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An inadvertent consequence of advances in stem cell research, neuroscience, and resuscitation science has been to enable scientific insights regarding what happens to the human brain in relation to death. The scientific exploration of death is in large part possible due to the recognition that brain cells are more resilient to the effects of anoxia than assumed. Hence, brain cells become irreversibly damaged and "die" over hours to days postmortem. Resuscitation science has enabled life to be restored to millions of people after their hearts had stopped. These survivors have described a unique set of recollections in relation to death that appear universal. We review the literature, with a focus on death, the recalled experiences in relation to cardiac arrest, post-intensive care syndrome, and related phenomena that provide insights into potential mechanisms, ethical implications, and methodologic considerations for systematic investigation. We also identify issues and controversies related to the study of consciousness and the recalled experience of cardiac arrest and death in subjects who have been in a coma, with a view to standardize and facilitate future research.

Introduction: Good quality basic life support (BLS) is associated with improved outcome from cardiac arrest. Chest compression fraction (CCF) is a BLS quality indicator, which may be influenced by the type of airway used. We aimed to assess CCF according to the airway strategy in the PARAMEDIC2 study: no advanced airway, supraglottic airway (SGA), tracheal intubation, or a combination of the two. Our hypothesis was that tracheal intubation was associated with a decrease in the CCF compared with alternative airway management strategies.Methods: PARAMEDIC2 was a multicentre double-blinded placebo-controlled trial of adrenaline vs placebo in out-of-hospital cardiac arrest. Data showing compression rate and ratio from patients recruited by London Ambulance Service (LAS) as part of this study was collated and analysed according to the advanced airway used during the resuscitation attempt.Results: CPR process data were available from 286/ 2058 (13.9%) of the total patients recruited by LAS. The mean compression rate for the first 5 min of data recording was the same in all groups (P = 0.272) and ranged from 104.2 (95% CI of mean: 100.5, 107.8) min-1 to 108.0 (95% CI of mean: 105.1, 108.3) min-1. The mean compression fraction was also similar across all groups (P = 0.159) and ranged between 74.7% and 78.4%. There was no difference in the compression rates and fractions across the airway management groups, regardless of the duration of CPR.Conclusion: There was no significant difference in the compression fraction associated with the airway management strategy. [ABSTRACT FROM AUTHOR]

Introduction: Cardiac arrests associated with shockable rhythms such as ventricular fibrillation or pulseless VT (VF/pVT) are associated with improved outcomes from cardiac arrest. The more defibrillation attempts required to terminate VF/pVT, the lower the survival. Double sequential defibrillation (DSD) has been used for refractory VF/pVT cardiac arrest despite limited evidence examining this practice. We performed a systematic review to summarize the evidence related to the use of DSD during cardiac arrest.Methods: This review was performed according to PRISMA and registered on PROSPERO (ID: CRD42020152575). We searched Embase, Pubmed, and the Cochrane library from inception to 28 February 2020. We included adult patients with VF/pVT in any setting. We excluded case studies, case series with less than five patients, conference abstracts, simulation studies, and protocols for clinical trials. We predefined our outcomes of interest as neurological outcome, survival to hospital discharge, survival to hospital admission, return of spontaneous circulation (ROSC), and termination of VF/pVT. Risk of bias was examined using ROBINS-I or ROB-2 and certainty of studies were reported according to GRADE methodology.Results: Overall, 314 studies were identified during the initial search. One hundred and thirty studies were screened during title and abstract stage and 10 studies underwent full manuscript screening, nine included in the final analysis. Included studies were cohort studies (n = 4), case series (n = 3), case-control study (n = 1) and a prospective pilot clinical trial (n-1). All studies were considered to have serious or critical risk of bias and no meta-analysis was performed. Overall, we did not find any differences in terms of neurological outcome, survival to hospital discharge, survival to hospital admission, ROSC, or termination of VF/pVT between DSD and a standard defibrillation strategy.Conclusion: The use of double sequential defibrillation was not associated with improved outcomes from out-of-hospital cardiac arrest, however the current literature has a number of limitations to interpretation. Further high-quality evidence is needed to answer this important question. [ABSTRACT FROM AUTHOR]

Background: The 'Prehospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration In Cardiac Arrest' (PARAMEDIC2) trial showed that adrenaline improves overall survival, but not neurological outcomes. We sought to determine the within-trial and lifetime health and social care costs and benefits associated with adrenaline, including secondary benefits from organ donation.Methods: We estimated the costs, benefits (quality-adjusted life years (QALYs)) and incremental cost-effectiveness ratios (ICERs) associated with adrenaline during the 6-month trial follow-up. Model-based analyses explored how results altered when the time horizon was extended beyond 6 months and the scope extended to include recipients of donated organs.Results: The within-trial (6 months) and lifetime horizon economic evaluations focussed on the trial population produced ICERs of £1,693,003 (€1,946,953) and £81,070 (€93,231) per QALY gained in 2017 prices, respectively, reflecting significantly higher mean costs and only marginally higher mean QALYs in the adrenaline group. The probability that adrenaline is cost-effective was less than 1% across a range of cost-effectiveness thresholds. Combined direct economic effects over the lifetimes of survivors and indirect economic effects in organ recipients produced an ICER of £16,086 (€18,499) per QALY gained for adrenaline with the probability that adrenaline is cost-effective increasing to 90% at a £30,000 (€34,500) per QALY cost-effectiveness threshold.Conclusions: Adrenaline was not cost-effective when only directly related costs and consequences are considered. However, incorporating the indirect economic effects associated with transplanted organs substantially alters cost-effectiveness, suggesting decision-makers should consider the complexity of direct and indirect economic impacts of adrenaline.Trial Registration: ISRCTN73485024 . Registered on 13 March 2014. [ABSTRACT FROM AUTHOR]

