Hintergrund und Zielsetzung Die traditionell zu Beginn des Kongresses der Arbeitsgemeinschaft für Notfallmedizin stattfindende Diskussion bedient sich bereits gewohntermaßen neuer und innovativer Formate, um bedeutende und kontroverse Themen in der Notfallmedizin aufzuarbeiten. So wurde beim Kongress 2022 die klassische Podiumsdiskussion durch eine Publikumsdiskussion abgelöst, in der hunderte Teilnehmer*innen über Abstimmung und Eingaben auf ihren Smartphones die Diskussion lenkten, während Expert*innen bestimmte Aspekte in Impulsreferaten einbrachten. Im Rahmen der Kongresseröffnung 2024 wird mit dem Einsatz von künstlicher Intelligenz und Digitalisierung in der Notfallmedizin ein sehr spezifisches Thema bearbeitet. Aufgrund dessen gehen die Autor*innen davon aus, dass das Vorwissen auch im Fachpublikum sehr inhomogen ist. Weiters wird angenommen, dass die Teilnahme an einer Diskussion möglichst zielführend ist, wenn ein Mindestmaß an Vorwissen vorhanden ist, und dass die aktive Beteiligung zunimmt, wenn auch ein persönlicher Bezug zu dem Thema vorhanden ist. Methoden Um eine informierte Diskussion anzuregen, wurde ein Eröffnungsfilm konzipiert, der Inhalte zu einer Auswahl von neuen Technologien in der Notfallmedizin vermitteln soll, und gleichzeitig den Teilnehmer*innen – durchaus auch in emotionalisierender Form - vermitteln soll, wie sich neue Technologien auf ihr persönliches Tätigkeitsfeld und ihre Möglichkeiten in der Behandlung kritisch kranker Notfallpatient*innen auswirken können. Handlung Als Handlung des Kurzfilms wurde die präklinische Versorgung eines jungen Notfallpatienten gewählt, der aufgrund einer unbekannten Erregungsstörung des Herzens einen plötzlichen Herz-Kreislaufstillstand erleidet. Der Patient empfindet ohne sichtbaren Auslöser, während er sich auf die Geburtstagsfeier seiner sieben Jahre alten Tochter vorbereitet, plötzlich ein massives thorakales Druckgefühl und Herzrasen, weil eine ventrikuläre Tachykardie auftritt. Er wird über seine Smartwatch auf die hohe Herzfrequenz aufmerksam gemacht – diese bietet in diesem Kontext auch sofort die Möglichkeit an, den Notruf zu wählen [1,2]. Während der ersten Sekunden des Notrufs erfolgt eine künstliche Intelligenz gestützte Sprachanalyse, die mit hoher Wahrscheinlichkeit das Vorliegen eines kritischen Notfalls detektiert. Automatisch wird das nächstgelegene und bestgeeignete Notfallmittel alarmiert. [3] Der Patient gibt direkt über sein Smartphone seine relevante Krankengeschichte, Vitalparameter, sowie die Frontkamera des Smartphones frei. Die erhobenen Daten werden nicht nur der Rettungsleitstelle, sondern auch allen an der Versorgung beteiligten Notfallmitteln bereits am Weg zum Einsatzort zugänglich gemacht. Der Notfallpatient verliert das Bewusstsein, welches anhand der Smartphonekamera und den übertragenen Vitalparametern sofort bemerkt wird. Es erfolgt die sofortige Alarmierung von Ersthelfer*innen, die sich in unmittelbarer Umgebung befinden [4] . Zusätzlich wird ein halbautomatischer Defibrillator via Drohne zum Notfallort transportiert [5]. Nach Herzdruckmassage und einmaliger Defibrillation durch die Ersthelfer*innen übernehmen das Team eines Rettungswagens und eines Notarzthubschraubers die Patientenversorgung. Während durchgehender Herzdruckmassage wird eine transösophageale Echokardiographie durchgeführt, um einerseits reversible Ursachen zu identifizieren und andererseits die Qualität der Herzdruckmassage zu optimieren [6]. Es wird ein frontales EEG abgeleitet, um ein mögliches Wiedererlangen des Bewusstseins frühzeitig erkennen zu können [7]. Ein Algorithmus analysiert laufend alle Biosignale und detektiert, dass eine hohe Wahrscheinlichkeit für ein Wiedereinsetzen eines Spontankreislaufs erreicht werden konnte. Die Herzdruckmassage muss dafür nicht unterbrochen werden [8]. Ein Point-of-Care-System ermöglicht mittels PCR (Polymerase-Ketten-Reaktion) die Durchführung einer fokussierten genetischen Untersuchung bereits vor Ort und detektiert eine Ionenkanalerkrankung [9]. Während der weiteren Versorgung des Patienten erfolgt die Voranmeldung im Krankenhaus: Dabei werden zuvor erhobene Daten und Vitalparameter in Echtzeit an die übernehmende Intensivstation übertragen [10]. Nach einer kurzen Ungewissheit erfolgt im Film die Auflösung: Der Protagonist hat den plötzlichen Herzstillstand ohne neurologische Einschränkungen überlebt. Ihm und seiner Tochter, bei welcher dieselbe Mutation entdeckt wurde, wurde ein ICD implantiert (Sekundär- und Primärprävention) [11]. Diskussion und Limitationen Im Rahmen des Films wurden einige Technologien thematisiert, welche teils bereits im Einsatz sind, teils noch experimenteller Natur sind. Durch diesen Kurzausschnitt kann die Optimierung der Patient*innenversorgung durch Technologien in der Notfallmedizin aufgezeigt werden. Am Beispiel des kardialen Notfalls, welcher die führende Todesursache erwachsener Notfallpatient*innen darstellt, wird der Nutzen der Technologie verbildlicht. Sowohl was die Erkennung, Diagnostik und auch die Therapie betrifft. Der Fall soll auch verdeutlichen, dass fortschrittliche und innovative Technologien nicht nur in das akute Geschehen eingreifen, sondern auch in die Primär- und Sekundärprävention und dieses positiv beeinflussen können Das gewählte Medium „Film“, die Beschränkung auf ein Szenario und der begrenzte zeitliche Umfang des Films von rund sechs Minuten, bedingen einen Großteil der Limitationen, aber auch der Stärken dieser Arbeit. Die Kombination aus Vermittlung von grundlegendem Wissen aber auch der Unterstützung bei der Meinungsbildung durch die Übertragung auf den eigenen Tätigkeitsbereich stellt nach Ansicht der Autor*innen eine sinnvolle Grundlage für eine informierte und rege Beteiligung an einer darauffolgenden Diskussion zu einem komplexen Thema dar. Interessenkonflikt Finanzielle Unterstützung, wie auch Produkteleihstellungen erfolgten durch die Firma GS Elektromedizinische Geräte G. Stemple GmbH. Die Firma hatte keinen Einfluss auf das Drehbuch und die Auswahl dargestellter Technologien.

