Hyperinvasive approach to out-of hospital cardiac arrest using mechanical chest compression device, prehospital intraarrest cooling, extracorporeal life support and early invasive assessment compared to standard of care. A randomized parallel groups comparative study proposal. "Prague OHCA study".

BACKGROUND: Out of hospital cardiac arrest (OHCA) has a poor outcome. Recent non-randomized studies of ECLS (extracorporeal life support) in OHCA suggested further prospective multicenter studies to define population that would benefit from ECLS. We aim to perform a prospective randomized study comparing prehospital intraarrest hypothermia combined with mechanical chest compression device, intrahospital ECLS and early invasive investigation and treatment in all patients with OHCA of presumed cardiac origin compared to a standard of care. METHODS: This paper describes methodology and design of the proposed trial. Patients with witnessed OHCA without ROSC (return of spontaneous circulation) after a minimum of 5 minutes of ACLS (advanced cardiac life support) by emergency medical service (EMS) team and after performance of all initial procedures (defibrillation, airway management, intravenous access establishment) will be randomized to standard vs. hyperinvasive arm. In hyperinvasive arm, mechanical compression device together with intranasal evaporative cooling will be instituted and patients will be transferred directly to cardiac center under ongoing CPR (cardiopulmonary resuscitation). After admission, ECLS inclusion/exclusion criteria will be evaluated and if achieved, veno-arterial ECLS will be started. Invasive investigation and standard post resuscitation care will follow. Patients in standard arm will be managed on scene. When ROSC achieved, they will be transferred to cardiac center and further treated as per recent guidelines. PRIMARY OUTCOME: 6 months survival with good neurological outcome (Cerebral Performance Category 1-2). Secondary outcomes will include 30 day neurological and cardiac recovery. DISCUSSION: Authors introduce and offer a protocol of a proposed randomized study comparing a combined "hyperinvasive approach" to a standard of care in refractory OHCA. The protocol is opened for sharing by other cardiac centers with available ECLS and cathlab teams trained to admit patients with refractory cardiac arrest under ongoing CPR. A prove of concept study will be started soon. The aim of the authors is to establish a net of centers for a multicenter trial initiation in future. ETHICS AND REGISTRATION: The protocol has been approved by an Institutional Review Board, will be supported by a research grant from Internal Grant Agency of the Ministry of Health, Czech Republic NT 13225-4/2012 and has been registered under ClinicalTrials.gov identifier: NCT01511666.

A sudden increase in partial pressure end-tidal carbon dioxide (P(ET)CO(2)) at the moment of return of spontaneous circulation.

BACKGROUND: Previous studies established that a level of partial pressure end-tidal carbon dioxide (P(ET)CO(2)) of 10 mm Hg divided patients undergoing advanced life support (ALS) into those likely to be resuscitated (values > 10 mm Hg) and those likely to die during ALS (values < 10 mm Hg). OBJECTIVE: The study tested the significance of a sudden increase in the P(ET)CO(2) in signaling the return of spontaneous circulation (ROSC) during ALS. MATERIAL AND METHODS: P(ET)CO(2) values were continuously recorded during ALS in out-of-hospital patients with cardiac arrest. Constant ventilation was maintained by an automatic device. There were 108 patients, representing two extreme outcomes of ALS, who were subdivided into two groups. The first group included 59 patients with a single ROSC followed by a stable spontaneous circulation. The second group included 49 patients with no signs of ROSC. RESULTS: ROSC was associated with a sudden increase in P(ET)CO(2) that remained significantly higher than before ROSC. P(ET)CO(2) did not rise during the entire ALS in the second group of patients without ROSC and was lower than in the first group of patients. CONCLUSIONS: In constantly ventilated patients, P(ET)CO(2) is significantly higher (about 10 mm Hg) after ROSC than before ROSC. A sudden increase in P(ET)CO(2) exceeding 10 mm Hg may indicate ROSC. Consequently, the rule of 10 mm Hg may be extended to include a sudden increase in continuously recorded P(ET)CO(2) by more than 10 mm Hg as an indicator of the possibility of ROSC.

How accurately can the aetiology of cardiac arrest be established in an out-of-hospital setting? Analysis by "concordance in diagnosis crosscheck tables".

INTRODUCTION: Several previous studies have focused on establishing the cause of cardiac arrest (CA) during cardiopulmonary resuscitation (CPR) provided in an out-of-hospital setting. OBJECTIVES: To analyze the ability of professional advanced life support providers to correctly establish the aetiology of cardiac arrest during out-of-hospital CPR. STUDY DESIGN: A retrospective cohort study analysing 211 cases of out-of-hospital cardiac arrest. METHOD: The aetiology assumed by out-of-hospital physicians was compared with the diagnosis that was later established by clinicians or pathologists. RESULTS: Cases were sorted into five diagnostic groups and the overall diagnostic concordance was 74.4% (157 of 211 cases). The cardiac aetiology was presumed in 132 out of 211 patients and confirmed in 135 out of 211 patients. However, an analysis of individual cases of the cardiac causes of cardiac arrest revealed diagnostic matches in only 112 cases. Acute myocardial infarction (AMI) or pulmonary embolism (PE), both of which represent cases that can be potentially influenced by thrombolytic therapy, were presumed in 74 (53+21) and confirmed in 97 (77+20) cases, however with individual diagnostic matches in only 55 cases. CONCLUSION: This study demonstrates the importance of analysing concordance in presumed and definitive diagnosis of individual cases, since an overall comparison in a cohort of cases may be highly misleading. It introduces the method of the crosscheck table for visualization and comparison of presumed and final diagnoses. The two alternative approaches of inclusion rule for applying the thrombolytic therapy in out-of-hospital care were discussed with regard to the recent TROICA study.