Unveiling pseudo-pulseless electrical activity (pseudo-PEA) in ultrasound-integrated infant resuscitation.

Point-of-care ultrasound (POCUS) holds immense potential to manage critically deteriorating infants within the neonatal intensive care unit (NICU) and is increasingly used in neonatal clinical practice worldwide. Recent ultrasound-based protocols such as the Sonographic Assessment of liFe-threatening Emergencies-Revised (SAFE-R) and Crashing Neonate Protocol (CNP) offer step-by-step guidance for diagnosing and addressing reversible causes of cardiorespiratory collapse. Traditionally, pulseless electrical activity (PEA) has been diagnosed solely based on absent pulses on clinical examination, disregarding myocardial activity. However, integrating POCUS into resuscitation unveils the concept of pseudo-PEA, where cardiac motion activity is observed visually on the ultrasound but fails to generate a detectable pulse due to inadequate cardiac output. Paradoxically, existing neonatal resuscitation protocols lack directives for identifying and effectively leveraging pseudo-PEA insights in infants, limiting their potential to enhance outcomes. Pseudo-PEA is extensively described in adult literature owing to routine POCUS use in resuscitation. This review article comprehensively evaluates the adult pseudo-PEA literature to glean insights adaptable to neonatal care. Additionally, we propose a simple strategy to integrate POCUS during neonatal resuscitation, especially in infants who do not respond to routine measures. CONCLUSION: Pseudo-PDA is a newly recognized diagnosis in infants with the use of POCUS during resuscitation. This article highlights the importance of cross-disciplinary learning in tackling emerging challenges within neonatal medicine. WHAT IS KNOWN: • Point-of-Care ultrasound (POCUS) benefits adult cardiac arrest management, particularly in distinguishing true Pulseless Electrical Activity (PEA) from pseudo-PEA. • Pseudo-PEA is when myocardial motion can be seen on ultrasound but fails to generate palpable pulses or sustain circulation despite evident cardiac electrical activity. WHAT IS NEW: • Discuss recognition and management of pseudo-PEA in infants. • A proposed algorithm to integrate POCUS into active neonatal cardiopulmonary resuscitation (CPR) procedures.

Outcomes of in-hospital cardiac arrest in COVID-19 patients: A proportional prevalence meta-analysis.

BACKGROUND: Limited epidemiological data are available on the outcomes of in-hospital cardiac arrest (CA) in COVID-19 patients. METHODS: We performed literature search of PubMed, EMBASE, Cochrane, and Ovid to identify research articles that studied outcomes of in-hospital cardiac arrest in COVID-19 patients. The primary outcome was survival at discharge. Secondary outcomes included return of spontaneous circulation (ROSC) and types of cardiac arrest. Pooled percentages with a 95% confidence interval (CI) were calculated for the prevalence of outcomes. RESULTS: A total of 7,891 COVID patients were included in the study. There were 621 (pooled prevalence 8%, 95% CI 4-13%) cardiac arrest patients. There were 52 (pooled prevalence 3.0%; 95% CI 0.0-10.0%) patients that survived at the time of discharge. ROSC was achieved in 202 (pooled prevalence 39%;95% CI 21.0-59.0%) patients. Mean time to ROSC was 7.74 (95% CI 7.51-7.98) min. The commonest rhythm at the time of cardiac arrest was pulseless electrical activity (pooled prevalence 46%; 95% 13-80%), followed by asystole (pooled prevalence 40%; 95% CI 6-80%). Unstable ventricular arrhythmia occurred in a minority of patients (pooled prevalence 8%; 95% CI 4-13%). CONCLUSION: This pooled analysis of studies showed that the survival post in-hospital cardiac arrest in COVID patients is dismal despite adequate ROSC obtained at the time of resuscitation. Nonshockable rhythm cardiac arrest is commoner suggesting a non-cardiac cause while cardiac related etiology is uncommon. Future studies are needed to improve the survival in these patients.

