Cardiocerebral Resuscitation

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.

Association between Conversion to Shockable Rhythms and Survival with Favorable Neurological Outcomes for Out-of-Hospital Cardiac Arrests

BACKGROUND

The initial cardiac rhythm in out-of-hospital cardiac arrest (OHCA) portends different prognoses and affects treatment decisions. Initial shockable rhythms are associated with good survival and neurological outcomes but there is conflicting evidence for those who initially present with non-shockable rhythms. The aim of this study is to evaluate if OHCA with conversion from non-shockable (i.e., asystole and pulseless electrical activity) rhythms to shockable rhythms compared to OHCA remaining in non-shockable rhythms is associated with better survival and neurological outcomes.

METHOD

OHCA cases from the Pan-Asian Resuscitation Outcomes Study registry in 13 countries between January 2009 and February 2018 were retrospectively analyzed. Cases with missing initial rhythms, age <18 years, presumed non-medical cause of arrest, and not conveyed by emergency medical services were excluded. Multivariable logistic regression analysis was performed to evaluate the relationship between initial and subsequent shockable rhythm, survival to discharge, and survival with favorable neurological outcomes (cerebral performance category 1 or 2).

RESULTS

Of the 116,387 cases included. 11,153 (9.6%) had initial shockable rhythms and 9,765 (8.4%) subsequently converted to shockable rhythms. Japan had the lowest proportion of OHCA patients with initial shockable rhythms (7.3%). For OHCA with initial shockable rhythm, the adjusted odds ratios (aOR) for survival and good neurological outcomes were 8.11 (95% confidence interval [CI] 7.62-8.63) and 15.4 (95%CI 14.1-16.8) respectively. For OHCA that converted from initial non-shockable to shockable rhythms, the aORs for survival and good neurological outcomes were 1.23 (95%CI 1.10-1.37) and 1.61 (95%CI 1.35-1.91) respectively. The aORs for survival and good neurological outcomes were 1.48 (95%CI 1.22-1.79) and 1.92 (95%CI 1.3 - 2.84) respectively for initial asystole, while the aOR for survival in initial pulseless electrical activity patients was 0.83 (95%CI 0.71-0.98). Prehospital adrenaline administration had the highest aOR (2.05, 95%CI 1.93-2.18) for conversion to shockable rhythm.

CONCLUSION

In this ambidirectional cohort study, conversion from non-shockable to shockable rhythm was associated with improved survival and neurologic outcomes compared to rhythms that continued to be non-shockable. Continued advanced resuscitation may be beneficial for OHCA with subsequent conversion to shockable rhythms.

Teaching Hands-Only CPR (HOCPR) skills to 8th-grade students in urban Bengaluru: Development of a comprehensive Hands-Only CPR programme for high school students

Background and Aims:

Methods:

Results:

Conclusion:

Shoulder strap fixation of LUCAS-2 to facilitate continuous CPR during non-supine (stair) stretcher transport of OHCAs patients

Early recognition and rapid initiation of high-quality cardiopulmonary resuscitation (CPR) are key to maximising chances of achieving successful return of spontaneous circulation in patients with out-of-hospital cardiac arrests (OHCAs), as well as improving patient outcomes both inside and outside hospital. Mechanical chest compression devices such as the LUCAS-2 have been developed to assist rescuers in providing consistent, high-quality compressions, even during transportation. However, providing uninterrupted and effective compressions with LUCAS-2 during transportation down stairwells and in tight spaces in a non-supine position is relatively impossible. In this study, we proposed adaptations to the LUCAS-2 to allow its use during transportation down stairwells and examined its effectiveness in providing high-quality CPR to simulated OHCA patients. 20 volunteer emergency medical technicians were randomised into 10 pairs, each undergoing 2 simulation runs per experimental arm (LUCAS-2 versus control) with a loaded Resusci Anne First Aid full body manikin weighing 60 kg. Quality of CPR compressions performed was measured using the CPRmeter placed on the sternum of the manikin. The respective times taken for each phase of the simulation protocol were recorded. Fisher’s exact tests were used to analyse categorical variables and median test to analyse continuous variables. The LUCAS-2 group required a longer time (~ 35 s) to prepare the patient prior to transport (p < 0.0001) and arrive at the ambulance (p < 0.0001) compared to the control group. The CPR quality in terms of depth and rate for the overall resuscitation period did not differ significantly between the LUCAS-2 group and control group, though there was a reduction in both parameters when evaluating the device’s automated compressions during transport. Nevertheless, the application of the LUCAS-2 device yielded a significantly higher chest compression fraction of 0.76 (p < 0.0001). Our novel adaptations to the LUCAS-2 device allow for uninterrupted compressions in patients being transported down stairwells, thus yielding better chest compression fractions for the overall resuscitation period. Whether potentially improved post-OHCA survival rates may be achieved requires confirmation in a real-world scenario study.