Introduction: Public access defibrillation is a key component of the early links in the chain of survival. Despite growing numbers of PADs in the community, actual use remains poor, partly because of the difficulties in locating the nearest PAD. We aimed to establish the cover that would be provided if PADs were located in any given building type, which would enable the public to know where the nearest PAD was located.Methods: Mapping software was used to classify each and every building type in the South Central Ambulance Service region. The 52 commonest building types were then mapped to all cardiac arrest calls in the same geographical area from Jan 2014 - July 2018. The walking distance from each cardiac arrest to each nearest building type was calculated.Results: A total of 22,382 cardiac arrests were mapped to a total of 24,155 buildings considered suitable for potential PAD location. Post boxes ranked first in both urban and rural areas, covering 11.7% of cardiac arrests at 100 m and 85.6% of cardiac arrests at 500 m. In urban areas, bus shelters and telephone boxes also provided good coverage (9.7%, 9.5% @ 100 m; 69.2%, 71.9% @ 500 m respectively). In rural areas, good coverage was provided by nursing/care homes and pubs/bars (4.9%, 4.6% @ 100 m; 15.2%, 31.8% @ 500 m respectively).Conclusion: Locating PADs at all post boxes would provide the most effective geographical coverage in both urban and rural areas according to building type. This may be an effective strategy to improve rapid PAD locating. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effectiveness of the intravenous (IV) and intraosseous (IO) routes for drug administration in adults with a cardiac arrest enrolled in the Pre-Hospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration in Cardiac Arrest (PARAMEDIC2) randomised, controlled trial.Methods: Patients were recruited from five National Health Service Ambulance Services in England and Wales from December 2014 through October 2017. Patients with an out-of-hospital cardiac arrest who were unresponsive to initial resuscitation attempts were randomly assigned to 1 mg adrenaline or matching placebo. Intravascular access was established as soon as possible, and IO access was considered if IV access was not possible after two attempts.Results: Among patients with out-of-hospital cardiac arrest, 3631 received adrenaline and 3686 received placebo. Amongst these, 1116 (30.1%) and 1121 (30.4%) received the study drug via the IO route. The odds ratios were similar in the IV and IO groups for return of spontaneous circulation (ROSC) at hospital handover [adjusted odds ratio (aOR) 4.07 (95% CI 3.42-4.85) and (aOR 3.98 (95% CI 2.86-5.53), P value for interaction 0.90]; survival to 30 days [aOR 1.67 (1.18-2.35) versus 0.9 (0.4-2.05), P = 0.18]; and favourable neurological outcome [aOR 1.39 (0.93-2.06) versus 0.62 (0.23-1.67), P = 0.14].Conclusion: There was no significant difference in treatment effect (adrenaline versus placebo) on ROSC at hospital handover between drugs administered by the intraosseous route or by the intravenous route. We could not detect any difference in the treatment effect between the IV and IO routes on the longer term outcomes of 30-day survival or favourable neurological outcome at discharge (ISRCTN73485024). [ABSTRACT FROM AUTHOR]

Introduction: Out-of-hospital cardiac arrest trials can prove challenging and there is a need to share learning from those that have recruited successfully. We have just completed three years of recruitment to PARAMEDIC2, a placebo-controlled trial of adrenaline in out-of-hospital cardiac arrest. This study was designed to describe the experience of operational ambulance staff involved in recruiting patients into PARAMEDIC2. Methods: Four focus groups involving trial paramedics and supporting members of the emergency care team were conducted across different geographical regions of a single UK ambulance service participating in the PARAMEDIC2 study. Data analysis was supported by NVivo 12 and themes were identified using a thematic analysis approach. Results: Forty-four participants contributed to the focus groups. Four overarching themes were identified: context for the research, ethical concerns, concerns at the patient's side and ongoing trial support. Participants felt that research such as PARAMEDIC2 is important and necessary to drive medical progress. They valued the opportunity to be part of a large project. Due to the deferred consent model employed, public awareness of the trial was felt to be important. Most expressed equipoise regarding adrenaline, but some felt concerned about enrolling younger patients and there was discussion around what constitutes a successful outcome. Struggles with ethical concerns were overcome through training and one-to-one discussion with research paramedics. Participants valued feedback on their performance of trial tasks, but also wanted feedback on their resuscitation skills. Cardiac arrest places a high cognitive demand on paramedics; simplicity and reinforcement of trial processes were key to facilitating recruitment. Caring for relatives was a high priority for paramedics and some felt conflicted about not discussing the trial with them. Conclusions: This study has provided insights into paramedic experience of a large-scale prehospital trial. Investment in time and resource to provide face-to-face training and personalised feedback to paramedics can foster engagement and optimise performance. [ABSTRACT FROM AUTHOR]

Introduction: Public access defibrillation doubles the chances of neurologically intact survival following out-of-hospital cardiac arrest (OHCA). Although there are increasing numbers of defibrillators (automated external defibrillator (AEDs)) available in the community, they are used infrequently, despite often being available. We aimed to match OHCAs with known AED locations in order to understand AED availability, the effects of reduced AED availability at night and the operational radius at which they can be effectively retrieved.Methods: All emergency calls to South Central Ambulance Service from April 2014 to April 2016 were screened to identify cardiac arrests. Each was mapped to the nearest AED, according to the time of day. Mapping software was used to calculate the actual walking distance for a bystander between each OHCA and respective AED, when travelling at a brisk walking speed (4 mph).Results: 4012 cardiac arrests were identified and mapped to one of 2076 AEDs. All AEDs were available during daytime hours, but only 713 at night (34.3%). 5.91% of cardiac arrests were within a retrieval (walking) radius of 100 m during the day, falling to 1.59% out-of-hours. Distances to rural AEDs were greater than in urban areas (P<0.0001). An AED could potentially have been retrieved prior to actual ambulance arrival in 25.3% cases.Conclusion: Existing AEDs are underused; 36.4% of OHCAs are located within 500 m of an AED. Although more AEDs will improve availability, greater use can be made of existing AEDs, particularly by ensuring they are all available on a 24/7 basis. [ABSTRACT FROM AUTHOR]