Association between wide QRS pulseless electrical activity and hyperkalemia in cardiac arrest patients.

AIM: We evaluated the relationship between hyperkalemia and wide QRS complex in patients with pulseless electrical activity (PEA) cardiac arrest. METHODS: This was a single-center, retrospective observational study of patients over the age of 18 treated for cardiac arrest at a tertiary referral hospital whose initial electrocardiogram rhythm was PEA from February 2010 to December 2019. Wide QRS PEA was defined as a QRS interval of 120 ms or more. Hyperkalemia was defined as serum potassium level > 5.5 mmol/L. The primary outcome was hyperkalemia. Multivariable logistic regression analysis was used to evaluate the relationship between wide QRS and hyperkalemia. RESULTS: Among 617 patients, we analyzed 111 episodes in the wide QRS group and 506 episodes in the narrow QRS group. The potassium level in the wide QRS group was significantly higher than in the narrow QRS group (5.4 mmol/L, IQR 4.4-6.7 vs. 4.6 mmol/L, IQR 4.0-5.6, P < 0.001). Among all patients, 49.6% (n = 55/111) in the wide QRS group had hyperkalemia, which was significantly higher than the 26.7% (n = 135/506) in the narrow QRS group (P < 0.001). In multivariable logistic regression analysis, wide QRS PEA was significantly associated with hyperkalemia (odds ratio = 2.86, 95% confidence interval: 1.80-4.53, P < 0.001). CONCLUSIONS: Wide QRS PEA as an initial cardiac rhythm was significantly associated with hyperkalemia in cardiac arrest patients.

Induced Hypothermia in Patients with Cardiac Arrest and a Non-shockable Rhythm: Meta-analysis and Trial Sequential Analysis.

BACKGROUND: Controversy surrounds utilization of induced hypothermia (IHT) in comatose cardiac arrest (CA) survivors with a non-shockable rhythm. METHODS: We conducted a meta-analysis and trial sequential analysis (TSA) comparing IHT with no IHT approaches in patients with CA and a non-shockable rhythm. The primary outcome of interest was favorable neurological outcomes (FNO) defined using the Cerebral Performance Category (CPC) score of 1 or 2. Secondary endpoints were survival at discharge and survival beyond 90 days. RESULTS: A total of 9 studies with 10,386 patients were included. There was no difference between both groups in terms of FNO (13% vs. 13%, RR 1.34, 95% CI 0.96-1.89, p = 0.09, I2 = 88%), survival at discharge (20% vs. 22%, RR 1.09, 95% CI 0.88-1.36, p = 0.42, I2 = 76%), or survival beyond 90 days (16% vs. 15%, RR 0.92, 95% CI 0.61-1.40, p = 0.69, I2 = 83%). The TSA showed firm evidence supporting the lack of benefit of IHT in terms of survival at discharge. However, the Z-curves failed to cross the conventional and TSA (futility) boundaries for FNO and survival beyond 90 days, indicating lack of sufficient evidence to draw firm conclusions regarding these outcomes. CONCLUSION: In this meta-analysis of 9 studies, the utilization of IHT was not associated with a survival benefit at discharge. Although the meta-analysis showed lack of benefit of IHT in terms of FNO and survivals beyond 90 days, the corresponding TSA showed high probability of type-II statistical error, and therefore more randomized controlled trials powered for these outcomes are needed.

Pulseless Electrical Activity: Detection of Underlying Causes in a Prehospital Setting.

