A prospective, randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in out-of-hospital cardiac arrest

Emergency medicine updates: Defibrillation strategies in cardiac arrest

INTRODUCTION

Cardiac arrest is a commonly managed condition in the emergency department (ED), and defibrillation of shockable rhythms is a key component of treatment, along with high-quality chest compressions.

OBJECTIVE

This narrative review seeks to evaluate evidence-based updates concerning defibrillation in cardiac arrest.

DISCUSSION

Cardiac arrest management includes cardiopulmonary resuscitation (CPR) and defibrillation of shockable rhythms. CPR should be provided until a defibrillator is applied. In those with pulseless ventricular tachycardia or ventricular fibrillation, defibrillation should be performed as soon as possible. If the arrest is unwitnessed, or there will be a delay in rhythm analysis or applying/obtaining a defibrillator, CPR should be performed while the defibrillator is being obtained and prepared for use. Biphasic waveform defibrillators are recommended. Shorter pre- and peri-shock pauses are associated with higher survival rates. Charging the defibrillator during chest compressions, holding compressions for rhythm analysis alone, and immediately resuming compressions following defibrillation are recommended to maximize chest compression fraction. Two common defibrillator pad configurations include anterolateral (AL) and anterior-posterior (AP). Vector-change defibrillation can be attempted if the first defibrillation attempt is unsuccessful. Double defibrillation (DD) includes either double simultaneous defibrillation (DSD) or dual sequential external defibrillation (DSED), though DSED is more common. DD utilizes two biphasic defibrillators and two sets of defibrillator pads in an AL and AP configuration. If the patient is refractory to 3 or more defibrillation attempts, DD may be attempted. Defibrillator damage with DD is rare, and clinicians must consider the potential survival benefit with DD, patient and provider safety issues, cost, and system-level impact when using two defibrillators.

CONCLUSIONS

An understanding of literature updates focused on defibrillation can improve the ED care of patients in cardiac arrest.

Associations of manual defibrillator compared to automated external defibrillator usage with defibrillation and resuscitation quality during in-hospital cardiac arrest

BACKGROUND

Manual Defibrillators and Automated external defibrillators (AEDs) are frequently used during in-hospital cardiac arrest (IHCA), yet comparisons of their performance remain limited. This study aimed to compare the accuracy of rhythm analyses and chest compression pause durations of manual defibrillator and AED usage during IHCA.

METHODS

In this multicenter cohort study, we analysed thoracic impedance data and electrocardiograms from manual defibrillators and AEDs used during IHCA occurring in the Central Denmark Region between April 2019 and March 2024. The primary outcome was the difference in accuracy of rhythm analyses, while secondary outcomes included chest compression pause duration for rhythm analysis and defibrillation.

RESULTS

A total of 529 cardiac arrests were analysed, yielding 1715 rhythm analyses from manual defibrillators and 602 AED analyses. The difference in the accuracy of rhythm analyses between a manual defibrillator and an AED was statistically not significant with an adjusted odds ratio of 0.5 (95%-CI: 0.2; 1.3). Manual defibrillator use was associated with 3.2 s (95%-CI: 1.7; 4.9) shorter pauses for rhythm analysis and 7.9 s (95%-CI: 5.9; 9.9) shorter peri-shock pauses.

CONCLUSION

Using manual defibrillators compared to AEDs was not associated with a higher accuracy of rhythm analyses, but with shorter chest compression pause durations for rhythm analysis and shorter peri-shock pauses.

International Consensus on Evidence Gaps and Research Opportunities in Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-of-Hospital Cardiac Arrest: A Report From the National Heart, Lung, and Blood Institute Workshop

The increased accessibility of extracorporeal membrane oxygenation following the COVID-19 pandemic and the publication of the first randomized trial of extracorporeal cardiopulmonary resuscitation (ECPR) prompted the National Heart, Lung, and Blood Institute to sponsor a workshop on ECPR. Two more randomized trials have since been published in 2022 and 2023. Based on the combined findings and review of the evidence, an international panel of authors identified gaps in science, inequities in care and diversity in outcomes, and suggested research opportunities and next steps. The science pertaining to ECPR would benefit from the United States contributing uniform data to existing registries and sharing common data with the ELSO (Extracorporeal Life Support Organization) international registry to increase the sample size for observational research. In addition, well-designed efficacy trials, recruiting across different regions of care evaluating long-term follow-up, including patient reported outcomes, cost effectiveness, and equity measures, would contribute significantly to the body of science. Workshop participants defined the population of patients with out-of-hospital cardiac arrest most likely to benefit from ECPR. ECPR-eligible patients include those aged 18 to 75 years functioning independently without comorbidity; before suffering a witnessed out-of-hospital cardiac arrest and without any obvious cause of the cardiac arrest; presenting in a shockable rhythm and transported with mechanical cardiopulmonary resuscitation to an ECPR-capable institute within 30 minutes, which is recommended after 3 rounds of advanced life support treatment without return of spontaneous circulation. There are significant inequities in out-of-hospital cardiac arrest care that need to be addressed such that outcomes are optimized for each target region before implementing ECPR in a clinical or implementation trial.

The association between initial defibrillation dose and outcomes following adult out-of-hospital cardiac arrest resuscitation: A retrospective, multi-agency study

INTRODUCTION

Effective defibrillation is essential to out-of-hospital cardiac arrest (OHCA) survival. International guidelines recommend initial defibrillation energies between 120 and 360 Joules, which has led to widespread practice variation. Leveraging this natural experiment, we aimed to explore the association between initial defibrillation dose and outcome following OHCA.

