Part 8: Advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

Temperature Control in Acute Brain Injury: An Update

Temperature control in severe acute brain injury (SABI) is a key component of acute management. This manuscript delves into the complex role of temperature management in SABI, encompassing conditions like traumatic brain injury (TBI), acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), aneurysmal subarachnoid hemorrhage (aSAH), and hypoxemic/ischemic brain injury following cardiac arrest. Fever is a common complication in SABI and is linked to worse neurological outcomes due to increased inflammatory responses and intracranial pressure (ICP). Temperature management, particularly hypothermic temperature control (HTC), appears to mitigate these adverse effects primarily by reducing cerebral metabolic demand and dampening inflammatory pathways. However, the effectiveness of HTC varies across different SABI conditions. In the context of post-cardiac arrest, the impact of HTC on neurological outcomes has shown inconsistent results. In cases of TBI, HTC seems promising for reducing ICP, but its influence on long-term outcomes remains uncertain. For AIS, clinical trials have yet to conclusively demonstrate the benefits of HTC, despite encouraging preclinical evidence. This variability in efficacy is also observed in ICH, aSAH, bacterial meningitis, and status epilepticus. In pediatric and neonatal populations, while HTC shows significant benefits in hypoxic-ischemic encephalopathy, its effectiveness in other brain injuries is mixed. Although the theoretical basis for employing temperature control, especially HTC, is strong, the clinical outcomes differ among various SABI subtypes. The current consensus indicates that fever prevention is beneficial across the board, but the application and effectiveness of HTC are more nuanced, underscoring the need for further research to establish optimal temperature management strategies. Here we provide an overview of the clinical evidence surrounding the use of temperature control in various types of SABI.

Diagnosis and Management of Acute Respiratory Failure

Acute hypoxemic respiratory failure is defined by Pao2 less than 60 mm Hg or SaO2 less than 88% and may result from V/Q mismatch, shunt, hypoventilation, diffusion limitation, or low inspired oxygen tension. Acute hypercapnic respiratory failure is defined by Paco2 ≥ 45 mm Hg and pH less than 7.35 and may result from alveolar hypoventilation, increased fraction of dead space, or increased production of carbon dioxide. Early diagnostic maneuvers, such as measurement of SpO2 and arterial blood gas, can differentiate the type of respiratory failure and guide next steps in evaluation and management.

Acute liver failure after out-of-hospital cardiac arrest: An observational study

RATIONALE

Apart from hypoxic hepatitis (HH), the hepatic consequences of out-of-hospital cardiac arrest (OHCA) have been little studied. This cohort study aimed to investigate the characteristics of liver dysfunction resulting from OHCA and its association with outcomes.

METHODS

Among the conventional static liver function tests used to define acute liver failure (ALF), we determined which one correlated more closely with the reference indocyanine green (ICG) clearance test in a series of OHCA patients from the CYRUS trial (NCT01595958). Subsequently, we assessed whether ALF, in addition to HH (i.e., acute liver injury), was an independent risk factor for death in a large cohort of OHCA patients admitted to two intensive care units between 2007 and 2017.

RESULTS

ICG clearance, available for 22 patients, was impaired in 17 (77.3%) cases. Prothrombin time (PT) ratio was the only static liver function test that correlated significantly (r = -0.66, p < 0.01) with ICG clearance and was therefore used to define ALF, with the usual cutoff of < 50%. Of the 418 patients included in the analysis (sex ratio: 1.4; median age: 64 [53-75] years; non-shockable rhythm: 73%), 67 (16.0%) presented with ALF, and 61 (14.6%) had HH at admission. On day 28, 337 (80.6%) patients died. Following multivariate analysis, ALF at admission, OHCA occurring at home, absence of bystander, non-cardiac cause of OHCA, low-flow duration ≥ 20 min, and SOFA score excluding liver subscore at admission were independently associated with day 28 mortality.

CONCLUSIONS

ALF occurred frequently after OHCA and, unlike HH, was independently associated with day 28 mortality.

Maternal cardiopulmonary resuscitation

The perinatal resuscitation history in Japan is short, with the earliest efforts in the field of neonatology. In contrast, the standardization and dissemination of maternal resuscitation is lagging. With the establishment of the Maternal Death Reporting Project and the Maternal Death Case Review and Evaluation Committee in 2010, with the aim of reducing maternal deaths, the true situation of maternal deaths came to light. Subsequently, in 2015, the Japan Council for the Dissemination of Maternal Emergency Life Support Systems (J-CIMELS) was established to educate and disseminate simulations in maternal emergency care; training sessions on maternal resuscitation are now conducted in all prefectures. Since the launch of the project and council, the maternal mortality rate in Japan (especially due to obstetric critical hemorrhage) has gradually decreased. This has been probably achieved due to the tireless efforts of medical personnel involved in perinatal care, as well as the various activities conducted so far. However, there are no standardized guidelines for maternal resuscitation yet. Therefore, a committee was set up within the Japan Resuscitation Council to develop a maternal resuscitation protocol, and the Guidelines for Maternal Resuscitation 2020 was created in 2021. These guidelines are expected to make the use of high-quality resuscitation methods more widespread than ever before. This presentation will provide an overview of the Guidelines for Maternal Resuscitation 2020.

The evolution of hypothermia for neuroprotection after cardiac arrest: a history in the making

While much has been observed regarding hypothermia by way of environmental exposure, it is modern day medicine that deployed hypothermia as a therapeutic. From the early 1930s, when Temple Fay deployed "refrigeration" to treat pain, to the work of Wilfred Bigelow and Charles Drew, who utilized hypothermia in open heart surgery-the opportunities seemed endless. However, questions arose surrounding appropriate temperatures to achieve best outcomes and how to minimize adverse events, such as coagulopathy and infection. In the 1980s, hypothermia underwent a resurgence through Peter Safar's critical studies in large animals, which quickly translated into feasibility studies and the landmark trials of 2002 that paved the way for postcardiac arrest care as we currently know it. Through clinical and observational trials, modern-day targeted temperature management continues to adapt, striving to improve patient outcomes. While hypothermia has come a long way from the writings of Hippocrates, the ideal therapy has not yet been defined, and more work is needed. While the history is long, there is more to be written and advances to be achieved as we optimize the neuroprotective effects of hypothermia for comatose survivors of cardiac arrest.

[Adult advanced life support]

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.

Adrenaline to improve survival in out-of-hospital cardiac arrest: the PARAMEDIC2 RCT

BACKGROUND

Adrenaline has been used as a treatment for cardiac arrest for many years, despite uncertainty about its effects on long-term outcomes and concerns that it may cause worse neurological outcomes.

OBJECTIVES

The objectives were to evaluate the effects of adrenaline on survival and neurological outcomes, and to assess the cost-effectiveness of adrenaline use.

DESIGN

This was a pragmatic, randomised, allocation-concealed, placebo-controlled, parallel-group superiority trial and economic evaluation. Costs are expressed in Great British pounds and reported in 2016/17 prices.

SETTING

This trial was set in five NHS ambulance services in England and Wales.

PARTICIPANTS

Adults treated for an out-of-hospital cardiac arrest were included. Patients were ineligible if they were pregnant, if they were aged < 16 years, if the cardiac arrest had been caused by anaphylaxis or life-threatening asthma, or if adrenaline had already been given.

INTERVENTIONS

Participants were randomised to either adrenaline (1 mg) or placebo in a 1 : 1 allocation ratio by the opening of allocation-concealed treatment packs.

MAIN OUTCOME MEASURES

The primary outcome was survival to 30 days. The secondary outcomes were survival to hospital admission, survival to hospital discharge, survival at 3, 6 and 12 months, neurological outcomes and health-related quality of life through to 6 months. The economic evaluation assessed the incremental cost per quality-adjusted life-year gained from the perspective of the NHS and Personal Social Services. Participants, clinical teams and those assessing patient outcomes were masked to the treatment allocation.