Background The assessment of illness severity in the prehospital setting is essential for guiding appropriate medical interventions. The National Advisory Committee for Aeronautics (NACA) score is a validated tool commonly used for this purpose. However, the potential benefits of using bitemporal documentation of NACA scores to capture the dynamic changes in emergency situations remain uncertain. The objective of this study was to evaluate the potential benefit of bitemporal NACA score documentation in the prehospital setting, specifically in assessing the dynamic changes of emergencies and facilitating quality improvement through enhanced documentation practices. Methods In this retrospective study, data from prehospital emergency patients were analyzed who received care from the physician response unit between January 1, 2018, and May 31, 2021. Patient demographics, NACA scores, indications for emergency care, and changes in NACA scores were extracted from medical records. Statistical analyses were performed to examine the associations between NACA scores, emergency categories, indications, and changes in NACA scores. Results The study included 4005 patients, predominantly categorized as NACA III (33.7% at initial assessment, 41.8% at subsequent assessment) and NACA IV (31.6% at initial assessment, 22.4% at subsequent assessment). There was a significant improvement in NACA scores during the provision of prehospital care ( p < 0.01). Notably, prehospital emergencies attributed to internal medical, neurological, traumatic, and paediatric causes demonstrated significant improvements in NACA scores ( p < 0.01). Gender-specific differences were also observed. Conclusion Our study suggests that the bitemporal documentation of NACA scores can be advantageous in the prehospital setting and may have implications for research, practice, and policy.

Sudden cardiac arrest represents a critical medical emergency where the quality of resuscitation measures is crucial for favorable outcomes[1,2]. The quality of cardiopulmonary resuscitation (CPR) can be assessed through the analysis of data recorded by the defibrillator during CPR. The data is routinely recorded at the base of the emergency medical vehicles at the University Hospital of Graz. To assess CPR quality, algorithms were implemented to identify chest compressions based on the chest impedance and ventilations using the capnography signals. With these algorithms, parameters for CPR quality can be determined. A dataset with 522 cases was used, of which 97 cases were automatically discarded as they contained no or no relevant impedance signals. The mean chest compression rate of the cases is 116.3 ± 9.1 compressions per minute, which is within the target range of 90 – 120. However, in 31% of cases, the rate was found to be too high. The proportion of minutes without an adequate mean chest compression rate was 29.2 ([6.2; 60.4]) %. The mean ventilation frequency of all cases with capnography signal (150 cases) was 13.5 ± 3.6 ventilations per minute and, therefore, within the target range of a maximum of 15 ventilations. However, in 34% of cases, the ventilation frequency was too high. This work shows that a systematic and automated evaluation of defibrillator recordings is suitable for assessing the quality of resuscitation measures. The determined parameters produced plausible results and are consistent with the results of preliminary studies at the Medical University of Graz, which were carried out manually on significantly smaller datasets.

BACKGROUND:Prehospital blood gas analysis (BGA) is an evolving field that offers the potential for early identification and management of critically ill patients. However, the utility and accuracy of prehospital BGA are subjects of ongoing debate. OBJECTIVES:We aimed to provide a comprehensive summary of the current literature on prehospital BGA, including its indications, methods, and feasibility. METHODS:We performed a scoping review of prehospital BGA. A thorough search of the PubMed, Embase, and Web of Science databases was conducted to identify relevant studies focusing on prehospital BGA in adult patients. RESULTS:Fifteen studies met the inclusion criteria. Prehospital BGA was most frequently performed in patients in out-of-hospital cardiac arrest, followed by traumatic and nontraumatic cases. The parameters most commonly analyzed were pH, pCO2, pO2, and lactate. Various sampling methods, including arterial, venous, and intraosseous, were reported for prehospital BGA. While prehospital BGA shows promise in facilitating early identification of critical patients and guiding resuscitation efforts, logistical challenges are to be considered. The handling of preclinical BGA is described as feasible and useful in most of the included studies. CONCLUSION:Prehospital BGA holds significant potential for enhancing patient care in the prehospital setting, though technical challenges need to be considered. However, further research is required to establish optimal indications and demonstrate the benefits for prehospital BGA in specific clinical contexts.