Background: A recent study reported that a compression depth of 4.56 cm optimised survival following cardiac arrest, which is at variance with the current guidelines of 5.0-6.0 cm. A reduction in recommended compression depth is only likely to improve survival if healthcare professionals can accurately deliver a relatively small change in target depth. This study aimed to determine if healthcare professionals could accurately judge their delivered compression depth by 0.5 cm increments.Method: This randomised interventional trial asked BLS-trained healthcare professionals to complete two minutes of continuous chest compressions on an adult manikin, randomised (without any feedback device), to compress to one of three target depth ranges of 4.0-5.0 cm, 4.5-5.5 cm or 5.0-6.0 cm, at the recommended rate of 100-120 compressions min-1. Basic demographic data, compression rate, and compression depth were recorded.Results: One hundred and one participants were recruited, of whom one withdrew. Median depths of 3.66 cm (IQR: 3.37-4.16 cm), 4.13 cm (IQR: 3.65-4.36 cm) and 4.76 cm (IQR: 4.16-5.24 cm) were found for the target depths of 4.0-5.0 cm (n = 30), 4.5-5.5 cm (n = 35) and 5.0-6.0 cm (n = 35) respectively (P < 0.001). Overall, 18 participants successfully compressed to their target depth.Conclusions: Rescuers are able to judge 0.5 cm differences in compression depth with precision, but remain unable to accurately judge overall target depth. Reducing the current recommended compression depth to 4.56 cm is likely to result in delivered compressions significantly below the optimal depth. [ABSTRACT FROM AUTHOR]

Background: Most out-of-hospital paediatric cardiac arrests (CA) are not identified until a call is made to the emergency medical services. Accurate identification increases overall survival by enabling immediate ambulance dispatch and delivery of bystander CPR. European ambulance services use a variety of didactic telephone scripts to interrogate the caller and rapidly identify paediatric CA. The performance of these scripts has not been reported. This study aims to evaluate the diagnostic accuracy of the NHS Pathways as a telephone triage tool to identify patients less than 16 years age in cardiac arrest.Methods: All emergency calls to South Central Ambulance Service (SCAS) over a 12-month period screened by 'NHS Pathways' v9.04 were identified. All actual or presumed paediatric CAs (<16 years age) identified by the emergency call taker were cross-referenced with the ambulance crew's Patient Report Form to identify all confirmed CAs.Results: Over a 12-month period from March 2015, a total of 540,715 emergency calls were received by SCAS, of which 53,213 related to children, 2052 (3.86%) being categorised by 'NHS Pathways' as paediatric CA. On arrival of the ambulance crew, only 87/2052 (4.24%) patients were in CA. Sensitivity=71.3%; specificity=96.3%; positive predictive value=4.2%. NHS Pathways missed the CA in 28.7% cases.Conclusions: This is the first reported evaluation of any currently used European paediatric telephone triage system for identifying CA. Further work is required to refine telephone triage pathways for paediatric cardiac arrest. [ABSTRACT FROM AUTHOR]

Background: UK ambulance services are called to 30 000 cardiac arrests (CAs) annually where resuscitation is attempted. Correct identification by the ambulance service trebles survival by facilitating bystander-cardiopulmonary resuscitation (CPR) and immediate ambulance dispatch. Identification of CA by telephone is challenging and involves algorithms to identify key features. 'NHS Pathways' is now used for triage by six of 12 UK ambulance services, covering a population of 20 million. With the significant improvements in survival when CA is accurately identified, it is vital that 'NHS Pathways' is able to identify CA correctly.Methods: All '999' emergency calls to South Central Ambulance Service (SCAS) over a 12-month period screened by NHS Pathways v9.04 were identified. All actual or presumed CAs identified by the emergency call taker were cross-referenced with the ambulance crew's Patient Report Form to identify all confirmed CAs.Results: A total of 469 400 emergency (999) calls were received by SCAS. Of the 3119 CA identified by ambulance crew, 753 were not initially classified as CA by NHS Pathways (24.1%). Overall, sensitivity=0.759 (95% CI 0.743 to 0.773); specificity=0.986 (95% CI 0.9858 to 0.98647); and positive predictive value=26.80% (95% CI 25.88 to 27.73%).Conclusions: NHS Pathways accurately identifies 75.9% of adult CAs. The remainder represents approximately 7500 treatable CAs in the UK annually where the diagnosis is missed, with significant implications for patient outcome. Further work is required to improve this first link in the chain of survival. [ABSTRACT FROM AUTHOR]

Background: Epinephrine has been presumed to improve cerebral oxygen delivery during cardiopulmonary resuscitation (CPR), but animal and registry studies suggest that epinephrine-induced capillary vasoconstriction may decrease cerebral capillary blood flow and worsen neurological outcome. The effect of epinephrine on cerebral oxygenation (rSO2) during CPR has not been documented in the clinical setting.Methods: rSO2 was measured continuously using cerebral oximetry in patients with in-hospital cardiac arrest. During CPR, time event markers recorded the administration of 1mg epinephrine. rSO2 values were analysed for a period beginning 5min before and ending 5min after the first epinephrine administration.Results: A total of 56 epinephrine doses were analysed in 36 patients during CPR. The average rSO2 value in the 5-min following epinephrine administration was 1.40% higher (95% CI=0.41-2.40%; P=0.0059) than in the 5-min period before epinephrine administration. However, there was no difference in the overall rate of change of rSO2 when comparing the 5-min period before, with the 5-min period immediately after a single bolus dose of epinephrine (0.88%/min vs 1.07%/min respectively; P=0.583), There was also no difference in the changes in rSO2 at individual 1, 2, 3, or 4-min time windows before and after a bolus dose of epinephrine (P=0.5827, 0.2371, 0.2082, and 0.6707 respectively).Conclusions: A bolus of 1mg epinephrine IV during CPR produced a small but clinically insignificant increase in rSO2 in the five minutes after administration. This is the first clinical data to demonstrate the effects of epinephrine on cerebral rSO2 during CPR. [ABSTRACT FROM AUTHOR]