RESULTS

From December 2014 to October 2017, 8014 participants were assigned to the adrenaline (n = 4015) or to the placebo (n = 3999) arm. At 30 days, 130 out of 4012 participants (3.2%) in the adrenaline arm and 94 out of 3995 (2.4%) in the placebo arm were alive (adjusted odds ratio for survival 1.47, 95% confidence interval 1.09 to 1.97). For secondary outcomes, survival to hospital admission was higher for those receiving adrenaline than for those receiving placebo (23.6% vs. 8.0%; adjusted odds ratio 3.83, 95% confidence interval 3.30 to 4.43). The rate of favourable neurological outcome at hospital discharge was not significantly different between the arms (2.2% vs. 1.9%; adjusted odds ratio 1.19, 95% confidence interval 0.85 to 1.68). The pattern of improved survival but no significant improvement in neurological outcomes continued through to 6 months. By 12 months, survival in the adrenaline arm was 2.7%, compared with 2.0% in the placebo arm (adjusted odds ratio 1.38, 95% confidence interval 1.00 to 1.92). An adjusted subgroup analysis did not identify significant interactions. The incremental cost-effectiveness ratio for adrenaline was estimated at £1,693,003 per quality-adjusted life-year gained over the first 6 months after the cardiac arrest event and £81,070 per quality-adjusted life-year gained over the lifetime of survivors. Additional economic analyses estimated incremental cost-effectiveness ratios for adrenaline at £982,880 per percentage point increase in overall survival and £377,232 per percentage point increase in neurological outcomes over the first 6 months after the cardiac arrest.

LIMITATIONS

The estimate for survival with a favourable neurological outcome is imprecise because of the small numbers of patients surviving with a good outcome.

CONCLUSIONS

Adrenaline improved long-term survival, but there was no evidence that it significantly improved neurological outcomes. The incremental cost-effectiveness ratio per quality-adjusted life-year exceeds the threshold of £20,000-30,000 per quality-adjusted life-year usually supported by the NHS.

FUTURE WORK

Further research is required to better understand patients' preferences in relation to survival and neurological outcomes after out-of-hospital cardiac arrest and to aid interpretation of the trial findings from a patient and public perspective.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN73485024 and EudraCT 2014-000792-11.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 25. See the NIHR Journals Library website for further project information.

European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation and organ donation.

European Resuscitation Council and European Society of Intensive Care Medicine Guidelines 2021: Post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation, and organ donation.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

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.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

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.

Association of Intra-arrest Transport vs Continued On-Scene Resuscitation With Survival to Hospital Discharge Among Patients With Out-of-Hospital Cardiac Arrest

Importance

There is wide variability among emergency medical systems (EMS) with respect to transport to hospital during out-of-hospital cardiac arrest (OHCA) resuscitative efforts. The benefit of intra-arrest transport during resuscitation compared with continued on-scene resuscitation is unclear.

Objective

To determine whether intra-arrest transport compared with continued on-scene resuscitation is associated with survival to hospital discharge among patients experiencing OHCA.

Design, Setting, and Participants

Cohort study of prospectively collected consecutive nontraumatic adult EMS-treated OHCA data from the Resuscitation Outcomes Consortium (ROC) Cardiac Epidemiologic Registry (enrollment, April 2011-June 2015 from 10 North American sites; follow-up until the date of hospital discharge or death [regardless of when either event occurred]). Patients treated with intra-arrest transport (exposed) were matched with patients in refractory arrest (at risk of intra-arrest transport) at that same time (unexposed), using a time-dependent propensity score. Subgroups categorized by initial cardiac rhythm and EMS-witnessed cardiac arrests were analyzed.

Exposures

Intra-arrest transport (transport initiated prior to return of spontaneous circulation), compared with continued on-scene resuscitation.

Main Outcomes and Measures

The primary outcome was survival to hospital discharge, and the secondary outcome was survival with favorable neurological outcome (modified Rankin scale <3) at hospital discharge.

Results

The full cohort included 43 969 patients with a median age of 67 years (interquartile range, 55-80), 37% were women, 86% of cardiac arrests occurred in a private location, 49% were bystander- or EMS-witnessed, 22% had initial shockable rhythms, 97% were treated by out-of-hospital advanced life support, and 26% underwent intra-arrest transport. Survival to hospital discharge was 3.8% for patients who underwent intra-arrest transport and 12.6% for those who received on-scene resuscitation. In the propensity-matched cohort, which included 27 705 patients, survival to hospital discharge occurred in 4.0% of patients who underwent intra-arrest transport vs 8.5% who received on-scene resuscitation (risk difference, 4.6% [95% CI, 4.0%- 5.1%]). Favorable neurological outcome occurred in 2.9% of patients who underwent intra-arrest transport vs 7.1% who received on-scene resuscitation (risk difference, 4.2% [95% CI, 3.5%-4.9%]). Subgroups of initial shockable and nonshockable rhythms as well as EMS-witnessed and unwitnessed cardiac arrests all had a significant association between intra-arrest transport and lower probability of survival to hospital discharge.

Conclusions and Relevance

Among patients experiencing out-of-hospital cardiac arrest, intra-arrest transport to hospital compared with continued on-scene resuscitation was associated with lower probability of survival to hospital discharge. Study findings are limited by potential confounding due to observational design.

Clinical experience of whole-body computed tomography as the initial evaluation tool after extracorporeal cardiopulmonary resuscitation in patients of out-of-hospital cardiac arrest

Background

The routine application of whole-body CT after extracorporeal cardiopulmonary resuscitation (ECPR) in out-of-hospital cardiac arrest (OHCA) has not been extensively investigated. We aimed to evaluate the benefit of CT in this context.

Methods

We retrospectively analyzed all OHCA patients who had received ECPR between January 2006 to May 2019. Electronic records were reviewed to filter out patients who had a whole-body CT as their first clinical evaluation after ECPR. CT findings and major hospital outcomes were evaluated.

Results

From January 2006 to May 2019, 700 patients had received ECPR in our institution. We identified 93 OHCA patients who received whole-body CT as the first clinical evaluation after ECPR. 22.6% of those had no acute findings detected on CT requiring immediate treatment. In the remaining 77.4%, CT had findings that might lead to alterations in clinical course. Most important findings were myocardial infarction (57.0%), hypoxic brain injury (29.0%), sternal/rib fractures (16.1%), aortic dissection (7.5%), pulmonary embolism (5.4%), and cardiac tamponade (5.4%). There were no significant differences in ICU/hospitalization days, time on ECMO support, survival and neurological outcomes between those with and without immediate CT. In our OHCA cohort, there were 27 patients with CT evidence of hypoxic brain injury, of whom 22.2% (n = 2) managed to wean from ECMO support, 14.8% (n = 4) survived to discharge, but only 3.7% (n = 1) survived with good neurological outcome. Hypoxic brain injury on CT has a 95% specificity in predicting poor neurological outcome, with a false positive rate of only 3.7%. Logistic regression suggested a potential correlation between CT findings of hypoxic brain injury and poor neurological outcome [Odds ratio (OR) = 12.53 (1.55 to 10.1), p = 0.02)].

Conclusions

Routine whole-body CT after ECPR in OHCA patients appears to have a limited role, as the majority is caused by ACS. However, it may be a useful tool when CPR-related injury or non-ACS causes of OHCA are suspected, as well as in cases where the cause of OHCA is unknown. On the contrary, routine brain CT may be a valuable tool in guiding anticoagulant therapy during ECMO and in aiding outcome prediction.

