Benno Wolcke

Multicenter, Randomized, Controlled Trial of 150-J Biphasic Shocks Compared With 200- to 360-J Monophasic Shocks in the Resuscitation of Out-of-Hospital Cardiac Arrest Victims

BackgroundIn the present study, we compared an automatic external defibrillator (AED) that delivers 150-J biphasic shocks with traditional high-energy (200- to 360-J) monophasic AEDs. Methods and ResultsAEDs were prospectively randomized according to defibrillation waveform on a daily basis in 4 emergency medical services systems. Defibrillation efficacy, survival to hospital admission and discharge, return of spontaneous circulation, and neurological status at discharge (cerebral performance category) were compared. Of 338 patients with out-of-hospital cardiac arrest, 115 had a cardiac etiology, presented with ventricular fibrillation, and were shocked with an AED. The time from the emergency call to the first shock was 8.9±3.0 (mean±SD) minutes. ConclusionsThe 150-J biphasic waveform defibrillated at higher rates, resulting in more patients who achieved a return of spontaneous circulation. Although survival rates to hospital admission and discharge did not differ, discharged patients who had been resuscitated with biphasic shocks were more likely to have good cerebral performance.

Comparison of Standard Cardiopulmonary Resuscitation Versus the Combination of Active Compression-Decompression Cardiopulmonary Resuscitation and an Inspiratory Impedance Threshold Device for Out-of-Hospital Cardiac Arrest

Background—Active compression-decompression (ACD) CPR combined with an inspiratory impedance threshold device (ITD) improves vital organ blood flow during cardiac arrest. This study compared survival rates with ACD+ITD CPR versus standard manual CPR (S-CPR). Methods and Results—A prospective, controlled trial was performed in Mainz, Germany, in which a 2-tiered emergency response included early defibrillation. Patients with out-of-hospital arrest of presumed cardiac pathogenesis were sequentially randomized to ACD+ITD CPR or S-CPR by the advanced life support team after intubation. Rescuers learned which method of CPR to use at the start of each work shift. The primary end point was 1-hour survival after a witnessed arrest. With ACD+ITD CPR (n=103), return of spontaneous circulation and 1- and 24-hour survival rates were 55%, 51%, and 37% versus 37%, 32%, and 22% with S-CPR (n=107) (P =0.016, 0.006, and 0.033, respectively). One- and 24-hour survival rates in witnessed arrests were 55% and 41% with ACD+ITD CPR versus 33% and 23% in control subjects (P =0.011 and 0.019), respectively. One- and 24-hour survival rates in patients with a witnessed arrest in ventricular fibrillation were 68% and 58% after ACD+ITD CPR versus 27% and 23% after S-CPR (P =0.002 and 0.009), respectively. Patients randomized ≥10 minutes after the call for help to the ACD+ITD CPR had a 3 times higher 1-hour survival rate than control subjects (P =0.002). Hospital discharge rates were 18% after ACD+ITD CPR versus 13% in control subjects (P =0.41). In witnessed arrests, overall neurological function trended higher with ACD+ITD CPR versus control subjects (P =0.07). Conclusions—Compared with S-CPR, ACD+ITD CPR significantly improved short-term survival rates for patients with out-of-hospital cardiac arrest. Additional studies are needed to evaluate potential long-term benefits of ACD+ITD CPR.

Dynamic computed tomography: a novel technique to study lung aeration and atelectasis formation during experimental CPR.

OBJECTIVE To develop an image based technique to study the effect of different ventilatory strategies on lung ventilation and alveolar recruitment during cardiopulmonary resuscitation (CPR). DESIGN (1) Technical development of the following components: (a) construction of an external chest compression device, which does not interfere with CT imaging, and (b) development of a software tool to detect lung parenchyma automatically and to calculate radiological density parameters. (2) Feasibility studies: three strategies of CPR ventilation were performed and imaged in one animal each (pigs, 25 kg): volume-constant ventilation (VCV), no ventilation, or continuous airway pressure (CPAP). One minute after induction of circulatory arrest inside the CT scanner, external chest compressions started at a rate of 100 cpm, and one of the ventilation modes was initiated. After 1 min, intravenous epinephrine was added as a bolus (40 microg/kg), followed by a continuous infusion (13 microg/kg per min). Six minutes later, dynamic CT acquisitions (temporal resolution: 100 ms) commenced. Simultaneously, arterial blood gases, acid base status and haemodynamics were sampled. RESULTS Using a modified chest compression device, dynamic CT acquisitions are feasible during closed-chest CPR. In three pilot experiments with different ventilation strategies, the dedicated software tool allowed to quantify ventilated, atelectatic and over-distended fractions of total lung area. VCV showed a large amount of atelectasis, which was recruited during every respiratory cycle. No ventilation led to atelectasis to govern over 50% of the total lung area. CPAP caused less atelectasis as VCV, and no cyclic recruitment and de-recruitment phenomena were observed. CONCLUSIONS We demonstrate a novel experimental set up, which allows quantification of different lung compartments during ongoing CPR and may become useful in comparing the direct pulmonary effects of different ventilatory strategies in the settings of Basic and Advanced Cardiac Life Support.

