[Intraosseous vascular access - step by step]. / Intraossärer Zugang ­ Schritt für Schritt.

Probably everyone who works in emergency medicine has been in the situation of having to insert a peripheral vein under time pressure in difficult venous conditions. So what do I do if I don't succeed? Establish a peripheral venous catheter? In recent years, the intraosseous approach has become increasingly popular as an alternative procedure. In this article, you will be guided step by step through the creation of an intraosseous access.

Effects of COVID-19 on a mature citizen first responder system in the German district of Gütersloh: an observational study.

BACKGROUND: The aim of this study was to examine the impact of COVID-19 on the response rate of community-first-responders (CFR) and other out-of-hospital-cardiac-arrest (OHCA) outcomes using the smartphone-first-responder-system (SFRS) "Mobile Retter." METHODS: All adult non-traumatic OHCA in the district of Gütersloh between 01.01.2018-31.12.2021 were included. Periods of interest were 1) prior to the first COVID-19-lockdown; to 2) both lockdowns; and 3) the time in between, as well as after the COVID-19-lockdowns (pre-COVID-19, COVID-19-lockdown and COVID-19-pandemic respectively). The primary outcome was the CFR response rate defined as proportion of CFR alerts that were accepted by a CFR and in which at least one CFR arrived on scene of the emergency out of all CFR alerts. Secondary outcomes included the rate of CFR alerts, defined as proportion of OHCA to which CFR were summoned by the emergency medical dispatcher, as well as the rate of return-of-spontaneous-circulation (ROSC) and rate of survival until hospital discharge. We also examined the incidence COVID-19-infection of CFR in context of the SFRS. RESULTS: A total of 1064 OHCA-patients (mean age: 71.4±14.5 years; female: 33.8%) were included in the study (Pre-COVID-19: 539; COVID-19-lockdown: 109; COVID-19-pandemic: 416). The response rate was 64.0% (pre-COVID-19: 58.7%; COVID-19-lockdown: 63.5%; COVID-19-pandemic: 71.8%, P=0.002 vs. pre-COVID-19). The alert rate was 52.7% (pre-COVID-19: 56.2%; COVID-19-lockdown: 47.7%, P=0.04 vs. Pre-COVID-19; COVID-19-Pandemic: 49.5%, P=0.02 vs. pre-COVID-19). The ROSC-rate was 40.4% (pre-COVID-19: 41.0%; COVID-19-lockdown: 33.9%; COVID-19-pandemic: 41.4%) and hospital discharge rate 31.2% (Pre-COVID-19: 33.0%; COVID-19-lockdown: 36.8%; COVID-19-pandemic: 28.7%). The use of CFR was associated with favorable effects in terms of hospital admission (odds ratio [OR]: 0.654 (CI95: 0.444-0.963), P=0.03), hospital discharge (OR: 2.343 (CI95: 1.002-5.475), P=0.04). None of the CFR became infected with COVID-19. CONCLUSIONS: "Mobile-Retter" was associated with high response rates, improved outcome in OHCA patients and no COVID-19-infections of CFR during the COVID-19-pandemic and -lockdowns.

Blood taken immediately after fatal resuscitation attempts yields higher quality DNA for genetic studies as compared to autopsy samples.

BACKGROUND: The out-of-hospital cardiac arrest (OHCA) in the young may be associated with a genetic predisposition which is relevant even for genetic counseling of relatives. The identification of genetic variants depends on the availability of intact genomic DNA. DNA from autopsy may be not available due to low autopsy frequencies or not suitable for high-throughput DNA sequencing (NGS). The emergency medical service (EMS) plays an important role to save biomaterial for subsequent molecular autopsy. It is not known whether the DNA integrity of samples collected by the EMS is better suited for NGS than autopsy specimens. MATERIAL AND METHODS: DNA integrity was analyzed by standardized protocols. Fourteen blood samples collected by the EMS and biomaterials from autopsy were compared. We collected 172 autopsy samples from different tissues and blood with postmortem intervals of 14-168 h. For comparison, DNA integrity derived from blood stored under experimental conditions was checked against autopsy blood after different time intervals. RESULTS: DNA integrity and extraction yield were higher in EMS blood compared to any autopsy tissue. DNA stability in autopsy specimens was highly variable and had unpredictable quality. In contrast, collecting blood samples by the EMS is feasible and delivered comparably the highest DNA integrity. CONCLUSIONS: Isolation yield and DNA integrity from blood samples collected by the EMS is superior in comparison to autopsy specimens. DNA from blood samples collected by the EMS on scene is stable at room temperature or even for days at 4 °C. We conclude that the EMS personnel should always save a blood sample of young fatal OHCA cases died on scene to enable subsequent genetic analysis.