Background: There is an urgent need to develop prehospital research capability in order to improve the care of patients presenting to emergency medical services (EMS). The Prehospital Randomised Assessment of a Mechanical compression Device In Cardiac arrest trial, a pragmatic cluster randomised trial evaluating the LUCAS-2 device, represents the largest randomised controlled trial conducted by UK ambulance services to date. The aim of this study was to identify and analyse factors that may influence paramedic attitudes to, and participation in, clinical trials.Methods: Personal and organisational experience from this trial was assessed by feedback from a workshop attended by collaborators from participating EMS and a survey of EMS personnel participating in the trial. A work systems model was used to explain the impact of five interwoven themes-person, organisation, tasks, tools & technology and environment-on trial conduct including gathering of high-quality data.Results: The challenge of training a geographically diverse EMS workforce required development of multiple educational solutions. In order to operationalise the trial protocol, internal organisational relationships were perceived as essential. Staff perceptions of the normalisation of participation and ownership of the trial influenced protocol compliance rates. Undertaking research was considered less burdensome when additional tasks were minimised and more difficult when equipment was unavailable. The prehospital environment presents practical challenges for undertaking clinical trials, but our experience suggests these are not insurmountable and should not preclude conducting high-quality research in this setting.Conclusions: Application of a human factors model to the implementation of a clinical trial protocol has improved understanding of the work system, which can inform the future conduct of clinical trials and foster a research culture within UK ambulance services.Trial Registration Number: ISRCTN08233942. [ABSTRACT FROM AUTHOR]

Purpose Of the Study: Out-of-hospital cardiac arrest (OHCA) has a poor prognosis despite bystander resuscitation and rapid transfer to hospital. Optimal management of patients after arrival to hospital continues to be contentious, especially the timing of emergency coronary angiography±revascularisation. Robust predictors of inhospital outcome would be of clinical value for initial decision-making.Study Design: A retrospective analysis of consecutive patients who presented to a university hospital following OHCA over a 70-month period (2008-2013). Patients were identified from the emergency department electronic patient registration and coding system. For those patients who underwent emergency percutaneous coronary intervention, details were crosschecked with national databases.Results: We identified 350 consecutive patients who were brought to our hospital following OHCA. Return of spontaneous circulation (ROSC) for >20 min was achieved either before arrival or inhospital in 196 individuals. From the 350 subjects, 114 (32.6%) survived to hospital discharge. When sustained ROSC was achieved, either before or inhospital, survival to discharge was 58.2% (114 of 196). Non-shockable rhythm, absence of bystander cardiopulmonary resuscitation, 'downtime' >15 min and initial pH ≤7.11 were predictors of inhospital death. 12% patients who underwent angiography in the presence of ST elevation had no acute coronary occlusion. 21% patients with acute coronary occlusion at angiography did not have ST elevation.Conclusions: In our cohort of patients with OHCA, those who achieve ROSC had a survival-to-discharge rate of 58.2%. We identified four predictors of inhospital death, which are readily available at the time of patient presentation. Reliance on ST elevation to decide about coronary angiography and revascularisation may be flawed. More data are required. [ABSTRACT FROM AUTHOR]

The chain of survival aims to demonstrate the interrelationship between key stages of resuscitation and emphasises the need for all links to be effective in order to optimise the chances of survival. The contribution of each of the four links diminishes rapidly as patients succumb at each stage and the actual attrition rate results in rapidly decreasing numbers of patients progressing along the chain. This revised representation adjusts the area of each link in order to graphically represent the flow of patients through the chain. Greatest benefit in improving outcome will be achieved by focussing on improving care at links in the chain where there is the greatest number of patients. [ABSTRACT FROM AUTHOR]

Introduction Growing numbers of public access defibrillators aim to improve the effectiveness of bystander cardiopulmonary resuscitation prior to ambulance arrival. In the UK, however, public access defibrillators are only deployed successfully in 1.7% of out-of-hospital cardiac arrests. We aimed to understand whether this was due to a lack of devices, lack of awareness of their location or a reflection of lack of public knowledge and confidence to use a defibrillator. Methods Face-to-face semistructured open quantitative questionnaire delivered in a busy urban shopping centre, to identify public knowledge relating to public access defibrillation. Results 1004 members of the public aged 9-90 years completed the survey. 61.1% had been first aid trained to a basic life support level. 69.3% claimed to know what an automatic external defibrillator was and 26.1% reported knowing how to use one. Only 5.1% knew where or how to find their nearest public access defibrillator. Only 3.3% of people would attempt to locate a defibrillator in a cardiac arrest situation, and even fewer (2.1%) would actually retrieve and use the device. Conclusions These findings suggest that a lack of public knowledge, confidence in using a defibrillator and the inability to locate a nearby device may be more important than a lack of defibrillators themselves. Underused public access defibrillation is a missed opportunity to save lives, and improving this link in the chain of survival may require these issues to be addressed ahead of investing more funds in actual defibrillator installation. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The relationship between the neurological status at the time of handover from the ambulance crew to a Heart Attack Centre (HAC) in patients who have achieved return of spontaneous circulation (ROSC) and subsequent outcome, in the context of current treatment standards, is unknown. Methods: A retrospective review of all patients treated by London Ambulance Service (LAS) from 1st April 2011 to 31st March 2013 admitted to a HAC in Greater London was undertaken. Neurological status (A - alert; V - responding to voice; P - responding to pain; U - unresponsive) recorded by the ambulance crew on handover was compared with length of hospital stay and survival to hospital discharge. Results: A total of 475 sequential adult cardiac arrests of presumed cardiac origin, achieving ROSC on admission to a HAC were identified. Outcome data was available for 452 patients, of whom 253 (56.0%) survived to discharge. Level of consciousness on admission to the HAC was a predictor of duration of hospital stay (P <0.0001) and survival to hospital discharge (P <0.0001). Of those presenting with a shockable rhythm, 32.3% (120/371) were ‘A’ or ‘V’, compared with 9.1% (9/99) of those with non-shockable rhythms (P <0.001). Conclusion: Patients with shockable rhythms achieving ROSC are more likely to be conscious (A or V) compared with those with non-shockable rhythms. Most patients who are conscious on admission to the HAC will survive, compared with approximately half of those who are unconscious (P or U), suggesting that critical care is generally appropriate at all levels of consciousness if ROSC has been achieved. [Copyright &y& Elsevier]