METHODS

The ESO Data Collaborative (2018-2022) was used for this nationwide, retrospective study of adult (18-80 years of age) non-traumatic OHCA patients who presented with an initially shockable ECG rhythm. We excluded patients if they had ROSC prior to initial defibrillation, a resuscitation-limiting advanced directive, or were residents in a healthcare institution. The primary exposure was initial defibrillation dose, defined as Joules per kilogram of body weight, and the primary outcome was return of spontaneous circulation (ROSC). We included survival to discharge as a secondary outcome. We used multivariable logistic regression modeling to assess the relationship between defibrillation dose and outcome.

RESULTS

We analyzed data from 21,121 patients. Of the 12,160 patients linked to a defibrillator manufacturer, 7,240 (59.5%) were treated using a biphasic truncated exponential (BTE) waveform and 4,920 (40.5%) were treated using a rectilinear biphasic (RLB) waveform. Defibrillation dose (per 1 J/kg increase) was not associated with ROSC (BTE aOR: 0.97 [0.92, 1.01], n = 7,240; RLB aOR: 1.00 [0.92, 1.09], n = 4,920; all aOR: 1.01 [0.98, 1.04], 21,121) or survival (BTE aOR: 0.98 [0.87, 1.10], n = 1,245; RLB aOR: 0.89 [0.70, 1.12], n = 775; all aOR: 1.00 [0.92, 1.08], n = 2,981).

CONCLUSIONS

Initial defibrillation dose was not associated with outcome in this nationwide cohort.

Automated external defibrillator: Rhythm analysis and defibrillation on paediatric out-of-hospital cardiac arrest

Objective

This study aims to quantify the reliability of automated external defibrillators (AED) in paediatric out-of-hospital cardiac arrests (pOHCA) by evaluating the defibrillation and the shock advisory system efficacy. Furthermore, the relationship between the initial energy dose and patient outcomes is analysed.

Methods

We studied data from all pOHCA cases (age < 18 years) treated by the Paris Fire Brigade between January 2010 and December 2018, limited to those with available AED signals. The efficacy of shocks is the primary outcome. The secondary outcomes are the shock advisory system performance, pre-hospital return of a spontaneous circulation (ROSC), survival and energy dose. Energy dose, weight and age are compared using a Wilcoxon test according to the outcome's values.

Results

A total of 1,990 electrocardiogram strips extracted from 349 pOHCA cases were included in the study. Shock advisory system had a sensitivity of 89.4% and a specificity of 99.8% for the detection of shockable rhythms. Shock efficacy observed for all patients who received a shock was 83.1% and first shock efficacy for patients in initial ventricular fibrillation was 96%. Patients who received a shock had a pre-hospital ROSC rate of 74.3%, a survival rate at hospital admission of 71.4% and 34.3% at hospital discharge.

Conclusion

This study shows that AED detect shockable rhythm with a good sensitivity and specificity and that shocks are associated with a very high rates of termination of shockable rhythms in pOHCA.

Gaps in Public Access Defibrillation: Analysis of International Legislation

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a global health issue, for which rapid public access defibrillation (PAD) increases survival.

OBJECTIVES

The purpose of this study was to evaluate international legislation relating to PAD and develop legal recommendations to improve PAD in OHCA.

METHODS

Searches covering 5 domains (automated external defibrillator [AED] provision, funding, identification, maintenance, lay responder training) were conducted in 99 jurisdictions worldwide: United States (50) and Canada (13) analyzed at state/province level; 36 other countries analyzed at national level. Forty-nine legislation sources were searched from September 27, 2021, to May 5, 2022. Legislative data were classified: Enabling Legislation (facilitating PAD) or Disabling Legislation (hindering PAD). Based on retrieved data, recommendations for international AED laws were developed.

RESULTS

Searches identified 419,248 legal records. Enabling Legislation regarding AED provision in public areas was present in 60% U.S. states, 8% Canadian provinces, and 22% of nations studied from the rest of world. Disabling Legislation regarding registration of AEDs, that could potentially discourage AED ownership, was found in 37 North American jurisdictions. Enabling Legislation regarding AED signage was found in 66% U.S. states and 39% of all jurisdictions worldwide. Overall, 48% of worldwide jurisdictions studied had legislative requirements for AED maintenance, including 80% of all U.S. states. Internationally, 49.5% of jurisdictions studied had Enabling Legislation mandating AED training, and 66% United States had this for schools. Only 4 jurisdictions worldwide gave implicit authorization to laypersons for AED use in emergencies.

CONCLUSIONS

There is significant variability in international legislation relating to PAD. All countries should consider Enabling Legislation that could decrease delays to PAD. Similarly, Disabling Legislation potentially hindering prompt PAD during OHCA should be withdrawn.

Bolus intravenous potassium chloride for recurrent ventricular fibrillation

We report the feasibility and recommend the potential efficacy of a bolus intravenous potassium chloride during out-of-hospital cardiac arrest with recurrent ventricular fibrillation following an acute coronary syndrome in a man in his 40's.

Impact of Defibrillator Electrode Placement on Outcome of Electrical Cardioversion of Atrial Fibrillation: A Pilot Observational Study

BACKGROUND

Anterior-posterior electrode placement is preferred in electrical cardioversion of atrial fibrillation. However, the optimal anterior-posterior electrode position in relation to the heart is not studied.

