilot implementation in the clinical practice. Data of the first 50 consecutive patients undergoing minimally invasive cardiac valve surgery were analysed retrospectively. The key features of our multidisciplinary ERAS protocol are physiotherapeutic prehabilitation, minimally invasive valve surgery techniques, modified cardiopulmonary bypass management, fast-track anaesthesia with on- table extubation and early mobilisation. A total of 50 consecutive patients (mean age of 51.9±11.9 years, mean STS score of 0.6±0.3) underwent minimally-invasive mitral or aortic valve surgery. The adherence to the ERAS protocol was high and neither protocol related complications nor in-hospital mortality occurred. 12% of the patients developed postoperative atrial fibrillation, postoperative delirium emerged in two patients and reintubation was required in one patient. Intensive care unit stay was 14.0±7.4 hours and total hospital stay 6.2±2.9 days. Our ERAS protocol is feasible and safe in minimally-invasive cardiac surgery setting and has a clear potential to improve patients outcome.

Implementation of Basic Life Support training in schools: a randomised controlled trial evaluating self-regulated learning as alternative training concept.

BACKGROUND: The Kids save lives statement recommends annual Basic Life Support (BLS) training for school children but the implementation is challenging. Trainings should be easy to realise and every BLS training should be as effective as possible to prepare learners for lifesaving actions. Preparedness implies skills and positive beliefs in the own capability (high self-efficacy). METHODS: This randomized controlled cluster study investigates, if self-regulated learning promotes self-efficacy and long-term retention of practical BLS skills. Students in the age of 12 years participated in a practical training in BLS and a scenario testing of skills. In the control group the practical training was instructor-led. In the intervention group the students self-regulated their learning processes and feedback was provided by the peer-group. The primary outcome self-efficacy for helping in cardiac arrest after the training and 9 months later was analysed using a multilevel mixed model. Means and pass-rates for BLS skills were secondary outcomes. RESULTS: Contrary to the assumptions, this study could not measure a higher self-efficacy for helping in cardiac arrest of the students participating in the intervention (n = 307 students) compared to the control group (n = 293 students) after training and at the follow-up (mean difference: 0.11 points, 95% CI: - 0.26 to 0.04, P = 0.135). The odds to pass all items of the BLS exam was not significantly different between the groups (OR 1.11, 95% CI: 0.81 to 1.52, p = 0.533). Self-regulated learning was associated with a higher performance of male students in the BLS exam (mean score: 7.35) compared to females of the intervention (female: 7.05) and compared to males of the control (7.06). CONCLUSION: This study could not resolve the question, if self-regulated learning in peer-groups improves self-efficacy for helping in cardiac arrest. Self-regulated learning is an effective alternative to instructor-led training in BLS skills training and may be feasible to realise for lay-persons. For male students self-regulated learning seems to be beneficial to support long-term retention of skills. TRIAL REGISTRATION: ISRCTN17334920, retrospectively registered 07.03.2019.

Basic life support training using shared mental models improves team performance of first responders on normal wards: A randomised controlled simulation trial.

INTRODUCTION: Survival of in-hospital cardiac arrest (IHCA) depends on fast and effective action of the first responding team. Not only technical skills, but professional teamwork is required. Observational studies and theoretical models suggest that shared mental models of members improve teamwork. This study investigated if a training on shared mental models, improves team performance in simulated in-hospital cardiac arrest. METHODS: On the background of an introduction of mandatory Basic Life Support (BLS) training for clinical staff a randomized controlled trial was performed to compare two training methods. Staff from clinical departments was randomised to receive either a conventional instructor led training (control group) or an interventional training (intervention group). The interventional training was based on self-directed learning of the group in order to develop shared mental models. Primary outcome were mean scores of the team assessment scale (TAS) and the hands-off time. Secondary outcome were mean scores for quality of BLS. RESULTS: Performance of 75 teams of the interventional and 66 of the control group was analysed. The hands-off time was significantly lower in the interventional group (5.42% vs. 8.85%, p = 0.029). Scores of the TAS and the overall BLS score were high and not significantly different between the groups. Hands-off time correlated significantly negative with all TAS items. CONCLUSION: BLS training for clinical staff which creates shared mental models reduces hands-off time in a simulated cardiac arrest scenario. Training methods establishing shared mental models of team members can be considered for effective team trainings without adding additional training time.

Standardized Subannular Repair Improves Outcomes in Type IIIb Functional Mitral Regurgitation.

