Part 6: Electrical Therapies

Defibrillation strategies for patients with refractory ventricular fibrillation: A systematic review and meta-analysis

AIM

The aim of this study was to summarize the existing evidence about the effectiveness of double defibrillation (DD) in comparison to standard defibrillation for patients with refractory ventricular fibrillation (RVF). DD encompasses double "sequential" external defibrillation (DSeq-D) and double "simultaneous" defibrillation (DSim-D), with the study also shedding light on the respective effects of DSeq-D and DSim-D.

METHODS

Investigators systematically searched PubMed, EMBASE and Cochrane Central databases for randomized controlled trials (RCTs) and cohort studies from their inception until June 06, 2024. The rate of survival to hospital discharge was the primary outcome, while the incidence of return of spontaneous circulation (ROSC), termination of ventricular fibrillation (VF), survival to hospital admission and good neurologic outcome were secondary outcomes. Relative ratios (RR) and 95% confidence intervals (CIs) were calculated for each outcome. Heterogeneity was assessed using I square value.

RESULTS

A total of 6 trials, comprising 1360 patients, were included. One was an RCT, and five were observational cohort studies. The RCT showed that, compared to standard defibrillation, DSeq-D was associated with higher incidences of survival to hospital discharge, termination of VF, ROSC and good neurologic outcome. However, the pooled results of cohort studies found no benefit of DD over standard defibrillation in survival to hospital discharge (RR, 0.91; 95% CI, 0.46-1.78), nor in secondary outcomes. Furthermore, subgroup analysis suggested DSim-D was linked with lower ROSC rate compared to standard defibrillation (RR, 0.65; 95% CI, 0.49-0.86), while there was no significance between DSeq-D and standard defibrillation (RR, 1.00; 95% CI, 0.70-1.42).

CONCLUSIONS

The benefit of DSeq-D in survival to hospital discharge for RVF patients was found in the RCT, but not in cohort studies. Additionally, DSim-D should be applied with greater caution for RVF patients. Further validation is needed through larger-scale and higher-quality trials.

TRIAL REGISTRY

INPLASY; Registration number: INPLASY202340015; URL: https://inplasy.com/.

Are high school cardiopulmonary resuscitation education mandates working? Insights from a high school survey on CPR knowledge, attitudes, and readiness

BACKGROUND

The use of cardiopulmonary resuscitation (CPR) and automated external defibrillators (AEDs) significantly improve the chances of survival after out-of-hospital cardiac arrest. Subsequently, state laws mandate training in CPR and AED use for high school graduation. However, training and its impact vary and must be better understood.

OBJECTIVE

We assessed the current CPR training mandates and their impact.

METHODS

We performed a nationwide, cross-sectional, survey-based observational study of high schoolers in 9th to 12th grades in all 50 states from 2020 to 2022 (NCT04493970), assessing basic demographics, attitudes, knowledge and skills, and willingness to learn CPR and AED.

RESULTS

We had an 8% response rate, resulting in 2395 high school students surveyed. The mean age of respondents was 16.8 ± 0.7 years, with 52.5% female students. Of these, 86% underwent some form of training, and 25.1% had CPR training in the last year. Only 58.7% knew how to use an AED. Notably, 26.9% had previously witnessed CPR, and almost all (94%) realized the importance of learning CPR. Most respondents also believed recurrent and longitudinal would be beneficial.

CONCLUSION

Surprisingly, only a small cohort of students undergo CPR training even when it is mandatory. The quality of this training appears to be inadequate to impart appropriate confidence and knowledge levels. This suggests a need for a significant overhaul of CPR training mandates across the United States.

The impact of hyperbaric oxygen treatment for cardiovascular implantable electronic devices

Introduction

The safety of hyperbaric oxygen treatment (HBO2) in patients with cardiovascular implanted electronic devices (CIED) remains unclear.

Methods

We conducted a retrospective analysis of seven CIED patients (median age 79 [73-83] years, five males [71.4%]), including five with pacemakers and two with implantable cardioverter defibrillators (ICD), who underwent HBO2 between June 2013 and April 2023. During the initial session, electrocardiogram monitoring was conducted, and CIED checks were performed before and after the treatment. In addition, the medical records were scrutinized to identify any abnormal CIED operations.

Results

All seven CIED patients underwent HBO2 within the safety pressure range specified by the CIED manufacturers or general pressure test by the International Organization for Standardization (2.5 [2.5-2.5] atmosphere absolute × 18 [5-20] sessions). When comparing the CIED parameters before and after HBO2, no significant changes were observed in the waveform amplitudes, pacing thresholds, lead impedance of the atrial and ventricular leads, or battery levels. All seven patients, including two with the rate response function activated, exhibited no significant changes in the pacing rate or pacing failure. Two ICD patients did not deactivate the therapy, including the defibrillation; however, they did not experience any arrhythmia or inappropriate ICD therapy during the HBO2.

Conclusion

CIED patients who underwent HBO2 within the safety pressure range exhibited no significant changes in the parameters immediately after the HBO2 and had no observable abnormal CIED operations during the treatment. The safety of defibrillation by an ICD during HBO2 should be clarified.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 2: Ventricular and bradyarrhythmias

PURPOSE

This is the second article in a 2-part series reviewing the pathophysiology and treatment considerations for arrhythmias. Part 1 of the series discussed aspects related to treating atrial arrhythmias. Here in part 2, the pathophysiology of ventricular arrhythmias and bradyarrhythmias and current evidence on treatment approaches are reviewed.

SUMMARY

Ventricular arrhythmias can arise suddenly and are a common cause of sudden cardiac death. Several antiarrhythmics may be effective in management of ventricular arrhythmias, but there is robust evidence to support the use of only a few of these agents, and such evidence was largely derived from trials involving patients with out-of-hospital cardiac arrest. Bradyarrhythmias range from asymptomatic mild prolongation of nodal conduction to severe conduction delays and impending cardiac arrest. Vasopressors, chronotropes, and pacing strategies require careful attention and titration to minimize adverse effects and patient harm.

CONCLUSION

Ventricular arrhythmias and bradyarrhythmias can be consequential and require acute intervention. As experts in pharmacotherapy, acute care pharmacists can participate in providing high-level intervention by aiding in diagnostic workup and medication selection.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 1: Atrial arrhythmias

PURPOSE

This article, the first in a 2-part review, aims to reinforce current literature on the pathophysiology of cardiac arrhythmias and various evidence-based treatment approaches and clinical considerations in the acute care setting. Part 1 of this series focuses on atrial arrhythmias.

SUMMARY

Arrhythmias are prevalent throughout the world and a common presenting condition in the emergency department (ED) setting. Atrial fibrillation (AF) is the most common arrhythmia worldwide and expected to increase in prevalence. Treatment approaches have evolved over time with advances in catheter-directed ablation. Based on historic trials, heart rate control has been the long-standing accepted outpatient treatment modality for AF, but the use of antiarrhythmics is often still indicated for AF in the acute setting, and ED pharmacists should be prepared and poised to help in AF management. Other atrial arrhythmias include atrial flutter (AFL), atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT), which warrant distinction due to their unique pathophysiology and because each requires a different approach to utilization of antiarrhythmics. Atrial arrhythmias are typically associated with greater hemodynamic stability than ventricular arrhythmias but still require nuanced management according to patient subset and risk factors. Since antiarrhythmics can also be proarrhythmic, they may destabilize the patient due to adverse effects, many of which are the focus of black-box label warnings that can be overreaching and limit treatment options. Electrical cardioversion for atrial arrhythmias is generally successful and, depending on the setting and/or hemodynamics, often indicated.

