St. Josefskrankenhaus Freiburg

Fluid therapy is an integral component of perioperative management in geriatric trauma surgery. Sufficient evidence-based medicine in perioperative fluid management in older patients is still lacking. Our aim is to present practical algorithms for the perioperative phases of fluid management reflecting the current state of scientific knowledge, expert opinions and best clinical practices. These algorithms follow the rules of practical applicability. The final assessment as the basis for the targeted fluid management is always asynoptic view of the clinical findings, medical history, laboratory findings and diagnostic tests. Ongoing and prospective evaluation of the presented criteria and procedures is necessary.

Loss-of-function mutations in KCNQ1 and KCNH2 (α-subunits of the slow delayed IKs and rapid delayed IKr-conducting repolarising K+ channels) lead to long QT syndrome type 1 (LQT1) and 2 (LQT2), respectively. These channelopathies present with longer action potential duration (APD) and prolonged QT interval on electrocardiogram, which can ultimately lead to deadly arrhythmias. Here, we investigated the therapeutic potential of the polyunsaturated fatty acid docosahexaenoyl glycine (DHA-gly) in normalizing APD and QT interval in LQT2 by increasing IKs. The effects of DHA-gly on electrical and mechanical parameters were assessed in Xenopus laevis oocytes, wild-type (WT), LQT1 (KCNQ1-Y315S), and LQT2 (KCNH2-G628S) transgenic rabbit models and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). DHA-gly increased IKs in oocytes and WT ventricular cardiomyocytes (VCMs) in a dose-dependent manner. Consequently, DHA-gly shortened APD in vitro and QT interval ex vivo in WT and LQT2 rabbits, but not in LQT1. However, DHA-gly was unable to reduce arrhythmia formation in LQT2. Beneficial APD/QT shortening effects were accompanied by a detrimental decrease in both cellular and ventricular contraction across all genotypes, including LQT1, which could be due to a shortening in Ca2+ transient duration observed in VCMs and hiPSC-CMs. DHA-gly-induced IKs enhancement shows promising results in shortening APD/QT in LQT2 rabbits, while having no effect on LQT1 (impaired IKs). However, its adverse effect on cardiac contractility, even in LQT1, makes it unsuitable to treat LQTS patients. Our study highlights the importance of considering both electrical and mechanical effects of potential therapeutic compounds prior to clinical translation.

The emerging FLASH radiotherapy technique employs "Ultra-High Dose Rate" (UHDR) irradiations and offers the potential to spare normal tissue while maintaining iso-effective tumor treatment. Given the physical and biological advantages inherent to high "Linear Energy Transfer" (LET) particles, the combination of UHDR and high LET has the capability to enhance the normal tissues sparing, as indicated by initial in vivo trials. However, to ensure a safe implementation of this combined modality, it is essential to establish robust dosimetric protocols utilizing dose-, dose rate-, and LET-independent detectors. The objective of this study is to characterize the dose, dose rate, and LET dependency of two diamond detectors with high LET carbon and oxygen ion irradiation under "Standard Dose Rate" (SDR) and UHDR conditions. The "microDiamond" (mD) and a "flashDiamond" (fD) prototype were benchmarked against measurements with a monitoring ionization chamber, Advanced Markus chamber (AMC), and simulations for carbon and oxygen irradiation, with energies of 274.98MeV/u and 325.98MeV/u under SDR and UHDR conditions. First, the entire depth-dose profiles obtained during SDR irradiations and the partial in-depth profiles of the Bragg peak region in UHDR were compared to the corresponding simulation values. Secondly, the linearity of the diamond detector response during dose escalation measurements was investigated for both dose rates. The two detectors exhibited alignment with the simulated depth-dose distributions for oxygen and carbon irradiations across both dose rate conditions. The mD overestimated the dose values for carbon and oxygen measurements. This overestimation increased with "dose-averaged LET" (LETd) during SDR irradiation and maintained a stable value of 5% for UHDR. Meanwhile, the fD demonstrated a high degree of agreement with the simulation, with a maximum discrepancy of 5% across all irradiation modalities in the plateau and "Bragg Peak" (BP). Deviations were observed in the BP fall-off region, while both diamond detectors exhibited a strong alignment with the AMC measurements. Furthermore, both detectors exhibited dose linearity under SDR and UHDR irradiation for both carbon and oxygen irradiation, with a coefficient of determination (R2) above 0.99. In the context of heavy ion carbon and oxygen irradiation in UHDR and SDR, the two diamond detectors demonstrated dose-rate independence. While the mD exhibited a tendency to overestimate dose values with increasing LETd, the fD was found to be LET-independent. The fD appears to offer accurate and reliable dose assessments for UHDR heavy ion experiments.