BACKGROUND: The major drawback of isolated annuloplasty in secondary mitral regurgitation (MR) is the reoccurrence of MR. We prospectively compared the results of isolated annuloplasty vs annuloplasty with simultaneous standardized subannular repair. METHODS: The study comprised 101 patients with secondary type IIIb MR. Of these, 51 underwent annuloplasty plus standardized subannular repair with realignment of both papillary muscles (subannular repair) and 50 underwent isolated annuloplasty. The primary study end point was the reoccurrence of MR >2 at the 1-year follow-up. Secondary end points were survival, freedom from major adverse cardiac events, and residual leaflet tethering. RESULTS: Baseline characteristics were comparable in both groups. There was no significant difference in in-hospital mortality (P = .3). Although postrepair MR was comparable between the subannular repair and isolated annuloplasty subgroups, the residual leaflet tethering (tenting area, 127.6 ± 35.8 mm2 vs 166.3 ± 47.3 mm2, P = .02; posterior mitral leaflet angle, 19.2 ± 4.7 degrees vs 24.8 ± 5.2 degrees, P = .001; anterior mitral leaflet angle, 25.4 ± 5.8 degrees vs 34.1 ± 4.0 degrees, P = .001; and tenting height, 5.9 ± 1.4 mm vs 9.2 ± 2.2 mm, P = .001) were significantly increased in the isolated annuloplasty group (P < .001). At the 1-year follow-up, we found a significant difference between the groups in the freedom from MR >2 of 98% (50 of 51) for subannular repair vs 86.7% (39 of 45) for isolated annuloplasty (P = .045) and mortality of 0% (0 of 51) for subannular repair vs 10% (5 of 50) for isolated annuloplasty (P = .025). CONCLUSIONS: In secondary MR with reduced leaflet motion, the combination of annuloplasty and standardized subannular repair is associated with a significantly reduced MR reoccurrence, decreased residual leaflet tenting, and significantly improved 1-year outcome compared with annuloplasty alone.

Anaesthesiology students' Non-Technical skills: development and evaluation of a behavioural marker system for students (AS-NTS).

BACKGROUND: Non-Technical Skills (NTS) are becoming more important in medical education. A lack of NTS was identified as a major reason for unsafe patient care, favouring adverse events and team breakdown. Therefore, the training of NTS should already be implemented in undergraduate teaching. The goal of our study was to develop and validate the Anaesthesiology Students' Non-Technical Skills (AS-NTS) as a feasible rating tool to assess students' NTS in emergency and anaesthesiology education. METHODS: The development of AS-NTS was empirically grounded in expert- and focus groups, field observations and data from NTS in medical fields. Validation, reliability and usability testing was conducted in 98 simulation scenarios, during emergency and anaesthesiology training sessions. RESULTS: AS-NTS showed an excellent interrater reliability (mean 0.89), achieved excellent content validity indexes (at least 0.8) and was rated as feasible and applicable by educators. Additionally, we could rule out the influence of the raters' anaesthesiology and emergency training and experience in education on the application of the rating tool. CONCLUSIONS: AS-NTS provides a structured approach to the assessment of NTS in undergraduates, providing accurate feedback. The findings of usability, validity and reliability indicate that AS-NTS can be used by anaesthesiologists in different year of postgraduate training, even with little experience in medical education.

Minimally invasive mitral valve repair for functional mitral regurgitation.

Systolic heart failure is frequently accompanied by a relevant functional mitral valve regurgitation (FMR) which develops as a direct sequela of the ongoing left ventricular remodelling. The severity of mitral regurgitation is further aggravated by progressive left ventricular enlargement causing leaflet tethering and reduced systolic leaflet movement. The prognosis of such patients is obviously limited by an underlying left ventricular disease, and the correction of secondary FMR has been previously suggested as predominantly 'cosmetic' surgery in the setting of ongoing cardiomyopathy. Inferior results of an isolated annuloplasty in type IIIb FMR supported the philosophy of malignant course of progressive cardiomyopathy and resulted in increasingly restricted indications for mitral valve surgery for FMR in the guidelines. The lack of a standardized pathophysiological approach to correct type IIIb FMR led to the development of valve replacement strategy and edge-to-edge catheter-based mitral valve procedures, which became the most frequent procedures in the FMR setting in Europe. Modern mitral valve surgery combines the advantages of 3-dimensional endoscopic minimally invasive surgical approach with standardized subannular repair to address the pathophysiological background of type IIIb FMR. The perioperative results have been significantly improved, and there is a growing evidence of improved long-term stability of subannular repair procedures as compared to isolated annuloplasty. This review article aims to present the current state-of-the-art of the modern mitral valve surgery in FMR and provides suggestions for future trials analysing the potential advantages in these patients.

Patient safety in undergraduate medical education: Implementation of the topic in the anaesthesiology core curriculum at the University Medical Center Hamburg-Eppendorf.