Effectiveness of different supralottic airways during resuscitation manoeuvres. A systematic review

INTRODUCTION

Supraglottic airways, which are easily inserted and minimize interruptions in cardiopulmonary resuscitation manoeuvres, are now widely used in pre- and in-hospital emergencies. However, most studies in these devices do not specify whether they ensure good ventilation during CPR. This systematic review aims to determine whether there is evidence that supraglotic airways enable effective ventilation during resuscitation.

METHODS

The MEDLINE and COCHRANE databases were searched for studies published in English up to 30 November 2018. Eligible studies were all those that objectively evaluated tidal volume during resuscitation maneuvers in patients over 18 years of age using various supraglottic airways.

RESULTS

A total of 3734 articles were identified, of which 252 were duplicates. Only 1 objectively evaluated ventilation during resuscitation maneuvers and presented data relevant to this review. The study included 470 patients, 51 of which underwent spirometry. Only 4.48% of patients survived to hospital discharge; however, the correlation with ventilation effectiveness was not assessed.

CONCLUSION

There is no scientific evidence that supraglottic airways provide effective ventilation during resuscitation maneuvers. Evaluation by spirometry, chest impedance and ultrasound may help to determine the ventilatory efficacy of supraglottic airways during CPR, and clarify whether this factor contributes to the difficulties experienced in reversing cardiorespiratory arrest.

Concordance between the 2010 and 2015 Resuscitation Guidelines of International Liaison Committee of Resuscitation Councils (ILCOR) members and the ILCOR Consensus of Science and Treatment Recommendations (CoSTRs)

BACKGROUND

Cardiac arrests are associated with poor outcomes. The International Liaison Committee on Resuscitation (ILCOR) evaluates resuscitation science and produced, until 2015, five-yearly consensus on science and treatment recommendations (CoSTRs), informing global resuscitation guidelines. We aimed to identify similarities/differences in resuscitation guidelines from ILCOR members, noting concurrence over time, and CoSTRs influence on these guidelines.

METHODS

We considered the component elements of paediatric and adult, basic and advanced resuscitation guidelines, published in 2010 and 2015, along with matching ILCOR CoSTRs to examine their influence. We contacted the responsible councils when guidelines were unavailable online.

RESULTS

Complete resuscitation guidelines were found for six of the seven ILCOR council members. The Resuscitation Council of Asia only had adult basic life support (BLS) guidelines in English. Three members used the AHA guidelines. Therefore, five rather than seven sets of resuscitation guidelines were compared to the CoSTRs. Concurrence between CoSTRs recommendations and ILCOR council member's resuscitation guidelines has improved over time. Minor variations were identified in both basic and advanced life support, with most variance in paediatric guidelines, but these narrowed over time.

CONCLUSION

The improved concurrence across the resuscitation guidelines with the CoSTRs suggests that ILCOR members accept and hence incorporate CoSTRs recommendations to inform their own resuscitation guidelines. This is one step towards the development of international universal guidelines for adult and paediatric resuscitation.

The use of pressure-controlled mechanical ventilation in a swine model of intraoperative pediatric cardiac arrest

BACKGROUND

Current pediatric resuscitation guidelines suggest that resuscitators using an advanced airway deliver 8-10 breaths per minute while carefully avoiding excessive ventilation. In the intraoperative setting, having a dedicated ventilation rescuer may be difficult because of limited personnel. Continuing pressure-controlled mechanical ventilation during resuscitation for intraoperative cardiac arrest reduces personnel needed and the risk of hyperventilation but might risk hypoventilation during chest compression delivery.

AIMS

To determine whether the use of pressure-controlled mechanical ventilation at prearrest settings provides normoxia and normocarbia during resuscitation from cardiac arrest.

METHODS

We retrospectively analyzed combined data from preclinical randomized controlled trials. Two-week-old swine (3-4 kg) underwent asphyxia-induced cardiac arrest. Animals were resuscitated with periods of basic and advanced life support. During resuscitation, pressure-controlled mechanical ventilation was delivered at the prearrest respiratory rate, peak inspiratory pressure, and positive end-expiratory pressure. Arterial blood gases were measured prearrest, at 11 minutes of asphyxia, and at 8 and 20 minutes of cardiopulmonary resuscitation.

RESULTS

Piglets (n = 154) received pressure-controlled mechanical ventilation before and during cardiopulmonary resuscitation with a peak inspiratory pressure of 14-15 cm H₂ O, positive end-expiratory pressure of 4 cm H₂ O, 20 breaths/minute, and an inspiratory:expiratory ratio of 1:2. During asphyxia, the arterial blood gas showed the expected severe hypercarbia and hypoxia. Continuing pressure-controlled mechanical ventilation using prearrest parameters and increasing the FiO₂ to 1.0 returned the PaCO₂ to prearrest levels and slightly increased the partial pressure of arterial oxygen at 8 and 20 minutes of cardiopulmonary resuscitation.

CONCLUSION

In this piglet model of resuscitation from asphyxial arrest, pressure-controlled mechanical ventilation during cardiopulmonary resuscitation at the prearrest ventilator settings with an FiO₂ of 1.0 provides adequate oxygenation and restores normocarbia. Clinical investigation is warranted to determine the benefits of continuing pressure-controlled mechanical ventilation at prearrest parameters during pediatric cardiopulmonary resuscitation.

Optimising ambulance service contribution to clinical trials: a phenomenological exploration using focus groups

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 pre-hospital trial. Investment in time and resource to provide face-to-face training and personalised feedback to paramedics can foster engagement and optimise performance.

Factors for modifying the termination of resuscitation rule in out-of-hospital cardiac arrest

BACKGROUND

False positive rate (FPR) of the current basic life support (BLS) termination of resuscitation (TOR) rule in out-of-hospital cardiac arrest (OHCA) patients (not witnessed; no return of spontaneous circulation prior to transport; and no shocks were delivered) has been ethically challenging. We validated the current BLS TOR rule with using nationwide Korean Cardiac Arrest Research Consortium (KoCARC) registry and identified the factors for modifying the rules.

METHODS

This prospective, multicenter, registry-based study was performed using the nontraumatic OHCA registry data between October 2015 and June 2017. Independent factors associated with poor neurologic outcome were identified to propose new KoCARC TOR rules by using multivariable analysis. The diagnostic performances of the TOR rules were calculated respectively.

RESULTS

Among 4,360 OHCA patients, 2,801 (64.2%) satisfied all 3 criteria of the BLS TOR rule. The FPR and positive predictive value of the BLS TOR rule were 5.9% and 99.3%. Asystole as initial rhythm and age > 60 years were found as new factors for modifying the TOR rule. New KoCARC TOR rules, combination of asystole and age > 60 years with current TOR rule, showed lower FPR (0.3%-2.1%) and higher positive predictive value (99.7%-99.9%) for predicting poor neurologic outcome at discharge.

CONCLUSIONS

In this recent nationwide cohort, the current BLS TOR rule showed high FPR (5.9%) for predicting poor neurologic outcome. We anticipate that our new KoCARC TOR rules, application of 2 new factors (asystole as initial rhythm and age > 60 years) with BLS TOR rule, could reduce unwarranted death.

Twenty-year trends in the characteristic, management and outcome of patients with ST-elevation myocardial infarction and out-of-hospital reanimation. Insight from the national AMIS PLUS registry 1997-2017

BACKGROUND

Few studies describe recent changes in the incidence, treatment and outcome of successfully resuscitated STEMI patients after out-of-hospital cardiac arrest (OHCA) compared with non-OHCA STEMI patients.

OBJECTIVE

To examine temporal trends in the incidence, therapeutic management, most serious complications, mortality rate and outcome of OHCA patients fulfilling criteria of STEMI compared with a reference group of STEMI patients without OHCA.

METHODS

Analysis of registry data (AMIS Plus Registry) among STEMI patients both with and without OHCA between 1997 and 2017.

