Extracorporeal versus conventional cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a secondary analysis of the Prague OHCA trial.

BACKGROUND: Survival rates in refractory out-of-hospital cardiac arrest (OHCA) remain low with conventional advanced cardiac life support (ACLS). Extracorporeal life support (ECLS) implantation during ongoing resuscitation, a method called extracorporeal cardiopulmonary resuscitation (ECPR), may increase survival. This study examined whether ECPR is associated with improved outcomes. METHODS: Prague OHCA trial enrolled adults with a witnessed refractory OHCA of presumed cardiac origin. In this secondary analysis, the effect of ECPR on 180-day survival using Kaplan-Meier estimates and Cox proportional hazard model was examined. RESULTS: Among 256 patients (median age 58 years, 83% male) with median duration of resuscitation 52.5 min (36.5-68), 83 (32%) patients achieved prehospital ROSC during ongoing conventional ACLS prehospitally, 81 (32%) patients did not achieve prehospital ROSC with prolonged conventional ACLS, and 92 (36%) patients did not achieve prehospital ROSC and received ECPR. The overall 180-day survival was 51/83 (61.5%) in patients with prehospital ROSC, 1/81 (1.2%) in patients without prehospital ROSC treated with conventional ACLS and 22/92 (23.9%) in patients without prehospital ROSC treated with ECPR (log-rank p < 0.001). After adjustment for covariates (age, sex, initial rhythm, prehospital ROSC status, time of emergency medical service arrival, resuscitation time, place of cardiac arrest, percutaneous coronary intervention status), ECPR was associated with a lower risk of 180-day death (HR 0.21, 95% CI 0.14-0.31; P < 0.001). CONCLUSIONS: In this secondary analysis of the randomized refractory OHCA trial, ECPR was associated with improved 180-day survival in patients without prehospital ROSC. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01511666, Registered 19 January 2012.

Gender differences and survival after out of hospital cardiac arrest.

BACKGROUND: Published evidence regarding the effect of gender on outcome after out of hospital cardiac arrest (OHCA) is inconsistent. We aimed to investigate the association of gender to outcome and resuscitation characteristics in OHCA patients admitted to the cardiac arrest center. METHODS: In this retrospective analysis of prospective registry data, all patients admitted for OHCA were included. The influence of gender on 30-day survival and good neurological outcome (cerebral performance category of 1 or 2) were examined using Kaplan-Meier estimates and multivariable logistic regression. RESULTS: In total, 932 patients were analysed (239 women, 26%). Women were older (64 vs 60 years, p < 0.001) and less commonly had a shockable rhythm (47% vs 65%, P < 0.001) compared to men. Women were less likely to have a cardiac cause of arrest (54% vs. 75%, p < 0.001), received less therapeutic hypothermia (74% vs 86%, p < 0.001) and coronary angiography (63% vs. 79%, p < 0.001). The overall 30-day survival was lower for women (45% vs. 53%, log-rank p = 0.005) as well as good neurological outcome (37% vs. 46%, p = 0.008). However, according to the multivariate logistic regression, gender was not associated with survival (OR 0.98, 95% CI 0.65-1.50, p = 0.94) nor with good neurological outcome (OR 0.91, 95% CI 0.59-1.40, p = 0.67). CONCLUSION: Women admitted for OHCA to a cardiac center had a different cause of arrest that had a different treatment and outcome compared to men. Survival and good neurological outcome were lower in women, however, after adjusting for baseline characteristics, gender was not associated with survival nor neurological outcome.

Effect of Intra-arrest Transport, Extracorporeal Cardiopulmonary Resuscitation, and Immediate Invasive Assessment and Treatment on Functional Neurologic Outcome in Refractory Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial.