The proportion of out-of-hospital cardiac arrests (OHCAs) with pulseless electrical activity (PEA) as initial rhythm is increasing. PEA should be managed by identifying the underlying cause of the arrest and treating it accordingly. This often poses a challenge in the chaotic prehospital environment with only limited resources available. The aim of this study was to review the diagnostic tools available in a prehospital setting, and their interpretation during cardiac arrest (CA) with PEA as initial rhythm. A systematic literature search of the PubMed database was performed. Articles were assessed for eligibility by title, abstract, and full text. Ultrasonography has become a great asset in detecting underlying causes, and a variety of protocols have been proposed. There are currently no studies comparing these protocols regarding their feasibility and their effect on patient survival. Further research concerning the relationship between electrocardiogram characteristics and underlying causes is required. Limited evidence suggests a role for point-of-care testing in detecting hyperkalemia and a role for capnography in the diagnosis of asphyxia CA. Multiple studies describe a prognostic potential. Although evidence about the prognostic potential of cerebral oximetry in OHCA is accumulating, its diagnostic potential is still unknown. In the management of OHCA, anamnestic and clinical information remains the initial source of information in search for an underlying cause. Ultrasonographic evaluation should be performed subsequently, both for detecting an underlying cause and discriminating between true PEA and pseudo PEA. Comparative studies are required to identify the best ultrasonographic protocol, which can be included in resuscitation guidelines.

A Machine Learning Model for the Prognosis of Pulseless Electrical Activity during Out-of-Hospital Cardiac Arrest.

Pulseless electrical activity (PEA) is characterized by the disassociation of the mechanical and electrical activity of the heart and appears as the initial rhythm in 20-30% of out-of-hospital cardiac arrest (OHCA) cases. Predicting whether a patient in PEA will convert to return of spontaneous circulation (ROSC) is important because different therapeutic strategies are needed depending on the type of PEA. The aim of this study was to develop a machine learning model to differentiate PEA with unfavorable (unPEA) and favorable (faPEA) evolution to ROSC. An OHCA dataset of 1921 5s PEA signal segments from defibrillator files was used, 703 faPEA segments from 107 patients with ROSC and 1218 unPEA segments from 153 patients with no ROSC. The solution consisted of a signal-processing stage of the ECG and the thoracic impedance (TI) and the extraction of the TI circulation component (ICC), which is associated with ventricular wall movement. Then, a set of 17 features was obtained from the ECG and ICC signals, and a random forest classifier was used to differentiate faPEA from unPEA. All models were trained and tested using patientwise and stratified 10-fold cross-validation partitions. The best model showed a median (interquartile range) area under the curve (AUC) of 85.7(9.8)% and a balance accuracy of 78.8(9.8)%, improving the previously available solutions at more than four points in the AUC and three points in balanced accuracy. It was demonstrated that the evolution of PEA can be predicted using the ECG and TI signals, opening the possibility of targeted PEA treatment in OHCA.

Effect of ICD implantation on cardiovascular outcomes in patients with cardiac amyloidosis: A systematic review and meta-anaylsis.

INTRODUCTION: Cardiac amyloidosis is associated with a high rate of sudden cardiac death (SCD). Whether implantable cardioverter-defibrillator (ICD) use in such patients prevents SCD is uncertain. This study assesses outcomes of ICD use in patients with cardiac amyloidosis. METHODS: A systematic review and meta-analysis of data were performed after searching multiple databases and scientific sites pertaining to ICD use and cardiac amyloidosis. Of 8260 citations identified, six studies comprising 194 patients met inclusion criteria. RESULTS: Mean values and frequencies of patient characteristics were as follows: mean NT-proBNP: 6867.9 pg/mL, mean left ventricular ejection fraction: 48.1%, heart failure: 67%, nonsustained ventricular tachycardia: 51%, syncope: 21%, and secondary prevention: 33%. During the mean follow-up period of 18.21 months, 18% of patients received appropriate ICD treatment and 5% received inappropriate ICD treatment. The mortality rate was 31%. Two studies assessed the difference between patients with appropriate ICD treatment and patients with absence of appropriate ICD treatment. There was no difference between the two groups when stratified on multiple selected third variables except for two subgroups. Male gender was associated with a higher rate of appropriate ICD treatment, whereas New York Heart Association class III or IV heart failure patients was associated with a lower rate of appropriate ICD treatment. CONCLUSION: The frequency of appropriate ICD treatment in cardiac amyloidosis is low and is not predicted by nonsustained ventricular tachycardia. Male gender is associated with appropriate ICD treatment. New York Heart Association class III or IV heart failure is associated with lower rate of appropriate ICD treatment.