Medical support for children's mass gatherings.

INTRODUCTION Medical care must be well-planned for mass gatherings. Events such as fairs, concerts, parades, and rallies cause many people to gather in one place, increasing the chance of injuries and for the development of a disaster. In this study, the level and quality of medical care were evaluated at a mass gathering of approximately 100,000 children. The event was a television-sponsored fun fair. METHODS Every patient contact was documented on printed forms, including data such as the number of patients treated, gender of the patients, presence or absence of a parental escort, time distribution of patient contacts, the diagnoses for the patient contacts, specific therapies applied, duration of the treatment, and patient discharge information. All data were coded after the event and transferred into a computer database. These data were analyzed using descriptive statistics. RESULTS Of the 100,000 spectators, 192 patients (81 male [42.2%] and 111 female [57.8%]) were treated during the nine-hour period, from 09:00 hours (h) until 18:00 h. Twenty percent of all the children up to the age of 10 years needing medical assistance were not accompanied by an adult. Seventy-five percent of all patient contacts were made during the afternoon. Of those treated, 164 patients (85.4%) suffered only minor injuries and were seen for <10 minutes. The most common type of complaint was minor trauma (103 patients, 53.6%); followed by minor medical problems such as headaches or light allergic reactions (21 patients, 10.9%); insect bites (20 patients, 10.4%); and serious medical problems or trauma such as severe arterial hypertension or long bone fractures (19 patients, 9.9%). Treatment included, but was not limited to, dressings (100 patients; 52.1%), local therapy (68 patient, 35.4%), and analgesic therapy (10 patients, 5.2%). Four patients (2%) were transferred to local hospitals. CONCLUSION Most of the medical needs in the patients attending the childrens fun fair were minor. Nevertheless, for similar events in the future, the medical team should be qualified for all serious medical emergencies, as well as major trauma; and should be prepared to meet the requirements of the specific group of spectators. The overall usage rate in the childrens fun fair described was 19.2 patient encounters per 10,000 spectators. Half of all of the patients were children below the age of 14 years. Medical services should consider that this study shows that up to 33% of children seeking medical assistance may not be accompanied by adults.

Monitoring in der Notfallmedizin

ZusammenfassungIn der modernen Notfallmedizin werden hohe Ansprüche an die technische Überwachung der Patienten gestellt.Diese soll die Sicherheit des Patienten erhöhen, die Diagnostik spezifischer medizinischer Probleme erleichtern sowie die Beatmung oder die Gabe potenter Medikamente überwachen.Die verwendeten Medizingeräte müssen an die besonderen Erfordernisse in der Präklinik angepasst sein. Hier sind eine lange Unabhängigkeit von der Stromversorgung, anwenderfreundliche Bedieneroberfläche, kompakte Bauweise und geringes Gewicht zu fordern.Zu den Minimalstandards des Monitoring gehören die nicht invasive Blutdruckmessung, Pulsoximetrie und Elektrokardiographie.Situations- und patientenabhängig können die Messung des endexspiratorischen Kohlendioxidpartialdrucks und der Körpertemperatur hinzukommen. Zur Lagekontrolle des Endotrachealtubus bietet sich die Kapnometrie an, ergänzt durch klinische Untersuchungen, bei Patienten im Herz-Kreislauf-Stillstand auch das Esophageal Detector Device.Eine Ergänzung kann die Sonographie darstellen, mit Hilfe der Telemetrie können Parameter und Befunde an die Zielklinik übermittelt werden.Bei allen zur Verfügung stehenden technischen Möglichkeiten bleibt jedoch die Ausbildung und Erfahrung des medizinischen Personals die wichtigste Komponente.AbstractMonitoring of emergency patients in the pre-hospital setting requires high standards for the technical equipment to ensure the patients safety as well as to diagnose specific medical problems and to administer therapeutic measures such as artificial ventilation and potent drugs.Monitors have to be adapted to the specific necessities of the pre-hospital setting.They should be compact and light weighted, should have an independent power supply and a user friendly software interface.Minimal monitoring standards include non-invasive blood-pressure monitoring, pulse oxymetry, and electrocardiography. Depending on the individual patient,end tidal carbon dioxide concentration or body temperature should be registered.The position of the endotracheal tube should be assessed by capnometry, oesophageal detector devices are especially recommendable for patients in cardiac arrest.The use of ultrasonography and the development of telemedicine may serve to extended diagnostic and therapeutic options in the pre-hospital setting.Despite of all sophisticated technical equipment, the well trained and experienced medical professional remains the most important component of pre-hospital monitoring.