RESULTS

Among 31,650 patients with STEMI, 6.8% were successfully resuscitated prior to hospital admission. Increasing incidences of hospital-admitted patients following successful out-of-hospital CPR were observed (4.5% in 1999 vs. 8.6% in 2017). OHCA STEMI patients were at higher clinical risk at presentation (36.1% vs. 2.7%; p < 0.001 with cardiogenic shock) despite a shorter time span from the onset of symptoms to hospitalization (195 min vs. 107 min; p < 0.001) and a lower prevalence of cardiovascular risk factors except smoking. More PCIs were performed in STEMI patients with OHCA (78.9% vs. 74.5% for non-OHCA patients; p < 0.001). However, over time PCI became the preferred primary intervention irrespective of the OHCA status of STEMI patients. For STEMI patients without OHCA, there was a significant correlation between PCI and time periods on in-hospital mortality (p < 0.001), which was p = 0.002 when adjusted for age and gender. For STEMI patients with OHCA, the interaction between PCI and time was unadjusted p = 0.395 and p = 0.438 when adjusted for age and gender.

Using initial serum lactate level in the emergency department to predict the sustained return of spontaneous circulation in nontraumatic out-of-hospital cardiac arrest patients

Objective

To examine the initial level of lactate to predict sustained return of spontaneous circulation (ROSC) in nontraumatic out-of-hospital cardiac arrest (OHCA) patients.

Materials and methods

This was a 30-month retrospective cohort study in an emergency department (ED) of a tertiary care hospital. The inclusion criteria were adult nontraumatic OHCA patients who came to the ED with ongoing chest compression. The primary outcome was initial serum lactate level at the ED to predict sustained ROSC in nontraumatic OHCA. Logistic regression was used to determine any association between sustained ROSC and significant variables.

Results

There were 207 patients who met the inclusion criteria. Forty one percent of nontraumatic OHCA patients achieved sustained ROSC. The mean ± SD initial serum lactate in the ROSC group was lower than the non-ROSC group (12.0±4.8 vs 12.6±5), but without statistical significance. The significant factors to predict sustained ROSC were no underlying disease (adjusted odds ratio [aOR] 1.71, 95% CI 0.51–5.71, P=0.014), cardiac arrest in a public area (aOR 2.40, 95% CI 1.2–4.79, P=0.013), and witnessed arrest (aOR 2.39, 95% CI 1.26–4.52, P=0.008). The cut-off points of initial serum lactate to predict mortality at 24 and 48 hours after cardiopulmonary resuscitation were 9.1 (P=0.031) and 9.4 (P=0.049) mmol/L, respectively. Eleven survived to hospital discharge, and 54.5% had good neurological outcome without statistical significance (P=0.553). The significant variables and initial lactate levels were used to develop a scoring system which ranged from −4 to 11. The receiver operating characters curve indicated a cut-off point of 3.6 to predict ROSC with an area under the curve of 0.715.

Conclusion

The initial serum lactate had no association with sustained ROSC and hospital discharge with good neurological outcome but can be used to predict 24- and 48-hour postresuscitation mortality in nontraumatic OHCA patients with initial serum lactate cut-off points of 9.1 and 9.4 mmol/L, respectively.

Treatment Effect or Effective Treatment? Cardiac Compression Fraction and End-tidal Carbon Dioxide Are Higher in Patients Resuscitative Endovascular Balloon Occlusion of the Aorta Compared with Resuscitative Thoracotomy and Open-Chest Cardiac Massage

The purpose of this study is to compare end-tidal carbon dioxide (EtCO2) during resuscitation of open-chest cardiac massage (OCCM) with aortic cross-clamp (ACC) versus receiving resuscitative endovascular balloon occlusion of the aorta (REBOA) with closed-chest compressions (CCCs). Patients who received REBOA were compared with patients receiving OCCM for traumatic arrest using continuous vital sign monitoring and videography. Thirty-three patients were enrolled in the REBOA group and 18 patients were enrolled in the OCCM group. Of the total patients, 86.3 per cent were male with a mean age of 36.2 ± 13.9 years. Ninety-four percent of patients suffered penetrating trauma in the OCCM group compared with 30.3 per cent of the REBOA group ( P = <0.001). Before aortic occlusion (AO), there was no difference in initial EtCO2 values, but mean, median, peak, and final EtCO2 values were lower in OCCM ( P < 0.005). During CPR after AO, the initial, mean, and median values were higher with REBOA ( P = 0.015, 0.036, and 0.038). The rate of return of spontaneous circulation was higher in REBOA versus OCCM (20/33 [60.1%] vs 5/18 [33.3%]; P = 0.04), and REBOA patients survived to operative intervention more frequently ( P = 0.038). REBOA patients had greater total cardiac compression fraction (CCF) before AO than OCCM (85.3 ± 12.7% vs 35.2 ± 18.6%, P < 0.0001) and after AO (88.3 ± 7.8% vs 71.9 ± 24.4%, P = 0.0052). REBOA patients have higher EtCO2 and cardiac compression fraction before and after AO compared with patients who receive OCCM.

Prehospital randomised assessment of a mechanical compression device in out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised trial and economic evaluation

BACKGROUND

Mechanical chest compression devices may help to maintain high-quality cardiopulmonary resuscitation (CPR), but little evidence exists for their effectiveness. We evaluated whether or not the introduction of Lund University Cardiopulmonary Assistance System-2 (LUCAS-2; Jolife AB, Lund, Sweden) mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest (OHCA).

OBJECTIVE

Evaluation of the LUCAS-2 device as a routine ambulance service treatment for OHCA.

DESIGN

Pragmatic, cluster randomised trial including adults with non-traumatic OHCA. Ambulance dispatch staff and those collecting the primary outcome were blind to treatment allocation. Blinding of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. We also conducted a health economic evaluation and a systematic review of all trials of out-of-hospital mechanical chest compression.

SETTING

Four UK ambulance services (West Midlands, North East England, Wales and South Central), comprising 91 urban and semiurban ambulance stations. Clusters were ambulance service vehicles, which were randomly assigned (approximately 1 : 2) to the LUCAS-2 device or manual CPR.

PARTICIPANTS

Patients were included if they were in cardiac arrest in the out-of-hospital environment. Exclusions were patients with cardiac arrest as a result of trauma, with known or clinically apparent pregnancy, or aged < 18 years.

INTERVENTIONS

Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene.

MAIN OUTCOME MEASURES

Survival at 30 days following cardiac arrest; survival without significant neurological impairment [Cerebral Performance Category (CPC) score of 1 or 2].

RESULTS

We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 device and 2819 assigned to control) between 15 April 2010 and 10 June 2013. A total of 985 (60%) patients in the LUCAS-2 group received mechanical chest compression and 11 (< 1%) patients in the control group received LUCAS-2. In the intention-to-treat analysis, 30-day survival was similar in the LUCAS-2 (104/1652, 6.3%) and manual CPR groups [193/2819, 6.8%; adjusted odds ratio (OR) 0.86, 95% confidence interval (CI) 0.64 to 1.15]. Survival with a CPC score of 1 or 2 may have been worse in the LUCAS-2 group (adjusted OR 0.72, 95% CI 0.52 to 0.99). No serious adverse events were noted. The systematic review found no evidence of a survival advantage if mechanical chest compression was used. The health economic analysis showed that LUCAS-2 was dominated by manual chest compression.

LIMITATIONS

There was substantial non-compliance in the LUCAS-2 arm. For 272 out of 1652 patients (16.5%), mechanical chest compression was not used for reasons that would not occur in clinical practice. We addressed this issue by using complier average causal effect analyses. We attempted to measure CPR quality during the resuscitation attempts of trial participants, but were unable to do so.