Abstract Background Pneumothorax may occur as a complication of cardiopulmonary resuscitation (CPR) and could pose a potentially life-threatening condition. In this study we sought to investigate the incidence of pneumothorax following CPR for out-of-hospital cardiac arrest (OHCA), identify possible risk factors, and elucidate its association with outcomes. Methods This study was a retrospective data analysis of patients hospitalized following CPR for OHCA. We included cases from 1st March 2014 to 31st December 2021 which were attended by teams of the physician staffed ambulance based at the University Medical Centre Graz, Austria. Chest imaging after CPR was reviewed to assess whether pneumothorax was present or not. Logistic regression analysis was performed to identify factors for the development of pneumothorax relevant and to assess its association with outcomes [survival to hospital discharge and cerebral performance category (CPC)]. Results Pneumothorax following CPR was found in 26 out of 237 included cases (11.0%). History of obstructive lung disease was significantly associated with presence of pneumothorax after CPR. This subgroup of patients (n = 61) showed a pneumothorax rate of 23.0%. Pneumothorax was not identified as a relevant factor to predict survival to hospital discharge or favourable neurological outcome (CPC1 + 2). Conclusions Pneumothorax may be present in greater than one in ten patients hospitalized after CPR for OHCA. Pre-existent obstructive pulmonary disease seems to be a relevant risk factor for development of post-CPR pneumothorax. ClinicalTrials.gov ID: NCT06182007 (retrospectively registered). Trial Registration: NCT06182007 (retrospectively registered)

Einleitung Präklinische Kindernotfälle stellen in vielerlei Hinsicht eine Besonderheit in der Notfallmedizin dar. Geringe Einsatzzahlen sowie fehlende klinische Routine führen dazu, dass es sich bei pädiatrischen Einsätzen immer um Ausnahmesituationen handelt. 1 Diese Studie beschäftigt sich mit pädiatrischen Einsätzen des NEF-Stützpunkt Graz Ost. Material und Methoden Es handelt sich bei dieser Studie um eine retrospektive Analyse präklinischer Kindernotfälle aus dem Zeitraum 2010 bis 2020. Eingeschlossen wurden alle Einsätze mit Kindern bis zum vollendeten 18. Lebensjahr. Die Daten dazu stammen aus dem digitalen Einsatzprotokollsystem MEDEA. Das Hauptaugenmerk der Studie liegt auf den demographischen Einsatzdaten, den Einsatzindikationen, Erstbefunden sowie Erstdiagnosen, den präklinisch getroffenen Maßnahmen, der Medikamentenverabreichung und dem NACA-Score. Ergebnisse In der vorliegenden Analyse wurden 1361 Einsätze eingeschlossen. Hierbei handelt es sich um 6,6% aller notärztlichen Einsätze aus dem Untersuchungszeitraum. Am häufigsten betroffen waren Kinder im Alter von 1 bis 4 Jahren. Die häufigsten Einsatzindikationen konnten den Kategorien Krampf, Trauma und Atmung zugeordnet werden. Die häufigsten Erstdiagnosen bildeten ebenso Krampfgeschehen, respiratorische Erkrankungen und Verletzungen. In drei Viertel der Einsätze erfolgte eine Bewertung des NACA-Scores zwischen 1 und 3. In 15 Fällen konnte ein Hinweis auf eine präklinische Reanimation gefunden werden, bei 33 Einsätzen wurde eine präklinische Intubation dokumentiert. Diskussion/ConclusioZiel der Untersuchung war es anhand einer relativ großen Datenmenge einen Überblick über die notärztliche Betreuung präklinischer Kindernotfälle zu bekommen. Diese Studie konnte verdeutlichen, dass lediglich durch die präklinische Arbeit keine Routine in Hinblick auf Kindernotfälle gewonnen werden kann. Deshalb ist eine konsequente Schulung der Notärzt*innen umso wichtiger. Diese Analyse versucht eine Grundlage für zukünftige Fortbildungen in Österreich zu bilden.

The data presented in this article relate to the research article, "Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR" [1]. This article contains raw data of continuous recordings of airflow, airway and esophageal pressure during the whole experiment. Data of mechanical ventilation was obtained under ongoing chest compressions and from repetitive measurements of pressure-volume curves. All signals are presented as raw time series data with a sample rate of 200Hz for flow and 500 Hz for pressure. Additionally, we hereby publish extracted time series recordings of force and compression depth from the used automated chest compression device. Concomitantly, we report tables with time stamps from our laboratory book by which the data can be sequenced into different phases of the study protocol. We also present a dataset of derived volumes which was used for statistical analysis in our research article together with the used exclusion list. The reported dataset can help to understand mechanical properties of Thiel-embalmed cadavers better and compare different models of cardiopulmonary resuscitation (CPR). Future research may use this data to translate our findings from bench to bedside. Our recordings may become useful in developing respiratory monitors for CPR, especially in prototyping and testing algorithms of such devices.

AIM OF THE STUDY:This study sought to assess the effects of increasing the ventilatory rate from 10 min-1 to 20 min-1 using a mechanical ventilator during cardio-pulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) on ventilation, acid-base-status, and outcomes. METHODS:This was a randomised, controlled, single-centre trial in adult patients receiving CPR including advanced airway management and mechanical ventilation offered by staff of a prehospital physician response unit (PRU). Ventilation was conducted using a turbine-driven ventilator (volume-controlled ventilation, tidal volume 6 ml per kg of ideal body weight, positive end-expiratory pressure (PEEP) 0 mmHg, inspiratory oxygen fraction (FiO2) 100%), frequency was pre-set at either 10 or 20 breaths per minute according to week of randomisation. If possible, an arterial line was placed and blood gas analysis was performed. RESULTS:The study was terminated early due to slow recruitment. 46 patients (23 per group) were included. Patients in the 20 min-1 group received higher expiratory minute volumes [8.8 (6.8-9.9) vs. 4.9 (4.2-5.7) litres, p < 0.001] without higher mean airway pressures [11.6 (9.8-13.6) vs. 9.8 (8.5-12.0) mmHg, p = 0.496] or peak airway pressures [42.5 (36.5-45.9) vs. 41.4 (32.2-51.7) mmHg, p = 0.895]. Rates of ROSC [12 of 23 (52%) vs. 11 of 23 (48%), p = 0.768], median pH [6.83 (6.65-7.05) vs. 6.89 (6.80-6.97), p = 0.913], and median pCO2 [78 (51-105) vs. 86 (73-107) mmHg, p > 0.999] did not differ between groups. CONCLUSION:20 instead of 10 mechanical ventilations during CPR increase ventilation volumes per minute, but do not improve CO2 washout, acidaemia, oxygenation, or rate of ROSC. CLINICALTRIALS:gov Identifier: NCT04657393.