CONCLUSION

Atrial arrhythmias arise from a variety of mechanisms, and appropriate treatment depends on various factors. A firm understanding of physiological and pharmacological concepts serves as a foundation for exploring evidence supporting agents, indications, and adverse effects in order to provide appropriate care for patients.

Assessment and Prediction of Cardiovascular Contributions to Severe Maternal Morbidity

Severe maternal morbidity (SMM) refers to any unexpected outcome directly related to pregnancy and childbirth that results in both short-term delivery complications and long-term consequences to a women's health. This affects about 60,000 women annually in the United States. Cardiovascular contributions to SMM including cardiac arrest, arrhythmia, and acute myocardial infarction are on the rise, probably driven by changing demographics of the pregnant population including more women of extreme maternal age and an increased prevalence of cardiometabolic and structural heart disease. The utilization of SMM prediction tools and risk scores specific to cardiovascular disease in pregnancy has helped with risk stratification. Furthermore, health system data monitoring and reporting to identify and assess etiologies of cardiovascular complications has led to improvement in outcomes and greater standardization of care for mothers with cardiovascular disease. Improving cardiovascular disease-related SMM relies on a multipronged approach comprised of patient-level identification of risk factors, individualized review of SMM cases, and validation of risk stratification tools and system-wide improvements in quality of care. In this article, we review the epidemiology and cardiac causes of SMM, we provide a framework of risk prediction clinical tools, and we highlight need for organization of care to improve outcomes.

The ability of machine learning algorithms to predict defibrillation success during cardiac arrest: A systematic review

OBJECTIVE

To evaluate the existing knowledge on the effectiveness of machine learning (ML) algorithms inpredicting defibrillation success during in- and out-of-hospital cardiac arrest.

METHODS

MEDLINE, Embase, CINAHL and Scopus were searched from inception to August 30, 2022. Studies were included that utilized ML algorithms for prediction of successful defibrillation, observed as return of spontaneous circulation (ROSC), survival to hospital or discharge, or neurological status at discharge.Studies were excluded if involving a trauma, an unknown underlying rhythm, an implanted cardiac defibrillator or if focused on the prediction or onset of cardiac arrest. Risk of bias was assessed using the PROBAST tool.

RESULTS

There were 2399 studies identified, of which 107 full text articles were reviewed and 15 observational studies (n = 5680) were included for final analysis. 29 ECG waveform features were fed into 15 different ML combinations. The best performing ML model had an accuracy of 98.6 (98.5 - 98.7)%, with 4 second ECG intervals. An algorithm incorporating end-tidal CO2 reported an accuracy of 83.3% (no CI reported). Meta-analysis was not performed due to heterogeneity in study design, ROSC definitions, and characteristics.

CONCLUSION

Machine learning algorithms, specifically Neural Networks, have been shown to have potential to predict defibrillation success for cardiac arrest with high sensitivity and specificity.Due to heterogeneity, inconsistent reporting, and high risk of bias, it is difficult to conclude which, if any, algorithm is optimal. Further clinical studies with standardized reporting of patient characteristics, outcomes, and appropriate algorithm validation are still required to elucidate this. PROSPERO 2020 CRD42020148912.

Synchronized Cardioversion Performed During Cold Water Immersion of a Heatstroke Patient

We report a case of cardioversion that was successfully performed on a patient during cold water immersion. The patient deteriorated into unstable ventricular tachycardia while being treated for heatstroke. We elected to perform synchronized cardioversion without first removing the patient from the immersion body bag. The patient survived and was discharged neurologically intact on hospital day 5. There were no evident deleterious effects to the staff, the patient, or the equipment. To our knowledge, this is the first case report in the literature demonstrating the electrical cardioversion of a patient immersed in water.

Defibrillation Strategies for Refractory Ventricular Fibrillation

BACKGROUND

Despite advances in defibrillation technology, shock-refractory ventricular fibrillation remains common during out-of-hospital cardiac arrest. Double sequential external defibrillation (DSED; rapid sequential shocks from two defibrillators) and vector-change (VC) defibrillation (switching defibrillation pads to an anterior-posterior position) have been proposed as defibrillation strategies to improve outcomes in patients with refractory ventricular fibrillation.

METHODS

We conducted a cluster-randomized trial with crossover among six Canadian paramedic services to evaluate DSED and VC defibrillation as compared with standard defibrillation in adult patients with refractory ventricular fibrillation during out-of-hospital cardiac arrest. Patients were treated with one of these three techniques according to the strategy that was randomly assigned to the paramedic service. The primary outcome was survival to hospital discharge. Secondary outcomes included termination of ventricular fibrillation, return of spontaneous circulation, and a good neurologic outcome, defined as a modified Rankin scale score of 2 or lower (indicating no symptoms to slight disability) at hospital discharge.

RESULTS

A total of 405 patients were enrolled before the data and safety monitoring board stopped the trial because of the coronavirus disease 2019 pandemic. A total of 136 patients (33.6%) were assigned to receive standard defibrillation, 144 (35.6%) to receive VC defibrillation, and 125 (30.9%) to receive DSED. Survival to hospital discharge was more common in the DSED group than in the standard group (30.4% vs. 13.3%; relative risk, 2.21; 95% confidence interval [CI], 1.33 to 3.67) and more common in the VC group than in the standard group (21.7% vs. 13.3%; relative risk, 1.71; 95% CI, 1.01 to 2.88). DSED but not VC defibrillation was associated with a higher percentage of patients having a good neurologic outcome than standard defibrillation (relative risk, 2.21 [95% CI, 1.26 to 3.88] and 1.48 [95% CI, 0.81 to 2.71], respectively).

CONCLUSIONS

Among patients with refractory ventricular fibrillation, survival to hospital discharge occurred more frequently among those who received DSED or VC defibrillation than among those who received standard defibrillation. (Funded by the Heart and Stroke Foundation of Canada; DOSE VF ClinicalTrials.gov number, NCT04080986.).

A Systematic Review of the Transthoracic Impedance during Cardiac Defibrillation

For cardiac defibrillator testing and design purposes, the range and limits of the human TTI is of high interest. Potential influencing factors regarding the electronic configurations, the electrode/tissue interface and patient characteristics were identified and analyzed. A literature survey based on 71 selected articles was used to review and assess human TTI and the influencing factors found. The human TTI extended from 12 to 212 Ω in the literature selected. Excluding outliers and pediatric measurements, the mean TTI recordings ranged from 51 to 112 Ω with an average TTI of 76.7 Ω under normal distribution. The wide range of human impedance can be attributed to 12 different influencing factors, including shock waveforms and protocols, coupling devices, electrode size and pressure, electrode position, patient age, gender, body dimensions, respiration and lung volume, blood hemoglobin saturation and different pathologies. The coupling device, electrode size and electrode pressure have the greatest influence on TTI.

Optimizing Outcomes After Out-of-Hospital Cardiac Arrest With Innovative Approaches to Public-Access Defibrillation: A Scientific Statement From the International Liaison Committee on Resuscitation

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.