METHODS AND RESULTS

We performed a prospective observational study on patients presenting for cardioversion of atrial fibrillation. Electrodes were placed in the anterior-posterior position and shock was delivered in a step-up approach (100 J→200 J→360 J). Fluoroscopic images were obtained, and distances were measured from points A, midanterior electrode; and B, midposterior electrode, to midpoint of the cardiac silhouette. Patients requiring one 100 J shock for cardioversion success (group I) were compared with those requiring >1 shock/100 J (group II). Logistic regression was used to determine the impact of electrode distance on low energy (100 J) cardioversion success. Computed tomography scans from this cohort were analyzed for anatomic landmark correlation to the cardiac silhouette. Of the 87 patients included, 54 (62%) comprised group I and 33 (38%) group II. Group I had significantly lower distances from the mid-cardiac silhouette to points A (5.0±2.4 versus 7.4±3.3 cm; P<0.001) and B (7.3±3.0 versus 10.0±3.8 cm; P=0.002) compared with group II. On multivariate analysis, higher distances from the mid-cardiac silhouette to point A (odds ratio, 1.33 [95% CI, 1.07-1.70]; P=0.01) and B (odds rsatio, 1.24 [95% CI, 1.05-1.50]; P=0.01) were independent predictors of low energy (100 J) cardioversion failure. Based on review of computed tomography scans, we suggest that the xiphoid process may be an easy landmark to guide proximity to the myocardium.

CONCLUSIONS

In anterior-posterior electrode placement, closer proximity to the cardiac silhouette predicts successful 100 J cardioversion irrespective of clinical factors.

2024 RECOVER Guidelines: Advanced Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to ALS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by ALS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Seventeen questions pertaining to vascular access, vasopressors in shockable and nonshockable rhythms, anticholinergics, defibrillation, antiarrhythmics, and adjunct drug therapy as well as open-chest CPR were reviewed. Of the 33 treatment recommendations formulated, 6 recommendations addressed the management of patients with nonshockable arrest rhythms, 10 addressed shockable rhythms, and 6 provided guidance on open-chest CPR. We recommend against high-dose epinephrine even after prolonged CPR and suggest that atropine, when indicated, is used only once. In animals with a shockable rhythm in which initial defibrillation was unsuccessful, we recommend doubling the defibrillator dose once and suggest vasopressin (or epinephrine if vasopressin is not available), esmolol, lidocaine in dogs, and/or amiodarone in cats.

CONCLUSIONS

These updated RECOVER ALS guidelines clarify the approach to refractory shockable rhythms and prolonged CPR. Very low quality of evidence due to absence of clinical data in dogs and cats continues to compromise the certainty with which recommendations can be made.

Cardiopulmonary Resuscitation: The Importance of the Basics

Cardiac arrest is the loss of organized cardiac activity. Unfortunately, survival to hospital discharge is poor, despite recent scientific advances. The goals of cardiopulmonary resuscitation (CPR) are to restore circulation and identify and correct an underlying etiology. High-quality compressions remain the foundation of CPR, optimizing coronary and cerebral perfusion pressure. High-quality compressions must be performed at the appropriate rate and depth. Interruptions in compressions are detrimental to management. Mechanical compression devices are not associated with improved outcomes but can assist in several situations.

Defibrillation effectiveness and safety of the shock waveform used in a contemporary wearable cardioverter defibrillator: Results from animal and human studies

INTRODUCTION

The wearable cardioverter defibrillator (WCD) is used to protect patients at risk for sudden cardiac arrest. We examined defibrillation efficacy and safety of a biphasic truncated exponential waveform designed for use in a contemporary WCD in three animal studies and a human study.

METHODS

Animal (swine) studies: #1: Efficacy comparison of a 170J BTE waveform (SHOCK A) to a 150J BTE waveform (SHOCK B) that approximates another commercially available waveform. Primary endpoint first shock success rate. #2: Efficacy comparison of the two waveforms at attenuated charge voltages in swine at three prespecified impedances. Primary endpoint first shock success rate. #3: Safety comparison of SHOCK A and SHOCK B in swine. Primary endpoint cardiac biomarker level changes baseline to 6 and 24 hours post-shock. Human Study: Efficacy comparison of SHOCK A to prespecified goal and safety evaluation. Primary endpoint cumulative first and second shock success rate. Safety endpoint adverse events.

RESULTS

Animal Studies #1: 120 VF episodes in six swine. First shock success rates for SHOCK A and SHOCK B were 100%; SHOCK A non-inferior to SHOCK B (entire 95% CI of rate difference above -10% margin, p < .001). #2: 2,160 VF episodes in thirty-six swine. Attenuated SHOCK A was non-inferior to attenuated SHOCK B at each impedance (entire 95% CI of rate difference above -10% margin, p < .001). #3: Ten swine, five shocked five times each with SHOCK A, five shocked five times each with SHOCK B. No significant difference in troponin I (p = 0.658) or creatine phosphokinase (p = 0.855) changes from baseline between SHOCK A and SHOCK B. Human Study: Thirteen patients, 100% VF conversion rate. Mild skin irritation from adhesive defibrillation pads in three patients.

CONCLUSIONS

The BTE waveform effectively and safely terminated induced VF in swine and a small sample in humans.

TRIAL REGISTRATION

Human study clinical trial registration: URL: https://clinicaltrials.gov; Unique identifier: NCT04132466.

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.

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.

[Adult advanced life support]

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

European Resuscitation Council Guidelines 2021: Adult advanced life support

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

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.

Value of capnography to predict defibrillation success in out-of-hospital cardiac arrest

BACKGROUND AND AIM

Unsuccessful defibrillation shocks adversely affect survival from out-of-hospital cardiac arrest (OHCA). Ventricular fibrillation (VF) waveform analysis is the tool-of-choice for the non-invasive prediction of shock success, but surrogate markers of perfusion like end-tidal CO2 (EtCO2) could improve the prediction. The aim of this study was to evaluate EtCO2 as predictor of shock success, both individually and in combination with VF-waveform analysis.