Introduction Public access defibrillation (PAD) prior to ambulance arrival is a key determinant of survival from out-of-hospital (OOH) cardiac arrest. Implementation of PAD has been underway in the UK for the past 12 years, and its importance in strengthening the chain of survival has been recognised in the government's recent 'Cardiovascular Disease Outcomes Strategy'. The extent of use of PAD in OOH cardiac arrests in the UK is unknown. We surveyed all OOH cardiac arrests in Hampshire over a 12-month period to ascertain the availability and effective use of PAD. Methods A retrospective review of all patients with OOH cardiac arrest attended by South Central Ambulance Service (SCAS) in Hampshire during a 1-year period (1 September 2011 to 31 August 2012) was undertaken. Emergency calls were reviewed to establish the known presence of a PAD. Additionally, a review of all known PAD locations in Hampshire was undertaken, together with a survey of public areas where a PAD may be expected to be located. Results The current population of Hampshire is estimated to be 1.76 million. During the study period, 673 known PADs were located in 278 Hampshire locations. Of all calls confirmed as cardiac arrest (n=1035), the caller reported access to an automated external defibrillator (AED) on 44 occasions (4.25%), successfully retrieving and using the AED before arrival of the ambulance on only 18 occasions (1.74%). Conclusions Despite several campaigns to raise public awareness and make PADs more available, many public areas have no recorded AED available, and in those where an AED was available it was only used in a minority of cases by members of the public before arrival of the ambulance. Overall, a PAD was only deployed successfully in 1.74% OOH cardiac arrests. This weak link in the chain of survival contributes to the poor survival rate from OOH cardiac arrest and needs strengthening. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Uninterrupted chest compressions are a key factor in determining resuscitation success. Interruptions to chest compression are often associated with defibrillation, particularly the need to stand clear from the patient during defibrillation. It has been suggested that clinical examination gloves may provide adequate electrical resistance to enable safe hands-on defibrillation in order to minimise interruptions. We therefore examined whether commonly used nitrile clinical examination gloves provide adequate resistance to current flow to enable safe hands-on defibrillation. Methods: Clinical examination gloves (Kimberly Clark KC300 Sterling nitrile) worn by members of hospital cardiac arrest teams were collected immediately following termination of resuscitation. To determine the level of protection afforded by visually intact gloves, electrical resistance across the glove was measured by applying a DC voltage across the glove and measuring subsequent resistance. Results: Forty new unused gloves (control) were compared with 28 clinical (non-CPR) gloves and 128 clinical (CPR) gloves. One glove in each group had a visible tear and was excluded from analysis. Control gloves had a minimum resistance of 120kΩ (median 190kΩ) compared with 60kΩ in clinical gloves (both CPR (median 140kΩ) and non-CPR groups (median 160kΩ)). Discussion: Nitrile clinical examination gloves do not provide adequate electrical insulation for the rescuer to safely undertake ‘hands-on’ defibrillation and when exposed to the physical forces of external chest compression, even greater resistive degradation occurs. Further work is required to identify gloves suitable for safe use for ‘hands-on’ defibrillation. [Copyright &y& Elsevier]

Abstract: Introduction: Traditionally, anaesthetists have provided airway management skills on resuscitation teams. Because advanced life support (ALS) courses teach practical airway management, some UK hospitals have dropped anaesthetists from cardiac arrest teams. Does the ALS course give non-anaesthetists adequate skills to manage an airway during a cardiac arrest? Methods: We recruited adult surgical patients undergoing general anaesthesia and laryngeal mask airway (LMA) insertion as part of their routine care. Patients were randomly assigned to airway management by a junior doctor; either an ALS-qualified anaesthetist or an ALS-qualified non-anaesthetist. After induction of anaesthesia, five manual ventilations were delivered using a self-inflating bag-mask device before insertion of a LMA. We recorded the quality of manual ventilation (adequate, partially adequate or inadequate), the time to LMA insertion, and any complications. Results: Twenty anaesthetists and 16 non-anaesthetist ALS graduates participated. Of the anaesthetists, 18 (90%) demonstrated adequate and 2 (10%) demonstrated partially adequate manual ventilation skills, compared with non-anaesthetists of whom 5 (31.25%) demonstrated adequate, 5 (31.25%) demonstrated partially adequate, and 6 (37.5%) demonstrated inadequate manual ventilation skills (p <0.001). Eighteen anaesthetists (90%) and 4 non-anaesthetists (25%) met the ALS LMA insertion guideline time of 30s (p <0.0001). Median time for LMA insertion by anaesthetists and non-anaesthetists was 20.5s (range 16–40s, n =20) and 35.0s (range 18–168, n =10) respectively (p <0.05). Six of the 16 non-anaesthetists failed to insert the LMA (37.5%). There were four complications (laryngospasm, vomiting, and SaO2 <90%) in the non-anaesthetic group (25% of patients), compared with none in the anaesthetic group (p =0.01). Conclusions: The airway component of an ALS course alone does not give adequate practical skills for non-anaesthetists to manage an airway in an anaesthetised patient. Airway management at a cardiac arrest is unlikely to be any better. [Copyright &y& Elsevier]

