A. Allroggen

University of Münster, Münster, North Rhine-Westphalia, Germany

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Publications (19)27.02 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Zusammenfassung Hintergrund Die Rettungsleitstelle hat die Aufgabe, bei medizinischen Notfällen ein geeignetes Rettungsmittel zu disponieren. Hierbei muss aus den Angaben des Anrufers eine Verdachtsdiagnose formuliert und das geeignete Rettungsmittel entsendet werden. Material und Methoden Am Beispiel des akuten Schlaganfalls wurde für einen Zeitraum von 11 Monaten untersucht, inwieweit die Implementierung eines standardisierten Interviews mit einfachen Ja/Nein-Fragen in Anlehnung an den klinischen Teil des Face-, Arm-, Speech-Tests hilft, den akuten Schlaganfall im Rahmen der Notrufabfrage sicher zu erkennen. Die Krankheitsschwere wurde im Vergleich zum Gesamtkollektiv aller Notarzteinsätze retrospektiv analysiert. Ergebnisse Es konnten 109 Einsätze mit systematischer Notrufabfrage ausgewertet werden. Aus dem Vorjahreszeitraum standen 274 Einsätze ohne Verwendung eines standardisierten Interviews zum Vergleich zur Verfügung. Ein Schlaganfall konnte in 77% (Vorjahreszeitraum: 70%) durch die Notarztdiagnose bestätigt werden. Eine potenzielle vitale Bedrohung oder akute Lebensgefahr zeigte sich bei 16% der Patienten (Vorjahreszeitraum: 20%). Bei keinem Patienten mussten unmittelbare notärztliche Maßnahmen (kardiopulmonale Reanimation, Intubation) durchgeführt werden (Vorjahreszeitraum: 1,5%). Schlussfolgerung Für den akuten Schlaganfall besteht eine hohe Übereinstimmung zwischen dem Einsatzstichwort und der Notarztdiagnose. Die systematische Notrufabfrage führt gegenüber einer unsystematischen Notrufabfrage jedoch nicht zu einer höheren Übereinstimmung von Einsatzstichwort und Notarztdiagnose. Es lässt sich durch die Anwendung der systematischen Notrufabfrage eine Reduktion akut vital bedrohter Patienten für das Einsatzstichwort akuter Schlaganfall erreichen. Der Anteil vital bedrohter Patienten mit dem Einsatzstichwort akuter Schlaganfall hat ein ähnliches Ausmaß wie der Anteil an der Gesamtheit der Notarzteinsätze der Stadt Münster. Somit scheint die Notarztindikation beim Einsatzstichwort akuter Schlaganfall auch in Zeiten des steigenden Kostendruckes gerechtfertigt.
    Notfall & Rettungsmedizin - NOTFALL RETTUNGSMED. 01/2011; 14(4):286-290.
  • Resuscitation 01/2008; 77. · 4.10 Impact Factor
  • Resuscitation 01/2008; 77. · 4.10 Impact Factor
  • Clinical Neurophysiology. 04/2007; 118(4):e9.
  • Aktuelle Neurologie - AKTUEL NEUROL. 01/2007; 34.
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    ABSTRACT: Microembolic signals (MES) have shown to be associated with increased risk of ischemic stroke in patients with pulsatile left ventricular assist devices (LVADs) in contrast to continuous-flow DeBakey LVAD. The pathogenesis of microembolization in LVAD-patients is still not known. We investigated whether systemic markers of inflammation or pump dynamic correlate with cerebral microembolization in nine patients with DeBakey LVAD. We performed transcranial Doppler (TCD) for MES-detection and evaluated parameters of inflammation (i.e. Leukocytes, CRP, Fibrinogen) and pump dynamic (i.e. power, speed, flow). During a mean LVAD duration of 203.7 +/- 179 days, thromboembolic events occurred in five patients with an incidence of 0.38% (approximately 0.38 events/100 LVAD-days). We performed 290 TCD monitorings with a MES mean count of 50.4 +/- 346 signals/hour (0-5042) and prevalence of 42.8%. There was no association between individual microembolic activity and the markers of inflammation or pump dynamic. In patients with DeBakey LVAD, a high load of clinically silent cerebral microemboli can be detected. However, there is no correlation between markers of inflammation or pump dynamic and the individual amount of microembolization. We hypothesize that a gaseous nature of the majority of detected microemboli in the DeBakey LVAD may be the underlying reason for this discrepancy.