MATERIALS AND METHODS

In total 514 shocks from 214 OHCA patients (75 first shocks) were analysed. For each shock three predictors of defibrillation success were automatically calculated from the device files: two VF-waveform features, amplitude spectrum area (AMSA) and fuzzy entropy (FuzzyEn), and the median EtCO2 (MEtCO2) in the minute before the shock. Sensitivity, specificity, receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated, for each predictor individually and for the combination of MEtCO2 and VF-waveform predictors. Separate analyses were done for first shocks and all shocks.

RESULTS

MEtCO2 in first shocks was significantly higher for successful than for unsuccessful shocks (31mmHg/25mmHg, p<0.05), but differences were not significant for all shocks (32mmHg/29mmHg, p>0.05). MEtCO2 predicted shock success with an AUC of 0.66 for first shocks, but was not a predictor for all shocks (AUC 0.54). AMSA and FuzzyEn presented AUCs of 0.76 and 0.77 for first shocks, and 0.75 and 0.75 for all shocks. For first shocks, adding MEtCO2 improved the AUC of AMSA and FuzzyEn to 0.79 and 0.83, respectively.

CONCLUSIONS

MEtCO2 predicted defibrillation success only for first shocks. Adding MEtCO2 to VF-waveform analysis in first shocks improved prediction of shock success. VF-waveform features and MEtCO2 were automatically calculated from the device files, so these methods could be introduced in current defibrillators adding only new software.

Risk factors for sudden cardiac death to determine high risk patients in specific patient populations that may benefit from a wearable defibrillator

BACKGROUND

There is a high risk for sudden cardiac death (SCD) in certain patient groups that would not meet criteria for implantable cardioverter defibrillator (ICD) therapy. In conditions such as hypertrophic cardiomyopathy (HCM) there are clear risk scores that help define patients who are high risk for SCD and would benefit from ICD therapy. There are however many areas of uncertainty such as certain patients post myocardial infarction (MI). These patients are high risk for SCD but there is no clear tool for risk stratifying such patients.

AIM

To assess risk factors for sudden cardiac death in major cardiac disorders and to help select patients who might benefit from Wearable cardiac defibrillators (WCD).

METHODS

A literature search was performed looking for risk factors for SCD in patients post-MI, patients with left ventricular systolic dysfunction (LVSD), HCM, long QT syndrome (LQTS). There were 41 studies included and risk factors and the relative risks for SCD were compiled in table form.

RESULTS

We extracted data on relative risk for SCD of specific variables such as age, gender, ejection fraction. The greatest risk factors for SCD in post MI patients was the presence of diabetes [Hazard ratio (HR) 1.90-3.80], in patient with LVSD was ventricular tachycardia (Relative risk 3.50), in LQTS was a prolonged QTc (HR 36.53) and in patients with HCM was LVH greater than 20 mm (HR 3.10). A proportion of patients currently not suitable for ICD might benefit from a WCD

CONCLUSION

There is a very high risk of SCD post MI, in patients with LVSD, HCM and LQTS even in those who do not meet criteria for ICD implantation. These patients may be candidates for a WCD. The development of more sensitive risk calculators to predict SCD is necessary in these patients to help guide treatment.

Survival to hospital discharge with biphasic fixed 360 joules versus 200 escalating to 360 joules defibrillation strategies in out-of-hospital cardiac arrest of presumed cardiac etiology

INTRODUCTION

Guidelines recommend constant or escalating energy levels for shocks after the initial defibrillation attempt. Studies comparing survival to hospital discharge with escalating vs fixed high energy level shocks are lacking. We compared survival to hospital discharge for 200 J escalating to 360 J vs fixed 360 J in patients with initial ventricular fibrillation/pulseless ventricular tachycardia in a post-hoc analysis of the Circulation Improving Resuscitation Care trial database.

METHODS AND RESULTS

Pre-shock rhythm, rhythm 5 s after shock, shock energy levels, termination of ventricular fibrillation/pulseless ventricular tachycardia (TOF), and survival to hospital discharge were recorded. Association between defibrillation strategy and survival to hospital discharge was investigated with multivariable logistic regression. The escalating energy group included 260 patients and 883 shocks vs 478 patients and 1736 shocks in the fixed-high energy group. There was no difference in survival to hospital discharge between escalating (70/255 patients, 28%) and fixed energy group (132/478 patients, 28%) (unadjusted OR 1.00, 95% CI 0.72-1.42 and adjusted OR 0.81, 95% CI 0.54-1.22, p = 0.32). First shock TOF was 86% in the escalating group compared to 83% in the fixed-high group, p = 0.27.

CONCLUSION

There was no difference in survival to hospital discharge or the frequency of TOF between escalating energy and fixed-high energy group. ClinicalTrials.gov Identifier: NCT00597207.

Long-term outcome of elderly out-of-hospital cardiac arrest survivors as compared with their younger counterparts and the general population

BACKGROUND:

Over the past decade, prehospital and in-hospital treatment for out-of-hospital cardiac arrest (OHCA) has improved considerably. There are sparse data on the long-term outcome, especially in elderly patients. We studied whether elderly patients benefit to the same extent compared with younger patients and at long-term follow up as compared with the general population.

METHODS:

Between 2001 and 2010, data from all patients presented to our hospital after OHCA were recorded. Elderly patients (⩾75 years) were compared with younger patients. Neurological outcome was classified as cerebral performance category (CPC) at hospital discharge and long-term survival was compared with younger patients and predicted survival rates of the general population.