Ventilation volumes with different self-inflating bags with reference to the ERC guidelines for airway management: comparison of two compression techniques

The 1998 ERC-guidelines for airway-management recommend an tidal volume of 400-600 ml for adults undergoing CPR. As commercially available self-inflating bags were designed to meet former recommendations (800-1200 ml) we investigated how to meet the latest recommendations with these bags. We combined the head of a training manikin (Laerdal Medical) and a standard lung (VTTL; Michigan Instrument), adjusted to a physiological compliance and resistance. Volume was measured with a Wright spirometer (BOC). Seven self-inflating bags were investigated. Tests were carried out by ten people (five female and five male) for 5 min each using two different techniques. Technique 1: standard ventilation with one hand without compression of the self-inflating bag against the rescuers knee. Technique 2: modified open palm technique with total squeezing of the self-inflating bag by compression against the rescuers knee. The average tidal volumes for technique 1 ranged from 438 to 604 ml. Applying technique 2 the volumes ranged from 888 to 1192 ml. The latest recommendations were met using a single hand technique without compression against the rescuers knee for all seven bags tested. The modified open palm technique produced larger tidal volumes which were more in line with previous recommendations.

Ablauforganisation im Operationssaal

BACKGROUND The introduction of the diagnosis-related groups reimbursement system has increased cost pressures. Due to the interaction of many different professional groups, analysis and optimization of internal coordination and scheduling in the operating room (OR) is mandatory. The aim of this study was to analyze the processes at a university hospital in order to optimize strategies by identifying potential weak points. METHODS Over a period 6 weeks before and 4 weeks after intervention processes time intervals in the OR of a tertiary care hospital (university hospital) were documented in a structured data collection sheet. RESULTS The main reason for lack of efficiency of labor was underused OR utilization. Multifactorial reasons, particularly in the management of perioperative interfaces, led to vacant ORs. A significant deficit was in the use of OR capacity at the end of the daily OR schedule. After harmonization of working hours of different staff groups and implementation of several other changes an increase in efficiency could be verified. CONCLUSIONS These results indicate that optimization of perioperative processes considerably contribute to the success of OR organization. Additionally, the implementation of standard operating procedures and a generally accepted OR statute are mandatory. In this way an efficient OR management can contribute to the economic success of a hospital.

Alternative methods of mechanical Cardiopulmonary Resuscitation

Due to the relative ineffectiveness of standard resuscitation techniques, alternative methods have been explored for many years. The aim of new methods is to improve haemodynamics and increase survival rates. In spite of some encouraging haemodynamic results, all but one study failed to show an increase in long-term survival rates with an alternative method in a convincingly large group of patients (hospital discharge without neurological damage, and 1-year survival). In this study active compression-decompression resuscitation (ACD-CPR) increased long-term survival compared to standard-CPR. The results from certain individual studies, which showed a significant increase in short-term survival rate, could not be reproduced in other trials. This may be attributed in part to the fact that the alternative methods are not significantly superior, but also due to logistical and statistical problems in the conduct of the studies and differences in application within and between the study sites. ACD-CPR has been the most studied method amongst the alternatives and can be recommended for patients with asystole in centres with special training and where outcome quality is regularly verified and evaluated.