CONCLUSIONS

There was no evidence of improvement in 30-day survival with LUCAS-2 compared with manual compressions. Our systematic review of recent randomised trials did not suggest that survival or survival without significant disability may be improved by the use of mechanical chest compression.

FUTURE WORK

The use of mechanical chest compression for in-hospital cardiac arrest, and in specific circumstances (e.g. transport), has not yet been evaluated.

TRIAI REGISTRATION

Current Controlled Trials ISRCTN08233942.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 11. See the NIHR Journals Library website for further project information.

The International Liaison Committee on Resuscitation-Review of the last 25 years and vision for the future

2017 marks the 25th anniversary of the International Liaison Committee on Resuscitation (ILCOR). ILCOR was formed in 1992 to create a forum for collaboration among principal resuscitation councils worldwide. Since then, ILCOR has established and distinguished itself for its pioneering vision and leadership in resuscitation science. By systematically assessing the evidence for resuscitation standards and guidelines and by identifying national and regional differences, ILCOR reached consensus on international resuscitation guidelines in 2000, and on international science and treatment recommendations in 2005, 2010 and 2015. However, local variation and contextualization of guidelines are evident by subtle differences in regional and national resuscitation guidelines. ILCOR's efforts to date have enhanced international cooperation, and progressively more transparent and systematic collection and analysis of pertinent scientific evidence. Going forward, this sets the stage for ILCOR to pursue its vision to save more lives globally through resuscitation.

Changes in neutrophil-to-lymphocyte ratios in postcardiac arrest patients treated with targeted temperature management

OBJECTIVE

The prognostic value of changes in neutrophil-to-lymphocyte ratios (NLR) in cardiac arrest survivors receiving targeted temperature management (TTM) is unknown. The current study investigated NLR in postcardiac arrest (PCA) patients undergoing TTM.

METHODS

This retrospective single-center study included 95 patients (59 males, age: 55.0±17.0 years) with in-hospital and out-of-hospital cardiac arrests who underwent TTM for PCA syndrome within 6 h of cardiac arrest. Hypothermia was maintained for 24 h at a target temperature of 33°C. NLR was calculated as the absolute neutrophil count divided by the absolute lymphocyte count.

RESULTS

Of the 95 patients, 59 (62%) died during hospital stay. Fewer vasopressors were used in patients who survived. Out-of-hospital cardiac arrest was more frequent in decedents (p=0.005). Length of stay in the hospital and intensive care unit were significantly longer in patients who survived (p=0.0001 and p=0.001, respectively). NLR on admission and during rewarming did not differ between survivors and decedents. NLR during cooling was significantly higher in decedents (p=0.014). Delta NLR cut-off of 13.5 best separated survivors and decedents (AUC=0.68, 95% CI: 0.57-0.79, p=0.003 with a sensitivity and specificity of 64% and 67%, respectively). In multivariate logistic regression analysis, larger increase in NLR was significantly associated with decreased survival (OR: 0.96, 95% CI: 0.94-0.99, p=0.008).

CONCLUSION

Changes in NLR are an independent determinant of survival in patients with return of spontaneous circulation PCA treated with TTM. An NLR change can be used to predict survival in these patients.

Open chest cardiac massage offers no benefit over closed chest compressions in patients with traumatic cardiac arrest

BACKGROUND

Open chest cardiac massage (OCCM) is a commonly performed procedure after traumatic cardiac arrest (TCA). OCCM has been reported to be superior to closed chest compressions (CCC) in animal models and in non-TCA. The purpose of this study is to prospectively compare OCCM versus CCC in TCA using end-tidal carbon dioxide (ETCO2), the criterion standard for determining the effectiveness of chest compressions and detection of return of spontaneous circulation (ROSC), as the surrogate for cardiac output and marker for adequacy of resuscitation.

METHODS

This prospective observational study enrolled patients over a 9-month period directly presenting to a level 1 trauma center after TCA. Continuous high-resolution ETCO2 measurements were collected every 6 seconds for periods of CCC and OCCM, respectively. Patients receiving CCC only were compared with patients receiving CCC followed by OCCM. Student's t tests were used to compare ETCO2 within and between groups.

RESULTS

Thirty-three patients were enrolled (16 OCCM, 17 CCC-only). Mean time of CCC before OCCM was 66 seconds. Within the OCCM group, final, peak, mean, and median ETCO2 levels significantly increased when comparing the initial CCC period to the OCCM interval. Using a time-matched comparison, significant increases were observed in the final and peak but not mean and median values when comparing the first minute of CCC to the remaining time in the CCC-only group. However, when periods of OCCM were compared with equivalent periods of CCC-only, there were no differences in the initial, final, peak, mean, or median ETCO2 values. Correspondingly, no difference in rates of ROSC was observed between groups (OCCM 23.5% vs. CCC 38.9%; p = 0.53).

CONCLUSION

Although we could not control for confounders, we found no significant improvement in ETCO2 or ROSC with OCCM. With newer endovascular techniques for aortic occlusion, thoracotomy solely for performing OCCM provides no benefit over CCC.

LEVEL OF EVIDENCE

Therapeutic study, level III.

A Novel Cooling Method and Comparison of Active Rewarming of Mildly Hypothermic Subjects

OBJECTIVE

To compare the effectiveness of arteriovenous anastomosis (AVA) vs heated intravenous fluid (IVF) rewarming in hypothermic subjects. Additionally, we sought to develop a novel method of hypothermia induction.

METHODS

Eight subjects underwent 3 cooling trials each to a core temperature of 34.8±0.6 (32.7 to 36.3°C [mean±SD with range]) by 14°C water immersion for 30 minutes, followed by walking on a treadmill for 5 minutes. Core temperatures (Δtes) and rates of cooling (°C/h) were measured. Participants were then rewarmed by 1) control: shivering only in a sleeping bag; 2) IVF: shivering in sleeping bag and infusion of 2 L normal saline warmed to 42°C at 77 mL/min; and 3) AVA: shivering in sleeping bag and circulation of 45°C warmed fluid through neoprene pads affixed to the palms and soles of the feet.

RESULTS

Cold water immersion resulted in a decrease of 0.5±0.5°C Δtes and 1±0.3°C with exercise (P < .01); with an immersion cooling rate of 0.9±0.8°C/h vs 12.6±3.2°C/h with exercise (P < .001). Temperature nadir reached 35.0±0.5°C. There were no significant differences in rewarming rates between the 3 conditions (shivering: 1.3±0.7°C/h, R² = 0.683; IVF 1.3±0.7°C/h, R² = 0.863; and AVA 1.4±0.6°C/h, R² = 0.853; P = .58). Shivering inhibition was greater with AVA but was not significantly different (P = .07).

CONCLUSIONS

This study developed a novel and efficient model of hypothermia induction through exercise-induced convective afterdrop. Although there was not a clear benefit in either of the 2 active rewarming methods, AVA rewarming showed a nonsignificant trend toward greater shivering inhibition, which may be optimized by an improved interface.

External Validation of the Universal Termination of Resuscitation Rule for Out-of-Hospital Cardiac Arrest in British Columbia

STUDY OBJECTIVE

The Universal Termination of Resuscitation Rule (TOR Rule) was developed to identify out-of-hospital cardiac arrests eligible for field termination of resuscitation, avoiding futile transportation to the hospital. The validity of the rule in emergency medical services (EMS) systems that do not routinely transport out-of-hospital cardiac arrest patients to the hospital is unknown. We seek to validate the TOR Rule in British Columbia.

METHODS

This study included consecutive, nontraumatic, adult, out-of-hospital cardiac arrests treated by EMS in British Columbia from April 2011 to September 2015. We excluded patients with active do-not-resuscitate orders and those with missing data. Following consensus guidelines, we examined the validity of the TOR Rule after 6 minutes of resuscitation (to approximate three 2-minute cycles of resuscitation). To ascertain rule performance at the different time junctures, we recalculated TOR Rule classification accuracy at subsequent 1-minute resuscitation increments.

