Ellenberger, David

[["dc.bibliographiccitation.firstpage","e0199345"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","PloS one"],["dc.bibliographiccitation.lastpage","e0199345"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Korsten, Peter"],["dc.contributor.author","Mavropoulou, Eirini"],["dc.contributor.author","Wienbeck, Susanne"],["dc.contributor.author","Ellenberger, David"],["dc.contributor.author","Patschan, Daniel"],["dc.contributor.author","Zeisberg, Michael"],["dc.contributor.author","Vasko, Radovan"],["dc.contributor.author","Tampe, Björn"],["dc.contributor.author","Müller, Gerhard A."],["dc.date.accessioned","2019-07-09T11:45:40Z"],["dc.date.available","2019-07-09T11:45:40Z"],["dc.date.issued","2018"],["dc.description.abstract","RATIONALE: Central venous catheter (CVC) placement is a standard procedure in critical care. Ultrasound guidance during placement is recommended by current guidelines, but there is no consensus on the best method for evaluating the correct CVC tip position. Recently, the \"rapid atrial swirl sign\" (RASS) has been investigated in a limited number of studies. OBJECTIVES: We performed a prospective diagnostic accuracy study of focused echocardiography for the evaluation of CVC tip position in our medical ICU and IMC units. METHODS: We performed a prospective diagnostic accuracy study in 100 patients admitted to the Intensive Care Unit and Intermediate Care Unit at our center. The first 10 subjects were assessed by one staff physician investigator (reference cohort), the remaining 90 patients by different residents (test cohort). All patients received a post-procedural chest radiograph (CXR) as gold standard. CVC placement was assessed with focused echocardiography performed by residents after a short training session. A rapid opacification of the right atrium (RASS) after injection of 10 mL of normal saline was regarded as \"positive\", flush after more than two seconds was defined as \"delayed\", no flush was a \"negative\" test result. MEASUREMENTS AND MAIN RESULTS: Overall sensitivity of the RASS was 100% (95% CI 73.54-100%), specificity was 94.32% (CI 87.24-98.13%). Positive and negative predictive values were 70.59% (CI 44.04-89.09%) and 100% (CI 95.65-100%), respectively. Median time for echocardiographic testing was 5 minutes (1-28) in the whole cohort, CXRs were available after 49.5 minutes (13-254). Interrater agreement of the RASS was 0.77 (Cohen's kappa), Measurement of CVC tip position was not different between two observers. Test characteristics were similar among differently experienced residents. CONCLUSIONS: Presence of the RASS by focused echocardiography showed excellent sensitivity and specificity and was equally performed by residents after minimal training. In patients with a positive RASS, routine CXR can be safely omitted, reducing time, costs and radiation exposure. A negative RASS should lead to a search for misplaced catheters. CLINICAL TRIAL REGISTRATION: The study was registered with www.clinicaltrials.gov (NCT02661607)."],["dc.identifier.doi","10.1371/journal.pone.0199345"],["dc.identifier.pmid","30011285"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15276"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59280"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.ddc","610"],["dc.title","The \"rapid atrial swirl sign\" for assessing central venous catheters: Performance by medical residents after limited training."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Transportation"],["dc.bibliographiccitation.lastpage","15"],["dc.contributor.author","Siebert, Michael"],["dc.contributor.author","Ellenberger, David"],["dc.date.accessioned","2019-07-09T11:51:37Z"],["dc.date.available","2019-07-09T11:51:37Z"],["dc.date.issued","2019"],["dc.description.abstract","Automatic passenger counting (APC) in public transport has been introduced in the 1970s and has been rapidly emerging in recent years. Still, real-world applications continue to face events that are difficult to classify. The induced imprecision needs to be handled as statistical noise and thus methods have been defined to ensure that measurement errors do not exceed certain bounds. Various recommendations for such an APC validation have been made to establish criteria that limit the bias and the variability of the measurement errors. In those works, the misinterpretation of non-significance in statistical hypothesis tests for the detection of differences (e.g. Student’s t-test) proves to be prevalent, although existing methods which were developed under the term equivalence testing in biostatistics (i.e. bioequivalence trials, Schuirmann in J Pharmacokinet Pharmacodyn 15(6):657–680, 1987) would be appropriate instead. This heavily affects the calibration and validation process of APC systems and has been the reason for unexpected results when the sample sizes were not suitably chosen: Large sample sizes were assumed to improve the assessment of systematic measurement errors of the devices from a user’s perspective as well as from a manufacturers perspective, but the regular t-test fails to achieve that. We introduce a variant of the t-test, the revised t-test, which addresses both type I and type II errors appropriately and allows a comprehensible transition from the long-established t-test in a widely used industrial recommendation. This test is appealing, but still it is susceptible to numerical instability. Finally, we analytically reformulate it as a numerically stable equivalence test, which is thus easier to use. Our results therefore allow to induce an equivalence test from a t-test and increase the comparability of both tests, especially for decision makers."],["dc.identifier.doi","10.1007/s11116-019-09991-9"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16156"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59975"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1572-9435"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","610"],["dc.title","Validation of automatic passenger counting: introducing the t-test-induced equivalence test"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]