Masters Age Football And Cardiovascular Risk (MAFACARI)

BACKGROUND

Football (soccer) is popular among those of Masters age (≥35 years). Although regular exercise improves health, strenuous exercise causes a transient increase in cardiac risk.

AIM

The aim of this survey of Masters Age Footballers was to gain insight into cardiac risk factors, symptoms, and knowledge, attitudes and beliefs about myocardial infarction (MI), and support for prevention.

METHODS

A web-based survey using REDCap was completed by 153 amateur Masters footballers from A grade competition (n=24), B or lower grade (n=95) or social games (n=34) in Sydney, Australia.

RESULTS

Participants were aged 49.3±7.5 years and primarily male (92.2%), Caucasian (88.9%) and university educated (75.2%). Risk factors included hypercholesterolaemia (37.3%), hypertension (19.6%), smoker (7.8%), overweight (40.5%) or obese (13.1%). One fifth (21.6%) reported ≥1 potential cardiac symptom during activity in the prior year, for which one quarter (24.2%) sought medical attention. Knowledge of typical MI symptoms was high (>80%) but lower (<40%) for less typical symptoms. Half (49.6%) were unconfident to recognise MI in themselves. Half (49.0%) would remain on the field for 5-10 minutes with chest pain. Only 39.9% were aware that warning signs may precede MI by days. They overestimated survival from cardiac arrest (43%). Participants supported training in automatic external defibrillators (AED) and CPR (84%), AEDs at games (85%) and cardiac education (>70%).

CONCLUSIONS

Cardiac risk factors are common In Masters footballers, with one in five experiencing possible cardiac symptoms in the prior year. While gaps exist in knowledge and optimal responses, strong support exists for preventive measures. This article is protected by copyright. All rights reserved.

Impact of blended learning on manual defibrillator's use: A simulation-based randomized trial

Background

Blended learning, defined as the combination of traditional face‐to‐face instructor‐led learning and e‐learning course, has never been validated as a teaching method for the effective use of manual defibrillators in cardiopulmonary resuscitation.

Aim

To evaluate whether paediatric emergency and critical care providers exposed to a blended learning session performed better and recalled more defibrillator skills than those exposed to face‐to‐face learning only.

Study design

A two‐period prospective, stratified, single‐centre, simulation‐based, randomized, controlled trial.

Methods

Registered nurses and postgraduate residents from either a paediatric emergency department or an intensive care unit were randomly assigned to a blended learning or face‐to‐face learning sessions on the recommended use of a manual defibrillator. Participants' adherence to recommendations was assessed by testing defibrillator skills in three consecutive paediatric cardiopulmonary scenarios performed on the day of the training and once again 2 months later. The primary endpoint was the number of errors observed during defibrillation, cardioversion, and transcutaneous pacing at the time of the initial intervention.

Results

Fifty participants were randomized to receive the intervention and 51 to the control group. When pooling all three procedures, the median total errors per participant was lower (2 [IQR: 1‐4]) in providers exposed to blended learning than in those exposed to face‐to‐face learning only (3 [IQR: 2‐5]; P = .06). The median of total errors per procedure was also lower. However, both training methods appeared insufficient to maintain appropriate skill retention over time as a repetition of procedures 2 months later without any refresher learning session yielded more errors in both groups.

Conclusions

Learners exposed to blended learning showed a reduced number in the total amount of errors compared with those exposed to face‐to‐face learning alone, with waning of skills over time.

Relevance to clinical practice

Proficiently teaching the use of a manual defibrillator can be performed through blended learning.

Correction of the travel time estimation for ambulances of the red cross Tijuana using machine learning

This paper addresses the problem of estimating the response time to a medical emergency, specifically from the Red Cross of Tijuana (RCT), which provides most of the emergency medical services (EMS) in the city of Tijuana, Mexico. For institutions with low funding, such as the RCT, relying on free or open source mapping systems to estimate travel times is necessary but also error prone because these systems are not tuned for ambulance movements within a city. Therefore, this work formulates a supervised machine learning problem where the goal is to predict the difference in travel time between the ground truth travel time provided by a GPS and the approximation offered by two mapping systems, Google Maps (GM) and Open Source Routing Machine (OSRM). To this end, this work develops a new dataset based on the EMS logs of the RCT, considering calls from January 2017 to April 2017. The posed learning problem is solved under different scenarios, including using an off-the-shelf default configuration of a Random Forest classifier, applying a hyper-parameter optimization process and using an Auto Machine Learning (AutoML) system. Considering all of the dataset for GM, test accuracy was 69.6% for the first two learning approaches and 71.6% using AutoML. For OSRM, performance was 64.6%, 65.2% and 66.4% for each of the learning approaches, respectively. Results show that it is possible to predict the level by which a mapping system over or under estimates the true travel time of an ambulance. Finally, the impact of the model is demonstrated by using it to solve the ambulance location problem, with notable differences in ambulance deployments and percentage of double coverage achieved relative to using the standard mapping system. Results show that without correcting the travel time the percentage of double coverage is 83.90%; on the other hand, double coverage reaches 100% when applying travel time correction.

Sudden Death in the Young: Information for the Primary Care Provider

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Effect of Amplitude Spectral Area on Termination of Fibrillation and Outcomes in Pediatric Cardiac Arrest

Background

Amplitude spectral area (AMSA) predicts termination of fibrillation (TOF) with return of spontaneous circulation (ROSC) and survival in adults but has not been studied in pediatric cardiac arrest. We characterized AMSA during pediatric cardiac arrest from a Pediatric Resuscitation Quality Collaborative and hypothesized that AMSA would be associated with TOF and ROSC.

Methods and Results

Children aged <18 years with cardiac arrest and ventricular fibrillation were studied. AMSA was calculated for 2 seconds before shock and averaged for each subject (AMSA‐avg). TOF was defined as termination of ventricular fibrillation 10 seconds after defibrillation to any non‐ventricular fibrillation rhythm. ROSC was defined as >20 minutes without chest compressions. Univariate and multivariable logistic regression analyses controlling for weight, current, and illness category were performed. Primary end points were TOF and ROSC. Secondary end points were 24‐hour survival and survival to discharge. Between 2015 and 2019, 50 children from 14 hospitals with 111 shocks were identified. In univariate analyses AMSA was not associated with TOF and AMS‐Aavg was not associated with ROSC. Multivariable logistic regression showed no association between AMSA and TOF but controlling for defibrillation average current and illness category, there was a trend to significant association between AMSA‐avg and ROSC (odds ratio, 1.10 [1.00‒1.22] P=0.058). There was no significant association between AMSA‐avg and 24‐hour survival or survival to hospital discharge.

Conclusions

In pediatric patients, AMSA was not associated with TOF, whereas AMSA‐avg had a trend to significance for association in ROSC, but not 24‐hour survival or survival to hospital discharge.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02708134.

Sex differences in acute cardiovascular care: a review and needs assessment

Despite significant progress in the care of patients suffering from cardiovascular disease, there remains a persistent sex disparity in the diagnosis, management, and outcomes of these patients. These sex disparities are seen across the spectrum of cardiovascular care, but, are especially pronounced in acute cardiovascular care. The spectrum of acute cardiovascular care encompasses critically ill or tenuous patients with cardiovascular conditions that require urgent or emergent decision-making and interventions. In this narrative review, the disparities in the clinical course, management, and outcomes of six commonly encountered acute cardiovascular conditions, some with a known sex-predilection will be discussed within the basis of underlying sex differences in physiology, anatomy, and pharmacology with the goal of identifying areas where improvement in clinical approaches are needed.