Hands-On Times, Adherence to Recommendations and Variance in Execution among Three Different CPR Algorithms: A Prospective Randomized Single-Blind Simulator-Based Trial

Background: Alternative cardiopulmonary resuscitation (CPR) algorithms, introduced to improve outcomes after cardiac arrest, have so far not been compared in randomized trials with established CPR guidelines. Methods: 286 physician teams were confronted with simulated cardiac arrests and randomly allocated to one of three versions of a CPR algorithm: (1) current International Liaison Committee on Resuscitation (ILCOR) guidelines (“ILCOR”), (2) the cardiocerebral resuscitation (“CCR”) protocol (3 cycles of 200 uninterrupted chest compressions with no ventilation), or (3) a local interpretation of the current guidelines (“Arnsberg“, immediate insertion of a supraglottic airway and cycles of 200 uninterrupted chest compressions). The primary endpoint was percentage of hands-on time. Results: Median percentage of hands-on time was 88 (interquartile range (IQR) 6) in “ILCOR” teams, 90 (IQR 5) in “CCR” teams (p = 0.001 vs. “ILCOR”), and 89 (IQR 4) in “Arnsberg” teams (p = 0.032 vs. “ILCOR”; p = 0.10 vs. “CCR”). “ILCOR” teams delivered fewer chest compressions and deviated more from allocated targets than “CCR” and “Arnsberg” teams. “CCR” teams demonstrated the least within-team and between-team variance. Conclusions: Compared to current ILCOR guidelines, two alternative CPR algorithms advocating cycles of uninterrupted chest compressions resulted in very similar hands-on times, fewer deviations from targets, and less within-team and between-team variance in execution.

Epidemiology of pediatric cardiopulmonary resuscitation

OBJECTIVE

To analyze the main epidemiological aspects of prehospital and hospital pediatric cardiopulmonary resuscitation and the impact of scientific evidence on survival.

SOURCE OF DATA

This was a narrative review of the literature published at PubMed/MEDLINE until January 2019 including original and review articles, systematic reviews, meta-analyses, annals of congresses, and manual search of selected articles.

SYNTHESIS OF DATA

The prehospital and hospital settings have different characteristics and prognoses. Pediatric prehospital cardiopulmonary arrest has a three-fold lower survival rate than cardiopulmonary arrest in the hospital setting, occurring mostly at home and in children under 1year. Higher survival appears to be associated with age progression, shockable rhythm, emergency medical care, use of automatic external defibrillator, high-quality early life support, telephone dispatcher-assisted cardiopulmonary resuscitation, and is strongly associated with witnessed cardiopulmonary arrest. In the hospital setting, a higher incidence was observed in children under 1year of age, and mortality increased with age. Higher survival was observed with shorter cardiopulmonary resuscitation duration, occurrence on weekdays and during daytime, initial shockable rhythm, and previous monitoring. Despite the poor prognosis of pediatric cardiopulmonary resuscitation, an increase in survival has been observed in recent years, with good neurological prognosis in the hospital setting.

CONCLUSIONS

A great progress in the science of pediatric cardiopulmonary resuscitation has been observed, especially in developed countries. The recognition of the epidemiological aspects that influence cardiopulmonary resuscitation survival may direct efforts towards more effective actions; thus, studies in emerging and less favored countries remains a priority regarding the knowledge of local factors.