RESULTS

Of 6,994 consecutive, adult, EMS-treated, out-of-hospital cardiac arrests, overall survival was 15%. At 6 minutes of resuscitation, rule performance was sensitivity 0.72, specificity 0.91, positive predictive value 0.98, and negative predictive value 0.36. The TOR Rule recommended care termination for 4,367 patients (62%); of these, 92 survived to hospital discharge (false-positive rate 2.1%; 95% confidence interval 1.7% to 2.5%); however, this proportion steadily decreased with later application. The TOR Rule recommended continuation of resuscitation in 2,627 patients (38%); of these, 1,674 died (false-negative rate 64%; 95% confidence interval 62% to 66%). Compared with 6-minute application, test characteristics at 30 minutes demonstrated nearly perfect positive predictive value (1.0) and specificity (1.0) but a lower sensitivity (0.46) and negative predictive value (0.25).

CONCLUSION

In this cohort of adult out-of-hospital cardiac arrest patients, the TOR Rule applied at 6 minutes falsely recommended care termination for 2.1% of patients; however, this decreased with later application. Systems using the TOR Rule to cease resuscitation in the field should consider rule application at points later than 6 minutes.

Therapeutic hypothermia after cardiac arrest: outcome predictors

OBJECTIVE

The determination of coma patient prognosis after cardiac arrest has clinical, ethical and social implications. Neurological examination, imaging and biochemical markers are helpful tools accepted as reliable in predicting recovery. With the advent of therapeutic hypothermia, these data need to be reconfirmed. In this study, we attempted to determine the validity of different markers, which can be used in the detection of patients with poor prognosis under hypothermia.

METHODS

Data from adult patients admitted to our intensive care unit for a hypothermia protocol after cardiac arrest were recorded prospectively to generate a descriptive and analytical study analyzing the relationship between clinical, neurophysiological, imaging and biochemical parameters with 6-month outcomes defined according to the Cerebral Performance Categories scale (good 1-2, poor 3-5). Neuron-specific enolase was collected at 72 hours. Imaging and neurophysiologic exams were carried out in the 24 hours after the rewarming period.

RESULTS

Sixty-seven patients were included in the study, of which 12 had good neurological outcomes. Ventricular fibrillation and electroencephalographic theta activity were associated with increased likelihood of survival and improved neurological outcomes. Patients who had more rapid cooling (mean time of 163 versus 312 minutes), hypoxic-ischemic brain injury on magnetic resonance imaging or neuron-specific enolase > 58ng/mL had poor neurological outcomes (p < 0.05).

CONCLUSION

Hypoxic-ischemic brain injury on magnetic resonance imaging and neuron-specific enolase were strong predictors of poor neurological outcomes. Although there is the belief that early achievement of target temperature improves neurological prognoses, in our study, there were increased mortality and worse neurological outcomes with earlier target-temperature achievement.

Epinephrine in cardiac arrest: systematic review and meta-analysis

Objective

evaluate the effectiveness of epinephrine used during cardiac arrest and its effect on the survival rates and neurological condition.

Method

systematic review of scientific literature with meta-analysis, using a random effects model. The following databases were used to research clinical trials and observational studies: Medline, Embase and Cochrane, from 2005 to 2015.

Results

when the Return of Spontaneous Circulation (ROSC) with administration of epinephrine was compared with ROSC without administration, increased rates were found with administration (OR 2.02. 95% CI 1.49 to 2.75; I2 = 95%). Meta-analysis showed an increase in survival to discharge or 30 days after administration of epinephrine (OR 1.23; 95% IC 1.05-1.44; I2=83%). Stratification by shockable and non-shockable rhythms showed an increase in survival for non-shockable rhythm (OR 1.52; 95% IC 1.29-1.78; I2=42%). When compared with delayed administration, the administration of epinephrine within 10 minutes showed an increased survival rate (OR 2.03; 95% IC 1.77-2.32; I2=0%).

Conclusion

administration of epinephrine appears to increase the rate of ROSC, but when compared with other therapies, no positive effect was found on survival rates of patients with favorable neurological status.

Intravascular versus surface cooling for targeted temperature management after out-of-hospital cardiac arrest - an analysis of the TTM trial data

Background

Targeted temperature management is recommended after out-of-hospital cardiac arrest and may be achieved using a variety of cooling devices. This study was conducted to explore the performance and outcomes for intravascular versus surface devices for targeted temperature management after out-of-hospital cardiac arrest.

Method

A retrospective analysis of data from the Targeted Temperature Management trial. N = 934. A total of 240 patients (26%) managed with intravascular versus 694 (74%) with surface devices. Devices were assessed for speed and precision during the induction, maintenance and rewarming phases in addition to adverse events. All-cause mortality, as well as a composite of poor neurological function or death, as evaluated by the Cerebral Performance Category and modified Rankin scale were analysed.

Results

For patients managed at 33 °C there was no difference between intravascular and surface groups in the median time taken to achieve target temperature (210 [interquartile range (IQR) 180] minutes vs. 240 [IQR 180] minutes, p = 0.58), maximum rate of cooling (1.0 [0.7] vs. 1.0 [0.9] °C/hr, p = 0.44), the number of patients who reached target temperature (within 4 hours (65% vs. 60%, p = 0.30); or ever (100% vs. 97%, p = 0.47), or episodes of overcooling (8% vs. 34%, p = 0.15). In the maintenance phase, cumulative temperature deviation (median 3.2 [IQR 5.0] °C hr vs. 9.3 [IQR 8.0] °C hr, p = <0.001), number of patients ever out of range (57.0% vs. 91.5%, p = 0.006) and median time out of range (1 [IQR 4.0] hours vs. 8.0 [IQR 9.0] hours, p = <0.001) were all significantly greater in the surface group although there was no difference in the occurrence of pyrexia. Adverse events were not different between intravascular and surface groups. There was no statistically significant difference in mortality (intravascular 46.3% vs. surface 50.0%; p = 0.32), Cerebral Performance Category scale 3–5 (49.0% vs. 54.3%; p = 0.18) or modified Rankin scale 4–6 (49.0% vs. 53.0%; p = 0.48).

Conclusions

Intravascular and surface cooling was equally effective during induction of mild hypothermia. However, surface cooling was associated with less precision during the maintenance phase. There was no difference in adverse events, mortality or poor neurological outcomes between patients treated with intravascular and surface cooling devices.

Trial registration

TTM trial ClinicalTrials.gov number https://clinicaltrials.gov/ct2/show/NCT01020916NCT01020916; 25 November 2009

Conversion to shockable rhythms during resuscitation and survival for out-of hospital cardiac arrest

BACKGROUND

In out of hospital cardiac arrest (OHCA), the prognostic influence of conversion to shockable rhythms during resuscitation for initially non-shockable rhythms remains unknown. This study aimed to assess the relationship between initial and subsequent shockable rhythm and post-arrest survival and neurological outcomes after OHCA.

METHODOLOGY

This was a retrospective analysis of all OHCA cases collected from the Pan-Asian Resuscitation Outcomes Study (PAROS) registry in 7 countries in Asia between 2009 and 2012. We included OHCA cases of presumed cardiac etiology, aged 18-years and above and resuscitation attempted by EMS. We performed multivariate logistic regression analyses to assess the relationship between initial and subsequent shockable rhythm and survival and neurological outcomes. 2-stage seemingly unrelated bivariate probit models were developed to jointly model the survival and neurological outcomes. We adjusted for the clustering effects of country variance in all models.