RESULTS:

Of the 810 patients admitted after OHCA, a total of 551 patients (68%) achieved return of spontaneous circulation, including 125 (23%) elderly patients with a mean age of 81 ± 5 years. In-hospital survival was lower in elderly patients compared with younger patients with rates of 33% versus 57% ( p < 0.001). A CPC of 1 was present in 73% of the elderly patients versus 86% of the younger patients ( p = 0.031). In 7.3% of the elderly patients, a CPC >2 was observed versus 2.5% of their younger counterparts ( p = 0.103). Elderly patients had a median survival of 6.5 [95% confidence interval (CI) 2.0-7.9] years compared with 7.7 (95% CI 7.5-7.9) years of the general population ( p = 0.019).

CONCLUSIONS:

The survival rate after OHCA in elderly patients is approximately half that of younger patients. Elderly patients who survive to discharge frequently have favorable neurological outcomes and a long-term survival that approximates that of the general population.

Paddle Position and Contact Force: An Important Step to Check When Troubleshooting for Refractory Ventricular Fibrillation

Ventricular fibrillation (VF) is a lethal medical emergency that requires immediate defibrillation. VF is resistant when it persists after three or more defibrillator shocks. Successful defibrillation requires depolarisation of a critical mass of myocardium. Several variables, such as the length of time in VF, body type, total energy used, and energy waveform have been reported to be associated with the success rate of defibrillation. Correct paddle position and good contact force to create an adequate current flow through the heart is essential for defibrillation. We report a patient who developed VF because of acute myocardial infarction that was resistant to a total of 13 shocks. The cause of shock-resistant VF was diagnosed by noticing the skin marks caused by the defibrillator paddle that indicated incorrect paddle position and inadequate paddle force. By checking the skin marks, an emergency physician could make a correct diagnosis within a few seconds and save a patient.

Number of Prehospital Defibrillation Shocks and the Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest

OBJECTIVE

It has not been determined yet whether the number of defibrillation shocks delivered over the first 30 min of cardiopulmonary resuscitation (CPR) impacts the rate of successful return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted a retrospective observational study in non-traumatic OHCA. Patients who were administered defibrillation shocks using a public automated external defibrillator (AED) were consecutively enrolled in the study. We assessed the relationship between ROSC and the number of prehospital defibrillation shocks and constructed an receiver operating characteristic (ROC) curve to illustrate the ability of repeated defibrillation shocks to predict ROSC over the first 30 min of CPR.

RESULTS

Increasing the number of defibrillation shocks progressively decreased the probability to achieve ROSC. The highest rate of ROSC (33%) was observed when four shocks were delivered. The ROC curve illustrated that the fourth shock maximised sensitivity and specificity (area under the curve [AUC]=0.72). The positive and negative predictive values for ROSC reached 82% and 48%, respectively, when <4 shocks were delivered.

CONCLUSION

The delivery of four defibrillation shocks in OHCA most related to ROSC. The evaluation of the number of delivered shock during the first 30 min of CPR is a simple tool that can be used for an early decision in OHCA patient.

Return of spontaneous circulation and long-term survival according to feedback provided by automated external defibrillators

Background

We aimed to investigate the effect of automated external defibrillator (AED) feedback mechanisms on survival in out‐of‐hospital cardiac arrest (OHCA) victims. In addition, we investigated converting rates in patients with shockable rhythms according to AED shock waveforms and energy levels.

Methods

We collected data on OHCA occurring between 2011 and 2014 in the Capital Region of Denmark where an AED was applied prior to ambulance arrival. Patient data were obtained from the Danish Cardiac Arrest Registry and medical records. AED data were retrieved from the Emergency Medical Dispatch Centre (EMDC) and information on feedback mechanisms, energy waveform and energy level was downloaded from the applied AEDs.

Results

A total of 196 OHCAs had an AED applied prior to ambulance arrival; 62 of these (32%) provided audio visual (AV) feedback while no feedback was provided in 134 (68%). We found no difference in return of spontaneous circulation (ROSC) at hospital arrival according to AV‐feedback; 34 (55%, 95% confidence interval (CI) [13–67]) vs. 72 (54%, 95% CI [45–62]), P = 1 (odds ratio (OR) 1.1, 95% CI [0.6–1.9]) or 30‐day survival; 24 (39%, 95% CI [28–51]) vs. 53 (40%, 95% CI [32–49]), P = 0.88 (OR 1.1 (95% CI [0.6–2.0])). Moreover, we found no difference in converting rates among patients with initial shockable rhythm receiving one or more shocks according to AED energy waveform and energy level.

Conclusions

No difference in survival after OHCA according to AED feedback mechanisms, nor any difference in converting rates according to AED waveform or energy levels was detected.

A multicenter prospective randomized study comparing the efficacy of escalating higher biphasic versus low biphasic energy defibrillations in patients presenting with cardiac arrest in the in-hospital environment

Background

Biphasic defibrillation has been practiced worldwide for >15 years. Yet, consensus does not exist on the best energy levels for optimal outcomes when used in patients with ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT).

Methods

This prospective, randomized, controlled trial of 235 adult cardiac arrest patients with VF/VT was conducted in the emergency and cardiology departments. One group received low-energy (LE) shocks at 150–150–150 J and the other escalating higher-energy (HE) shocks at 200–300–360 J. If return of spontaneous circulation (ROSC) was not achieved by the third shock, LE patients crossed over to the HE arm and HE patients continued at 360 J. Primary end point was ROSC. Secondary end points were 24-hour, 7-day, and 30-day survival.

Results

Both groups were comparable for age, sex, cardiac risk factors, and duration of collapse and VF/VT. Of the 118 patients randomized to the LE group, 48 crossed over to the HE protocol, 24 for persistent VF, and 24 for recurrent VF. First-shock termination rates for HE and LE patients were 66.67% and 64.41%, respectively (P=0.78, confidence interval: 0.65–1.89). First-shock ROSC rates were 25.64% and 29.66%, respectively (P=0.56, confidence interval: 0.46–1.45). The 24-hour, 7-day, and 30-day survival rates were 85.71%, 74.29%, and 62.86% for first-shock ROSC LE patients and 70.00%, 50.00%, and 46.67% for first-shock ROSC HE patients, respectively. Conversion rates for further shocks at 200 J and 300 J were low, but increased to 38.95% at 360 J.