Intrathoracic Airway Closure Impacts CO2 Signal and Delivered Ventilation during Cardiopulmonary Resuscitation

RATIONALE

End-tidal CO₂ (EtCO₂) is used to monitor cardiopulmonary resuscitation (CPR), but it can be affected by intrathoracic airway closure. Chest compressions induce oscillations in expired CO₂, and this could reflect variable degrees of airway patency.

OBJECTIVES

To understand the impact of airway closure during CPR, and the relationship between the capnogram shape, airway closure, and delivered ventilation.

METHODS

This study had three parts: 1) a clinical study analyzing capnograms after intubation in patients with out-of-hospital cardiac arrest receiving continuous chest compressions, 2) a bench model, and 3) experiments with human cadavers. For 2 and 3, a constant CO₂ flow was added in the lung to simulate CO₂ production. Capnograms similar to clinical recordings were obtained and different ventilator settings tested. EtCO₂ was compared with alveolar CO₂ (bench). An airway opening index was used to quantify chest compression-induced expired CO₂ oscillations in all three clinical and experimental settings.

MEASUREMENTS AND MAIN RESULTS

A total of 89 patients were analyzed (mean age, 69 ± 15 yr; 23% female; 12% of hospital admission survival): capnograms exhibited various degrees of oscillations, quantified by the opening index. CO₂ value varied considerably across oscillations related to consecutive chest compressions. In bench and cadavers, similar capnograms were reproduced with different degrees of airway closure. Differences in airway patency were associated with huge changes in delivered ventilation. The opening index and delivered ventilation increased with positive end-expiratory pressure, without affecting intrathoracic pressure. Maximal EtCO₂ recorded between ventilator breaths reflected alveolar CO₂ (bench).

CONCLUSIONS

During chest compressions, intrathoracic airway patency greatly affects the delivered ventilation. The expired CO₂ signal can reflect CPR effectiveness but is also dependent on airway patency. The maximal EtCO₂ recorded between consecutive ventilator breaths best reflects alveolar CO₂.

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.

Chest compression release velocity factors during out-of-hospital cardiac resuscitation

BACKGROUND

Higher chest compression release velocity (CCRV) has been associated with better outcomes after out-of-hospital cardiac arrest (OHCA), and patient factors have been associated with variations in chest wall compliance and compressibility. We evaluated whether patient sex, age, weight, and time in resuscitation were associated with CCRV during pre-hospital resuscitation from OHCA.

METHODS

Observational study of prospectively collected OHCA quality improvement data in two suburban EMS agencies in Arizona between 10/1/2008 and 12/31/2016. Subject-level mean CCRV during the first 10 min of compressions was correlated with categorical variables by the Wilcoxon rank-sum test and with continuous variables by the Spearman's rank correlation coefficient. Generalized estimating equation and linear mixed-effect models were used to study the trend of CCRV over time.

RESULTS

During the study period, 2535 adult OHCA cases were treated. After exclusion criteria, 1140 cases remained for analysis. Median duration of recorded compressions was 8.70 min during the first 10 min of CPR. An overall decline in CCRV was observed even after adjusting for compression depth. The subject-level mean CCRV was higher for minutes 0-5 than for minutes 5-10 (mean 347.9 mm/s vs. 339.0 mm/s, 95% CI of the difference -12.4 to -5.4, p < 0.0001). Males exhibited a greater mean CCRV compared to females [344.4 mm/s (IQR 307.3-384.6) vs. 331.5 mm/s (IQR 285.3-385.5), p = 0.013]. Mean CCRV was negatively correlated with age and positively correlated with patient weight.

CONCLUSION

CCRV declines significantly over the course of resuscitation. Patient characteristics including male sex, younger age, and increased weight were associated with a higher CCRV.

Mechanical versus manual chest compressions for cardiac arrest

BACKGROUND

Mechanical chest compression devices have been proposed to improve the effectiveness of cardiopulmonary resuscitation (CPR).

OBJECTIVES

To assess the effectiveness of resuscitation strategies using mechanical chest compressions versus resuscitation strategies using standard manual chest compressions with respect to neurologically intact survival in patients who suffer cardiac arrest.