RESULTS

40,160 OHCA cases met the inclusion criteria. There were 5356 OHCA cases (13.3%) with initial shockable rhythm and 33,974 (84.7%) with initial non-shockable rhythm. After adjustment of baseline and prehospital characteristics, OHCA with initial shockable rhythm (odds ratio/OR=6.10, 95% confidence interval/CI=5.06-7.34) and subsequent conversion to shockable rhythm (OR=2.00,95%CI=1.10-3.65) independently predicted better survival-to-hospital-discharge outcomes. Subsequent shockable rhythm conversion significantly improved survival-to-admission, discharge and post-arrest overall and cerebral performance outcomes in the multivariate logistic regression and 2-stage analyses.

CONCLUSION

Initial shockable rhythm was the strongest predictor for survival. However, conversion to subsequent shockable rhythm significantly improved post-arrest survival and neurological outcomes. This study suggests the importance of early resuscitation efforts even for initially non-shockable rhythms which has prognostic implications and selection of subsequent post-resuscitation therapy.

The ReCaPTa study - a prospective out of hospital cardiac arrest registry including multiple sources of surveillance for the study of sudden cardiac death in the Mediterranean area

Background

Cardiovascular diseases are one of the leading causes of death in the industrialized world. Sudden cardiac death is very often the first manifestation of the disease and it occurs in the prehospital setting.

The determination of the sudden cardiac death phenotype is challenging. It requires prospective studies in the community including multiple sources of case ascertainment that help to identify the cause and circumstances of death.

The aim of the Clinical and Pathological Registry of Tarragona (ReCaPTa) is to study incidence and etiology of Sudden Cardiac Death in the Tarragona region (Catalonia, Spain).

Methods

ReCaPTa is a population-based registry of OHCA using multiple sources of surveillance. The population base is 511,662. This registry is compiled chronologically in a relational database and it prospectively contains data on all the OHCA attended by the EMS from April 2014 to April 2017. ReCaPTa collects data after each emergency medical assistance using an online application including variables of the onset of symptoms. A quality control is performed and it permits monitoring the percentage of cases included by the emergency crew. Simultaneously, data from the medico-legal autopsies is taken from the Pathology Center of the area. All the examination findings following a specific protocol for the sudden death study are entered into the ReCaPTa database by one trained person. Survivors admitted to hospital are followed up and their clinical variables are collected in each hospital. The primary care researchers analyze the digital clinical records in order to obtain medical background. All the available data will be reviewed after an adjudication process with the aim of identifying all cases of sudden cardiac death.

Discussion

There is a lack of population-based registries including multiple source of surveillance in the Mediterranean area. The ReCaPTa study could provide valuable information to prevent sudden cardiac death and develop new strategies to improve its survival.

Nifekalant Versus Amiodarone in the Treatment of Cardiac Arrest: an Experimental Study in a Swine Model of Prolonged Ventricular Fibrillation

PURPOSE

The purpose of the experiment was to compare the effects of nifekalant and amiodarone on the return of spontaneous circulation (ROSC), survival, as well as on the hemodynamic parameters in a swine model of prolonged ventricular fibrillation (VF).

METHODS

After 8 min of untreated VF, bolus doses of epinephrine (adrenaline) and either nifekalant, or amiodarone, or saline (n = 10 per group), were administered after randomization. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt and the same dose of adrenaline was given every 4th minute during CPR.

RESULTS

Forty-eight hour survival was significantly higher with nifekalant compared to amiodarone (p < 0.001) and saline (p = 0.02), (9/10 vs. 0/10 vs. 3/10, respectively). Systolic aortic pressure, diastolic aortic pressure and coronary perfusion pressure were significantly higher with nifekalant during CPR and immediate post-resuscitation period (p < 0.05). The animals in the amiodarone group had a slower heart rate at the 1st and 45th min post-ROSC (p < 0.001 and p = 0.006, respectively). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone compared to nifekalant (p < 0.001).

CONCLUSIONS

Nifekalant showed a more favorable hemodynamic profile and improved survival compared to amiodarone and saline in this swine model.

Pre-hospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug administration In Cardiac arrest (PARAMEDIC-2): Trial protocol

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).

The viability of transplanting organs from donors who underwent cardiopulmonary resuscitation: A systematic review

AIMS

To identify reports of patients who underwent cardiopulmonary resuscitation (CPR) prior to solid organ donation and compare recipient and organ function outcomes to those that did not undergo CPR. Donation after restoration of circulation then progressing to death and those donating with on-going CPR who would have otherwise have termination of efforts were both included.

METHODS

Systematic review. Clinical studies comparing the outcome of patients and organs retrieved from donors who underwent CPR with those that did not require CPR. Full-text articles were searched on EmBASE, MEDLINE, Cochrane Database of Systematic Reviews and the Cochrane Register of Controlled Trials.

RESULTS

Twenty-two observational studies were included. There were 12,206 adult and 2552 paediatric organ transplantation identified. Comparing donation after restoration of circulation there was no difference in immediate, one year, and five-year graft function. Donation with on-going CPR was associated with reduced immediate graft function for both renal and hepatic transplantation, however long term function was not different.

CONCLUSIONS

CPR does not appear to adversely affect graft function. Patients who have restored circulation after resuscitation and subsequently progress to death should be evaluated for organ donation. Those with on-going CPR should be considered for hepatic and renal transplantation but there may be worse initial graft function.

Therapeutic hypothermia after cardiac arrest: A systematic review/meta-analysis exploring the impact of expanded criteria and targeted temperature

AIMS OF THE STUDY

We aimed to determine the benefit of an expanded use of TH. We also described the impact of a targeted temperature management on outcomes at discharge.

DATA SOURCES

We identified studies by searching MEDLINE, EMBASE and Cochrane Library databases. We included RCTs and observational studies restricted to those reporting achieved temperature during TH after OHCA. No other patient, cardiac arrest or hypothermia protocol restrictions were applied. Outcomes of interest were hospital mortality and neurological outcome at discharge. Appropriate risk of bias assessment for meta-analyzed studies was conducted. Studies contrasting hypothermia and normothermia outcomes were meta-analyzed using a random-effect model. Outcomes of cooling arms, obtained from enrolled studies, were pooled and compared across achieved temperatures.

RESULTS

Search strategy yielded 32,275 citations of which 24 articles met inclusion criteria. Eleven studies were meta-analyzed. The use of TH after OHCA, even within an expanded use, decreased the mortality (OR 0.51, 95%CI [0.41-0.64]) and improved the odds of good neurological outcome (OR 2.48, 95%CI [1.91-3.22]). No statistical heterogeneity was found for either mortality (I²=4.0%) or neurological outcome (I²=0.0%). No differences in hospital mortality (p=0.86) or neurological outcomes at discharge (p=0.32) were found when pooled outcomes of 34 hypothermia arms grouped by cooling temperature were compared.

CONCLUSION

The use of TH after OHCA is associated with a survival and neuroprotective benefit, even when including patients with non-shockable rhythms, more lenient downtimes, unwitnessed arrest and/or persistent shock. We found no evidence to support one specific temperature over another during hypothermia.

Targeted temperature management for adult out-of-hospital cardiac arrest: current concepts and clinical applications

Targeted temperature management (TTM) (primarily therapeutic hypothermia (TH)) after out-of-hospital cardiac arrest (OHCA) has been considered effective, especially for adult-witnessed OHCA with a shockable initial rhythm, based on pathophysiology and on several clinical studies (especially two randomized controlled trials (RCTs) published in 2002). However, a recently published large RCT comparing TTM at 33 °C (TH) and TTM at 36 °C (normothermia) showed no advantage of 33 °C over 36 °C. Thus, this RCT has complicated the decision to perform TH after cardiac arrest. The results of this RCT are sometimes interpreted fever control alone is sufficient to improve outcomes after cardiac arrest because fever control was not strictly performed in the control groups of the previous two RCTs that showed an advantage for TH. Although this may be possible, another interpretation that the optimal target temperature for TH is much lower than 33 °C may be also possible. Additionally, there are many points other than target temperature that are unknown, such as the optimal timing to initiate TTM, the period between OHCA and initiating TTM, the period between OHCA and achieving the target temperature, the duration of maintaining the target temperature, the TTM technique, the rewarming method, and the management protocol after rewarming. RCTs are currently underway to shed light on several of these underexplored issues. In the present review, we examine how best to perform TTM after cardiac arrest based on the available evidence.