Compound Heterozygous FKTN Variants in a Patient with Dilated Cardiomyopathy Led to an Aberrant α-Dystroglycan Pattern.

Fukutin encoded by FKTN is a ribitol 5-phosphate transferase involved in glycosylation of α-dystroglycan. It is known that mutations in FKTN affect the glycosylation of α-dystroglycan, leading to a dystroglycanopathy. Dystroglycanopathies are a group of syndromes with a broad clinical spectrum including dilated cardiomyopathy and muscular dystrophy. In this study, we reported the case of a patient with muscular dystrophy, early onset dilated cardiomyopathy, and elevated creatine kinase levels who was a carrier of the compound heterozygous variants p.Ser299Arg and p.Asn442Ser in FKTN. Our work showed that compound heterozygous mutations in FKTN lead to a loss of fully glycosylated α-dystroglycan and result in cardiomyopathy and end-stage heart failure at a young age.

Sonification enables continuous surveillance of the ST segment in the electrocardiogram.

INTRODUCTION: ST segment elevation myocardial infarction is a common reason for out-of-hospital cardiac arrest in adult patients. The surveillance of the ST segment in the electrocardiogram is limited to visual presentation. However, the ST segment can change during the course of treatment. If ST elevation is present immediate coronary revascularization is needed, therefore detecting ST elevation changes the treatment fundamentally. Sonification of the ST segment is a new method which enables the emergency team to detect intermediate changes of the ST segment. MATERIAL AND METHODS: We have chosen two sonification designs which were introduced to two groups, medical students and computer science students. Twenty-one participants took part in the study. The sonification was designed for evaluation of the ST segment. The user was supposed to become empowered to distinguish between no, medium-low, medium-high or extreme ST elevation by listening to the sonification. The two groups were asked to evaluate the sounds for possible ST elevation as well as for aesthetics and usability. In a second study twenty-five medical students were taking part in a medical scenario in which sonification was played during a simulated case. The patient was suffering from a myocardial infarction, ST elevation was transient and sonification sounds were changing appropriately. The students were supposed to detect these changes and act accordingly by modifying the treatment. RESULTS: Both groups were able to classify ST segment elevation by listening to the sonification samples. The higher the ST segment, the better was the detection rate overall. In all of the three categories (pleasantness, informativeness and long-term listening) the Water Ambience sonification was rated higher compared to the Polarity sonification. Moreover, in the two groups that took part in the study, we found a significant difference when comparing classification performance using both sonification designs. For the group of medical students as t(20) = 4.31, p = 3.44 × 10-4, p < 0.01 and for the computer science students as t(19) = 3.40, p = 9.39 × 10-6, p < 0.01. In the simulated medical scenario participants indicated that 96% detected the ST elevation. 60% stated that sonification played a role whereas for 32% it did not play a role for the detection of ST elevation. CONCLUSIONS: Sonification has the potential to play an important role as a new supporting tool for the surveillance of the ST segment during the care of patients with suspicion of myocardial infarction. It can be helpful to differentiate between ST segment elevation myocardial infarction and non-ST segment myocardial infarction especially if ST elevation is transient. Furthermore, sonification is viewed as pleasant to listen to and might not contribute to alarm fatigue.

The emergency medical service has a crucial role to unravel the genetics of sudden cardiac arrest in young, out of hospital resuscitated patients: Interim data from the MAP-IT study.

BACKGROUND: Genetics of sudden cardiac deaths (SCD) remains frequently undetected. Genetic analysis is recommended in undefined selected cases in the 2021 ERC-guideline. The emergency medical service and physicians (EMS) may play a pivotal role for unraveling SCD by saving biomaterial for later molecular autopsy. Since for high-throughput DNA-sequencing (NGS) high quality genomic DNA is needed. We investigated in a prospective proof-of-concept study the role of the EMS for the identification of genetic forms of SCDs in the young. METHODS: We included patients aged 1-50 years with need for cardiopulmonary resuscitation attempts (CPR). Cases with non-natural deaths were excluded. In two German counties with 562,904 residents 39,506 services were analysed. Paired end panel-sequencing was performed, and variants were classified according to guidelines of the American College of Medical Genetics (ACMG). RESULTS: 769 CPR-attempts were recorded (1.95% of all EMS-services; CPR-incidence 68/100,000). In 103 cases CPR were performed in patients < 50y. 58% died on scene, 26% were discharged from hospital. 24 subjects were included for genotyping. Of these 33% died on scene, 37.5% were discharged from hospital. 25% of the genotyped patients were carriers of (likely) pathogenic (ACMG-4/-5) variants. 67% carried variants with unknown significance (ACMG-3). 2 of them had familial history for arrhythmogenic cardiomyopathy or had to be re-classified as ACMG-4 carriers due to whole exome sequencing. CONCLUSION: The EMS contributes especially in fatal OHCA-cases to increase the yield of identified genetic conditions by collecting a blood sample on scene. Thus, the EMS can contribute significantly to primary and secondary prophylaxis in affected families.