Association of beta-blockers and first-registered heart rhythm in out-of-hospital cardiac arrest: real-world data from population-based cohorts across two European countries.

AIMS: Conflicting results have been reported regarding the effect of beta-blockers on first-registered heart rhythm in out-of-hospital cardiac arrest (OHCA). We aimed to establish whether the use of beta-blockers influences first-registered rhythm in OHCA. METHODS AND RESULTS: We included patients with OHCA of presumed cardiac cause from two large independent OHCA-registries from Denmark and the Netherlands. Beta-blocker use was defined as exposure to either non-selective beta-blockers, ß1-selective beta-blockers, or α-ß-dual-receptor blockers within 90 days prior to OHCA. We calculated odds ratios (ORs) for the association of beta-blockers with first-registered heart rhythm using multivariable logistic regression. We identified 23 834 OHCA-patients in Denmark and 1584 in the Netherlands: 7022 (29.5%) and 519 (32.8%) were treated with beta-blockers, respectively. Use of non-selective beta-blockers, but not ß1-selective blockers, was more often associated with non-shockable rhythm than no use of beta-blockers [Denmark: OR 1.93, 95% confidence interval (CI) 1.48-2.52; the Netherlands: OR 2.52, 95% CI 1.15-5.49]. Non-selective beta-blocker use was associated with higher proportion of pulseless electrical activity (PEA) than of shockable rhythm (OR 2.38, 95% CI 1.01-5.65); the association with asystole was of similar magnitude, although not statistically significant compared with shockable rhythm (OR 2.34, 95% CI 0.89-6.18; data on PEA and asystole were only available in the Netherlands). Use of α-ß-dual-receptor blockers was significantly associated with non-shockable rhythm in Denmark (OR 1.21; 95% CI 1.03-1.42) and not significantly in the Netherlands (OR 1.37; 95% CI 0.61-3.07). CONCLUSION: Non-selective beta-blockers, but not ß1-selective beta-blockers, are associated with non-shockable rhythm in OHCA.

Synchronized Chest Compressions for Pseudo-PEA: Proof of Concept and a Synching Algorithm.

Objective: The two objectives of this report are: first, to describe a comparison of chest compressions unsynchronized or synchronized to native cardiac activity in a porcine model of hypotension, and second, to develop an algorithm to provide synchronized chest compressions throughout a range of native heart rates likely to be encountered when treating PEA cardiac arrest. Methods: We adapted our previously developed signal-guided CPR system to provide compressions synchronized to native electrical activity in a porcine model of hypotension as a surrogate of PEA arrest. We describe the first comparison of unsynchronized to synchronized compressions in a single animal as a proof-of-concept. We developed an algorithm to provide optimal synchronized chest compressions regardless of intrinsic PEA heart rate while simultaneously maintaining the chest compression rate within a desired range. We tested the algorithm with computer simulations measuring the proportion of intrinsic and compression beats that were synchronized, and the compression rate and its standard deviation, as a function of intrinsic heart rate and heart rate jitter. Results: We demonstrate and compare unsynchronized versus synchronized chest compressions in a single porcine model with an intrinsic rhythm and hypotension. Synchronized, but not unsynchronized, chest compressions were associated with increased blood pressure and coronary perfusion pressure. Our synchronized chest compression algorithm is able to provide synchronized chest compressions to over 90% of intrinsic beats for most heart rates while maintaining an average compression rate between 90 and 140 compressions per minute with relatively low variability. Conclusions: Synchronized chest compression therapy for pulseless electrical rhythms is feasible. A high degree of synchronization can be maintained over a broad range of intrinsic heart rates while maintaining the compression rate within a satisfactory range. Further investigation to assess benefit for treatment of PEA is warranted.