Summary: Introduction: The need for rescue breaths in bystander CPR has been questioned after several studies have shown that omitting ventilation does not worsen outcome. Chest compression may produce passive tidal volumes large enough to provide adequate ventilation in animal studies, but no recent clinical studies have examined this phenomenon. We measured passive ventilation during optimal chest compression to determine whether compression-only CPR provides adequate gas exchange during cardiac arrest. Methods: Adult cardiac arrest patients were treated according to European Resuscitation Council guidelines. Chest compressions were performed using a mechanical chest compression device (LUCAS) with active decompression disabled to mimic manual compression. Respiratory variables were measured during periods of compression-only CPR. Results: Emergency Department data were collected during compression-only CPR from 17 patients (11 male) aged 47–82 years who had suffered an out-of-hospital cardiac arrest. Median tidal volume per compression was 41.5ml (range 33.0–62.1ml), being considerably less than measured deadspace in all patients. Maximum end-tidal CO2 was 0.93kPa (range 0.0–4.6kPa). Minute volume CO2 was 19.5ml (range 15.9–33.8; normal range 150–180ml). Conclusions: At an advanced stage of cardiac arrest, passive ventilation during compression-only CPR is limited in its ability to maintain adequate gas exchange, with gas transport mechanisms associated with high frequency ventilation perhaps generating a very limited gas exchange. The effectiveness of passive ventilation during the early stages of CPR, when chest and lung compliance is greater, remains to be investigated. [Copyright &y& Elsevier]

Summary: Introduction: Telephone cardiopulmonary resuscitation (CPR) advice aims to increase the quality and quantity of bystander CPR, one of the few interventions shown to improve outcome in cardiac arrest. We evaluated a current telephone protocol (based on 2000 ILCOR guidelines) to assess the effectiveness of verbal CPR instructions. Methods: Emergency calls were identified from AMPDS codes for cardiac arrest and checked against the ambulance patient record form to confirm the diagnosis. Calls over a seven month period were analysed retrospectively, and the time taken to perform interventions calculated. Results: 176 calls were analysed; of those 145 (82.4%) were confirmed cases of cardiac arrest. CPR was already underway in 11 cases (7.5%), 101 callers (69.7%) agreed to attempt CPR with telephone instructions. The median time to open the airway was 128s (62–482s), to perform the first ventilation was 247s (80–633s), and to perform the first chest compression was 315s (153–750s). Of those attempting CPR, 21 (20.8%) stopped because they were unable to move the patient onto a hard surface, and 28 (27.7%) required multiple attempts to perform effective ventilations. In the telephone CPR group 42/101 (40.6%) did not receive any chest compressions before the arrival of the ambulance crew. Conclusions: Although current telephone-CPR instructions significantly improve the numbers of patients in whom bystander CPR is attempted, significant delays and poor quality CPR are likely to limit any benefits. [Copyright &y& Elsevier]

Summary: Introduction: Hyperventilation during cardiopulmonary resuscitation is detrimental to survival. Several clinical studies of ventilation during hospital and out-of-hospital cardiac arrest have demonstrated respiratory rates far in excess of the 10min−1 recommended by the ERC. We observed detailed ventilation variables prospectively during manual ventilation of 12 cardiac arrest patients treated in the emergency department of a UK Hospital. Methods: Adult cardiac arrest patients were treated according to ERC guidelines. Ventilation was provided using a self-inflating bag. A COSMOplus monitor (Respironics Inc.) was inserted into the ventilation circuit at the beginning of the resuscitation from which ventilation data were downloaded to a laptop. Results: Data were collected from 12 patients (7 male; age 47–82 years). The maximum respiratory rate was 9–41 breaths per minute (median 26). The median tidal volume was 619ml (374–923ml) and the median respiratory rate was 21min−1 (7–37min−1). The corresponding median minute volume was 13.0l/min (4.6–21.3min−1). Median peak inspiratory pressures were 60.6cmH2O (range 46–106). Airway pressure was positive for 95.3% of the respiratory cycle (range 87.9–100%). Conclusions: Hyperventilation was common, mostly through high respiratory rates rather than excessive tidal volumes. This is the first study to document tidal volumes and airway pressures during resuscitation. The persistently high airway pressures are likely to have a detrimental effect on blood flow during CPR. Guidelines on respiratory rates are well known, but it would appear that in practice they are not being observed. [Copyright &y& Elsevier]

Summary: Introduction: Bystander cardiopulmonary resuscitation (CPR) significantly improves the outcome from sudden cardiac arrest (SCA) and is therefore encouraged by offering telephone instructions to the bystander. The effectiveness of this technique was examined in a manikin-based study. Methods: Subjects performed CPR on an instrumented adult manikin by following Advanced Medical Priority Dispatch System v11.1 (AMPDS) instructions given by telephone from a different room. Results: Fifty-one volunteers (26 males, median age 56, range 27–76 years) with no previous experience of CPR were recruited. No volunteers followed the entire instructions correctly. Forty percent were unable to open the airway, only 18% achieved a median inspiration time of 2s or greater and only 30% delivered tidal volumes within the range 700–1000ml. Chest compressions were performed at a median rate of 52min−1 with only 4% of subjects achieving a rate of 100min−1. Depth of compression was also inadequate in 88% of subjects and hand positioning was incorrect in a third of subjects. The median duty cycle was 46% and there were significant delays between the commencement of the AMPDS protocol and the delivery of the first breath (123s) and first chest compression (163s). Discussion: Few bystanders perform CPR satisfactorily and further work is necessary to improve the effectiveness of telephone CPR instructions. [Copyright &y& Elsevier]