INTRODUCTION There has been some previous research in the field of cardiopulmonary resuscitation （CPR） using cadaver models. [1] The Thiel method was developed by Professor Walter Thiel （Graz, Austria） and described in 1992 and 2002. It consists of both an intravascular injection of the embalming solution and submersion of the bodies in a tank with the same solution for a determined period. [2,3]

OBJECTIVES National and regional systems for emergency medical care provision may differ greatly. We sought to determine whether or not physicians are utilized in prehospital care and to what extent they are present in differentEuropean countries. MATERIAL AND METHODS We collected information on 32 European countries by reviewing publications and sending questionnaires to authors of relevant articles as well as to officials of ministries of health (or equivalent), representatives of national societies in emergency medicine, or well-known experts in the specialty. RESULTS Thirty of the 32 of European countries we studied (94%) employ physicians in prehospital emergency medical services. In 17 of the 32 (53%), general practitioners also participate in prehospital emergency care. Emergency system models were described as Franco-German in 27 countries (84%), as hybrid in 17 (53%), and as Anglo-American in 14 (44%). Multiple models were present simultaneously in 17 countries (53%). We were able to differentiate between national prehospital emergency systems with a novel classification based on tiers reflecting the degree of physician utilization in the countries. We also grouped the national systems by average population and area served. CONCLUSION There are notable differences in system designs and intensity of physician utilization between different geographic areas, countries, and regions in Europe. Several archetypal models (Franco-German, hybrid, and Anglo- American) exist simultaneously across Europe.

Introduction: Public knowledge of out-of-hospital cardiac arrest (OHCA), and initiation of basic life support (BLS) is crucial to increase survival in OHCA.Methods: The study analysed the knowledge and willingness to perform BLS of laypersons passing an AED at a public train station. Interviewees were recruited at two time points before and after a four year-long structured regional awareness campaign, which focused on call, compress, shock in a mid-size European city (270,000 inhabitants). Complete BLS was defined as multiple responses for call for help; initiation of chest compressions; and usage of an AED, without mentioning recovery position. Minimal BLS was defined as call for help and initiation of chest compressions.Results: A total of 784 persons were interviewed, 257 at baseline and 527 post-campaign. Confronted with a fictional OHCA, at baseline 8.5% of the interviewees spontaneously mentioned actions for complete BLS and 17.9% post-campaign (p = 0.009). An even larger increase in knowledge was seen in minimal BLS (34.6% vs 60.6%, p < 0.001).Conclusion: After a regional cardiac arrest awareness campaign, we found an increase in knowledge of BLS actions in the lay public. However, our investigation revealed severe gaps in BLS knowledge, possibly resulting in weak first links of the chain of survival.

Hintergrund Bei der kardiopulmonalen Reanimation (CPR) kommt es im Rahmen der Herzdruckmassage nahezu unweigerlich zu Verletzungen am Thorax. Eine dieser Verletzungen stellt der Spannungspneumothorax dar, dessen rasche Diagnosestellung und Therapie essenziell sind. Die Rate eines Pneumothorax nach CPR wird in der Literatur höchst unterschiedlich angegeben und reicht von 2,5 bis 20,1% [1-4]. Ziel dieser Arbeit war es die Häufigkeit des Pneumothorax nach präklinischer CPR zu erheben und seinen Einfluss auf das Outcome der Reanimierten sowie Faktoren, die sein Auftreten begünstigen, zu analysieren. Methoden In einer retrospektiven Datenanalyse wurden hospitalisierte Patientinnen und Patienten nach präklinischer kardiopulmonaler Reanimation bei nicht-traumatischem Herz-Kreislaufstillstand im Zeitraum 2014-2020 anhand von Einträgen im deutschen Reanimationsregister, Standort Graz NEF LKH-Univ.-Klinikum Graz identifiziert. Unter Zuhilfenahme des Krankenhausinformationssystem sowie der Notarzteinsatzprotokolle und der Bildgebung nach Krankenhausaufnahme konnten versorgungsspezifische (u.a. CPR-Dauer, Delay, Versorgungszeit, Laienreanimation), patientenspezifische Faktoren (u.a. Alter, Geschlecht, Komorbiditäten mittels Pre-Emergency Status, präexistente Lungenerkrankungen) und Outcome-Parameter (u.a. Überleben bis Krankenhausentlassung sowie das mittels Cerebral Performance Category objektivierte neurologisches Outcome) in die statistische Analyse (logistische Regression) eingeschlossen werden. Ergebnisse Bei 24 von 176 Fällen (13,6%) konnte nach Krankenhausaufnahme ein Pneumothorax festgestellt werden. Die Ursachenanalyse identifizierte einen statistisch signifikanten Zusammenhang (p=0,013) zwischen vorbestehenden obstruktiven Lungenerkrankungen und dem Auftreten eines Pneumothorax nach CPR. Das Überleben bis Krankenhausentlassung und das neurologische Outcome wurden maßgeblich durch lange Reanimationsdauer (p<0,001), langes Delay (p<0,001) und hohem Pre-Emergency Status (p<0,001), jedoch nicht durch das Vorhandensein eines Pneumothorax (p=0,304), beeinflusst. Diksussion Ein Pneumothorax sollte im Rahmen der Reanimationsversorgung – insbesondere bei pulmonaler Komorbidität – frühzeitig ausgeschlossen werden. Die Ergebnisse der Outcome-Analyse identifizieren das Delay als wesentlichen das Outcome beeinflussenden Faktor, der durch die Förderung von Awareness für den Herz-Kreislauf-Stillstand in der Allgemeinbevölkerung sowie die Schulung in der Durchführung von lebensrettenden Sofortmaßnahmen wesentlich beeinflusst werden kann. Referenzen Champigneulle B, Haruel PA, Pirracchio R, et al. Major traumatic complications after out-of-hospital cardiac arrest: Insights from the Parisian registry. Resuscitation. 2018;128:70-75. doi:10.1016/j.resuscitation.2018.04.022. Miller AC, Rosati SF, Suffredini AF, Schrump DS. A systematic review and pooled analysis of CPR-associated cardiovascular and thoracic injuries. Resuscitation. 2014;85(6):724-731. doi:10.1016/j.resuscitation.2014.01.028. Kashiwagi Y, Sasakawa T, Tampo A, et al. Computed tomography findings of complications resulting from cardiopulmonary resuscitation. Resuscitation. 2015;88:86-91. doi:10.1016/j.resuscitation.2014.12.022. Betz S, Sassen M, Beutel B, Jerrentrup A, Kill C. Pneumothorax in out-of-hospital resuscitation: The need for early diagnostics in a cardiac arrest center. Resuscitation. 2018;130:e3. doi:10.1016/j.resuscitation.2018.07.042.