    ASAIO Journal 04/2006; 52(3):243-7. · 1.49 Impact Factor
  • Aktuelle Neurologie - AKTUEL NEUROL. 01/2006; 33.
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    ABSTRACT: Microembolic signals (MES) can be detected by transcranial Doppler sonography (TCD). To identify gaseous microemboli the inhalation of oxygen is an established method in patients with prosthetic heart valves. Time domain analysis of sample volume length (SVL) and of frequency modulation showed promising results in the discrimination between solid and gaseous microemboli. We investigated whether these time domain analyses allow the discrimination of different types of microemboli in patients with the non-pulsatile DeBakey left ventricular assist device (LVAD). Repeated unilateral detection of MES was performed by TCD in 20 patients supported with DeBakey LVAD. Each monitoring session consisted of 20 minutes without and 20 minutes with inhalation of 100% oxygen (6 l/min). A total of 500 MES, detected with (n=250) or without (n=250) the supply of oxygen, were randomly chosen for offline analysis. The SVL (in cm) was calculated by duration and velocity of the MES measured in the time domain mode. Additionally, frequency modulation of MES was classified into three main types: Without modulation (type I), with gradual changes (type II) and with rapid changes (type III). With oxygen supply, both prevalence (26.4% versus 36.2%, p<0.01) and mean counts of MES per hour (49+/-293 versus 108+/-550, p<0.001) significantly declined compared with the MES load while breathing room air. There was no significant difference in the SVL of MES under oxygen (0.85+/-0.38 cm) compared with those without oxygen delivery (0.92+/-0.37 cm, p=0.6). Furthermore, no significant differences were noted for the MES frequency modulation types in time domain analysis with regard to oxygen supply. The reduction of MES under oxygen delivery confirms the gaseous nature in a substantial number of circulating microemboli produced by the DeBakey LVAD. However, SVL and frequency modulation of MES did not appear to provide valuable information regarding the structural nature of the underlying microembolic material.
    Neurological Research 10/2005; 27(7):780-4. · 1.18 Impact Factor
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    ABSTRACT: Microembolic signals detected by transcranial Doppler ultrasonography have been demonstrated to be clinically relevant in patients supported with pulsatile left ventricular assist devices. We prospectively investigated the quantity of microembolic signals in patients supported with the continuous-flow DeBakey left ventricular assist device (MicroMed DeBakey VAD; MicroMed Technology, Inc, Houston, Tex) including the refined Carmeda BioActive Surface system (Carmeda AB, Stockholm, Sweden). Twenty-three patients (20 male) aged 14 to 62 years supported with DeBakey left ventricular assist devices (n = 6 with Carmeda) were enrolled in this study. Microembolic signal monitorings were performed twice weekly by insonating the middle cerebral artery for 20 minutes without and 20 minutes with oronasal application of oxygen (6 L/min). Evidence of clinically manifest thromboembolic events was based on regular questionnaires, clinical examinations, and results of diagnostic procedures. Despite a low incidence of thromboembolic complications (0.24 per 100 left ventricular assist device days), 20 patients (87%) showed circulating microemboli. Overall, microembolic signals were found in 175 of 499 transcranial Doppler ultrasonographic examinations (35.1%), with mean counts of 81.2 +/- 443 (range 0-5042 signals/h). Both microembolic signal prevalence (25% vs 34%, P = .01) and absolute signal counts (46.5 vs 104, P < .01) significantly declined with oxygen delivery. There was no significant correlation between the individual microembolic signal activity and the incidence of clinical thromboembolism or the intensity of antihemostatic treatment. Patients supported with the Carmeda device did not show reduced rates of clinical thromboembolization or cerebral microemboli. In patients with DeBakey left ventricular assist devices, a high load of clinically silent microemboli can be detected within the cerebral arteries despite a low incidence of embolic complications. It needs to be investigated whether such continuous, presumably gaseous microembolization causes cognitive or neuropsychologic deficits.