Summary: Objective: Biphasic waveforms have similar or greater efficacy at cardioverting atrial and ventricular arrhythmias at lower energy levels than monophasic waveforms, and cause less ST depression following defibrillation of ventricular fibrillation. No studies have investigated this effect on ST change with atrial arrhythmias. We studied the efficacy of the Welch Allyn-MRL PIC biphasic defibrillator. Methods: One hundred and thirty-nine patients undergoing elective DC cardioversion for atrial arrhythmias were randomised to cardioversion by monophasic (Hewlett Packard Codemaster XL; 100, 200, 300, 360 and 360J) or biphasic (Welch Allyn-MRL PIC; 70, 100, 150, 200 and 300J) defibrillator. We analysed success of cardioversion after 0 and 30min, cumulative energy, number of shocks and energy at successful cardioversion. The ST change in the recorded electrocardiogram was measured at 15s after all shocks using electronic callipers. Results: Immediately after cardioversion 59/68 (86.8%) of the monophasic group versus 56/60 (93.3%) of the biphasic group were in sinus rhythm. Of the monophasic group, 55/67 (82.1%) remained in sinus rhythm at 30min versus 53/58 (91.4%) of the biphasic group. These differences were not significant at 0min (P =0.35) or 30min (P =0.21). The biphasic group required significantly fewer shocks (P =0.006), less cumulative energy (P <0.0001) and required lower total energy for successful cardioversion (P <0.0001). Of the 102 patients with electrocardiogram recordings suitable for analysis, ST segment change was greater in the monophasic group (P =0.037). Conclusions: The Welch Allyn-MRL biphasic waveform for DC cardioversion results in fewer shocks, with less cumulative energy delivered and less post shock ST change than with a Hewlett Packard Codemaster XL damped sine wave monophasic waveform. [Copyright &y& Elsevier]

B CLINICAL IMPLICATIONS: b Results from further studies like this will help personalize CPR to an individual's specific resuscitative needs rather than standardizing CPR to all patients. Future studies examining hemodynamic-directed CPR vs current CPR standards are needed to enhance the effective use of physiologic measures to improve resuscitation outcomes. [Extracted from the article]

The authors stress the need for preventive programs for addressing drowning incidents involving children. They mention a study which point out the poor outcomes of resuscitation efforts. They discuss community and policy recommendations made by the World Health Organization for preventing drowning incidents such as the installation of barriers and the need to teach school age children basic swimming skills and safety.

Despite its use since the 1960s, the safety or effectiveness of adrenaline as a treatment for cardiac arrest has never been comprehensively evaluated in a clinical trial. Although most studies have found that adrenaline increases the chance of return of spontaneous circulation for short periods, many studies found harmful effects on the brain and raise concern that adrenaline may reduce overall survival and/or good neurological outcome. The PARAMEDIC-2 trial seeks to determine if adrenaline is safe and effective in out-of-hospital cardiac arrest. This is a pragmatic, individually randomised, double blind, controlled trial with a parallel economic evaluation. Participants will be eligible if they are in cardiac arrest in the out-of-hospital environment and advanced life support is initiated. Exclusions are cardiac arrest as a result of anaphylaxis or life threatening asthma, and patient known or appearing to be under 16 or pregnant. 8000 participants treated by 5 UK ambulance services will be randomised between December 2014 and August 2017 to adrenaline (intervention) or placebo (control) through opening pre-randomised drug packs. Clinical outcomes are survival to 30 days (primary outcome), hospital discharge, 3, 6 and 12 months, health related quality of life, and neurological and cognitive outcomes (secondary outcomes). Trial registration (ISRCTN73485024). [ABSTRACT FROM AUTHOR]

Aim To summarise the evidence from randomised controlled trials of mechanical chest compression devices used during resuscitation after out of hospital cardiac arrest. Methods Systematic review of studies evaluating the effectiveness of mechanical chest compression. We included randomised controlled trials or cluster randomised trials that compared mechanical chest compression (using any device) with manual chest compression for adult patients following out-of-hospital cardiac arrest. Outcome measures were return of spontaneous circulation, survival of event, overall survival, survival with good neurological outcome. Results were combined using random-effects meta-analysis. Data sources Studies were identified by searches of electronic databases, reference lists of other studies and review articles. Results Five trials were included, of which three evaluated the LUCAS or LUCAS-2 device and two evaluated the AutoPulse device. The results did not show an advantage to the use of mechanical chest compression devices for survival to discharge/30 days (average OR 0.89, 95% CI 0.77, 1.02) and survival with good neurological outcome (average OR 0.76, 95% CI 0.53, 1.11). Conclusions Existing studies do not suggest that mechanical chest compression devices are superior to manual chest compression, when used during resuscitation after out of hospital cardiac arrest. [ABSTRACT FROM AUTHOR]

Out-of-hospital cardiac arrest is a global public health issue experienced by ≈3.8 million people annually. Only 8% to 12% survive to hospital discharge. Early defibrillation of shockable rhythms is associated with improved survival, but ensuring timely access to defibrillators has been a significant challenge. To date, the development of public-access defibrillation programs, involving the deployment of automated external defibrillators into the public space, has been the main strategy to address this challenge. Public-access defibrillator programs have been associated with improved outcomes for out-of-hospital cardiac arrest; however, the devices are used in <3% of episodes of out-of-hospital cardiac arrest. This scientific statement was commissioned by the International Liaison Committee on Resuscitation with 3 objectives: (1) identify known barriers to public-access defibrillator use and early defibrillation, (2) discuss established and novel strategies to address those barriers, and (3) identify high-priority knowledge gaps for future research to address. The writing group undertook systematic searches of the literature to inform this statement. Innovative strategies were identified that relate to enhanced public outreach, behavior change approaches, optimization of static public-access defibrillator deployment and housing, evolved automated external defibrillator technology and functionality, improved integration of public-access defibrillation with existing emergency dispatch protocols, and exploration of novel automated external defibrillator delivery vectors. We provide evidence- and consensus-based policy suggestions to enhance public-access defibrillation and guidance for future research in this area. [ABSTRACT FROM AUTHOR]