The Combined Human Genotype of Truncating TTN and RBM20 Mutations Is Associated with Severe and Early Onset of Dilated Cardiomyopathy.

A major cause of heart failure is cardiomyopathies, with dilated cardiomyopathy (DCM) as the most common form. Over 40 genes are linked to DCM, among them TTN and RBM20. Next Generation Sequencing in clinical DCM cohorts revealed truncating variants in TTN (TTNtv), accounting for up to 25% of familial DCM cases. Mutations in the cardiac splicing factor RNA binding motif protein 20 (RBM20) are also known to be associated with severe cardiomyopathies. TTN is one of the major RBM20 splicing targets. Most of the pathogenic RBM20 mutations are localized in the highly conserved arginine serine rich domain (RS), leading to a cytoplasmic mislocalization of mutant RBM20. Here, we present a patient with an early onset DCM carrying a combination of (likely) pathogenic TTN and RBM20 mutations. We show that the splicing of RBM20 target genes is affected in the mutation carrier. Furthermore, we reveal RBM20 haploinsufficiency presumably caused by the frameshift mutation in RBM20.

Mechanical circulatory support does not reduce advanced myocardial fibrosis in patients with end-stage heart failure.

AIMS: Mechanical unloading by ventricular assist devices (VADs) has become increasingly important for the therapy of end-stage heart failure during the last decade. However, VAD support was claimed to be associated with partial reverse remodelling. Unfortunately, the literature describes the contradictory effects of VAD systems on cardiac fibrosis, a hallmark of cardiac remodelling. To clarify these inconsistent results, the effects on cardiac fibrosis before and after mechanical unloading in 125 patients were examined. METHODS AND RESULTS: Left ventricular myocardial tissue from ischaemic or non-ischaemic cardiomyopathy patients undergoing VAD implantation and subsequent cardiac transplantation and non-failing hearts of the control group were analysed for 4-hydroxyproline (4OH-P) content as a marker for collagen protein. In addition, collagen cross-linking and mRNAs of collagens I and III and transforming growth factor beta-1 were measured. 4OH-P content was significantly increased in failing hearts compared with the control group and increased (P < 0.05) after mechanical unloading (nmol/mg tissue, mean ± standard deviation: 16.74 ± 9.68 vs. 7.75 ± 2.39 and 18.57 ± 9.19). However, plotting of the 4OH-P ratios (post/pre-VAD) against the collagen content pre-VAD could be fitted by non-linear regression. Collagen cross-linking correlated strongly with the total collagen content in pre- and post-VAD myocardium (r2  = 0.73 and 0.71, respectively). In contrast to the total collagen content, all three mRNAs of fibrotic genes were significantly down-regulated during VAD support when compared to pre-VAD. CONCLUSIONS: This investigation of a comparably large patient cohort revealed that cardiac fibrosis was strongly increased in heart failure and increased even after mechanical unloading. The mRNAs of collagens I and III are independently regulated from the collagen protein.

Distinct Myocardial Transcriptomic Profiles of Cardiomyopathies Stratified by the Mutant Genes.

Cardiovascular diseases are the number one cause of morbidity and mortality worldwide, but the underlying molecular mechanisms remain not well understood. Cardiomyopathies are primary diseases of the heart muscle and contribute to high rates of heart failure and sudden cardiac deaths. Here, we distinguished four different genetic cardiomyopathies based on gene expression signatures. In this study, RNA-Sequencing was used to identify gene expression signatures in myocardial tissue of cardiomyopathy patients in comparison to non-failing human hearts. Therefore, expression differences between patients with specific affected genes, namely LMNA (lamin A/C), RBM20 (RNA binding motif protein 20), TTN (titin) and PKP2 (plakophilin 2) were investigated. We identified genotype-specific differences in regulated pathways, Gene Ontology (GO) terms as well as gene groups like secreted or regulatory proteins and potential candidate drug targets revealing specific molecular pathomechanisms for the four subtypes of genetic cardiomyopathies. Some regulated pathways are common between patients with mutations in RBM20 and TTN as the splice factor RBM20 targets amongst other genes TTN, leading to a similar response on pathway level, even though many differentially expressed genes (DEGs) still differ between both sample types. The myocardium of patients with mutations in LMNA is widely associated with upregulated genes/pathways involved in immune response, whereas mutations in PKP2 lead to a downregulation of genes of the extracellular matrix. Our results contribute to further understanding of the underlying molecular pathomechanisms aiming for novel and better treatment of genetic cardiomyopathies.

