Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: first results and outcomes of a newly established ECPR program in a large population area.

OBJECTIVES: Out-of-hospital cardiac arrest (OHCA) is associated with excessively high mortality rates. Recent studies suggest benefits from extracorporeal cardiopulmonary resuscitation (ECPR) performed in selected patients. We sought to present the first results from our interdisciplinary ECPR program with a particular focus on early outcomes and potential risk factors associated with in-hospital mortality. METHODS: Between January 2016 and December 2019, 44 patients who underwent ECPR selected according to our institutional ECPR protocol were retrospectively analyzed regarding pre-hospital, in-hospital, and early outcome parameters. Patients were divided into survivors (S) and non-survivors (NS). Statistical analysis of risk factors regarding in-hospital mortality of the patient cohort analyzed was performed. RESULTS: The mean age of the population was 53 ± 12 years, with most patients being male (n = 40). The leading cause of cardiac arrest (CA) was myocardial infarction (n = 24, 55%). The median hospital stay was 1 (1;13) day. Twenty-three percent of patients (n = 10) were discharged from hospital including eight patients (18%) with CPC 1-2. Survivors showed a trend toward shorter pre-hospital CPR duration (60 (59;60) min (S) vs 60 (55;90) min (NS), p = 0.07). CONCLUSION: Establishing ECPR programs in large population areas offers the option to improve survival rates for OHCA patients. Stringent compliance of institutional criteria (mainly age, witnessed arrest, and time of pre-hospital resuscitation) and providing ECPR to strictly selected patients seems to be a vital factor for such programs' success. Pre-clinical settings and therapeutic measures must be adjusted in this regard to improve outcomes for this highly demanding patient cohort.

How long is long enough? Good neurologic outcome in out-of-hospital cardiac arrest survivors despite prolonged resuscitation: a retrospective cohort study.

BACKGROUND: Despite all efforts, mortality of out of hospital cardiac arrest (OHCA) remains high. Patients with OHCA due to a primary shockable rhythm typically have a better prognosis. However, outcome worsens if return of spontaneous circulation (ROSC) cannot be achieved quickly. There is insufficient evidence for maximum duration of resuscitation in these patients and it is unclear, which patients profit from transport under ongoing CPR. OBJECTIVE: Investigate predictors for favourable neurologic outcome in OHCA patients with presumed cardiac cause due to refractory shockable rhythm (rSR). METHODS: Retrospective analysis of OHCA patients that presented to a tertiary hospital due to a rSR. RESULTS: One hundred seventy-five OHCA patients with presumed cardiac cause due to rSR were included. Overall hospital mortality was 50% and 83% of initial survivors were discharged with a good neurologic outcome [cerebral performance category (CPC) 1-2]. In patients with a time from cardiac arrest to ROSC of > 45 min, 18% survived to CPC 1-2. Independent predictors for good neurologic outcome were age, lower no-flow time and lower serum lactate levels at hospital arrival. CONCLUSION: In an urban setting, a significant proportion of OHCA patients with rSR can survive to a good neurologic outcome, despite very long time to ROSC.

One year experience with fast track algorithm in patients with refractory out-of-hospital cardiac arrest.

BACKGROUND: Overall prognosis in patients with out-of-hospital cardiac arrest (OHCA) remains poor, especially when return of spontaneous circulation (ROSC) cannot be achieved at the scene. It is unclear if rapid transport to the hospital with ongoing cardiopulmonary resuscitation (CPR) improves outcome in patients with refractory OHCA (rOHCA). The aim of this study was to evaluate the effect of a novel fast track algorithm (FTA) in patients with rOHCA. METHODS: This prospective single-center study analysed outcome in rOHCA patients treated with FTA. Historical patients before FTA-implementation served as controls. rOHCA was defined as: persistent shockable rhythm after three shocks and 300mg of amiodarone or persistent non-shockable rhythm and continuous CPR for 10min without ROSC after exclusion of treatable arrest causes. RESULTS: 110 consecutive patients with rOHCA (mean age 56±14 years) were included. 40 patients (36%) were treated with FTA, 70 patients (64%) served as historical controls. Pre-hospital time was significantly shorter after FTA implementation (69±18 vs. 79±24min, p=0.02). Favourable neurological outcome (defined as cerebral performance categories Score 1 or 2) was significantly more frequent in FTA patients (27.5% vs. 11.4%, p=0.038). FTA-implementation showed a trend towards improved mortality (70.0% vs. 82.9%, p=0.151). Extracorporeal Life Support was similar between the two groups. CONCLUSION: Our study suggests that a rapid transport algorithm with ongoing CPR is feasible, improves neurological outcome and may improve survival in carefully selected patients with rOHCA.

Is increased positive end-expiratory pressure the culprit? Autoresuscitation in a 44-year-old man after prolonged cardiopulmonary resuscitation: a case report.

BACKGROUND: The phenomenon of autoresuscitation is rare, yet it is known to most emergency physicians. However, the pathophysiology of the delayed return of spontaneous circulation remains enigmatic. Among other causes hyperinflation of the lungs and excessively high positive end-expiratory pressure have been suggested, but reports including cardiopulmonary monitoring during cardiopulmonary resuscitation are scarce to support this hypothesis. CASE PRESENTATION: We report a case of autoresuscitation in a 44-year-old white man after 80 minutes of advanced cardiac life support accompanied by continuous capnometry and repeated evaluation by ultrasound and echocardiography. After prolonged cardiopulmonary resuscitation, refractory electromechanical dissociation on electrocardiogram and ventricular akinesis were recorded. In addition, a precipitous drop in end-tidal partial pressure of carbon dioxide was noted and cardiopulmonary resuscitation was discontinued. Five minutes after withdrawal of all supportive measures his breathing resumed and a perfusing rhythm ensued. CONCLUSIONS: Understanding the underlying pathophysiology of autoresuscitation is hampered by a lack of reports including extensive cardiopulmonary monitoring during cardiopulmonary resuscitation in a preclinical setting. In this case, continuous capnometry was combined with repetitive ultrasound evaluation, which ruled out most assumed causes of autoresuscitation. Our observation of a rapid decline in end-tidal partial pressure of carbon dioxide supports the hypothesis of increased intrathoracic pressure. Continuous capnometry can be performed easily during cardiopulmonary resuscitation, also in a preclinical setting. Knowledge of the pathophysiologic mechanisms may lead to facile interventions to be incorporated into cardiopulmonary resuscitation algorithms. A drop in end-tidal partial pressure of carbon dioxide, for example, might prompt disconnection of the ventilation to allow left ventricular filling. Further reports and research on this topic are encouraged.