Michael Poppe

Age-specific prognostication after out-of-hospital cardiac arrest – The ethical dilemma between ‘life-sustaining treatment’ and ‘the right to die’ in the elderly:

Background: While prognostic values on survival after out-of-hospital cardiac arrest have been well investigated, less attention has been paid to their age-specific relevance. Therefore, we aimed to identify suitable age-specific early prognostication in elderly patients suffering out-of-hospital cardiac arrest in order to reduce the burden of unnecessary treatment and harm. Methods: In a prospective population-based observational trial on individuals suffering out-of-hospital cardiac arrest, a total of 2223 patients receiving resuscitation attempts by the local emergency medical service in Vienna, Austria, were enrolled. Patients were stratified according to age as follows: young and middle-aged individuals (<65 years), young old individuals (65–74 years), old individuals (75–84 years) and very old individuals (>85 years). Results: There was an increasing rate of 30-day mortality (+21.8%, p < 0.001) and unfavourable neurological outcome (+18.8%, p < 0.001) with increasing age among age groups. Established predictive variables lost their prognostic potential with increasing age, even after adjusting for potential confounders. Independently, an initially shockable electrocardiogram proved to be directly associated with survival, with an adjusted hazard ratio (HR) of 2.04 (95% confidence interval (CI) 1.89–2.38, p = 0.003) for >85-year-olds. Frailty was directly associated with mortality (HR 1.22, 95% CI 1.01–1.51, p = 0.049), showing a 30-day survival of 5.6% and a favourable neurological outcome of 1.1% among elderly individuals. Conclusion: An initially shockable electrocardiogram proved to be a suitable tool for risk assessment and decision making in order to predict a successful outcome in elderly victims of out-of-hospital cardiac arrest. However, the outcomes of elderly patients seemed to be exceptionally poor in frail individuals and need to be considered in order to reduce unnecessary treatment decisions.

Admission of out-of-hospital cardiac arrest victims to a high volume cardiac arrest center is linked to improved outcome ☆

AIM Cardiac arrest centers have been associated with improved outcome for patients after cardiac arrest. Aim of this study was to investigate the effect on outcome depending on admission to high-, medium- or low volume centers. METHODS Analysis from a prospective, multicenter registry for out of hospital cardiac arrest patients treated by the emergency medical service of Vienna, Austria. The frequency of cardiac arrest patients admitted per center/year (low <50; medium 50-100; high >100) was correlated to favorable outcome (30-day survival with cerebral performance category of 1 or 2). RESULTS Out of 2238 patients (years 2013-2015) with emergency medical service resuscitation, 861 (32% female, age 64 (51;73) years) were admitted to 7 different centers. Favorable outcome was achieved in 267 patients (31%). Survivors were younger (58 vs. 66 years; p<0.001), showed shockable initial heart rhythm more frequently (72 vs. 35%; p<0.001), had shorter CPR durations (22 vs. 29min; p<0.001) and were more likely to be treated in a high frequency center (OR 1.6; CI: 1.2-2.1; p=0.001). In multivariate analysis, age below 65 years (OR 15; CI: 3.3-271.4; p=0.001), shockable initial heart rhythm (OR 10.1; CI: 2.4-42.6; p=0.002), immediate bystander or emergency medical service CPR (OR 11.2; CI: 1.4-93.3; p=0.025) and admission to a center with a frequency of >100 OHCA patients/year (OR 5.2; CI: 1.2-21.7; p=0.025) was associated with favorable outcome. CONCLUSIONS High frequency of post-cardiac arrest treatment in a specialized center seems to be an independent predictor for favorable outcome in an unselected population of patients after out of hospital cardiac arrest.

The impact of airway strategy on the patient outcome after out-of-hospital cardiac arrest: A propensity score matched analysis:

Background: While guidelines mentioned supraglottic airway management in the case of out-of- hospital cardiac arrest, robust data of their impact on the patient outcome remain scare and results are inconclusive. Methods: To assess the impact of the airway strategy on the patient outcome we prospectively enrolled 2224 individuals suffering cardiac arrest who were treated by the Viennese municipal emergency medical service. To control for potential confounders, propensity score matching was performed. Patients were matched in four groups with a 1:1:1:1 ratio (n=210/group) according to bag-mask-valve, laryngeal tube, endotracheal intubation and secondary endotracheal intubation after primary laryngeal tube ventilation. Results: The laryngeal tube subgroup showed the lowest 30-day survival rate among all tested devices (p<0.001). However, in the case of endotracheal intubation after primary laryngeal tube ventilation, survival rates were comparable to the primary endotracheal tube subgroup. The use of a laryngeal tube was independently and directly associated with mortality with an adjusted odds ratio of 1.97 (confidence interval: 1.14–3.39; p=0.015). Additionally, patients receiving laryngeal tube ventilation showed the lowest rate of good neurological performance (6.7%; p<0.001) among subgroups. However, if patients received endotracheal intubation after initial laryngeal tube ventilation, the outcome proved to be significantly better (9.5%; p<0.001). Conclusion: We found that the use of a laryngeal tube for airway management in cardiac arrest was significantly associated with poor 30-day survival rates and unfavourable neurological outcome. A primary endotracheal airway management needs to be considered at the scene, or an earliest possible secondary endotracheal intubation during both pre-hospital and in-hospital post-return of spontaneous circulation critical care seems crucial and most beneficial for the patient outcome.