Conclusion

First-shock termination and ROSC rates were not significantly different between LE and HE biphasic defibrillation for cardiac arrest patients. Patients responded best at 150/200 J and at 360 J energy levels. For patients with VF/pulseless VT, consideration is needed to escalate quickly to HE shocks at 360 J if not successfully defibrillated with 150 or 200 J initially.

Sudden Cardiac Death in the Young

Although the occurrence of sudden cardiac death (SCD) in a young person is a rare event, it is traumatic and often widely publicized. In recent years, SCD in this population has been increasingly seen as a public health and safety issue. This review presents current knowledge relevant to the epidemiology of SCD and to strategies for prevention, resuscitation, and identification of those at greatest risk. Areas of active research and controversy include the development of best practices in screening, risk stratification approaches and postmortem evaluation, and identification of modifiable barriers to providing better outcomes after resuscitation of young SCD patients. Institution of a national registry of SCD in the young will provide data that will help to answer these questions.

The first single responders in Sweden - Evaluation of a pre-hospital single staffed unit

BACKGROUND

Single responder (SR) systems have been implemented in several countries. When the very first SR system in Sweden was planned, it was criticised because of concerns about sending single emergency nurses out on alerts. In the present study, the first Swedish SR unit was studied in order to register waiting times and assess the working environment.

METHOD

Quantitative data were collected from the ambulance dispatch register. Data on the working environment were collected using a questionnaire sent to the SR staff.

RESULTS

The SR system reduced the average patient waiting time from 26 to 13min. It also reduced the number of ambulance transports by 35% following triage of patient(s) priority determined by the SR. The staff perceived the working environment to be adequate.

CONCLUSION

The SR unit was successful in that it reduced waiting times to prehospital health care. Contrary to expectations, it proved to be an adequate working environment. There is good reason to believe that SR systems will spread throughout the country. In order to enhance in depth the statistical analysis, additional should be collected over a longer time period and from more than one SR unit.

A focused investigation of expedited, stack of three shocks versus chest compressions first followed by single shocks for monitored ventricular fibrillation/ventricular tachycardia cardiopulmonary arrest in an in-hospital setting

BACKGROUND

In cases of in-hospital-witnessed ventricular fibrillation/ventricular tachycardia (VF/VT) arrest, it is unclear whether cardiopulmonary resuscitation prior to defibrillation attempt or expedited stacked defibrillation attempt is superior.

METHODS

Retrospective, observational study of all admitted patients with continuous cardiac monitoring who suffered VF/VT arrest between July 2005 and June 2013. In the stacked shock period (2005-2008), institutional protocols advocated early defibrillation with administration of 3 stacked shocks with brief pauses between each single defibrillation attempt to confirm sustained VF/VT. During the initial chest compression period (2008-2011), the protocol was modified to perform a 2-minute period of chest compressions prior to each defibrillation, including the initial. In the modified stack shock period (2011-2013), for a monitored arrest, defibrillation attempts were expedited with up to 3 successive shocks administered for persistent VF/VT. In unmonitored arrest, chest compressions and ventilations were initiated prior to defibrillation. The primary outcome measure was survival to hospital discharge.

RESULTS

Six hundred sixty-one cardiopulmonary arrests were recorded during the study period, with 106 patients (16%) representing primary VF/VT. The incidence of VF/VT arrest did not vary significantly between the study periods (P= 0.16) Survival to hospital discharge for all primary VF/VT arrest victims decreased, then increased significantly from the stacked shock period to initial chest compression period to modified stacked shock period (58%, 18%, 71%, respectively, P < 0.01). Specific group differences were significant between the initial chest compression versus the stacked and modified stacked shock groups (all P < 0.01).

CONCLUSION

Data suggest that monitored VF/VT should undergo expeditious defibrillation with use of stacked shocks.

The effects of second and third phase duration on defibrillation efficacy of triphasic rectangle waveforms

BACKGROUND

Biphasic waveforms are superior to monophasic waveforms for the termination of ventricular fibrillation (VF). However, whether triphasic waveforms are more effective than biphasic ones is still controversial. In the present study, we investigated the effects of second and third phase duration of triphasic rectangle waveform on defibrillation efficacy in a rabbit model of VF.

METHODS

VF was electrically induced and untreated for 30s in 20 New Zealand rabbits. A defibrillatory shock was applied with one of the 7 waveforms: 6 triphasic rectangle waveforms and a biphasic rectangle waveform. The triphasic waveforms had identical first duration but with different second and third phase durations. A 5 step up-and-down protocol was utilized for determining the defibrillation threshold (DFT). After a 5min interval, the procedure was repeated. A total of 35 cardiac arrest events and defibrillations were investigated for each animal.

RESULTS

Two triphasic waveforms with identical first and second phase duration but shorter third phase duration had significantly lower DFT energy than biphasic waveform (0.57±0.18J vs. 0.80±0.28J, p=0.001; 0.60±0.18J vs. 0.80±0.28J, p=0.003). However, no statistical difference in DFT energy was observed between the two triaphsic waveforms that had identical phase duration but different voltages (0.57±0.18J vs. 0.60±0.18J, p=0.638).

CONCLUSIONS

Phase durations played a main role on defibrillation success for triphasic rectangle waveforms. The optimal triphasic rectangle waveforms that composed of identical second and first phase durations but with shorter third pulse were superior to biphasic rectangle waveform for ventricular defibrillation.