Cardiopulmonary arrest after cardiac surgery: A retrospective cohort of 142 patients with nine year follow up

BACKGROUND

Although the techniques and perioperative management in modern cardiac surgeries has improved, and mortality and morbidity have decreased dramatically, postoperative cardiac arrest after heart surgery (POCHS) is a life-threatening condition that should be assessed and managed precisely.

OBJECTIVE

To determine the mortality rate and causes of death in postoperative cardiac arrest after heart surgery (POCHS).

METHODS

A total of 3342 patients underwent cardiac surgery from 2010 to 2018 in Isfahan, Iran .142 of them experienced POCHS . POCHS patients were investigated for characteristics, causes of cardiopulmonary arrest, first-line treatment, and mortality. These items were compared between survived and deceased patients to find possible prognostic factors.

RESULTS

The incidence rate of cardiac arrest was 4.2% (142 ones from total of 3342). Success rate of cardiac arrest is 28.8% (41 from 142). Bradycardia was the most common cause of cardiorespiratory arrest (37.3%), followed by cardiogenic shock (30.3%) and ventricular fibrillation (23.2%). Younger patients (58±11.5 versus 62.9±11.3) and those who developed cardiopulmonary arrest due to ventricular fibrillation (42.4% versus 22.2%), bradycardia (21.2% versus 8.8%), and apnea (15.1% versus 6.6%) were more likely to survive, while, those with shock had the worst prognosis (P<0.05). The best response to resuscitation was found among those treated with defibrillator plus ECM (External Cardiac Massage) as compared to the other approaches (P-value=0.003).

CONCLUSION

Based on the current report, CPR success was found in 28.6% among whom respiratory etiology led to better outcomes than cardiac etiology. The second cause of cardiac arrest is ventricular fibrillation which immediate defibrillation has the best outcome. The highest numerical success in POCHS is combination of ECM with defibrillator.

A framework of current based defibrillation improves defibrillation efficacy of biphasic truncated exponential waveform in rabbits

Defibrillation is accomplished by the passage of sufficient current through the heart to terminate ventricular fibrillation (VF). Although current-based defibrillation has been shown to be superior to energy-based defibrillation with monophasic waveforms, defibrillators with biphasic waveforms still use energy as a therapeutic dosage. In the present study, we propose a novel framework of current-based, biphasic defibrillation grounded in transthoracic impedance (TTI) measurements: adjusting the charging voltage to deliver the desired current based on the energy setting and measured pre-shock TTI; and adjusting the pulse duration to deliver the desired energy based on the output current and intra-shock TTI. The defibrillation efficacy of current-based defibrillation was compared with that of energy-based defibrillation in a simulated high impedance rabbit model of VF. Cardiac arrest was induced by pacing the right ventricle for 60 s in 24 New Zealand rabbits (10 males). A defibrillatory shock was applied with one of the two defibrillators after 90 s of VF. The defibrillation thresholds (DFTs) at different pathway impedances were determined utilizing a 5-step up-and-down protocol. The procedure was repeated after an interval of 5 min. A total of 30 fibrillation events and defibrillation attempts were investigated for each animal. The pulse duration was significantly shorter, and the waveform tilt was much lower for the current-based defibrillator. Compared with energy-based defibrillation, the energy, peak voltage, and peak current DFT were markedly lower when the pathway impedance was > 120 Ω, but there were no differences in DFT values when the pathway impedance was between 80 and 120 Ω for current-based defibrillation. Additionally, peak voltage and the peak current DFT were significantly lower for current-based defibrillation when the pathway impedance was < 80 Ω. In sum, a framework of adjusting the charging voltage and shock duration to deliver constant energy for low impedance and constant current for high impedance via pre-shock and intra-shock impedance measurements, greatly improved the defibrillation efficacy of high impedance by lowering the energy DFT.

Relationship between D-dimer level upon emergency room arrival and the duration of cardiac arrest in patients with witnessed out-of-hospital cardiac arrest

In patients with out-of-hospital cardiac arrest (OHCA), the probability of resuscitation is strongly influenced by the duration of cardiac arrest, which activates the blood coagulation-fibrinolysis system. Because plasma D-dimer levels reflect activity of blood coagulation and fibrinolysis, they should increase with the duration of cardiac arrest. We evaluated 222 consecutive non-traumatic witnessed OHCA patients who underwent measurement of plasma D-dimer levels on arrival in the emergency room. Return of spontaneous circulation was achieved in 138 patients (62%), but only 42 (19%) were alive 30 days post-OHCA. D-dimer levels were elevated in 217 patients (97.7%). There was a positive correlation between plasma D-dimer levels and duration of cardiac arrest in the 222 patients (r = 0.623, p < 0.001). When the cause of OHCA was limited to cardiovascular disease, the positive correlation between level of D-dimer and the duration of cardiac arrest (r = 0.776, p < 0.001) increased.D-dimer levels were significantly lower in survivors than in non-survivors [9.5 (1.4-17.5) vs 54.2 (34.2-74.3) μg/mL, p = 0.024]. Receiver operating characteristic curve analysis showed that a cutoff value of D-dimer ≤ 10 μg/L led to sensitivity (69.0%) and specificity (72.8%) for 30 day survival (area under curve 0.75). Multivariate logistic regression analysis showed that D-dimer ≤ 10 μg/ml was an independent predictor for 30 day survival (odds ratio 4.39, 95% confidence interval 1.41-13.70; p = 0.01). D-dimer level correlates with duration of cardiac arrest, especially in OHCA patients due to cardiovascular causes, and may help physicians assess the probability of survival in OHCA patients.

The Psychological Burden of Retirement from Sport

Participation in sport is associated with numerous physical and psychological health benefits, but also can have negative consequences, such as career ending injuries, which may have long-term effects on mental health. Recent research suggests that involuntary retirement, due to injury, illness, or being cut from a sport, can be particularly detrimental. As such, this review focuses on the impact athletic retirement has on the psychological well-being of collegiate athletes. We provide an algorithm to inform clinical decision making regarding involuntary retirement, as well as recommendations for the development of support programs and educational resources for athletes struggling with career transition. Our aim is that in developing retirement algorithms, support programs, and educational resources for athletes who are retired from sport, we can intervene early thus reducing the potential long-term psychological burden they may experience.

Predicting defibrillation success in out-of-hospital cardiac arrested patients: Moving beyond feature design

OBJECTIVE

Optimizing timing of defibrillation by evaluating the likelihood of a successful outcome could significantly enhance resuscitation. Previous studies employed conventional machine learning approaches and hand-crafted features to address this issue, but none have achieved superior performance to be widely accepted. This study proposes a novel approach in which predictive features are automatically learned.

METHODS

A raw 4s VF episode immediately prior to first defibrillation shock was feed to a 3-stage CNN feature extractor. Each stage was composed of 4 components: convolution, rectified linear unit activation, dropout and max-pooling. At the end of feature extractor, the feature map was flattened and connected to a fully connected multi-layer perceptron for classification. For model evaluation, a 10 fold cross-validation was employed. To balance classes, SMOTE oversampling method has been applied to minority class.