    The Journal of thoracic and cardiovascular surgery 10/2005; 130(4):1159-66. · 3.41 Impact Factor
  • Journal of Neurology 12/2004; 251(11):1406-7. · 3.58 Impact Factor
  • D G Nabavi, A Allroggen, E B Ringelstein
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    ABSTRACT: Ischemic stroke in the young (age: 18-45 years) constitutes a diagnostic and therapeutic challenge. A broad spectrum of potential causes of juvenile strokes exists. Above all, nonatherosclerotic arteriopathies with dissections as their main proponent, paradoxical embolism, and thrombophilias have to be considered. Transient brief episodes with neurological deficits are difficult to discriminate from migrainous aura, epileptic seizure, psychogenic disorder. Therefore, the diagnostic work-up of juvenile stroke patients usually exceeds the amount of compulsory tests recommended in official guidelines. Various therapeutic modalities are not based on randomized large-scale studies and have to be selected on an individual basis. Despite good compliance, the annual risk of stroke recurrence is 2-3% and 1% for myocardial infarction.
    Der Nervenarzt 03/2004; 75(2):167-186. · 0.80 Impact Factor
  • D. Nabavi, A. Allroggen, E. Ringelstein
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    ABSTRACT: Der juvenile ischämische Insult (Alter bis 45 Jahre) stellt eine diagnostische und therapeutische Herausforderung unter den Schlaganfallsyndromen dar. Ätiologisch kommen eine Vielzahl von z. T. seltenen Krankheiten in Betracht. Vor allem müssen nichtatherosklerotische Arteriopathien — mit der Gefäßdissektion als Hauptvertreter —, paradoxe Embolien und Thrombophilien berücksichtigt werden. Bei flüchtigen Insulten ohne Nachweis struktureller Läsionen kann eine Abgrenzung zu nichtvaskulären Krankheiten (sog. Pseudoinsulten) v. a. einer Migräneaura, einem epileptischen Anfall und einer dissoziativen Störung schwierig sein. Daher führen juvenile Insulte zu einem erheblichen diagnostischen Mehraufwand, der die evidenzbasierten Mindestanforderungen weit übersteigt. Zahlreiche Therapiestrategien beruhen nicht auf großen randomisierten Studien und müssen auf individueller Basis gestaltet werden. Trotz guter Patientencompliance beträgt das jährliche Risiko für Reinsulte etwa 2–3% und für Myokardinfarkte etwa 1%.
    Der Nervenarzt 01/2004; 75(2). · 0.80 Impact Factor
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    ABSTRACT: The megadolichobasilar artery is a rare vascular disease, which usually becomes apparent either due to cerebral ischemia or due to compression of the brainstem or the cranial nerves, thereby leading to a large variety of neurological symptoms. We report on a patient who suffered a sudden right-sided deafness accompanied by vertigo and vomiting. Initially, an idiopathic sensorineural hearing loss was diagnosed and later on, after no improvement took place in spite of conservative therapy, a rupture of the round window membrane was suspected. Two weeks after the first symptoms had occurred the patient developed a hemiparesis on the left side.Radiology disclosed a dilated and partially thrombosed basilar artery as well as a paramedian pontine infarction. We therefore assumed that the patient's symptoms had been caused by thrombotic occlusion of the labyrinthine artery and several rami ad pontem. The article reviews the great variety of clinical symptoms caused by megadolichobasilar artery and discusses important therapeutic options.