Virtual reality (VR) appears to be a promising educational tool for otorhinolaryngology (ORL) residency training, as it allows for safe and effective practice immediate feedback and potential improvements in patient outcomes. Despite these advantages, VR has not yet been incorporated into residency training in ORL, which may be due to limited availability or validation and skepticism toward incorporation of new training methods. This study investigates whether a VR model of the temporal bone improves learning success for ORL residents in comparison to standard plastic models and whether it depends on surgeon's experience. We also included a subjective evaluation of the learning experience with both models. ORL residents and specialists at 2 German university hospitals were tested on their knowledge of temporal bone anatomy after training with either VR or standard plastic models. In addition, we compared knowledge of the temporal bone anatomy before- and after-VR training. Lastly, a subjective survey on the benefits and limitations of VR was conducted to assess participants' views on this new technology. About 85% of the participants considered VR to be better than conventional models and agreed that VR was a useful tool for teaching complex anatomy. Objective evaluation showed significant improvement in knowledge after using VR (before/after comparison), especially in participants with a higher level of preexisting knowledge. Direct comparison to conventional plastic models showed no superiority of the VR model. VR models in ORL are not only appealing and motivating for residents, but also objectively improve their anatomical knowledge, especially in advanced residency. In addition, VR-in contrast to the plastic model-offers opportunities for further development and optimization.

Radiotherapy with charged particles at high dose and ultra-high dose rate (uHDR) is a promising technique to further increase the therapeutic index of patient treatments. Dose rate is a key quantity to predict the so-called FLASH effect at uHDR settings. However, recent works introduced varying calculation models to report dose rate, which is susceptible to the delivery method, scanning path (in active beam delivery) and beam intensity. This work introduces an analytical dose rate calculation engine for raster scanned charged particle beams that is able to predict dose rate from the irradiation plan and recorded beam intensity. The importance of standardized dose rate calculation methods is explored here. Dose is obtained with an analytical pencil beam algorithm, using pre-calculated databases for integrated depth dose distributions and lateral penumbra. Dose rate is then calculated by combining dose information with the respective particle fluence (i.e., time information) using three dose-rate-calculation models (mean, instantaneous, and threshold-based). Dose rate predictions for all three models are compared to uHDR helium ion beam (145.7 MeV/u, range in water of approximatively 14.6cm) measurements performed at the Heidelberg Ion Beam Therapy Center (HIT) with a diamond-detector prototype. Three scanning patterns (scanned or snake-like) and four field sizes are used to investigate the dose rate differences. Dose rate measurements were in good agreement with in-silico generated distributions using the here introduced engine. Relative differences in dose rate were below 10% for varying depths in water, from 2.3 to 14.8cm, as well as laterally in a near Bragg peak area. In the entrance channel of the helium ion beam, dose rates were predicted within 7% on average for varying irradiated field sizes and scanning patterns. Large differences in absolute dose rate values were observed for varying calculation methods. For raster-scanned irradiations, the deviation between mean and threshold-based dose rate at the investigated point was found to increase with the field size up to 63% for a 10mm × 10mm field, while no significant differences were observed for snake-like scanning paths. This work introduces the first dose rate calculation engine benchmarked to instantaneous dose rate, enabling dose rate predictions for physical and biophysical experiments. Dose rate is greatly affected by varying particle fluence, scanning path, and calculation method, highlighting the need for a consensus among the FLASH community on how to calculate and report dose rate in the future. The here introduced engine could help provide the necessary details for the analysis of the sparing effect and uHDR conditions.

The latest resuscitation guidelines contain a new chapter, which focuses on systems improving care for patients with out-of-hospital cardiac arrest (OHCA). In this article, we describe recent developments regarding telephone cardiopulmonary resuscitation (CPR), first responder systems, cardiac arrest centers, and global campaigns. Telephone CPR has been implemented in many countries, and recent developments include artificial intelligence and video calls to improve dispatch assisted CPR. However, the degree of implementation is not yet satisfying. Smartphone alerting systems are effective in reducing the resuscitation-free interval, but many regions do not yet use this technology. Further improvements are needed to reduce response times. Cardiac arrest centers increase the survival chance after OHCA. Specific criteria need to be defined and professional societies should establish a certification process. Global campaigns are effective in reaching people around the world. However, we need to evaluate the effects of the campaigns. Telephone CPR, first responder systems, cardiac arrest centers, and global campaigns are highlighted in the recent resuscitation guidelines. However, the degree of implementation is not yet sufficient. We do not only need to implement these measures, but we should also aim to monitor the systems regarding their performance and further improve them.

Einleitung Die A. stapedia stellt eine seltene vaskuläre kongenitale Anomalie dar. Im Regelfall existiert sie lediglich während der Embryonalentwicklung als Verbindung zwischen den Ästen der zukünftigen A. carotis externa und der A. carotis interna. Mit einer Prävalenz von 1:4000 bis 1:10000 kann sie postnatal persistieren, oft einhergehend mit einem aberranten Verlauf der A. carotis interna und der A. meningea media.