Neonatal Kawasaki syndrome presenting as out of hospital cardiac arrest rescued by extracorporeal cardiopulmonary resuscitation.

A 7-week-old girl presented in severe shock to a local emergency department. During transfer to the quaternary pediatric hospital, the child had a cardiac arrest and cardiopulmonary resuscitation was commenced en route. Upon arrival to the pediatric intensive care unit, extracorporeal life support was initiated via trans-sternal cannulation. Chest CT performed after extracorporeal life support cannulation, demonstrated widespread aneurysms and a diagnosis of Kawasaki disease was made. Immunomodulatory therapy with immunoglobulin and glucocorticoid medication was commenced and the child was separated from extracorporeal life support after 48 hours. Our case highlights both an unusual presentation of Kawasaki disease and the role extracorporeal cardiopulmonary resuscitation can play in the treatment of this disease. It describes the youngest reported patient in the literature with Kawasaki disease rescued by extracorporeal cardiopulmonary resuscitation and highlights how extracorporeal life support therapy can facilitate appropriate investigations to resolve diagnostic uncertainty and treat the underlying condition.

Deep Neural Networks for ECG-Based Pulse Detection during Out-of-Hospital Cardiac Arrest.

The automatic detection of pulse during out-of-hospital cardiac arrest (OHCA) is necessary for the early recognition of the arrest and the detection of return of spontaneous circulation (end of the arrest). The only signal available in every single defibrillator and valid for the detection of pulse is the electrocardiogram (ECG). In this study we propose two deep neural network (DNN) architectures to detect pulse using short ECG segments (5 s), i.e., to classify the rhythm into pulseless electrical activity (PEA) or pulse-generating rhythm (PR). A total of 3914 5-s ECG segments, 2372 PR and 1542 PEA, were extracted from 279 OHCA episodes. Data were partitioned patient-wise into training (80%) and test (20%) sets. The first DNN architecture was a fully convolutional neural network, and the second architecture added a recurrent layer to learn temporal dependencies. Both DNN architectures were tuned using Bayesian optimization, and the results for the test set were compared to state-of-the art PR/PEA discrimination algorithms based on machine learning and hand crafted features. The PR/PEA classifiers were evaluated in terms of sensitivity (Se) for PR, specificity (Sp) for PEA, and the balanced accuracy (BAC), the average of Se and Sp. The Se/Sp/BAC of the DNN architectures were 94.1%/92.9%/93.5% for the first one, and 95.5%/91.6%/93.5% for the second one. Both architectures improved the performance of state of the art methods by more than 1.5 points in BAC.

Echocardiography in cardiac arrest: An emergency medicine review.

INTRODUCTION: Cardiac arrest management primarily focuses on optimal chest compressions and early defibrillation for shockable cardiac rhythms. Non-shockable rhythms such as pulseless electrical activity (PEA) and asystole present challenges in management. Point-of-care ultrasound (POCUS) in cardiac arrest is promising. OBJECTIVES: This review provides a focused assessment of POCUS in cardiac arrest, with an overview of transthoracic (TTE) and transesophageal echocardiogram (TEE), uses in arrest, and literature support. DISCUSSION: Cardiac arrest can be distinguished between shockable and non-shockable rhythms, with management varying based on the rhythm. POCUS provides a diagnostic and prognostic tool in the emergency department (ED), which may improve accuracy in clinical decision-making. Several protocols incorporate POCUS based on different cardiac views. TTE includes parasternal long axis, parasternal short axis, apical 4-chamber, and subxiphoid views, which may be used in cardiac arrest for diagnosis of underlying cause and potential prognostication. TEE is conducted by inserting the probe into the esophagus of intubated patients, with several studies evaluating its use in cardiac arrest. It is associated with few adverse effects, while allowing continued compressions (and evaluation of those compressions) and not interrupting resuscitation efforts. CONCLUSIONS: POCUS is a valuable diagnostic and prognostic tool in cardiac arrest, with recent literature supporting its diagnostic ability. TTE can guide resuscitation efforts dependent on the rhythm, though TTE should not interrupt other resuscitation measures. TEE can be useful during arrest, but further studies based in the ED are needed.