Introduction: The focus of public attention and health policy is increasingly being drawn to patient safety. According to studies, more than 30,000 patients die each year as a result of medical errors. To date, learning objectives such as patient safety have not played a role in the core curriculum for medical education in Germany. The National Competence-Based Catalogue of Learning Objectives for Undergraduate Medical Education contains a total of 13 learning objectives relating to this subject. Methods: In a descriptive study, learning content was implemented within the "Operative Medicine" study block offered by the Faculty of Medicine at Universität Hamburg. The definition and occurrence of errors as well as strategies for dealing with and avoiding errors were set as the learning objectives for an interactive lecture, problem-based learning (PBL) case as well as the bedside teaching on anaesthesiology. Students were able to evaluate the lecture directly. During the simulator session on anaesthesia, the safety-relevant information that students requested from patients was compared with the questions asked by a control group in the previous trimester. Results: The topic of patient safety could be integrated into the "Operative Medicine" curriculum through a number of minor changes to classes. The accounts of personal experiences and importance assigned to the subject were considered positive, while content perceived as redundant was criticised. In the simulator, the students appeared to request more comprehensive preoperative safety-relevant information than the control group. Conclusion: The subject's relevance, positive feedback and trend towards a change in behaviour in the simulator lead the authors to deem introduction of the topic of patient safety a success.

Risk of spinal cord ischemia after fenestrated or branched endovascular repair of complex aortic aneurysms.

OBJECTIVE: The aim of our study was to analyze the incidence of spinal cord ischemia (SCI) in patients presenting with complex aortic aneurysms treated with endovascular aneurysm repair (EVAR) and to identify risk factors associated with this complication. METHODS: A retrospective study was undertaken of prospectively collected data including patients presenting with complex aortic aneurysm (pararenal abdominal aortic aneurysm and thoracoabdominal aortic aneurysm) treated with fenestrated EVAR (F-EVAR) or branched EVAR (B-EVAR). The primary end point was the incidence of SCI and the assessment of any associated factors. RESULTS: Between January 2011 and August 2017, a total of 243 patients (mean aneurysm diameter, 65.2 ± 15.3 mm; mean age, 72.4 ± 7.5 years; 73% male) were treated with F-EVAR or B-EVAR. Asymptomatic patients were treated in 73% of the cases (177/243, in contrast to 27% urgent), and 52% (126/243) were treated for thoracoabdominal aortic aneurysm (in contrast to 48% for pararenal abdominal aortic aneurysm). F-EVAR (mean number of fenestrations, 3.3/case) and B-EVAR (mean number of branches, 3.7/case) were undertaken in 67% (164/243) and 33% (79/243), respectively. The total incidence of SCI was 17.7% [43/243; paraplegia in 4% (10/243) and paraparesis in 13.7% (33/243)]. Most of the patients with SCI presented with immediate postoperative symptoms (72% [31/43]). A spinal drain was preoperatively placed in 53% (130/243) and was associated with the prevention of SCI (SCI with spinal drainage, 12% [16/130]; SCI without spinal drainage, 24% [27/113]; P = .018). The 30-day mortality rate was 9% (21/243). After multiple logistic regression analysis, SCI was associated with preoperative renal function (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: odds ratio [OR], 2.43; 95% confidence interval [CI], 1.18-4.99; P = .016) and the number of vertebral segments covered (SCI with higher position of proximal stent in terms of vertebra: OR, 1.2; 95% CI, 1.1-1.3; P = .000). A similar outcome was derived when the height of the proximal end of the stent graft was replaced by the total length of aortic coverage (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: OR, 2.36 [95% CI, 1.11-5.00; P = .025]; SCI with longer length of aortic coverage: OR, 1.01 [95% CI, 1.003-1.009; P = .000]). CONCLUSIONS: The majority of SCI incidence after F-EVAR or B-EVAR of complex aortic aneurysms is manifested immediately postoperatively. The use of preoperative spinal drainage may prevent SCI. Patients with GRF <60 mL/min/1.73 m2 and with longer aortic stent graft coverage are at higher risk of SCI.

Hemadsorption during cardiopulmonary bypass reduces interleukin 8 and tumor necrosis factor α serum levels in cardiac surgery: a randomized controlled trial.