Biphasic versus monophasic waveforms for transthoracic defibrillation in out-of-hospital cardiac arrest

BACKGROUND

Transthoracic defibrillation is a potentially life-saving treatment for people with ventricular fibrillation (VF) and haemodynamically unstable ventricular tachycardia (VT). In recent years, biphasic waveforms have become more commonly used for defibrillation than monophasic waveforms. Clinical trials of internal defibrillation and transthoracic defibrillation of short-duration arrhythmias of up to 30 seconds have demonstrated the superiority of biphasic waveforms over monophasic waveforms. However, out-of-hospital cardiac arrest (OHCA) involves a duration of VF/VT of several minutes before defibrillation is attempted.

OBJECTIVES

To determine the efficacy and safety of biphasic defibrillation waveforms, compared to monophasic, for resuscitation of people experiencing out-of-hospital cardiac arrest.

SEARCH METHODS

We searched the following electronic databases for potentially relevant studies up to 10 September 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Also we checked the bibliographies of relevant studies and review articles, contacted authors of published reviews and reviewed webpages (including those of device manufacturers) relevant to the review topic. We handsearched the abstracts of conference proceedings for the American Heart Association, American College of Cardiology, European Society of Cardiology, European Resuscitation Council, Society of Critical Care Medicine and European Society of Intensive Care Medicine. Regarding language restrictions, we did not apply any.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared biphasic and monophasic waveform defibrillation in adults with OHCA. Two review authors independently screened the literature search results.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the included trials and performed 'Risk of bias' assessments. We resolved any disagreements by discussion and consensus. The primary outcome was the risk of failure to achieve return of spontaneous circulation (ROSC). Secondary outcomes included risk of failure to revert VF to an organised rhythm following the first shock or up to three shocks, survival to hospital admission and survival to discharge.

MAIN RESULTS

We included four trials (552 participants) that compared biphasic and monophasic waveform defibrillation in people with OHCA. Based on the assessment of five quality domains, we identified two trials that were at high risk of bias, one trial at unclear risk of bias and one trial at low risk of bias. The risk ratio (RR) for failure to achieve ROSC after biphasic compared to monophasic waveform defibrillation was 0.86 (95% CI 0.62 to 1.20; four trials, 552 participants). The RR for failure to defibrillate on the first shock following biphasic defibrillation compared to monophasic was 0.84 (95% CI 0.70 to 1.01; three trials, 450 participants); and 0.81 (95% CI 0.61 to 1.09; two trials, 317 participants) for one to three stacked shocks. The RR for failure to achieve ROSC after the first shock was 0.92 (95% CI 0.81 to 1.04; two trials, 285 participants). Biphasic waveforms did not reduce the risk of death before hospital admission (RR 1.05, 95% CI 0.90 to 1.23; three trials, 383 participants) or before hospital discharge (RR 1.05, 95% CI 0.78 to 1.42; four trials, 550 participants). There was no statistically significant heterogeneity in any of the pooled analyses. None of the included trials reported adverse events.

AUTHORS' CONCLUSIONS

It is uncertain whether biphasic defibrillators have an important effect on defibrillation success in people with OHCA. Further large studies are needed to provide adequate statistical power.

Minor Variations in Electrode Pad Placement Impact Defibrillation Success

Defibrillation is essential for resuscitating patients with ventricular fibrillation (VF), but shocks often fail to defibrillate. We hypothesized that small variations in pad placement affect shock success, and that defibrillation waveform and shock dose could compensate for suboptimal pad placement. In 10 swine experiments, electrode pads were attached at 3 adjacent anterolateral positions, less than 3 centimeters apart. At each position, 24 episodes of VF were induced and shocked, 8 episodes for each of 3 defibrillation therapies. This resulted in 9 tested combinations of pad position and defibrillation therapy, with 80 episodes of VF for each combination. An episode consisted of 15 seconds of untreated VF, followed by a first shock and, if necessary, a repeat shock. Episodes were separated by four minutes of recovery. Both electrode pad position and therapy order were randomized by experiment. Primary outcome was defined as successful VF termination after the first shock; secondary outcome was the cumulative success of the first and second shocks. First shock efficacy varied widely across the 9 tested combinations of pad position and defibrillation therapy, ranging from 11.3% to 86.3%. When grouped by therapy, first shock efficacy varied significantly between the 3 pad positions: 38.3%, 48.3%, 36.7% (p = 0.02, ANOVA), and, when grouped by pad position, it varied significantly between therapies: 15.0%, 32.5%, 75.8% (p < 0.001, ANOVA). Cumulative 2-shock success varied significantly with therapy (p < 0.001, ANOVA) but not with pad position (p = 0.30, ANOVA). The lowest first shock success was at one position in 6 of 10 animals, at another position in 4 of 10 animals, and never at the third position. Small variations in pad placement can significantly affect defibrillation shock efficacy. However, anatomical variation between individuals and the challenging conditions of real-world resuscitations make optimal pad placement impractical. Suboptimal pad placement can be overcome with defibrillation waveform and shock dose.

Long-term outcome of patients after out-of-hospital cardiac arrest in relation to treatment: a single-centre study

INTRODUCTION

Outcome after out-of-hospital cardiac arrest (OHCA) remains poor. With the introduction of automated external defibrillators, percutaneous coronary intervention (PCI) and mild therapeutic hypothermia (MTH) the prognosis of patients after OHCA appears to be improving. The aim of this study was to evaluate short and long-term outcome among a non-selected population of patients who experienced OHCA and were admitted to a hospital working within a ST elevation myocardial infarction network.