Electrocardiographic manifestations of severe hyperkalemia.

Severe hyperkalemia is a hazardous condition that warrants urgent intervention. In critically ill patients, the electrocardiogram (ECG) can be the most immediately available diagnostic tool in identifying patients with potentially lethal hyperkalemia. Peaking of the T waves, the most widely appreciated ECG sign, is actually rarely a manifestation of life-threatening hyperkalemia. In this review, we provide several clinical-electrocardiographic manifestations that can help identify those patients with hyperkalemia who require prompt intervention.

Emergency Medicine Myths: Epinephrine in Cardiac Arrest.

BACKGROUND: Sudden cardiac arrest accounts for approximately 15% of deaths in developed nations, with poor survival rate. The American Heart Association states that epinephrine is reasonable for patients with cardiac arrest, though the literature behind its use is not strong. OBJECTIVE: To review the evidence behind epinephrine for cardiac arrest. DISCUSSION: Sudden cardiac arrest causes over 450,000 deaths annually in the United States. The American Heart Association recommends epinephrine may be reasonable in patients with cardiac arrest, as part of Advanced Cardiac Life Support. This recommendation is partly based on studies conducted on dogs in the 1960s. High-dose epinephrine is harmful and is not recommended. Epinephrine may improve return of spontaneous circulation, but does not improve survival to discharge or neurologic outcome. Literature suggests that three phases of resuscitation are present: electrical, circulatory, and metabolic. Epinephrine may improve outcomes in the circulatory phase prior to 10 min post arrest, though further study is needed. Basic Life Support measures including adequate chest compressions and early defibrillation provide the greatest benefit. CONCLUSIONS: Epinephrine may improve return of spontaneous circulation, but it does not improve survival to discharge or neurologic outcome. Timing of epinephrine may affect patient outcome, but Basic Life Support measures are the most important aspect of resuscitation and patient survival.

Recurrent pulseless electrical activity in a patient with coronary vasospasm and supravalvular aortic stenosis: a case report.

BACKGROUND: Pulseless electrical activity cardiac arrest is associated with poor outcomes and the identification of potentially reversible reasons for cardiac arrest is fundamental. CASE PRESENTATION: We describe the case of a 46-year-old male with the rare coincidental finding of supravalvular aortic stenosis and coronary vasospasm leading to recurrent pulseless electrical activity cardiac arrest. Extracorporeal life support was successfully applied for hemodynamic stabilization. Supravalvular aorticstenosis underwent surgical repair. The patient survived five time resuscitation and was discharged after full neurological recovery. CONCLUSIONS: Coronary vasospasm and supravalvular aortic stenosis are rare but potentially reversible causes of pulseless electrical activity cardiac arrest. Extracorporeal life support allows accurate diagnostic and possibly therapy even of uncommon reasons for cardiac arrest.

The Outcome and Predictors of Mortality in Patients Therapeutically Cooled Postcardiac Arrest.

PURPOSE: To review the outcomes of patients postcardiac arrest admitted to a metropolitan intensive care unit (ICU) where therapeutic hypothermia is practiced. MATERIALS AND METHODS: Patients admitted from 2004 to 2012 were reviewed. The management protocol included cooling to 33°C for 24 hours. The primary outcome assessed was hospital mortality. Secondary outcome measures included mortality in patients admitted to ICU after in-hospital cardiac arrest (IHCA) when compared to those with out-of-hospital cardiac arrest (OHCA) and to review initial cardiac rhythm as an indicator of mortality. RESULTS: A total of 330 patients were included. The overall hospital mortality was 58.1%. Hospital mortality was significantly higher in patients who had OHCA when compared to IHCA (62.5% vs 51%; P = .04). Patients who had asystole and pulseless electrical activity (PEA) had a higher mortality when compared to ventricular tachycardia/ventricular fibrillation (VT/VF) arrest (81.7% vs 67.8% vs 41.9%, respectively; P < .01). CONCLUSION: Patients admitted to ICU postcardiac arrest after therapeutic cooling have a high mortality. An initial rhythm of VT/VF confers a mortality benefit when compared to asystole and PEA.