Influence of α-stat and pH-stat blood gas management strategies on cerebral blood flow and oxygenation in patients treated with therapeutic hypothermia after out-of-hospital cardiac arrest: a crossover study

OBJECTIVES

In patients treated with therapeutic hypothermia after out-of-hospital cardiac arrest, two blood gas management strategies are used regarding the PaCO2 target: α-stat or pH-stat. We aimed to compare the effects of these strategies on cerebral blood flow and oxygenation.

DESIGN

Prospective observational single-center crossover study.

SETTING

ICU of University hospital.

PATIENTS

Twenty-one therapeutic hypothermia-treated patients after out-of-hospital cardiac arrest more than 18 years old without history of cerebrovascular disease were included.

INTERVENTIONS

Cerebral perfusion and oxygenation variables were compared in α-stat (PaCO2 measured at 37 °C) versus pH-stat (PaCO2 measured at 32-34 °C), both strategies maintaining physiological PaCO2 values: 4.8-5.6 kPa (36-42 torr).

MEASUREMENTS AND MAIN RESULTS

Bilateral transcranial middle cerebral artery flow velocities using Doppler and jugular vein oxygen saturation were measured in both strategies 18 hours (14-23 hr) after the return of spontaneous circulation. Pulsatility and resistance indexes and cerebral oxygen extraction were calculated. Data are expressed as median (interquartile range 25-75) in α-stat versus pH-stat. No differences were found in temperature, arterial blood pressure, and oxygenation between α-stat and pH-stat. Significant differences were found in minute ventilation (p = 0.006), temperature-corrected PaCO2 (4.4 kPa [4.1-4.6 kPa] vs. 5.1 kPa [5.0-5.3 kPa], p = 0.0001), and temperature-uncorrected PaCO2 (p = 0.0001). No differences were found in cerebral blood velocities and pulsatility and resistance indexes in the overall population. Significant differences were found in jugular vein oxygen saturation (83.2% [79.2-87.6%] vs. 86.7% [83.2-88.2%], p = 0.009) and cerebral oxygen extraction (15% [11-20%] vs. 12% [10-16%], p = 0.01), respectively. In survivors, diastolic blood velocities were 25 cm/s (19-30 cm/s) versus 29 cm/s (23-35 cm/s) (p = 0.004), pulsatility index was 1.10 (0.97-1.18) versus 0.94 (0.89-1.05) (p = 0.027), jugular vein oxygen saturation was 79.2 (71.1-81.8) versus 83.3% (76.6-87.8) (p = 0.033), respectively. However, similar results were not found in nonsurvivors.

CONCLUSIONS

In therapeutic hypothermia-treated patients after out-of-hospital cardiac arrest at physiological PaCO2, α-stat strategy increases jugular vein blood desaturation and cerebral oxygen extraction compared with pH-stat strategy and decreases cerebral blood flow velocities in survivors.

Early administration of epinephrine (adrenaline) in patients with cardiac arrest with initial shockable rhythm in hospital: propensity score matched analysis

OBJECTIVES

To evaluate whether patients who experience cardiac arrest in hospital receive epinephrine (adrenaline) within the two minutes after the first defibrillation (contrary to American Heart Association guidelines) and to evaluate the association between early administration of epinephrine and outcomes in this population.

DESIGN

Prospective observational cohort study.

SETTING

Analysis of data from the Get With The Guidelines-Resuscitation registry, which includes data from more than 300 hospitals in the United States.

PARTICIPANTS

Adults in hospital who experienced cardiac arrest with an initial shockable rhythm, including patients who had a first defibrillation within two minutes of the cardiac arrest and who remained in a shockable rhythm after defibrillation.

INTERVENTION

Epinephrine given within two minutes after the first defibrillation.

MAIN OUTCOME MEASURES

Survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and survival to hospital discharge with a good functional outcome. A propensity score was calculated for the receipt of epinephrine within two minutes after the first defibrillation, based on multiple characteristics of patients, events, and hospitals. Patients who received epinephrine at either zero, one, or two minutes after the first defibrillation were then matched on the propensity score with patients who were "at risk" of receiving epinephrine within the same minute but who did not receive it.

RESULTS

2978 patients were matched on the propensity score, and the groups were well balanced. 1510 (51%) patients received epinephrine within two minutes after the first defibrillation, which is contrary to current American Heart Association guidelines. Epinephrine given within the first two minutes after the first defibrillation was associated with decreased odds of survival in the propensity score matched analysis (odds ratio 0.70, 95% confidence interval 0.59 to 0.82; P<0.001). Early epinephrine administration was also associated with a decreased odds of return of spontaneous circulation (0.71, 0.60 to 0.83; P<0.001) and good functional outcome (0.69, 0.58 to 0.83; P<0.001).

CONCLUSION

Half of patients with a persistent shockable rhythm received epinephrine within two minutes after the first defibrillation, contrary to current American Heart Association guidelines. The receipt of epinephrine within two minutes after the first defibrillation was associated with decreased odds of survival to hospital discharge as well as decreased odds of return of spontaneous circulation and survival to hospital discharge with a good functional outcome.

The optic nerve sheath diameter as a useful tool for early prediction of outcome after cardiac arrest: A prospective pilot study

INTRODUCTION

Optic nerve sheath diameter (ONSD) measurement could detect increased intracranial pressure, and might predict outcome in post-cardiac arrest (CA) patients. We assessed the ability of bedside ONSD ultrasonographic measurement performed within day 1 after CA occurrence to predict in-hospital survival in patients treated with therapeutic hypothermia (TH).

METHODS

In two French ICUs, a prospective study included all consecutive patients with CA without traumatic or neurological etiology, successfully resuscitated and TH-treated. ONSD measurements were performed on day 1, 2, and 3 (ONSD1, 2, 3 respectively) after return of spontaneous circulation. All records were registered according to Utstein style.

RESULTS

ONSD1, 2, 3 were assessed in 36, 21, and 14 patients respectively. 19/36 patients (53%) were discharged alive from hospital, including 14/36 (39%) with favorable neurological outcome (Cerebral Performance Category [CPC] score 1-2). Survivors and non-survivors were similar regarding age, sex, cardiovascular risk factors, location and etiology of CA, simplified acute physiology score II, occurrence of post-CA shock, and clinical parameters collected during ONSD measurements. Median ONSD1 was significantly larger in non-survivors versus survivors (7.2mm [interquartile: 6.8-7.4] versus 6.5mm [interquartile: 6.0-6.8]; p=0.008). After adjustment on predictive factors, ONSD1 was significantly associated with in-hospital mortality (OR 6.3; 95%CI [1.05-40] per mm of ONSD1 above 5.5mm; p=0.03), and CPC score (OR for 1 point increase in CPC score: 3.2; 95%CI [1.2-9.4] per mm of ONSD1 above 5.5mm; p=0.03). ONSD1 was significantly correlated with brain edema assessed by the cerebrum gray matter attenuation to white matter attenuation ratio, measured by the brain computed tomography scan performed on admission in 20 patients (Spearman rho=-0.5, p=0.04).

CONCLUSIONS

ONSD seems a promising tool to early assess outcome in post-CA patients treated with TH.