RESULTS

The obtained results show that the proposed model is highly accurate in predicting defibrillation outcome (Acc = 93.6 %). Since recommendations on classifiers suggest at least 50 % specificity and 95 % sensitivity as safe and useful predictors for defibrillation decision, the reported sensitivity of 98.8 % and specificity of 88.2 %, with the analysis speed of 3 ms/input signal, indicate that the proposed model possesses a good prospective to be implemented in automated external defibrillators.

CONCLUSIONS

The learned features demonstrate superiority over hand-crafted ones when performed on the same dataset. This approach benefits from being fully automatic by fusing feature extraction, selection and classification into a single learning model. It provides a superior strategy that can be used as a tool to guide treatment of OHCA patients in bringing optimal decision of precedence treatment. Furthermore, for encouraging replicability, the dataset has been made publicly available to the research community.

Pediatric Cardiac Arrest Resuscitation

Pediatric cardiac arrest is a relatively rare but devastating presentation in infants and children. In contrast to adult patients, in whom a primary cardiac dysrhythmia is the most likely cause of cardiac arrest, pediatric patients experience cardiovascular collapse most frequently after an initial respiratory arrest. Aggressive treatment in the precardiac arrest state should be initiated to prevent deterioration and should focus on support of oxygenation, ventilation, and hemodynamics, regardless of the presumed cause. Unfortunately, outcomes for pediatric cardiac arrest, whether in hospital or out of hospital, continue to be poor.

Effect of Optimized Versus Guidelines-Based Automated External Defibrillator Placement on Out-of-Hospital Cardiac Arrest Coverage: An In Silico Trial

Background

Mathematical optimization of automated external defibrillator (AED) placement may improve AED accessibility and out‐of‐hospital cardiac arrest (OHCA) outcomes compared with American Heart Association (AHA) and European Resuscitation Council (ERC) placement guidelines. We conducted an in silico trial (simulated prospective cohort study) comparing mathematically optimized placements with placements derived from current AHA and ERC guidelines, which recommend placement in locations where OHCAs are usually witnessed.

Methods and Results

We identified all public OHCAs of presumed cardiac cause from 2008 to 2016 in Copenhagen, Denmark. For the control, we computationally simulated placing 24/7‐accessible AEDs at every unique, public, witnessed OHCA location at monthly intervals over the study period. The intervention consisted of an equal number of simulated AEDs placements, deployed monthly, at mathematically optimized locations, using a model that analyzed historical OHCAs before that month. For each approach, we calculated the number of OHCAs in the study period that occurred within a 100‐m route distance based on Copenhagen’s road network of an available AED after it was placed (“OHCA coverage”). Estimated impact on bystander defibrillation and 30‐day survival was calculated by multivariate logistic regression. The control scenario involved 393 AEDs at historical, public, witnessed OHCA locations, covering 15.8% of the 653 public OHCAs from 2008 to 2016. The optimized locations provided significantly higher coverage (24.2%; P<0.001). Estimated bystander defibrillation and 30‐day survival rates increased from 15.6% to 18.2% (P<0.05) and from 32.6% to 34.0% (P<0.05), respectively. As a baseline, the 1573 real AEDs in Copenhagen covered 14.4% of the OHCAs.

Conclusions

Mathematical optimization can significantly improve OHCA coverage and estimated clinical outcomes compared with a guidelines‐based approach to AED placement.

The automated external defibrillator, an underused simple life-saving device: a review of the literature. A joint document from the Italian Resuscitation Council (IRC) and Associazione Italiana di Aritmologia e Cardiostimolazione (AIAC)

: The role of early defibrillation has been well established as a pivotal ring of the chain of survival since the nineties. In the following years, the scientific evidences about the beneficial role of early defibrillation have grown, and most of all, it has been demonstrated that the main determinant of survival is the time of defibrillation more than the type of rescuer. Early lay defibrillation was shown to be more effective than delayed defibrillation by healthcare providers. Moreover, because of the ease of use of automated external defibrillators (AEDs), it has been shown that also untrained lay rescuers can safely use an AED leading the guidelines to encourage early defibrillation by untrained lay bystanders. Although strong evidence has demonstrated that an increase in AED use leads to an increase in out-of-hospital cardiac arrest (OHCA) survival, the rate of defibrillation by laypeople is quite variable worldwide and very low in some realities. Our review of the literature about lay defibrillation highlights that the AED is a life-saving device as simple and well tolerated as underused.

A primer on proning in the emergency department

Historically, the prone position was used almost exclusively in the ICU for patients suffering from refractory hypoxemia due to acute respiratory distress syndrome (ARDS). Amidst the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic, however, this technique has been increasingly utilized in settings outside of the ICU, particularly in the emergency department. With emerging evidence that patients diagnosed with COVID‐19 who are not intubated and mechanically ventilated may benefit from the prone position, this strategy should not be isolated to only those with critical illness. This is a review of the pertinent physiology and evidence supporting prone positioning along with a step‐by‐step guide meant to familiarize those who are not already comfortable with the maneuver. Placing a patient in the prone position helps to improve ventilation‐perfusion matching, dorsal lung recruitment, and ultimately gas exchange. Evidence also suggests there is improved oxygenation in both mechanically ventilated patients and those who are awake and spontaneously breathing, further reinforcing the utility of the prone position in non‐ICU settings. Given present concerns about resource limitations because of the pandemic, prone positioning has especially demonstrable value as a technique to delay or even prevent intubation. Patients who are able to self‐prone should be directed into the ''swimmer's position'' and then placed in reverse Trendelenburg position if further oxygenation is needed. If a mechanically ventilated patient is to be placed in the prone position, specific precautions should be taken to ensure the patient's safety and to prevent any unwanted sequelae of prone positioning.

Self-restoration of cardiac excitation rhythm by anti-arrhythmic ion channel gating

Homeostatic regulation protects organisms against hazardous physiological changes. However, such regulation is limited in certain organs and associated biological processes. For example, the heart fails to self-restore its normal electrical activity once disturbed, as with sustained arrhythmias. Here we present proof-of-concept of a biological self-restoring system that allows automatic detection and correction of such abnormal excitation rhythms. For the heart, its realization involves the integration of ion channels with newly designed gating properties into cardiomyocytes. This allows cardiac tissue to i) discriminate between normal rhythm and arrhythmia based on frequency-dependent gating and ii) generate an ionic current for termination of the detected arrhythmia. We show in silico, that for both human atrial and ventricular arrhythmias, activation of these channels leads to rapid and repeated restoration of normal excitation rhythm. Experimental validation is provided by injecting the designed channel current for arrhythmia termination in human atrial myocytes using dynamic clamp.

How to Manage Atrial Fibrillation in the Emergency Department: a Critical Appraisal

Atrial fibrillation is the most common cardiac arrhythmia in emergency departments. There is growing evidence that certain patients with acute atrial fibrillation can be safely managed in the emergency room without the need for hospitalization, minimizing costs and reducing unnecessary exposures. This review addresses the emergency management of atrial fibrillation based on the latest updates on the subject with a focus on the assessment and prevention of thromboembolic phenomena, control of frequency x control of rhythm and strategies for cardioversion and restoration of sinus rhythm or for heart rate control.

Improving perception and confidence towards bystander cardiopulmonary resuscitation and public access automated external defibrillator program: how does training program help?