METHODS

All patients who achieved return of spontaneous circulation (ROSC) (n=456) admitted to one hospital after OHCA were included. Initial rhythm, reperfusion therapy with PCI, implementation of MTH and additional medical management were recorded. The primary outcome measure was survival (hospital and long term). Neurological status was measured as cerebral performance category. The inclusion period was January 2003 to August 2010. Follow-up was complete until April 2014.

RESULTS

The mean patient age was 63±14 years and 327 (72%) were men. The initial rhythm was ventricular fibrillation, pulseless electrical activity, asystole and pulseless ventricular tachycardia in 322 (71%), 58 (13%), 55 (12%) and 21 (5%) of the 456 patients, respectively. Treatment included PCI in 191 (42%) and MTH in 188 (41%). Overall in-hospital and long-term (5-year) survival was 53% (n=240) and 44% (n=202), respectively. In the 170 patients treated with primary PCI, in-hospital survival was 112/170 (66%). After hospital discharge these patients had a 5-year survival rate of 99% and cerebral performance category was good in 92%.

CONCLUSIONS

In this integrated ST elevation myocardial infarction network survival and neurological outcome of selected patients with ROSC after OHCA and treated with PCI was good. There is insufficient evidence about the outcome of this approach, which has a significant impact on utilisation of resources. Good quality randomised controlled trials are needed. In selected patients successfully resuscitated after OHCA of presumed cardiac aetiology, we believe that a more liberal application of primary PCI may be considered in experienced acute cardiac referral centres.

Cardiac Arrest Resuscitation

Cardiac arrest is a dynamic disease that tests the multitasking and leadership abilities of emergency physicians. Providers must simultaneously manage the logistics of resuscitation while searching for the cause of cardiac arrest. The astute clinician will also realize that he or she is orchestrating only one portion of a larger series of events, each of which directly affects patient outcomes. Resuscitation science is rapidly evolving, and emergency providers must be familiar with the latest evidence and controversies surrounding resuscitative techniques. This article reviews evidence, discusses controversies, and offers strategies to provide quality cardiac arrest resuscitation.

Year in review 2012: Critical Care--Out-of-hospital cardiac arrest and trauma

In 2012 Critical Care published many articles pertaining to the resuscitation of out-of-hospital cardiac arrest and trauma. In this review, we summarize several of these articles, including those regarding advances in resuscitation techniques and methods. We examine articles pertaining to prehospital endotracheal intubation, the use of specialized devices for cardiopulmonary resuscitation and policies regarding transport destinations for both cardiac arrest and trauma patients. Articles on the predictors of outcome in both pediatric and adult populations are evaluated, including articles on the effects of obesity on survival from hemorrhage and pediatric outcomes from traumatic cardiac arrest. The effects of the type and volume of resuscitation fluids for both adult and pediatric patients are discussed, as are the factors contributing to hypothermia in trauma patients.

Biphasic versus monophasic defibrillation in out-of-hospital cardiac arrest: a systematic review and meta-analysis

OBJECTIVE

Biphasic defibrillation is more effective than monophasic one in controlled in-hospital conditions. The present review evaluated the performance of both waveforms in the defibrillation of patients of out-of-hospital cardiac arrest (OHCA) with initial ventricular fibrillation (Vf) rhythm under the context of current recommendations for cardiopulmonary resuscitation.

METHODS

From inception to June 2012, Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched systemically for randomized controlled trials (RCTs) and observational cohort studies that compared the effects of biphasic and monophasic shocks on Vf termination, return of spontaneous circulation (ROSC), and survival to hospital discharge in OHCA patients with initial Vf rhythm. No restrictions were applied regarding language, population, or publication year.

RESULTS

Four RCTs including 572 patients were identified from 131 potentially relevant references for meta-analysis. The synthesis of these RCTs yielded fixed-effect pooled risk ratios (RRs) for biphasic and monophasic waveforms on Vf termination survival to hospital discharge (RR, 1.14; 95% CI, [0.84-1.54]).

CONCLUSION

Biphasic waveforms did not seem superior to monophasic ones with respect to Vf termination, ROSC, or survival to hospital discharge in OHCA patients with initial Vf rhythm under the context of current guidelines. However, most trials were conducted in accordance with previous guidelines for cardiopulmonary resuscitation. Therefore, further trials are needed to clarify this issue.

Updates in the American Heart Association guidelines for cardiopulmonary resuscitation and potential applications to veterinary patients

OBJECTIVE

To review the updates in the American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and identify potential applications to veterinary patients.

ETIOLOGY

Cardiopulmonary arrest is common in veterinary emergency and critical care, and consensus guidelines are lacking. Human resuscitation guidelines are continually evolving as new clinical and experimental studies support updated recommendations. Synthesis of human, experimental animal model, and veterinary literature support the potential for updates and advancement in veterinary CPR practices.

THERAPY

This review serves to highlight updates in the AHA guidelines for CPR and evaluate their application to small animal veterinary patients. Interventions identified will be evaluated for trans-species potential, raise questions regarding best resuscitation recommendations, and offer opportunities for further research to continue to advance veterinary CPR.

PROGNOSIS

The prognosis for any patient undergoing cardiopulmonary arrest remains guarded.

Critical cardiovascular skills and procedures in the emergency department

The management of cardiovascular emergencies is a fundamental component of the practice of an emergency practitioner. Delays in the evaluations and management can lead to significant morbidity or mortality. It is of vital importance to be familiar with procedures such as pericardiocentesis, cardioversion, defibrillation, temporary pacing, and options for the management of tachyarrhythmias. This article discusses the most common cardiovascular procedures encountered in an emergency setting, including the indications, contraindications, equipment, technique, and complications for each procedure.