In unconscious individuals, rapid sequence intubation (RSI) may be necessary for cardiopulmonary stabilisation and avoidance of secondary damage. Opinions on such invasive procedures in people of older age vary. We thus sought to evaluate a possible association between the probability of receiving prehospital RSI in unconsciousness and increasing age. We conducted a retrospective study in all missions (traumatic and non-traumatic) of the prehospital emergency physician response unit in Graz between January 1st, 2010 and December 31st, 2019, which we searched for Glasgow Coma Scale (GCS) below 9. Cardiac arrests were excluded. We performed multivariable regression analysis for RSI with age, GCS, independent living, and suspected cause as independent variables. Of the 769 finally included patients, 256 (33%) received RSI, whereas 513 (67%) did not. Unadjusted rates of RSI were significantly lower in older patients (aged 85 years and older) compared to the reference group aged 50–64 years (13% vs. 51%, p < 0.001). In multivariable regression analysis, patients aged 85 years and older were also significantly less likely to receive RSI [OR (95% CI) 0.76 (0.69–0.84)]. We conclude that advanced age, especially 85 years or older, is associated with significantly lower odds of receiving prehospital RSI in cases of unconsciousness.

Fragestellung Die präklinische Blutgasanalyse (BGA) ist ein hilfreiches Tool zur Quantifizierung des metabolischen und respiratorischen Zustands von kritischen Notfallpatient*innen und eine Hilfe für therapeutische und prognostische Entscheidungen. Ziel dieser Arbeit war es die Assoziation zwischen dem präklinischen Laktatwert mit dem Base Excess (BE), sowie der außerklinischen Mortalität zu untersuchen. Methodik Es wurde eine retrospektive Kohortenstudie von präklinischen Patient*innen des Notarztstützpunktes der Universitätsklinik Graz durchgeführt. Daten vom 01.01.2010 bis zum 23.03.2020 wurden analysiert. Ausgewertet wurden das elektronische Notarztprotokoll und die Ergebnisse der jeweiligen BGA. Diese wurden zusammengeführt und deskriptiven bzw. exploratorischen Analysen unterzogen. Ergebnisse 313 Personen sind eingeschlossen worden, weshalb sich eine Power von >99,9% ergeben hat, um eine Korrelation von 0,1 zu detektieren. Der Median des BE hat-5,00 bei einem Interquartilsabstand [IQR] von -11.05 bis -0.35 betragen und der des Laktats 4.13 mmol/l [1.67;9.19]. BE und Laktat sind mittels Spearman Rank-Korrelations-Schätzung von -0.75 (p<0.001) negativ miteinander korreliert worden. Ein multiples lineares Regressionsmodel ist geeignet gewesen, um die Assoziation zwischen beiden Biomarkern zu evaluieren, nach Adjustierung von Alter, Geschlecht und Notfallart. Diese hat -0.35 [95% CI:-0.39;-0.30] ergeben. Bei verstorbenen Patient*innen haben die Mediane von BE bzw. Laktat -24.55 [-25.50;-20.65] und 15.25 [12.80;16.99] betragen. Die Auslenkungen sind bei kombinierten Azidosen am stärksten gewesen (Laktat 8.67 [5.36;11.51], BE -10.5 [-15.40;- 6.00]), bei respiratorischen Störungen am geringsten (Laktat 1.62 [0.97;2.68], BE 1.65 [0.23;3.25]). Interpretation Höhere Laktatwerte sind mit geringeren BE-Werten assoziiert gewesen. Bei Änderung des BE um 1 hat sich das Laktat durchschnittlich um 0,35 mmol/l unterschieden. Kombinierte Azidosen haben die stärksten metabolischen Auslenkungen gezeigt, welche bei deutlicher Ausprägung auch mit erhöhter Mortalität einhergegangen sind.