BACKGROUND

In conjunction with an automated external defibrillator (AED) placement program at various locations within a public university in Malaysia, a series of structured training programs were conducted. The objectives of this study is to (1) evaluate the effectiveness of a structured training program in improving the perception of the importance of AED and cardiopulmonary resuscitation (CPR), (2) evaluate the confidence of the employees in using an AED and performing bystander CPR, (3) identify the fears and concerns of these employees in using AED and performing CPR, and (4) determine the perception of these employees towards the strategy of the AEDs placed at various locations within the university.

METHODS

In this single-center observational study, a validated questionnaire aimed to assess the university employees' attitude and confidence in handling AED and performing CPR before (pre-test) and immediately after (post-test) the training program was conducted.

RESULTS

A total of 184 participants participated in this study. Using the Wilcoxon signed-rank test, the training programs appeared to have improved the perception that "using AED is important for unresponsive victims" (z = 4.32, p < 0.001) and that "AED practice drills should be performed on a regular basis" (z = - 2.41, p = 0.02) as well as increased the confidence to perform CPR (z = - 8.56, p < 0.001), use AED (z = - 8.93, p < 0.001), identify victims with no signs of life (z = - 7.88, p < 0.001), and the willingness to perform CPR and AED without hesitancy (z = - 8.91, p < 0.001). Fears and concerns on performing CPR and using AED also appeared to have been significantly reduced, and the perception on placement strategies of these AEDs was generally positive.

CONCLUSION

Using the theory of planned behavior as the explanatory framework, training programs appear to be helpful in improving the perception and the confidence of the participants towards performing CPR and using AED through the promotion of positive attitude, positive societal expectation, and a positive sense of empowerment. But whether this positive effect will translate into actual CPR performance and AED application in a real cardiac arrest is yet to be seen.

The changes in cardiopulmonary resuscitation guidelines: from 2000 to the present

This review aims to determine the changes made in the cardiopulmonary resuscitation (CPR) guidelines from 2000 to the present. The study was mainly undertaken by using International Guidelines from American Heart Association. The main change of CPR was chest compression skill. The guidelines have improved high-quality CPR through the change of chest compression skill. The latest adult CPR guidelines are as follows: (a) push chest quickly (100-120/min), (b) compress appropriately (5-6 cm), (c) relax chest fully (complete chest recoil), (d) avoid interruption of compression, and (e) avoid hyperventilation. The understanding of the latest CPR skills will be helpful in improving survival rate from sudden cardiac death.

Out-of-hospital cardiac arrest (OHCA) Survey in Lombardy: data analysis through prospective short time period assessment

BACKGROUND AND AIM OF THE WORK

The results of out-of-hospital cardiac arrests (OHCA) are usually reported through data collected collected via "ad hoc"  registries, but in large populations, samples of short time periods can be used to apply the results to the entire population. We would like to describe the situation of Lombardy to provide evidence on successful procedures, which may be carried out in a larger context.

METHODS

Observational, prospective, analytical, single cohort study in Lombardy population. Data of OHCA of cardiac aetiology, according to "Utstein Style", with resuscitation attempts started by the Emergency Medical Service (EMS), were collected for 40 days subdivided in 10-day-periods in all seasons 2014-15 via Operating System "Emergency Management" (EmMa).

RESULTS

Of 1219 cases, 536 events of witnessed OHCA of presumed cardiac etiology were analyzed. Outcomes were: sustained Return Of Spontaneous Circulation ROSC (25.6%), Survival Event in Emergency Department (22.8%), Survival after 24 hours (21.2%) and Survival after hospital discharge at home 30 days after (11.2%). Statistically significant results were found in age, rhythm of presentation, and resuscitation by bystanders. Sex, seasonality and rescue timing did not differ statistically.

CONCLUSIONS

Overall the thirty-day survival rate was similar to studies with larger databases. Our data are consistent with the concept that all emergency service should provide CPR instructions for every citizen who activate the EMS in the suspect of a SCA; further investigation should clarify how long interval could be useful for ROSC and sustained ROSC in patients resuscitated by lay people using CPR instructions.

Implications of Initial Recorded Rhythm on Cardioverter-Defibrillator Insertion and Subsequent All-Cause Mortality in Sudden Cardiac Arrest Survivors

Sudden cardiac arrest (SCA) rhythms have been traditionally divided into shockable [ventricular tachycardia (VT)/ventricular fibrillation (VF)] and nonshockable [(asystole (ASY)/pulseless electrical activity (PEA)] rhythms. It is unclear if the specific rhythm has implications on patient management and outcomes. We evaluated 1,433 patients who were admitted with SCA from 2000 to 2012 and were discharged alive. Of those, 1,123 patients had a recorded initial SCA rhythm. Subjects included were >18 years of age, and without an implantable cardioverter-defibrillator (ICD) in place at the time of the event. The likelihood of receiving an ICD for each SCA rhythm and the time to death were analyzed. Of the overall cohort of 1,123 SCA survivors (age of 62 ± 15 years; 39.2% women; 56.3% in-hospital SCA; 83% white; 67% coronary artery disease), 355 (31.6%) received an ICD, and 493 (43.9%) died over a mean follow-up of 3.8 ± 3.2 years. Patients with VF (n = 254, 43.6%) or VT (n = 83, 43.9%) were more likely to receive ICD therapy compared with those with ASY (n = 9, 5.3%) or PEA (n = 9, 4.8%; p <0.001). All-cause mortality was lower in VF patients compared with the other groups (p <0.0001). ICD therapy was associated with lower risk of death in the VF group (hazard ratio [HR] 0.61 [0.45 to 0.83]; p = 0.002) and strong trends toward less mortality in patients with VT (HR 0.64 [0.40 to 1.03]; p = 0.07) and ASY (HR 0.39 [0.12 to 1.31]; p = 0.13) but not in those with PEA (HR 0.93 [0.39 to 2.23]; p = 0.88). In conclusion, long-term survival in post-SCA patients is influenced by initial SCA rhythm. Although SCA survivors with shockable rhythms were more likely to receive ICDs, the ICD was associated with lower risk of death in most patients, including those with ASY. In conclusion, our data suggest that a more detailed SCA rhythm classification has important implications to patient management and long-term survival in this population.

Evaluating health facility access using Bayesian spatial models and location analysis methods

BACKGROUND

Floating catchment methods have recently been applied to identify priority regions for Automated External Defibrillator (AED) deployment, to aid in improving Out of Hospital Cardiac Arrest (OHCA) survival. This approach models access as a supply-to-demand ratio for each area, targeting areas with high demand and low supply for AED placement. These methods incorporate spatial covariates on OHCA occurrence, but do not provide precise AED locations, which are critical to the initial intent of such location analysis research. Exact AED locations can be determined using optimisation methods, but they do not incorporate known spatial risk factors for OHCA, such as income and demographics. Combining these two approaches would evaluate AED placement impact, describe drivers of OHCA occurrence, and identify areas that may not be appropriately covered by AED placement strategies. There are two aims in this paper. First, to develop geospatial models of OHCA that account for and display uncertainty. Second, to evaluate the AED placement methods using geospatial models of accessibility. We first identify communities with the greatest gap between demand and supply for allocating AEDs. We then use this information to evaluate models for precise AED location deployment.