Importance: Out-of-hospital cardiac arrest (OHCA) has poor outcome. Whether intra-arrest transport, extracorporeal cardiopulmonary resuscitation (ECPR), and immediate invasive assessment and treatment (invasive strategy) is beneficial in this setting remains uncertain. Objective: To determine whether an early invasive approach in adults with refractory OHCA improves neurologically favorable survival. Design, Setting, and Participants: Single-center, randomized clinical trial in Prague, Czech Republic, of adults with a witnessed OHCA of presumed cardiac origin without return of spontaneous circulation. A total of 256 participants, of a planned sample size of 285, were enrolled between March 2013 and October 2020. Patients were observed until death or day 180 (last patient follow-up ended on March 30, 2021). Interventions: In the invasive strategy group (n = 124), mechanical compression was initiated, followed by intra-arrest transport to a cardiac center for ECPR and immediate invasive assessment and treatment. Regular advanced cardiac life support was continued on-site in the standard strategy group (n = 132). Main Outcomes and Measures: The primary outcome was survival with a good neurologic outcome (defined as Cerebral Performance Category [CPC] 1-2) at 180 days after randomization. Secondary outcomes included neurologic recovery at 30 days (defined as CPC 1-2 at any time within the first 30 days) and cardiac recovery at 30 days (defined as no need for pharmacological or mechanical cardiac support for at least 24 hours). Results: The trial was stopped at the recommendation of the data and safety monitoring board when prespecified criteria for futility were met. Among 256 patients (median age, 58 years; 44 [17%] women), 256 (100%) completed the trial. In the main analysis, 39 patients (31.5%) in the invasive strategy group and 29 (22.0%) in the standard strategy group survived to 180 days with good neurologic outcome (odds ratio [OR], 1.63 [95% CI, 0.93 to 2.85]; difference, 9.5% [95% CI, -1.3% to 20.1%]; P = .09). At 30 days, neurologic recovery had occurred in 38 patients (30.6%) in the invasive strategy group and in 24 (18.2%) in the standard strategy group (OR, 1.99 [95% CI, 1.11 to 3.57]; difference, 12.4% [95% CI, 1.9% to 22.7%]; P = .02), and cardiac recovery had occurred in 54 (43.5%) and 45 (34.1%) patients, respectively (OR, 1.49 [95% CI, 0.91 to 2.47]; difference, 9.4% [95% CI, -2.5% to 21%]; P = .12). Bleeding occurred more frequently in the invasive strategy vs standard strategy group (31% vs 15%, respectively). Conclusions and Relevance: Among patients with refractory out-of-hospital cardiac arrest, the bundle of early intra-arrest transport, ECPR, and invasive assessment and treatment did not significantly improve survival with neurologically favorable outcome at 180 days compared with standard resuscitation. However, the trial was possibly underpowered to detect a clinically relevant difference. Trial Registration: ClinicalTrials.gov Identifier: NCT01511666.

UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction.

A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1-5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally.

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.

Coronary angiography and percutaneous coronary intervention in cardiac arrest patients without return of spontaneous circulation.

OBJECTIVES: This study aimed to examine coronary angiography (CAG) findings, percutaneous coronary intervention (PCI) results and outcomes in out-of-hospital cardiac arrest patients (OHCA) without return of spontaneous circulation (ROSC) on admission to hospital. METHODS: We analyzed the OHCA register and compared CAG, PCI, and outcome data in patients with and without ROSC on admission to hospital. RESULTS: Between January 2012 and December 2020, 697 OHCA patients were analyzed. Of these, 163 (23%) did not have ROSC at admission. Patients without ROSC were younger (59 vs. 61 years, p = 0.001) and had a longer resuscitation time (62 vs. 18 minutes, p < 0.001) than patients with ROSC. Significant coronary artery disease was highly prevalent in both groups (65% vs. 68%, p = 0.48). Patients without ROSC had higher rates of acute coronary occlusions (42% vs. 33%, p = 0.046), specifically affecting the left main stem (16% vs. 1%, p < 0.001). PCI was performed in 81 patients (50%) without ROSC and in 295 (55%) with ROSC (p = 0.21). The success rate was 86% in patients without ROSC and 90% in patients with ROSC (p = 0.33). Thirty-day survival was 24% in patients without ROSC and 70% in patients with ROSC. CONCLUSIONS: OHCA patients without ROSC on admission to hospital had higher acute coronary occlusion rates than patients with prehospital ROSC. PCI is feasible with a high success rate in patients without ROSC. Despite prolonged resuscitation times, meaningful survival in patients admitted without ROSC is achievable.

Initial rhythm and survival in refractory out-of-hospital cardiac arrest. Post-hoc analysis of the Prague OHCA randomized trial.

BACKGROUND: The prognosis of refractory out-of-hospital cardiac arrest (OHCA) is generally poor. A recent Prague OHCA study has demonstrated that an invasive approach (including extracorporeal cardiopulmonary resuscitation, ECPR) is a feasible and effective treatment strategy in refractory OHCA. Here we present a post-hoc analysis of the role of initial rhythm on patient outcomes. METHODS: The study enrolled patients who had a witnessed OHCA of presumed cardiac cause without early recovery of spontaneous circulation. The initial rhythm was classified as either a shockable or a non-shockable rhythm. The primary outcome was a composite of 180 day-survival with Cerebral Performance in Category 1 or 2. RESULTS: 256 (median age 58y, 17% females) patients were enrolled. The median (IQR) duration of resuscitation was 52 (33-68) minutes. 156 (61%) and 100 (39%) of patients manifested a shockable and non-shockable rhythm, respectively. The primary outcome was achieved in 63 (40%) patients with a shockable rhythm and in 5 (5%) patients with a non-shockable rhythm (p < 0.001). When patients were analyzed separately based on whether the treatment was invasive (n = 124) or standard (n = 132), the difference in the primary endpoint between shockable and non-shockable initial rhythms remained significant (35/72 (49%) vs 4/52 (8%) in the invasive arm and 28/84 (33%) vs 1/48 (2%) in the standard arm; p < 0.001). CONCLUSION: An initial shockable rhythm and treatment with an invasive approach is associated with a reasonable neurologically favorable survival for 180 days despite refractory OHCA. Non-shockable initial rhythms bear a poor prognosis in refractory OHCA even when ECPR is readily available.