Research question Chest compressions and ventilation are essentials in cardiopulmonary resuscitation (CPR). [1] During CPR, excessive ventilation frequencies are observed, while blood gas analyses indicate that hypoventilation is prevalent. [2,3] Transport ventilators can control ventilation frequency. The impact of chest compressions on tidal volumes remains uncertain. This study was previously published and investigated whether transport ventilators can generate tidal volumes adequate for gas exchange during continuous chest compressions. [4] Methodology Three transport ventilators – ‘MEDUMAT Standard2’, ‘Oxylog 3000 plus’, ‘Monnal T60’ – were investigated in a randomized cross-over study. Six Thiel-embalmed cadavers served as CPR models. They received volume-controlled ventilation with tidal volumes of 6 ml/kg ideal predicted bodyweight (IPBW) and continuous chest compressions. Airflow, airway pressure, and esophageal pressure were recorded. Derived volumes and their deviation from preset volumes were compared and analyzed in a linear mixed model. Results 715 ventilations were included. Median preset tidal volume was 390 (40, [290; 410]) ml. Median inspiratory tidal volume was 275 (68, [47; 464]) ml, corresponding to 4.75 (1.2, [0.7; 7.6]) ml/kg PIBW. Median deviation from preset value was −21.2 (19.6, [−87.9; 25.8]) %. For ‘MEDUMAT Standard2’ median deviation was −31.5 (16.6, [−56.5; −14.8]) %, −22.7 (22.1, [−70; −12.3]) % for ‘Oxylog 3000 plus’ and −8.3 (20.5, [−87.9; 25.8]) % for ‘Monnal T60’. Linear mixed model estimates were −31 [95%-CI: −38.9; −23] % (p < 0.0001), −30.6 [95%-CI: −38.6; −22.6] % (p < 0.0001), −14.5 [95%-CI: −22.5; −6.5] % (p = 0.0004) for ‘MEDUMAT Standard2’, ‘Oxylog 3000 plus’ and ‘Monnal T60’ respectively. Interpretation Transport ventilators can deliver tidal volumes that contribute to gas exchange during continuous chest compressions. However, tidal volumes are significantly reduced. Therefore, tidal volumes should be continuously monitored during CPR. [1] Soar, Jasmeet et al. “European Resuscitation Council Guidelines 2021: Adult advanced life support.” Resuscitation vol. 161 (2021): 115-151. doi:10.1016/j.resuscitation.2021.02.010 [2] Aufderheide, Tom P et al. “Hyperventilation-induced hypotension during cardiopulmonary resuscitation.” Circulation vol. 109,16 (2004): 1960-5. doi:10.1161/01.CIR.0000126594.79136.61 [3] Prause, Gerhard et al. “Hyperventilation is uncommon during cardio-pulmonary resuscitation: A preliminary observational study.” Resuscitation vol. 162 (2021): 257-258. doi:10.1016/j.resuscitation.2021.03.008 [4] Orlob, Simon et al. “Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR.” Scandinavian journal of trauma, resuscitation and emergency medicine vol. 29,1 102. 28 Jul. 2021, doi:10.1186/s13049-021-00921-2

This study seeks to identify factors that are associated with decisions of prehospital physicians to start (continue, if ongoing) or withhold (terminate, if ongoing) CPR in patients with OHCA. We conducted a retrospective study using anonymised data from a prehospital physician response system. Data on patients attended for cardiac arrest between January 1st, 2010 and December 31st, 2018 except babies at birth were included. Logistic regression analysis with start of CPR by physicians as the dependent variable and possible associated factors as independent variables adjusted for anonymised physician identifiers was conducted. 1525 patient data sets were analysed. Obvious signs of death were present in 278 cases; in the remaining 1247, resuscitation was attempted in 920 (74%) and were withheld in 327 (26%). Factors significantly associated with higher likelihood of CPR by physicians (OR 95% CI) were resuscitation efforts by EMS before physician arrival (60.45, 19.89-184.29), first monitored heart rhythm (3.07, 1.21-7.79 for PEA; 29.25, 1.93-442. 51 for VF / pVT compared to asystole); advanced patient age (modelled using cubic splines), physician response time (0.92, 0.87-0.97 per minute) and malignancy (0.22, 0.05-0.92) were significantly associated with lower odds of CPR. We thus conclude that prehospital physicians make decisions to start or withhold resuscitation routinely and base those mostly on situational information and immediately available patient information known to impact outcomes.