METHODS

Case study data set consisted of 2802 OHCA events and 719 AEDs. Spatial OHCA occurrence was described using a geospatial model, with possible spatial correlation accommodated by introducing a conditional autoregressive (CAR) prior on the municipality-level spatial random effect. This model was fit with Integrated Nested Laplacian Approximation (INLA), using covariates for population density, proportion male, proportion over 65 years, financial strength, and the proportion of land used for transport, commercial, buildings, recreation, and urban areas. Optimisation methods for AED locations were applied to find the top 100 AED placement locations. AED access was calculated for current access and 100 AED placements. Priority rankings were then given for each area based on their access score and predicted number of OHCA events.

RESULTS

Of the 2802 OHCA events, 64.28% occurred in rural areas, and 35.72% in urban areas. Additionally, over 70% of individuals were aged over 65. Supply of AEDs was less than demand in most areas. Priority regions for AED placement were identified, and access scores were evaluated for AED placement methodology by ranking the access scores and the predicted OHCA count. AED placement methodology placed AEDs in areas with the highest priority, but placed more AEDs in areas with more predicted OHCA events in each grid cell.

CONCLUSION

The methods in this paper incorporate OHCA spatial risk factors and OHCA coverage to identify spatial regions most in need of resources. These methods can be used to help understand how AED allocation methods affect OHCA accessibility, which is of significant practical value for communities when deciding AED placements.

Bystander Defibrillation for Out-of-Hospital Cardiac Arrest in Public vs Residential Locations

Importance

Bystander-delivered defibrillation (hereinafter referred to as bystander defibrillation) of patients with out-of-hospital cardiac arrests (OHCAs) remains limited despite the widespread dissemination of automated external defibrillators (AEDs).

Objective

To examine calendar changes in bystander defibrillation and subsequent survival according to a public or a residential location of the cardiac arrest after nationwide initiatives in Denmark to facilitate bystander-mediated resuscitative efforts, including bystander defibrillation.

Design, Setting, and Participants

This nationwide study identified 18 688 patients in Denmark with first-time OHCA from June 1, 2001, to December 31, 2012, using the Danish Cardiac Arrest Registry. Patients had a presumed cardiac cause of arrest that was not witnessed by emergency medical services personnel. Data were analyzed from April 1, 2015, to December 10, 2016.

Exposures

Nationwide initiatives to facilitate bystander resuscitative efforts, including bystander defibrillation, consisted of resuscitation training of Danish citizens, dissemination of on-site AEDs, foundation of an AED registry linked to emergency medical dispatch centers, and dispatcher-assisted guidance of bystander resuscitation efforts.

Main Outcomes and Measures

The proportion of patients who received bystander defibrillation according to the location of the cardiac arrest and their subsequent 30-day survival.

Results

Of the 18 688 patients with OHCAs (67.8% men and 32.2% women; median [interquartile range] age, 72 [62-80] years), 4783 (25.6%) had a cardiac arrest in a public location and 13 905 (74.4%) in a residential location. The number of registered AEDs increased from 141 in 2007 to 7800 in 2012. The distribution of AED location was consistently skewed in favor of public locations. Bystander defibrillation increased in public locations from 3 of 245 (1.2%; 95% CI, 0.4%-3.5%) in 2001 to 78 of 510 (15.3%; 95% CI, 12.4%-18.7%) in 2012 (P < .001) but remained unchanged in residential locations from 7 of 542 (1.3%; 95% CI, 0.6%-2.6%) in 2001 to 21 of 1669 (1.3%; 95% CI, 0.8%-1.9%) in 2012 (P = .17). Thirty-day survival after bystander defibrillation increased in public locations from 8.3% (95% CI, 1.5%-35.4%) in 2001/2002 to 57.5% (95% CI, 48.6%-66.0%) in 2011/2012 (P < .001) in residential locations, from 0.0% (95% CI, 0.0%-19.4%) in 2001/2002 to 25.6% (95% CI, 14.6%-41.1%) in 2011/2012 (P < .001).

Conclusions and Relevance

Initiatives to facilitate bystander defibrillation were associated with a marked increase in bystander defibrillation in public locations, whereas bystander defibrillation remained limited in residential locations. Concomitantly, survival increased after bystander defibrillation in residential and public locations.

Audit of defibrillators at an urban public sector hospital

Introduction

Life-threatening emergencies are not limited to the emergency department. Any delay in intervention during an emergency often culminates into a poor outcome. Early electrical defibrillation is one of the most important interventions in patients with cardiac arrest. This study aimed to conduct a clinical audit of defibrillator devices at an urban public sector hospital in Johannesburg.

Methods

All defibrillator devices within various areas of the hospital were assessed. Device characteristics were recorded into a data collection sheet and subjected to further analysis.

Results

This study assessed 112 out of 123 areas in the hospital with a total of 143 defibrillators comprising 139(97.2%) manual external defibrillators (MED) and four(2.8%) automated external defibrillators (AED). MEDs were located in the general wards (n=52, 37.4%), theatre complex (n=25, 17.9%), high dependency areas (n=27, 19.4%) and non-sleepover areas (n=35, 25.2%). Daily checklist books were available for 101 (72.7%) MEDs, 26 (18.7%) had at least once daily documented checks over a 5-day period while 57 (41.0%) had been serviced in the last 12 months. Seven MEDs (4.9%) and one AED (0.7%) had critical problems.

Conclusion

Compliance with regard to the availability of defibrillator checklist books, conducting and recording of daily defibrillator checks, timely service maintenance of defibrillators and identification of critical device problems was suboptimal in this study. There is a need for ongoing training of hospital staff as well as the establishment of systems to prevent potential adverse consequences due to device failure.

Fuzzy and Sample Entropies as Predictors of Patient Survival Using Short Ventricular Fibrillation Recordings during out of Hospital Cardiac Arrest

Optimal defibrillation timing guided by ventricular fibrillation (VF) waveform analysis would contribute to improved survival of out-of-hospital cardiac arrest (OHCA) patients by minimizing myocardial damage caused by futile defibrillation shocks and minimizing interruptions to cardiopulmonary resuscitation. Recently, fuzzy entropy (FuzzyEn) tailored to jointly measure VF amplitude and regularity has been shown to be an efficient defibrillation success predictor. In this study, 734 shocks from 296 OHCA patients (50 survivors) were analyzed, and the embedding dimension (m) and matching tolerance (r) for FuzzyEn and sample entropy (SampEn) were adjusted to predict defibrillation success and patient survival. Entropies were significantly larger in successful shocks and in survivors, and when compared to the available methods, FuzzyEn presented the best prediction results, marginally outperforming SampEn. The sensitivity and specificity of FuzzyEn were 83.3% and 76.7% when predicting defibrillation success, and 83.7% and 73.5% for patient survival. Sensitivities and specificities were two points above those of the best available methods, and the prediction accuracy was kept even for VF intervals as short as 2s. These results suggest that FuzzyEn and SampEn may be promising tools for optimizing the defibrillation time and predicting patient survival in OHCA patients presenting VF.

Association of the time to first epinephrine administration and outcomes in out-of-hospital cardiac arrest: SOS-KANTO 2012 study

OBJECTIVE

This study assessed the association between the timing of first epinephrine administration (EA) and the neurological outcomes following out-of-hospital cardiac arrests (OHCAs) with both initial shockable and non-shockable rhythms.