Neue Aspekte der elektrischen Defibrillation

ZusammenfassungIn allen internationalen Empfehlungen stellt die schnellstmögliche Defibrillation die Maßnahme der Wahl bei Kammerflimmern (VF) und pulsloser ventrikulärer Tachykardie (VT) dar. Der Defibrillation kommt eine Schlüsselrolle bei der Bekämpfung des plötzlichen Herztodes zu. Technische Neuerungen: Entwicklungen auf technischem Gebiet haben einerseits eine weitere Miniaturisierung und Vereinfachung der Geräte, andererseits eine Anpassung der Energiemenge an die individuellen Patientenbedingungen zum Ziel. Implantierbare Kardioverter-Defibrillatoren (ICD) und automatisierte externe Defibrillatoren (AED) basieren auf der gleichen Technologie, einer geräteinternen Analyse des EKG-Signals mit nachfolgender „Schock-” oder „Kein-Schock”-Entscheidung. Die Verwendung von AED stellt die Grundlage für die Defibrillation durch nicht-ärztliches Personal dar. Die automatische Messung der Thoraximpedanz soll die für die erfolgreiche Defibrillation erforderliche Energie den Bedürfnissen des Patienten anpassen und unnötig hohe Energiemengen vermeiden. In diese Richtung zielen auch alternative Stromkurvenformen, wie die biphasische, bei welcher der Stromfluß nach einem vorgegebenen Intervall die Polarität ändert. Die Bestimmung der medianen Frequenz des VF als nicht-invasives Verfahren zur Bestimmung des metabolischen und elektrischen Zustands des Myokards soll helfen, den optimalen Zeitpunkt für eine erfolgreiche Defibrillation im Verlauf der kardiopulmonalen Reanimation (CPR) festzulegen. Strukturänderungen: Strukturelle Reformen des präklinischen Rettungs- und des innerklinischen Notfallsystems sollen das Zeitintervall vom Kollaps des Patienten bis zur Abgabe der ersten Defibrillation verkürzen. Unter der Maßgabe, daßärztliche Hilfe nicht rechtzeitig zur Verfügung steht, stellt die Defibrillation mittels automatisierter Geräte durch speziell ausgebildetes nicht-ärztliches Personal eine sichere und effektive Methode dar. Sie erfolgt im Rahmen der Notkompetenz des Rettungsassistenten oder von prä- und innerklinischen Frühdefibrillationsprogrammen. In der Diskussion sind momentan sog. First-Responder-Projekte, bei denen z.B. Feuerwehrleute oder Polizei- und Sicherheitspersonal schon vor Eintreffen des Rettungsdienstes mit Hilfe einfacher AED Patienten mit VF defibrillieren. In den USA wird momentan die weite Verbreitung einfachster automatisierter Defibrillatoren, ähnlich Feuerlöschern in öffentlichen Gebäuden, diskutiert.AbstractEarly defibrillation is the standard of care for patients with ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). Technical developments aim at further miniaturization and simplification of defibrillators as well as adaptation of energy requirements to the patient´s needs. Implantable Cardioverter-Defibrillators (ICD) and automated external defibrillators (AED) are based upon the same technology. Both devices analyze the ECG signal internally, followed by a ”shock” or ”no shock” decision. Use of automated devices is the prerequisite for defibrillation by non-physicians. Chest impedance measurements and use of alternative shock waveforms, such as biphasic, aim at adaptation of energy or current to the patient’s individual needs and avoid application of unnecessarily high amounts of energy to the myocardium. Calculation of median frequency is a non-invasive method for analyzing the heart´s metabolic and electrical state. It helps to determine the optimal moment for defibrillation during cardiopulmonary resuscitation (CPR). Developments concerning the structure of in-hospital emergency systems or pre-hospital emergency medical services (EMS) aim at further reductions in time from collapse of a patient until first defibrillation. Such developments include early defibrillation programs for emergency medical technicians (EMT), nurses, and fire or police department first responders as well as wide distribution of easy-to-operate defibrillators in public areas, as discussed during the American Heart Association’s Public Access Defibrillation conferences. All programs of that kind have to be organized and supervised by a physician who is responsible for training and supervision of the personnel involved.

Notarzt im Rettungsdiensteinsatz: Leichenschau oder „vorläufige Todesbescheinigung“?

ZusammenfassungDie Gesetze und Verordnungen der Bundesländer zum Leichen-, Bestattungs- und Friedhofswesen regeln die Verpflichtung des Arztes zur Leichenschau. In den meisten Bundesländern muss der Notarzt im Rettungsdiensteinsatz keine Leichenschau durchführen, sondern kann sich auf die Todesfeststellung und das Ausfüllen der so genannten „vorläufigen Todesbescheinigung“ beschränken. Der vorliegende Beitrag gibt einen Überblick zu den bestehenden Regelungen der einzelnen Bundesländer.AbstractThe law concerning further requirements after death differs throughout the federal states of Germany. In some areas emergency physicians only need to sign a death certification, in others a complete post-mortem examination has to be done. The table includes an overview on the regulations.