No effect of TETRA hand portable transmission signals on human cognitive function and symptoms.

Current radio frequency radiation exposure guidelines rest on well-established thermal effects. However, recent research into analogue and digital transmission fields at levels covered by the exposure guidelines has indicated possible detrimental effects on human cognitive performance. To investigate this, we conducted a controlled climate chamber study of possible changes in cognitive performance in healthy volunteers exposed to transmission signals from TETRA hand portables (TETRA handsets). The trial deployed a balanced, randomized, double-blinded cross-over design. Performance on different paper-and-pencil, auditory and computer-based cognitive tasks was monitored in 53 male volunteers (mean age 36.41 years, SD 8.35) during 45-min exposure to a TETRA handset and sham control signals remotely controlled from a laboratory more than 100 km away. The main cognitive outcome was the Trail Making B (TMB) test. In addition, the participants completed a computer-based questionnaire measuring self-reported psychological and physical symptoms. No statistically significant differences (P < 0.05) between the TETRA and sham conditions were found for either TMB (estimated difference 3.8%, confidence interval (CI) -1.6% to 9.2%) or any of the remaining cognitive tasks or symptoms. In conclusion, we found no evidence that brief exposure to hand-held TETRA transmitters' affects human cognitive function or subjective symptoms.

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.

The Examination of Restrained Joints Created in the Process of Multi-Material FFF Additive Manufacturing Technology.

The paper is focused on the examination of the internal quality of joints created in a multi-material additive manufacturing process. The main part of the work focuses on experimental production and non-destructive testing of restrained joints of modified PLA (polylactic acid) and ABS (Acrylonitrile butadiene styrene) three-dimensional (3D)-printed on RepRap 3D device that works on the "open source" principle. The article presents the outcomes of a non-destructive materials test in the form of the data from the Laser Amplified Ultrasonography, microscopic observations of the joints area and tensile tests of the specially designed samples. The samples with designed joints were additively manufactured of two materials: Specially blended PLA (Market name-PLA Tough) and conventionally made ABS. The tests are mainly focused on the determination of the quality of material connection in the joints area. Based on the results obtained, the samples made of two materials were compared in the end to establish which produced material joint is stronger and have a lower amount of defects.

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.

Pre-hospital cardiac arrest in Prague, Czech Republic--the Utstein-style report.

OBJECTIVE: This study aimed to report results of pre-hospital cardiopulmonary resuscitation (CPR) in the city of Prague in accordance with 'Utstein-style' recommendations. MATERIALS AND METHODS: This is a prospective study of out-of-hospital cardiac arrest (OHCA) survival in the city of Prague treated by emergency medical service (EMS). EMS Prague is a typical municipal, two-tiered ambulance service, based on the presence of a physician on the scene in all life-threatening emergencies, especially in cardiac arrests, serious breathing problems, chest-pain cases, seizures, serious trauma, etc. Since 2002, all cases of OHCA CPRs performed by EMS Prague ambulance crew are evaluated in accordance with 'Utstein-style' recommendations, including hospital-outcome score as measured by Cerebral Performance Categories (CPCs). RESULTS: In 2008, our ambulance crew performed 493 CPRs. Return of spontaneous circulation (ROSC) was achieved in 278 cases (56.3%), survival of the event in 211 cases (42.8%) and survival to hospital discharge with good neurological outcome (CPC 1 or 2) in 74 cases (15.0%). Appropriate figures for patients with first shockable rhythm (n=146) were 106 (72.6%) for ROSC, 91 (62.3%) for survived event and 51 (34.9%) for survival to discharge with good neurological outcome. Pre-hospital CPR incidence was 41.1 per 100,000 inhabitants. The majority of cases had a cardiac origin (363, 73.6%). The physician attending the arrest declared the reason unknown in 40 cases (8.1%), as a respiratory disease in 20 cases (4.1%) and in 36 cases (7.3%) the arrest was a result of trauma, drowning or poisoning.