    Der Nervenarzt 03/2003; 74(2):172-4. · 0.80 Impact Factor
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    ABSTRACT: Die Megadolichobasilaris ist eine seltene Gefäßerkrankung, die aufgrund von Ischämien im hinteren Stromgebiet oder der Kompression von Hirnstamm und Hirnnerven manifest wird und zu einem ungewöhnlich großen Spektrum an neurologischen Symptomen führen kann.Wir berichten von einem Patienten, der wegen einer plötzlich aufgetretenen rechtsseitigen Ertaubung verbunden mit Drehschwindel und Erbrechen zunächst unter dem Verdacht auf einen Hörsturz und anschließend unter dem Verdacht auf eine Rundfensterruptur HNO-ärztlich behandelt wurde.Zwei Wochen nach Beschwerdebeginn entwickelte der Patient eine progrediente Hemiparese links. In der bildgebenden Diagnostik fanden sich eine massiv dilatierte und teilthrombosierte A. basilaris sowie ein paramedianer Ponsinfarkt. Ursächlich für die Beschwerden waren daher sich zeitversetzt ereignende thrombotische Verschlüsse der A. labyrinthi und mehrerer Rami ad pontem.Die Arbeit gibt einen Überblick über die vielfältigen klinischen Manifestationsmöglichkeiten der Megadolichobasilaris, Therapiekonzepte werden diskutiert. The megadolichobasilar artery is a rare vascular disease, which usually becomes apparent either due to cerebral ischemia or due to compression of the brainstem or the cranial nerves, thereby leading to a large variety of neurological symptoms.We report on a patient who suffered a sudden right-sided deafness accompanied by vertigo and vomiting. Initially, an idiopathic sensorineural hearing loss was diagnosed and later on, after no improvement took place in spite of conservative therapy, a rupture of the round window membrane was suspected.Two weeks after the first symptoms had occurred the patient developed a hemiparesis on the left side.Radiology disclosed a dilated and partially thrombosed basilar artery as well as a paramedian pontine infarction.We therefore assumed that the patient's symptoms had been caused by thrombotic occlusion of the labyrinthine artery and several rami ad pontem.The article reviews the great variety of clinical symptoms caused by megadolichobasilar artery and discusses important therapeutic options.
    Der Nervenarzt 01/2003; 74(2):172-174. · 0.80 Impact Factor
  • D. G. Nabavi, A. Allroggen
    Klinische Neurophysiologie - KLIN NEUROPHYSIOL. 01/2002; 33(2):88-99.
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    ABSTRACT: Electrical cardioversion (CV) of atrial fibrillation (AF) is associated with an increased risk of stroke, and its appropriate prevention is still a matter of debate. It is known that, besides dislodgement of pre-existing intra-atrial thrombi, the "stunned" atrium after CV is an important cause of thrombus formation and subsequent embolism. We investigated whether CV of AF is associated with occurrence of circulating microemboli (ME) representing a sensitive marker of the actual thromboembolic activity. Twenty-nine patients (22 men) aged 54 +/- 13 years suffering from valvular (n = 5) or nonvalvular (n = 24) AF were studied. All but 1 patient (with recent-onset AF) had been put on oral anticoagulation (INR >2.0) for at least 3 weeks before and 4 weeks after successful CV. In all patients, exclusion of internal carotid artery stenosis and atrial thrombus was performed prior to CV. Five unilateral 1-hour transcranial Doppler ME monitorings over the middle cerebral artery were performed (1) before CV, and (2) immediately, (3) 4-6 h, (4) 24 h, and (5) 2-4 weeks after CV. Total absence of circulating ME was found before CV as well as during a cumulative monitoring time of 115 h after successful CV. Electrical CV of AF after at least 3 weeks of effective anticoagulation is not associated with occurrence of cerebral circulating ME. This finding requires further investigation including high-risk patients with AF undergoing CV based on different treatment protocols.
    Cerebrovascular Diseases 02/2001; 11(2):95-9. · 2.81 Impact Factor
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    ABSTRACT: Thromboembolic events represent a major complication of cardiovascular diseases and interventions. Although general risk factors and predictors for thromboembolic events are well known from population-based studies, hardly any therapeutic consequences for the individual patient can be drawn, e.g. for a well-balanced therapy with anticoagulants. A new approach towards an optimised therapy adapted to the individual risk of each patient may be based on the detection of circulating microemboli by transcranial Doppler sonography. With this technique, gaseous or solid microparticles circulating in the blood can noninvasively be detected. Due to their small size, they do not induce thromboembolic events themselves. However, several studies demonstrate that they indicate an increased thromboembolic activity and correlate directly with manifest stroke or emboli. From a transcranial Doppler probe positioned on the temporal plane at the patient's skull, the middle cerebral artery's blood flow is recorded and is analysed acoustically and optically for circulating microemboli. This technique has already been used for risk stratification of high-risk patients and therapeutic decision-making in neurologic routine, e.g. for the indication to anticoagulate the patient or for carotis surgery. Data to evaluate its value in cardiology are limited and based on few clinical studies. In this review, the basic principles and the methodological and technical background for the detection of microemboli, as well as current limitations, are discussed. Furthermore, clinical studies and their results evaluating this technique in patients with cardiological diseases and during cardiovascular interventions are reviewed.