Out-of-hospital cardiac arrest is a global public health issue experienced by ≈3.8 million people annually. Only 8% to 12% survive to hospital discharge. Early defibrillation of shockable rhythms is associated with improved survival, but ensuring timely access to defibrillators has been a significant challenge. To date, the development of public-access defibrillation programs, involving the deployment of automated external defibrillators into the public space, has been the main strategy to address this challenge. Public-access defibrillator programs have been associated with improved outcomes for out-of-hospital cardiac arrest; however, the devices are used in <3% of episodes of out-of-hospital cardiac arrest. This scientific statement was commissioned by the International Liaison Committee on Resuscitation with 3 objectives: (1) identify known barriers to public-access defibrillator use and early defibrillation, (2) discuss established and novel strategies to address those barriers, and (3) identify high-priority knowledge gaps for future research to address. The writing group undertook systematic searches of the literature to inform this statement. Innovative strategies were identified that relate to enhanced public outreach, behavior change approaches, optimization of static public-access defibrillator deployment and housing, evolved automated external defibrillator technology and functionality, improved integration of public-access defibrillation with existing emergency dispatch protocols, and exploration of novel automated external defibrillator delivery vectors. We provide evidence- and consensus-based policy suggestions to enhance public-access defibrillation and guidance for future research in this area. [ABSTRACT FROM AUTHOR]

Background: Early defibrillation is an essential element of the chain of survival for out-of-hospital cardiac arrest (OHCA). Public access defibrillation (PAD) programmes aim to place automated external defibrillators (AED) in areas with high OHCA incidence, but there is sometimes a mismatch between AED density and OHCA incidence.Objectives: This study aimed to assess whether there were any disparities in the characteristics of areas that have an AED and those that do not in England.Methods: Details of the location of AEDs registered with English Ambulance Services were obtained from individual services or internet sources. Neighbourhood characteristics of lower layer super output areas (LSOA) were obtained from the Office for National Statistics. Comparisons were made between LSOAs with and without a registered AED.Results: AEDs were statistically more likely to be in LSOAs with a lower residential but higher workplace population density, with people predominantly from a white ethnic background and working in higher socio-economically classified occupations (p < 0.05). There was a significant correlation between AED coverage and the LSOA Index of Multiple Deprivation (IMD) (r = 0.79, p = 0.007), with only 27.4% in the lowest IMD decile compared to about 45% in highest. AED density varied significantly across the country from 0.82/km2 in the north east to 2.97/km2 in London.Conclusions: In England, AEDs were disproportionately placed in more affluent areas, with a lower residential population density. This contrasts with locations where OHCAs have previously occurred. Future PAD programmes should give preference to areas of higher deprivation and be tailored to the local community. [ABSTRACT FROM AUTHOR]

These European Resuscitation Council Advanced Life Support guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest. [ABSTRACT FROM AUTHOR]

Aims: We recently reported early outcomes in patients enrolled in a randomised trial of adrenaline in out-of-hospital cardiac arrest: the PARAMEDIC2 (Prehospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration in Cardiac Arrest) trial. The purpose of the present paper is to report long-term survival, quality of life, functional and cognitive outcomes at 3, 6 and 12-months.Methods: PARAMEDIC2 was a pragmatic, individually randomised, double blind, controlled trial with an economic evaluation. Patients were randomised to either adrenaline or placebo. This paper reports results on the modified Rankin Scale scores at 6-months, survival at 6 and 12-months, as well as other cognitive, functional and quality of life outcomes collected at 3 and 6 months (Two Simple Questions, the Mini Mental State Examination, the Informant Questionnaire on Cognitive Decline Evaluation for Cardiac Arrest, Hospital Anxiety and Depression Scale, the Post Traumatic Stress Disorder Checklist - Civilian Version, Short-Form 12-item Health Survey and the EuroQoL EQ-5D-5L).Results: 8014 patients were randomised with confirmed trial drug administration. At 6-months, 78 (2.0%) of the patients in the adrenaline group and 58 (1.5%) of patients in the placebo group had a favourable neurological outcome (adjusted odds ratio 1.35 [95% confidence interval: 0.93, 1.97]). 117 (2.9%) patients were alive at 6-months in the adrenaline group compared with 86 (2.2%) in the placebo group (1.43 [1.05, 1.96], reducing to 107 (2.7%) and 80 (2.0%) respectively at 12-months (1.38 [1.00, 1.92]). Measures of 3 and 6-month cognitive, functional and quality of life outcomes were reduced, but there was no strong evidence of differences between groups.Conclusion: Adrenaline improved survival through to 12-months follow-up. The study did not find evidence of improvements in favourable neurological outcomes. (ISCRTN 73485024). [ABSTRACT FROM AUTHOR]

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations for advanced life support includes updates on multiple advanced life support topics addressed with 3 different types of reviews. Topics were prioritized on the basis of both recent interest within the resuscitation community and the amount of new evidence available since any previous review. Systematic reviews addressed higher-priority topics, and included double-sequential defibrillation, intravenous versus intraosseous route for drug administration during cardiac arrest, point-of-care echocardiography for intra-arrest prognostication, cardiac arrest caused by pulmonary embolism, postresuscitation oxygenation and ventilation, prophylactic antibiotics after resuscitation, postresuscitation seizure prophylaxis and treatment, and neuroprognostication. New or updated treatment recommendations on these topics are presented. Scoping reviews were conducted for anticipatory charging and monitoring of physiological parameters during cardiopulmonary resuscitation. Topics for which systematic reviews and new Consensuses on Science With Treatment Recommendations were completed since 2015 are also summarized here. All remaining topics reviewed were addressed with evidence updates to identify any new evidence and to help determine which topics should be the highest priority for systematic reviews in the next 1 to 2 years. [ABSTRACT FROM AUTHOR]