With great interest we read the recently published guidelines of the European Resuscitation Council (ERC) on adult cardiopulmonary resuscitation (CPR).1Perkins G.D. Graesner J.-T. Semeraro F. et al.European Resuscitation Council Guidelines 2021: executive summary.Resuscitation. 2021; 161: 1-60https://doi.org/10.1016/j.resuscitation.2021.02.003Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar, 2Olasveengen T.M. Semeraro F. Ristagno G. et al.European Resuscitation Council Guidelines 2021: basic life support.Resuscitation. 2021; 161: 98-114https://doi.org/10.1016/j.resuscitation.2021.02.009Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar, 3Soar J. Böttiger B.W. Carli P. et al.European Resuscitation Council Guidelines 2021: adult advanced life support.Resuscitation. 2021; 161: 115-151https://doi.org/10.1016/j.resuscitation.2021.02.010Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar Notably, the risk of hyperventilation and its deleterious effects are barely mentioned. This is in striking contrast to previous guidelines. In 2004, the debate on hyperventilation in CPR was ignited by Aufderheide et al. when they published "Hyperventilation-Induced Hypotension During Cardiopulmonary Resuscitation".4Aufderheide T.P. Sigurdsson G. Pirrallo R.G. Yannopoulos D. McKnite S. von Briesen C. et al.Hyperventilation-induced hypotension during cardiopulmonary resuscitation.Circulation. 2004; 109: 1960-1965https://doi.org/10.1161/01.cir.0000126594.79136.61Crossref PubMed Scopus (0) Google Scholar They observed a mean ventilatory rate of 30 min−1 and an inspiratory time of 1 s in 13 consecutive out-of-hospital cardiac arrest (OHCA) resuscitation attempts with no survivors. Subsequently, they studied the effects of hyperventilation in a pig model during cardiac arrest, with a respiratory rate of 30 min−1 and an inspiratory duration of 1 s. Of the pigs 17% had a sustained ROSC compared to 86% when the ventilatory rate was 12 min−1. It is noteworthy that they used a ventilatory device with a constant flow rate of 160 L/min, which corresponds to a tidal volume of 2.7 L, resulting in minute volumes of 80 L and 32 L, respectively. These findings sparked a broad academic discourse5Pitts S. Kellermann A.L. Hyperventilation during cardiac arrest.Lancet. 2004; 364: 313-315https://doi.org/10.1016/S0140-6736(04)16740-8Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar and triggered a reprint of the same results under the title "Death by hyperventilation: A common and life-threatening problem during cardiopulmonary resuscitation".6Aufderheide T.P. Lurie K.G. Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation.Crit Care Med. 2004; 32: S345https://doi.org/10.1097/01.ccm.0000134335.46859.09Crossref PubMed Scopus (387) Google Scholar In the following year ILCOR included those publications into the Consensus of Science with Treatment Recommendations.7Resuscitation ILC on Part 2: adult basic life support.Resuscitation. 2005; 67: 187-201https://doi.org/10.1016/j.resuscitation.2005.09.016Abstract Full Text Full Text PDF PubMed Scopus (195) Google Scholar Much less attention was spent on the work of Gazmuri et al., published in 2011, which could not reproduce the deleterious hemodynamic effects of hyperventilation, also in a pig model during cardiac arrest, with ventilatory rates of 33 min−1 and tidal volumes of 18 mL/kg body weight.8Gazmuri R.J. Ayoub I.M. Radhakrishnan J. Motl J. Upadhyaya M.P. Clinically plausible hyperventilation does not exert adverse hemodynamic effects during CPR but markedly reduces end-tidal PCO₂.Resuscitation. 2011; 83: 259-264https://doi.org/10.1016/j.resuscitation.2011.07.034Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar Until recently, the ERC guidelines explicitly warned of inadvertent hyperventilation. Now it appears that the evidence on hyperventilation was re-evaluated in the guideline process. Therefore, we need to ask ourselves what we have learned so far and face what we do not know about ventilation during CPR. Aufderheide uncovered the impressively deleterious effects of the utmost extremes of ventilation in CPR. We believe those findings polarized the discussion of intra-arrest ventilation, formed a general perception of harmfulness of ventilation and narrowed down our focus to the ventilatory rate. We might want to ask ourselves if we should continue to decouple ventilatory rate from tidal volume in science, as well as in the discussion of intra-arrest ventilation?9Vissers G. Duchatelet C. Huybrechts S.A. Wouters K. Hachimi-Idrissi S. Monsieurs K.G. The effect of ventilation rate on outcome in adults receiving cardiopulmonary resuscitation.Resuscitation. 2019; 138: 243-249https://doi.org/10.1016/j.resuscitation.2019.03.037Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar The present guidelines leave us with limited recommendations regarding intra-arrest ventilation for our clinical practice. We might should have learned to consider tidal volumes as well, as measuring tidal volumes had already been suggested by Ornato in 1983.10Ornato J. Bryson B. Donovan P. Farquharson R. Jaeger C. Measurement of ventilation during cardiopulmonary resuscitation.Crit Care Med. 1983; 11: 79-82https://doi.org/10.1097/00003246-198302000-00004Crossref PubMed Scopus (92) Google Scholar "Never quite there" is a phrase Chamberlain coined within resuscitation medicine to point out the historical odyssey towards modern CPR11Chamberlain D. Never quite there: a tale of resuscitation medicine.Resuscitation. 2004; 60: 3-11https://doi.org/10.1016/s0300-9572(03)00443-xAbstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar:So often our predecessors 'did not learn' when it seems in retrospect they should have done, and so often they were 'never quite there' for developments that then had to wait many years. These and other sound precepts were not followed, but we share the same frailties and are not doubt guilty of the same sorts of errors. History will be our judge too.- Douglas Chamberlain, 2004 The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

To the Editor: We read with great interest the paper “Mechanical Ventilation Management During Mechanical Chest Compressions” by Orso et al,[1][1] in which they identified available knowledge on mechanical ventilation strategies during cardiopulmonary resuscitation (CPR). We share their