Cardiomyopathy-associated mutations in the RS domain affect nuclear localization of RBM20.

Mutations in RBM20 encoding the RNA-binding motif protein 20 (RBM20) are associated with an early onset and clinically severe forms of cardiomyopathies. Transcriptome analyses revealed RBM20 as an important regulator of cardiac alternative splicing. RBM20 mutations are especially localized in exons 9 and 11 including the highly conserved arginine and serine-rich domain (RS domain). Here, we investigated in several cardiomyopathy patients, the previously described RBM20-mutation p.Pro638Leu localized within the RS domain. In addition, we identified in a patient the novel mutation p.Val914Ala localized in the (glutamate-rich) Glu-rich domain of RBM20 encoded by exon 11. Its impact on the disease was investigated with a novel TTN- and RYR2-splicing assay based on the patients' cardiac messenger RNA. Furthermore, we showed in cell culture and in human cardiac tissue that mutant RBM20-p.Pro638Leu is not localized in the nuclei but causes an abnormal cytoplasmic localization of the protein. In contrast the splicing deficient RBM20-p.Val914Ala has no influence on the intracellular localization. These results indicate that disease-associated variants in RBM20 lead to aberrant splicing through different pathomechanisms dependent on the localization of the mutation. This might have an impact on the future development of therapeutic strategies for the treatment of RBM20-induced cardiomyopathies.

A homozygous DSC2 deletion associated with arrhythmogenic cardiomyopathy is caused by uniparental isodisomy.

AIMS: We aimed to unravel the genetic, molecular and cellular pathomechanisms of DSC2 truncation variants leading to arrhythmogenic cardiomyopathy (ACM). METHODS AND RESULTS: We report a homozygous 4-bp DSC2 deletion variant c.1913_1916delAGAA, p.Q638LfsX647hom causing a frameshift carried by an ACM patient. Whole exome sequencing and comparative genomic hybridization analysis support a loss of heterozygosity in a large segment of chromosome 18 indicating segmental interstitial uniparental isodisomy (UPD). Ultrastructural analysis of the explanted myocardium from a mutation carrier using transmission electron microscopy revealed a partially widening of the intercalated disc. Using qRT-PCR we demonstrated that DSC2 mRNA expression was substantially decreased in the explanted myocardial tissue of the homozygous carrier compared to controls. Western blot analysis revealed absence of both full-length desmocollin-2 isoforms. Only a weak expression of the truncated form of desmocollin-2 was detectable. Immunohistochemistry showed that the truncated form of desmocollin-2 did not localize at the intercalated discs. In vitro, transfection experiments using induced pluripotent stem cell derived cardiomyocytes and HT-1080 cells demonstrated an obvious absence of the mutant truncated desmocollin-2 at the plasma membrane. Immunoprecipitation in combination with fluorescence measurements and Western blot analyses revealed an abnormal secretion of the truncated desmocollin-2. CONCLUSION: In summary, we unraveled segmental UPD as the likely genetic reason for a small homozygous DSC2 deletion. We conclude that a combination of nonsense mediated mRNA decay and extracellular secretion is involved in DSC2 related ACM.

Molecular autopsy and family screening in a young case of sudden cardiac death reveals an unusually severe case of FHL1 related hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy with a prevalence of about 1:200. It is characterized by left ventricular hypertrophy, diastolic dysfunction and interstitial fibrosis; HCM might lead to sudden cardiac death (SCD) especially in the young. Due to low autopsy frequencies of sudden unexplained deaths (SUD) the true prevalence of SCD and especially of HCM among SUD remains unclear. Even in cases of proven SCD genetic testing is not a routine procedure precluding appropriate risk stratification and counseling of relatives. METHODS: Here we report a case of SCD in a 19-year-old investigated by combined forensic and molecular autopsy. RESULTS: During autopsy of the index-patient HCM was detected. As no other possible cause of death could be uncovered by forensic autopsy the event was classified as SCD. Molecular autopsy identified two (probably) pathogenic genetic variants in FHL1 and MYBPC3. The MYBPC3 variant had an incomplete penetrance. The FHL1 variant was a de novo mutation. We detected reduced FHL1 mRNA levels and no FHL1 protein in muscle samples suggesting nonsense-mediated mRNA decay and/or degradation of the truncated protein in the SCD victim revealing a plausible disease mechanism. CONCLUSION: The identification of the genetic cause of the SCD contributed to the rational counseling of the relatives and risk assessment within the family. Furthermore our study revealed evidences for the pathomechanism of FHL1 mutations.