METHODS

This was a post-hoc analysis of a multicenter prospective cohort study (SOS-KANTO 2012), which registered OHCA patients in the Kanto region of Japan from January 2012 to March 2013. We included consecutive adult OHCA patients who received epinephrine. The primary result included 1-month favorable neurological outcomes defined as cerebral performance category (CPC) 1 or 2. Secondary results included 1-month survival and return of spontaneous circulation (ROSC) after arrival at the hospital. Multivariable logistic regression analysis determined the association between delay per minute of the time from call to first EA in both pre- or in-hospital settings and outcomes.

RESULTS

Of the 16,452 patients, 9344 were eligible for our analyses. In univariable analysis, the delay in EA was associated with decreased favorable neurological outcomes only when the initial rhythm was a non-shockable rhythm. In multivariable analyses, delay in EA was associated with decreased ROSC (adjusted odds ratio [OR] for one minute delay, 0.97; 95% confidence interval [CI], 0.96-0.98) and 1-month survival (adjusted OR, 0.95; 95% CI, 0.92-0.97) when the initial rhythm was a non-shockable rhythm, whereas during a shockable rhythm, delay in EA was not associated with decreased ROSC and 1-month survival.

CONCLUSIONS

While assessing the effectiveness of epinephrine for OHCA, we should consider the time-limited effects of epinephrine. Additionally, consideration of early EA based on the pathophysiology is needed.

Wearable Cardioverter-defibrillators for the Prevention of Sudden Cardiac Death: A Meta-analysis

Wearable cardioverter-defibrillators (WCDs) protect patients from sudden cardiac death (SCD) by detecting and treating life-threatening ventricular tachycardia/fibrillation (VT/VF). Recently, two large studies evaluating WCDs were published. However, the results of older and newer studies have yet to be systematically summarized. The objective of the current study was to conduct a meta-analysis assessing the use and effectiveness of WCDs. We searched MEDLINE and Scopus (January 1998–July 2017) as well as the gray literature. We included registry/observational studies that (1) evaluated adult patients using WCDs; (2) provided data on one or more outcomes of interest; and (3) were full-text studies published in English. We calculated pooled incidence and/or rate [with 95% confidence intervals (CIs)] estimates from nonoverlapping populations using a random-effects meta-analysis model. Statistical heterogeneity was assessed via the I² statistic. We identified 11 studies (19,882 patients) with nonoverlapping populations/endpoints; seven of them evaluated WCD use across various indications, while the remaining studies restricted their focus to a single indication. Most of the studies were retrospective (82%) and multicenter (64%) in nature, with 45% using manufacturers’ registry data. The median duration of WCD use was three or more months in nine (82%) studies, and daily wear time ranged from a mean/median of 17 hours to 24 hours per day across included studies. Seven (64%) studies reported a mean/median daily wear time of more than 20 hours. This meta-analysis showed that the incidences of all-cause and SCD-related mortality among WCD patients were 1.4% (95% CI: 0.7%–2.4%) and 0.2% (95% CI: 0.1%–0.3%), respectively. VT/VF occurred in 2.6% (95% CI: 1.8%–3.5%) of patients. Across patients, 1.7% (95% CI: 1.4%–2.0%) received appropriate WCD treatment, corresponding to a rate of 9.1 patients/100 person-years (95% CI: 6.2–11.9 patients/100 person-years). Successful VT/VF termination following appropriate treatment occurred in 95.5% of patients (95% CI: 92.0%–98.0%) and the incidence of inappropriate treatment was infrequent (0.9%; 95% CI: 0.5%–1.4%). A moderate-to-high degree of statistical heterogeneity was observed in pooled analyses of mortality, VT/VF occurrence, and appropriate/inappropriate treatment (I² ≥ 41% for all). In conclusion, WCDs appear to be successful in terms of terminating VT/VF in patients with an elevated risk of SCD and are appropriate for use while long-term risk management strategies are being identified.

Manual Versus Semiautomatic Rhythm Analysis and Defibrillation for Out-of-Hospital Cardiac Arrest

BACKGROUND

Although manual and semiautomatic external defibrillation (SAED) are commonly used in the management of out-of-hospital cardiac arrest, the optimal strategy is not known. We hypothesized that SAED would reduce the time to first shock and lead to higher rates of cardioversion and survival compared with a manual strategy.

METHODS AND RESULTS

Between July 2005 and June 2015, we included adult out-of-hospital cardiac arrest of presumed cardiac pathogenesis. On October 2012, a treatment protocol using SAED was introduced after years of manual defibrillation. The effect of the SAED implementation on the time to first shock, successful cardioversion, and patient outcomes was assessed using interrupted time series regression adjusting for arrest factors and temporal trend. Of the 14 776 cases, 10 224 (69.2%) and 4552 (30.8%) occurred during the manual and SAED protocols, respectively. Although the proportion of patients shocked within 2 minutes of arrival increased during the SAED protocol for initial shockable rhythms (from 58.9% to 69.2%; P<0.001), there was no difference in unadjusted rate of successful cardioversion after first shock (from 12.3% to 13.8%; P=0.13). After adjustment, the odds of delivering the first shock within 2 minutes of arrival increased under the SAED protocol (adjusted odds ratio [AOR], 1.72; 95% confidence interval [CI], 1.32-2.26; P<0.001). Despite this, the SAED protocol was associated with a reduction in survival to hospital discharge (AOR, 0.71; 95% CI, 0.55-0.92; P=0.009), event survival (AOR, 0.74; 95% CI, 0.62-0.88; P=0.001), and prehospital return of spontaneous circulation (AOR, 0.81; 95% CI, 0.68-0.96; P=0.01) when compared with the manual protocol. There was also no improvement in the rate of successful cardioversion after first shock (AOR, 0.73; 95% CI, 0.51-1.06; P=0.10).

CONCLUSIONS

Although SAED improved the time to first shock, this did not translate into higher rates of successful cardioversion or survival after out-of-hospital cardiac arrest. Advanced life support providers should be trained to use a manual defibrillation protocol.

Cardiopulmonary resuscitation by Emergency Medical Services in South Africa: Barriers to achieving high quality performance

INTRODUCTION

Survival rates from out-of-hospital cardiac arrest significantly improve when high-quality cardiopulmonary resuscitation (CPR) is performed. Despite sudden cardiac arrest being a leading cause of death in many parts of the world, no studies have determined the quality of CPR delivery by Emergency Medical Services (EMS) personnel in South Africa. The aim of this study was to determine the quality of CPR provision by EMS staff in a simulated setting.

METHODS

A descriptive study design was used to determine competency of CPR among intermediate-qualified EMS personnel. Theoretical knowledge was determined using a multiple-choice questionnaire, and psychomotor skills were video-recorded then assessed by independent reviewers. Correlational and regression analysis were used to determine the effect of demographic information on knowledge and skills.

RESULTS

Overall competency of CPR among participants (n = 114) was poor: median knowledge was 50%; median skill 33%. Only 25% of the items tested showed that participants applied relevant knowledge to the equivalent skill, and the nature and strength of knowledge influencing skills was small. Demographic factors that significantly influenced both knowledge and skill were the sector of employment, the guidelines EMS personnel were trained to, age, experience, and the location of training.

CONCLUSION

Overall knowledge and skill performance was below standard. This study suggests that theoretical knowledge has a small but notable role to play on some components of skill performance. Demographic variables that affected both knowledge and skill may be used to improve training and the overall quality of Basic Life Support CPR delivery by EMS personnel.