The CPR outcomes of online medical video instruction versus on-scene medical instruction using simulated cardiac arrest stations.

BACKGROUND: Non-traumatic cardiac arrest is a fatal emergency condition. Its survival rate and outcomes may be better with quick and effective cardiopulmonary resuscitation (CPR). Telemedicine such as telephone or real time video has been shown to improve chest compression procedures. There are limited data on the effects of telemedicine in cardiac arrest situations in the literature particularly in Asian settings. METHODS: This study was conducted by using two simulated cardiac arrest stations during the 2014 annual Thai national conference in emergency medicine. These two stations, nos. 5 and 11, were a part of the conference activity called "EMS rally" which was comprised of 14 stations. Both stations were shockable and out-of-hospital cardiac arrest situations; station 5 was online instructed, while station 11 was on-scene instructed. There were 14 representative teams from each province from all over Thailand who participated in the rally. Each team had one physician, one nurse, and two emergency medicine technicians. Eight CPR outcomes were evaluated and compared between the online versus on-scene situations. RESULTS: There were 14 representative teams that participated in the study; a total of 14 physicians, 14 nurses, and 28 emergency medicine technicians. The average ages of participants in all three occupations were between the second and third decade of life. The percentages of participants with more than 3 years in ambulance experience was 7.1, 64.3, and 53.6 % in the physicians, nurses, and EMTs groups. The median times of all outcomes were significantly longer in the online group than the on-scene group including times from start to chest compression (total 102 vs 36 s), total times from the start to VT/VF detection (187 vs 99 s); times from VT/VF detection to the first defibrillation (57 vs 28 s); and times from the start of adrenaline injection (282 vs 165 s). The percentages of using amiodarone (21.43 % vs 57.14 %; p value < 0.001), establishment of a definitive airway (35.71 % vs 100 %; p value 0.003), and correct detections of pulseless electrical activity (PEA) (28.57 % vs 100 %; p value < 0.001) were significantly lower in the online group than the on-scene group. The high quality CPR outcomes between the online group and on-scene group were comparable. CONCLUSIONS: The online medical instruction may have worse CPR outcomes compared with on-scene medical instruction in shockable, simulated CPR scenarios. Further studies are needed to confirm these results.

Out-of-hospital Cardiac Arrest Patient Characteristics: Comparing ventricular arrhythmia and Pulseless Electrical Activity.

BACKGROUND: The proportion of patients suffering out-of-hospital cardiac arrest presenting with ventricular arrhythmias/ventricular fibrillation (VT/VF) is decreasing, while the proportion presenting with pulseless electrical activity (PEA) is increasing. Cardiac arrest interventions target VT/VF and survival rates from PEA are much lower. The aim of this study was to compare clinical characteristics of those suffering PEA and VT/VF. METHODS: We examined the past medical history of all patients suffering cardiac arrest in the Wellington region between 2008-2012 and compared clinical features of those with PEA to VT/VF. RESULTS: We identified 749 cardiac arrests in the study period, and were able to obtain detailed medical histories in 735 (98%) cases. The presenting rhythm was VF/VT in 337 (46%) cases, PEA in 127 (17%), and asystole in 271 (37%). Patients with PEA were older (68±14 versus 63±15 years, p=0.003), a higher proportion were female (35% versus 22%, p=0.002) and were less likely to have prior cardiovascular disease than those with VT/VF (48% versus 59%, p=0.03). Respiratory disease was more common in those with PEA (35% versus 23%, p=0.008). CONCLUSION: The population suffering PEA differs from the VT/VF cohort in a number of ways, and PEA is associated with significantly worse outcomes.