Relapse of typhoid fever following delayed response to meropenem: A case report and review of previously published cases indicating limited clinical efficacy of meropenem for the treatment of typhoid fever.

In times of emerging multi-drug resistance among Gram-negative bacteria (including Salmonella enterica, Serovar Typhi), we observed relapse of typhoid fever following delayed response to treatment with meropenem, suggestive for limited clinical efficacy of the drug. Three previously published cases supported our suspicion. Within this context, we discuss the case details with a focus on potential explanations for insufficient clinical response to meropenem (e.g. limited intracellular penetration, phenomena of tolerance and persistence). Meropenem is a last-resort antimicrobial agent for the treatment of multi-drug resistant Gram-negative infections. Reliable clinical data evaluating the efficacy of meropenem for the treatment of typhoid fever are urgently needed. Future clinical studies evaluating typhoid fever outcome should also investigate the impact of (i) intracellular penetration of antibiotics, and (ii) tolerance and persistence on outcome.

Evolution of FLT3-ITD and D835 activating point mutations in relapsing acute myeloid leukemia and response to salvage therapy.

Internal tandem duplications (ITDs) of the juxtamembrane region of the FLT3 tyrosine kinase receptor are the most frequent genetic alterations in acute myeloid leukemia (AML). The presence of this mutation has been recognized as an independent poor prognostic factor. In this study, we compared the FLT3 mutational status between diagnosis and subsequent relapses in 31 patients with AML. At diagnosis, seven patients were identified to contain FLT3-ITD mutations and one patient to harbor the D835 mutation. Five patients remained FLT3-ITD positive throughout the disease course (+/+). Three patients lost the FLT3 gene mutation at first (one FLT3-ITD, one D835 mutation), or second relapse (one FLT3-ITD) (+/-). One additional patient lost a small FLT3-ITD positive clone at relapse and at the same time gained an apparently unrelated FLT3-ITD positive clone. One patient without FLT3 mutation at diagnosis relapsed with an FLT3-ITD mutation (-/+). A shorter median duration of first remission (6 months versus 11.5 months) and a higher relapse rate after salvage therapy (e.g. allogeneic peripheral blood stem cell transplantation) resulted in a lower leukemia-free survival in the FLT3 mutated group (11% versus 31%). The loss of a clone with a mutation in the FLT3 gene at relapse did not improve the prognosis.

Rectal adenocarcinoma with choriocarcinomatous differentiation: clinical and genetic aspects.

Nongestational choriocarcinomas are rare tumors. In the gastrointestinal tract, they are characterized by a biphasic tumor growth with separated areas of adenocarcinomatous and choriocarcinomatous differentiation. We here report a case of a combined adenocarcinoma-choriocarcinoma of the rectum. The tumor showed an aggressive clinical behavior with metastasis to the liver and lungs. A transient partial remission was achieved after 4 cycles of cisplatinum, etoposide, and ifosfamide chemotherapy, with normalization of serum beta-human chorionic gonadotropin levels. At this time, viable residual choriocarcinoma cells were found in surgically resected lung metastasis. The patient succumbed 8 months after initial diagnosis to a rapid abdominal relapse. We used comparative genomic hybridization (CGH) and fluorescence in situ hybridization to elucidate the genetic relationship of adenocarcinoma and choriocarcinoma in this neoplasm. We found genetic changes characteristic for colorectal adenocarcinomas, a loss of chromosomal regions 8p21-pter as well as 18q21-pter, and a gain of 5p and 20q, in both tumor parts. This provides evidence for the common origin of both components. A differential pattern of additional genetic changes suggests a clonal evolution from a common ancestor cell. In contrast to findings from a comparative study on a choriocarcinoma of the renal pelvis, we did not find an amplification of the germ cell cancer-associated chromosomal region 12p11.2-p12.1 in the areas of choriocarcinoma but found instead a loss of Xp11.3-pter. To our knowledge, this is the first report of a CGH comparison of the adenocarcinomatous and choriocarcinomatous tumor parts in a nongestational choriocarcinoma of the gastrointestinal tract.