BACKGROUND: Surgical trauma and cardiopulmonary bypass (CPB) are associated with the liberation of pro-inflammatory cytokines. With hemadsorption (Cytosorb®) during CPB, pro-inflammatory cytokines may be reduced and the inflammatory response may be decreased. METHODS: In this prospective, randomized single center study, serum cytokine levels of interleukin 8 (Il-8), interleukin 6 (Il-6) and tumor-necrosis-factor α (TNFα) were assessed in elective on-pump cardiac surgery patients with hemadsorption on CPB (study group [SG], N.=20) and without (control group [CG], N.=20). Cytokine levels were assessed prior to CPB, at the end of CPB, and 6 hours (h) and 24 h after the end of CPB, together with a hemodynamic assessment. Cardiac-Index (CI) was assessed with transcardiopulmonary thermodilution. RESULTS: For Il-8, significantly lower serum levels were observed in the SG compared to the CG at the end of CPB (P=0.008). In the SG, TNFα levels were also below those in the CG at both the end of and 6h after CPB (P=0.034). After 24 hours, TNFα levels were at baseline in both groups. No significant differences were found for Il-6. The CI was significantly higher in the SG at the end of CPB (P=0.025). However, there was no difference between both groups 6 h after CPB. CONCLUSIONS: This prospective study shows a significant reduction in pro-inflammatory cytokine levels of Il-8 and TNFα with hemadsorption in on-pump cardiac surgery whilst also demonstrating safety in its applications. However, the differences in cytokine levels and CI between patients treated with hemadsorption and those without were minor and of short duration.

For beginners in anaesthesia, self-training with an audiovisual checklist improves safety during anaesthesia induction: A randomised, controlled two-centre study.

BACKGROUND: Beginners in residency programmes in anaesthesia are challenged because working environment is complex, and they cannot rely on experience to meet challenges. During this early stage, residents need rules and structures to guide their actions and ensure patient safety. OBJECTIVE: We investigated whether self-training with an electronic audiovisual checklist app on a mobile phone would produce a long-term improvement in the safety-relevant actions during induction of general anaesthesia. DESIGN, SETTING AND PARTICIPANTS: During the first month of their anaesthesia residency, we randomised 26 residents to the intervention and control groups. The study was performed between August 2013 and December 2014 in two university hospitals in Germany. INTERVENTION: In addition to normal training, the residents of the intervention group trained themselves on well tolerated induction using the electronic checklist for at least 60 consecutive general anaesthesia inductions. MAIN OUTCOME MEASURES: After an initial learning phase, all residents were observed during one induction of general anaesthesia. The primary outcome was the number of safety items completed during this anaesthesia induction. Secondary outcomes were similar observations 4 and 8 weeks later. RESULTS: Immediately, and 4 weeks after the first learning phase, residents in the intervention group completed a significantly greater number of safety checks than residents in the control group 2.8 [95% confidence interval (CI) 0.4 to 5.1, P = 0.021, Cohen's d = 0.47] and 3.7 (95% CI 1.3 to 6.1, P = 0.003, Cohen's d = 0.61), respectively. The difference between the groups had disappeared by 8 weeks: mean difference in the number of safety checks at 8 weeks was 0.4, 95% CI -2.0 to 2.8, P = 0.736, Cohen's d = 0.07). CONCLUSION: The use of an audiovisual self-training checklists improves safety-relevant behaviour in the early stages of a residency training programme in anaesthesia.

Reliability of transcardiopulmonary thermodilution cardiac output measurement in experimental aortic valve insufficiency.

BACKGROUND: Monitoring cardiac output (CO) is important to optimize hemodynamic function in critically ill patients. The prevalence of aortic valve insufficiency (AI) is rising in the aging population. However, reliability of CO monitoring techniques in AI is unknown. The aim of this study was to investigate the impact of AI on accuracy, precision, and trending ability of transcardiopulmonary thermodilution-derived COTCPTD in comparison with pulmonary artery catheter thermodilution COPAC. METHODS: Sixteen anesthetized domestic pigs were subjected to serial simultaneous measurements of COPAC and COTCPTD. In a novel experimental model, AI was induced by retraction of an expanded Dormia basket in the aortic valve annulus. The Dormia basket was delivered via a Judkins catheter guided by substernal epicardial echocardiography. High (HPC), moderate (MPC) and low cardiac preload conditions (LPC) were induced by fluid unloading (20 ml kg-1 blood withdrawal) and loading (subsequent retransfusion of the shed blood and additional infusion of 20 ml kg-1 hydroxyethyl starch). Within each preload condition CO was measured before and after the onset of AI. For statistical analysis, we used a mixed model analysis of variance, Bland-Altman analysis, the percentage error and concordance analysis. RESULTS: Experimental AI had a mean regurgitant volume of 33.6 ± 12.0 ml and regurgitant fraction of 42.9 ± 12.6%. The percentage error between COTCPTD and COPAC during competent valve function and after induction of substantial AI was: HPC 17.7% vs. 20.0%, MPC 20.5% vs. 26.1%, LPC 26.5% vs. 28.1% (pooled data: 22.5% vs. 24.1%). The ability to trend CO-changes induced by fluid loading and unloading did not differ between baseline and AI (concordance rate 95.8% during both conditions). CONCLUSION: Despite substantial AI, transcardiopulmonary thermodilution reliably measured CO under various cardiac preload conditions with a good ability to trend CO changes in a porcine model. COTCPTD and COPAC were interchangeable in substantial AI.