    Zeitschrift für Kardiologie 02/2001; 90(1):43-51. · 0.97 Impact Factor
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    ABSTRACT: Patienten, z.B. für eine Therapie mit Antikoagulanzien, lassen sich hieraus nicht ableiten. Ein neuer möglicher Ansatz für eine individuell abgestimmte Behandlung besteht in der Detektion zirkulierender Mikroemboli mittels transkranieller Dopplersonographie. Mit dieser Technik lassen sich kleinste gasförmige oder solide Partikel im Blutstrom detektieren, die aufgrund der geringen Größe selbst nicht zu einem klinisch fassbaren thromboembolischen Ereignis führen. Ihr Auftreten korreliert aber nach den Ergebnissen zahlreicher Studien eng mit einem klinisch relevanten Embolierisiko. Zur Untersuchung wird ein Schallkopf am Kopf des Patienten befestigt, der dopplersonographisch Flusssignale der Arteria cerebri media erfasst. Diese werden akustisch und optisch auf zirkulierende Mikroemboli ausgewertet. In der Neurologie wird diese Methode bereits für eine individuelle Risikostratifizierung von Patienten eines Hochrisikokollektivs eingesetzt, z.B. bei der Indikationsstellung zu einer Antikoagulanzientherapie oder Karotisendatherektomie. In der Kardiologie wird die Mikroembolus-Detektion bisher nicht routinemäßig eingesetzt und wurde nur in geringem Maß durch klinische Studien evaluiert. In diesem Überblick sollen die grundlegenden Prinzipien, die methodisch-technischen Voraussetzungen sowie Möglichkeiten und Grenzen der Mikroembolus-Detektion dargestellt werden. Weiterhin werden die wesentlichen Studienergebnisse zum Einsatz dieser Technik bei kardiologischen Erkrankungen und kardiovaskulären Interventionen zusammengefasst. Schlüsselwörter Mikroemboli–Thromboembolische Ereignisse–Transkranielle Dopplersono-–graphie–RisikostratifizierungKey words Microemboli–thromboembolic events–transcranial dopplersonography–risk stratification
    Zeitschrift für Kardiologie 01/2001; 90(1):43-51. · 0.97 Impact Factor
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    ABSTRACT: Atrial fibrillation (AF) is a well-recognized independent risk factor of ischemic stroke. The aim of this study was to investigate the amount of microembolic signals (MES) in 15 patients with 'lone' AF representing the subgroup of AF patients with the lowest lifelong risk of stroke. All patients had been put on effective anticoagulation due to a scheduled electric cardioversion. Additional cardiac and arterial sources of embolism were excluded by echocardiography and extracranial color-coded duplex sonography of the carotid arteries. Unilateral one-hour transcranial Doppler monitorings revealed complete absence of MES in this series. This observation fits the concept that the amount of microembolisation is related to the risk of manifest thromboembolism. Further studies on this patient group treated with less intensive antihemostatic therapy should be undertaken to define more clearly the disease-specific microembolic activity.
    Neurological Research 10/1999; 21(6):566-8. · 1.18 Impact Factor

Publication Stats

49 Citations
27.02 Total Impact Points

Institutions

  • 1999–2006
    • University of Münster
      • Department of Neurology
      Münster, North Rhine-Westphalia, Germany
  • 2004
    • Universitätsklinikum Münster
      • Klinik und Poliklinik für Neurologie
      Münster, North Rhine-Westphalia, Germany