Feasibility of profound hypothermia as part of extracorporeal life support in a pig model

Objective: To investigate the feasibility of a refined aortic flush catheter and pump system to induce emergency preservation and resuscitation before extracorporeal cardiopulmonary resuscitation in a normovolemic cardiac arrest swine model simulating near real size/weight conditions of adults. Methods: In this feasibility study, 8 female Large White breed pigs weighing 70 to 80 kg underwent ventricular fibrillation cardiac arrest for 15 minutes, followed by 4°C aortic flush (150 mL/kg for the brain; 50 mL/kg for the spine) via a new hardware ensued by resuscitation with extracorporeal cardiopulmonary resuscitation. Results: Brain temperature was lowered from 39.9°C (interquartile range [IQR] 39.6‐40.3) to 24.0°C (IQR 20.8‐28.9) in 12 minutes (IQR 11‐16) with a median cooling rate of 1.3°C (IQR 0.7‐1.6) per minute. A median of 776 mL (IQR 673‐840) per minute with a median pump pressure of 1487 mm Hg (IQR 1324‐1545) were pumped to the brain. Conclusions: With the new hardware, we were able to cool the brain within a few minutes in a large pig cardiac arrest model. The exact position; the design, diameter, and length of the flush catheter; and the brain perfusion pressure seem to be critical to effectively reduce brain temperature. Redistribution of peripheral blood could lead to sterile inflammation again and might be avoided.

Initial electrical frequency predicts survival and neurological outcome in out of hospital cardiac arrest patients with pulseless electrical activity

BACKGROUND Outcome is generally poor in out of hospital cardiac arrests (OHCA) with initial non-shockable rhythms. Termination of resuscitation rules facilitate early prognostication at the scene to cease resuscitation attempts in futile situations and to proceed advanced life support in promising conditions. As pulseless electrical activity (PEA) is present as first rhythm in every 4th OHCA we were interested if the initial electrical frequency in PEA predicts survival. METHODS All patients >18 years of age with non-traumatic OHCA and PEA as first rhythm between August 2013 and August 2015 from the Vienna Cardiac Arrest Registry were included in this retrospective observational study. Defibrillator and epidemiological data from the emergency medical system as survival data were processed considering the initial electrical activity in PEA and 30 days survival. RESULTS Out of 2149 OHCA patients, a total of 504 PEA patients were eligible for analyses. These patients were stratified into 4 groups according the initial electrical frequency in PEA: 10-24/min, 25-39/min, 40-59/min, >60/min. Compared to a frequency >60/min all other subgroups were associated with higher mortality especially those with an initial electrical frequency 10-24 (adjusted OR 0.56 (0.39-0.79) p = .001 for each category chance). QRS duration in PEA did not influence outcome. Patients in the >60/min group showed a 30-days-survival rate of 22% and a good neurological outcome in 15% of all patients - comparable to shockable cardiac arrest rhythms. CONCLUSION Regardless of other resuscitation factors, higher initial electrical frequency in PEA is associated with increased odds of survival and good neurological outcome.

Advanced life support in pediatric out-of-hospital cardiac arrest—A two-year review and critical appraisal of quality of care and clinical outcome in a European metropolitan area

Recent evidence revealed an extraordinary poor outcome in ediatric patients after cardiac arrest, demonstrating that more han 90% of children will not survive until hospital discharge with ood neurological outcome [1]. In this context, several studies ven enlightened that advanced life support (ALS) in pediatric cariac arrest often failed to achieve compliance with international uidelines [2]. Additionally, the performance of ALS and outcome easures in a European setting has not been investigated so fa. To address this gap of knowledge, we prospectively enrolled 466 cases of out-of-hospital cardiac arrest in Vienna (Austria), dentifying a total of 33 children (1.3%; aged <18 years) suffering ediatric out-of-hospital cardiac arrest (P-OHCA). Patient-specific haracteristics were assessed via event documentation. To evalute the quality of ALS, trans-thoracic impedance measures and vital arameters were analyzed via defibrillator-tracings.

Improvements in the quality of advanced life support and patient outcome after implementation of a standardized real-life post-resuscitation feedback system

BACKGROUND Educational aspects in the training of advanced life support (ALS) represent a key role in critical care management of patients with out-of-hospital cardiac arrest (OHCA) and received special attention in guidelines of various international societies. While a positive association of feedback on ALS performance in training conditions is well established, data on the impact of a real-life post-resuscitation feedback on both ALS quality and outcome remain scarce and inconclusive. We aimed to elucidate the impact of a standardized post-resuscitation feedback on quality of ALS and improvements in patient outcome, in a real-life out-of-hospital setting. METHODS We prospectively enrolled and analyzed 2209 patients presenting with OHCA receiving resuscitation attempts by the municipal emergency medical service (EMS) of Vienna over a two-year period. A standardized post-resuscitation feedback protocol was delivered to the respective EMS-team to elucidate its impact on the quality of ALS. RESULTS We observed that both chest compression rates and ratios were in accordance to recommendations of recent guidelines. While interruptions of chest compressions longer than 30s declined during the observation period (-6.5%) rates of the recommended chest compressions during defibrillator-charging periods increased (+8.9%). Since the percentage of ROSC and 30-day survival remained balanced, the frequencies of both survival until hospital discharge (+6.3%) and favorable neurological outcome (+16%) in survivors significantly increased during the observation period. CONCLUSION Improvements in the quality of advanced life support as well the patient outcome were observed after the implementation of a standardized post-resuscitation feedback protocol.