Current guidelines on cardiopulmonary resuscitation (CPR) urge avoidance of hyperventilation based on a small number of studies that have reported hyperventilation to be common in CPR and associated high ventilation rates with adverse outcomes.1Aufderheide T.P. Lurie K.G. Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation.Crit Care Med. 2004; 32https://doi.org/10.1097/01.ccm.0000134335.46859.09Crossref PubMed Scopus (378) Google Scholar, 2Aufderheide T.P. Sigurdsson G. Pirrallo R.G. et al.Hyperventilation-induced hypotension during cardiopulmonary resuscitation.Circulation. 2004; 109: 1960-1965https://doi.org/10.1161/01.CIR.0000126594.79136.61Crossref PubMed Scopus (614) Google Scholar, 3O'Neill J.F. Deakin C.D. Do we hyperventilate cardiac arrest patients?.Resuscitation. 2007; 73: 82-85https://doi.org/10.1016/j.resuscitation.2006.09.012Abstract Full Text Full Text PDF PubMed Scopus (104) Google Scholar Contrarily, studies analysing arterial blood gases during CPR at our institution suggest that hypercapnia and acidaemia, mostly caused by hypoventilation, are commonly encountered.4Spindelboeck W. Schindler O. Moser A. et al.Increasing arterial oxygen partial pressure during cardiopulmonary resuscitation is associated with improved rates of hospital admission.Resuscitation. 2013; 84: 770-775https://doi.org/10.1016/j.resuscitation.2013.01.012Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar, 5Spindelboeck W. Gemes G. Strasser C. et al.Arterial blood gases during and their dynamic changes after cardiopulmonary resuscitation: a prospective clinical study.Resuscitation. 2016; : 1-6https://doi.org/10.1016/j.resuscitation.2016.06.013Abstract Full Text Full Text PDF Scopus (40) Google Scholar We hypothesise low ventilation rates to be the cause for these findings: at a rate of 10 breaths per minute, inspiration-to-expiration ratio of 1:2, and ongoing chest compressions at a rate of 100 min−1, 3 compressions coincide with every breath and obstruct ventilation. We thus performed a preliminary analysis of data from adult patients (age ≥ 18 years) receiving prehospital CPR and ventilation for OHCA, in whom capnography and blood gas analysis results were available, to evaluate, whether hyperventilation is common during CPR for out-of-hospital cardiac arrest (OHCA), whether capnometry is viable to assess ventilation during CPR, and whether ventilation rates higher than currently recommended can be applied without hyperventilation. The local ethics committee (IRB00002556) approved of the underlying clinical trial (30-541 ex 17/18) and deferred the need for informed consent; local registry data collection, storage, extraction, and analysis for controls were also approved by the ethics committee (29-579 ex 16/17). 8 patients included into the run-in phase of a clinical trial (NCT04657393) were ventilated a rate of 20 min−1 using a mobile turbine-driven emergency ventilator (Monnal T60, AirLiquide, France); 9 controls documented in a local registry were ventilated at a rate of 10 min−1 using a conventional flow-chopping emergency ventilator (Draeger Oxylog 3000, Draeger, Germany). Values of arterial carbon-dioxide tension (paCO2), pH, and end-tidal carbon-dioxide (etCO2) were measured using blood gas analysis (epoc®, Siemens Healthineers/Alere, Erlangen, Germany) and side-stream waveform-capnography (LifePak15®, Stryker/Physio Control, Redmond, WA), respectively. Hypoventilation and hypercapnia were found to be common; median paCO2 in the overall cohort was 70 (56–101) mmHg, without significant differences between the 20 min−1 and 10 min−1 ventilation patterns [61 (57−80) mmHg vs. 74 (62−97) mmHg, p = 0.48]. Concomitantly, patients were mostly severely acidaemic; overall median pH was 7.04 (6.74−7.09), with no discernible difference between the 20 min−1 and the 10 min−1 ventilation patterns [6.92 (6.80−7.05) vs. 7.04 (6.75−7.09), p = 0.61] (Table 1).Table 1Ventilation and metabolic status derived from arterial blood gas analysis (epoc®, Siemens Healthineers/Alere, Erlangen, Germany) and capnography (LifePak15®, Stryker/Physio Control, Redmond, WA). AaDCO2 = alveolo-arterial carbon dioxide difference, BE = base excess, etCO2 = end-tidal carbon dioxide, IQR = inter-quartile range, paCO2 = arterial carbon dioxide partial pressure, paO2 = arterial oxygen partial pressure, max = maximum, min = minimum. p-Values calculated by Mann–Whitney U test using IBM® SPSS Statistics 26.Overall20 min−1 ventilation pattern10 min−1 ventilation patternpn of patients1789pH (median, IQR)7.04 (6.74−7.09)6.92 (6.80−7.05)7.04 (6.75−7.09)0.61 Min6.526.526.58 Max7.387.137.38paCO2 [mmHg] (median, IQR)70 (57−101)61 (57−80)74 (62−97)0.48 Min393944 Max131118131etCO2 [mmHg] (median, IQR)26 (22−39)24 (20−26)38 (23−49)0.09 Min141416 Max612861AaDCO2 [mmHg] (median, IQR)43 (29−58)37 (29−67)46 (32−51)0.92 Min6296 Max1046771paO2 [mmHg] (median, IQR)71 (52−86)68 (47−91)71 (58−86)>0.99 Min153215 Max12712791BE (median, IQR)−17.8 (−22.1 to −12.2)−19.1 (−22.8 to −17.7)−12.2 (−21.7 to −10.9)0.11 Min<-30<-30.0<-30 Max0.4−14.40.4Lactate [mmol/l] (median, IQR)11.1 (9.7−13.9)11.9 (10.7−14.0)10.2 (8.6−11.9)0.28 Min6.29.76.2 Max>20.016.6>20.0 Open table in a new tab 15 (88%) patients were hypercapnic (CO2>45 mmHg) based on paCO2 measurements whereas only 3 (18%) patients would have been classified as hypercapnic using etCO2 levels. 0 (0%) patients were actually hyperventilated and thus hypocapnic (CO2 < 35 mmHg) based in paCO2 measurements, while 12 (71%) patients would have been reported to be hyperventilated based on capnometry. Correlation between paCO2 and etCO2 was weak; Pearson's correlation coefficient was 0.42 (p = 0.11) We conclude that hyperventilation during CPR for OHCA is uncommon. Currently recommended ventilation patterns are associated with hypercapnia and acidaemia. Capnometry is not a viable tool to guide ventilation during CPR. Mechanical ventilation at a rate of 20 min−1 is not associated with hyperventilation. Further studies, such as the planned VICA trial (NCT04657393), are needed to identify optimal ventilation patterns during CPR. GP received speaker fees from RWM medical supplies (regional distributor of Monnal T60). Simon Orlob optimised the monitor-database interface and improved data transmission processes.

Introduction: Cardiopulmonary resuscitation is one of the core competencies in prehospital care. As the population of Austria is getting older, the amount of prehospital emergency calls to elderly patients in cardiac arrest is rising as well. The aim of this study was to describe possible differences in the resuscitation process in the elderly population compared to a younger cohort.