SEARCH METHODS

On 19 August 2017 we searched the Cochrane Central Register of Controlled Studies (CENTRAL), MEDLINE, Embase, Science Citation Index-Expanded (SCI-EXPANDED) and Conference Proceedings Citation Index-Science databases. Biotechnology and Bioengineering Abstracts and Science Citation abstracts had been searched up to November 2009 for prior versions of this review. We also searched two clinical trials registries for any ongoing trials not captured by our search of databases containing published works: Clinicaltrials.gov (August 2017) and the World Health Organization International Clinical Trials Registry Platform portal (January 2018). We applied no language restrictions. We contacted experts in the field of mechanical chest compression devices and manufacturers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs and quasi-randomised studies comparing mechanical chest compressions versus manual chest compressions during CPR for patients with cardiac arrest.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included five new studies in this update. In total, we included 11 trials in the review, including data from 12,944 adult participants, who suffered either out-of-hospital cardiac arrest (OHCA) or in-hospital cardiac arrest (IHCA). We excluded studies explicitly including patients with cardiac arrest caused by trauma, drowning, hypothermia and toxic substances. These conditions are routinely excluded from cardiac arrest intervention studies because they have a different underlying pathophysiology, require a variety of interventions specific to the underlying condition and are known to have a prognosis different from that of cardiac arrest with no obvious cause. The exclusions were meant to reduce heterogeneity in the population while maintaining generalisability to most patients with sudden cardiac death.The overall quality of evidence for the outcomes of included studies was moderate to low due to considerable risk of bias. Three studies (N = 7587) reported on the designated primary outcome of survival to hospital discharge with good neurologic function (defined as a Cerebral Performance Category (CPC) score of one or two), which had moderate quality evidence. One study showed no difference with mechanical chest compressions (risk ratio (RR) 1.07, 95% confidence interval (CI) 0.82 to 1.39), one study demonstrated equivalence (RR 0.79, 95% CI 0.60 to 1.04), and one study demonstrated reduced survival (RR 0.41, CI 0.21 to 0.79). Two other secondary outcomes, survival to hospital admission (N = 7224) and survival to hospital discharge (N = 8067), also had moderate quality level of evidence. No studies reported a difference in survival to hospital admission. For survival to hospital discharge, two studies showed benefit, four studies showed no difference, and one study showed harm associated with mechanical compressions. No studies demonstrated a difference in adverse events or injury patterns between comparison groups but the quality of data was low. Marked clinical and statistical heterogeneity between studies precluded any pooled estimates of effect.

AUTHORS' CONCLUSIONS

The evidence does not suggest that CPR protocols involving mechanical chest compression devices are superior to conventional therapy involving manual chest compressions only. We conclude on the balance of evidence that mechanical chest compression devices used by trained individuals are a reasonable alternative to manual chest compressions in settings where consistent, high-quality manual chest compressions are not possible or dangerous for the provider (eg, limited rescuers available, prolonged CPR, during hypothermic cardiac arrest, in a moving ambulance, in the angiography suite, during preparation for extracorporeal CPR [ECPR], etc.). Systems choosing to incorporate mechanical chest compression devices should be closely monitored because some data identified in this review suggested harm. Special attention should be paid to minimising time without compressions and delays to defibrillation during device deployment.

The mechanism of blood flow during chest compressions for cardiac arrest is probably influenced by the patient's chest configuration

Aim

Mechanical assist devices are sometimes needed during resuscitation efforts of patients with prolonged cardiac arrest. Two such devices, the AutoPulse and the LUCAS, have different mechanisms of action. We propose that the effectiveness of mechanical assist devices is somewhat dependent on the configuration and compliance of the patient's chest wall.

Methods

A previous study of patients with out‐of‐hospital cardiac arrest in Arizona reported that survivors were younger and many were observed to have narrow anterior–posterior chest diameters. These observations suggest that the predominant mechanism of blood flow during cardiopulmonary resuscitation of individuals with primary cardiac arrest is influenced by the patient's anterior–posterior chest diameter and compliance. It is proposed that in older individuals with an increased anterior–posterior chest diameter and decreased chest compliance that the AutoPulse, which works by increasing intrathoracic pressures, may be more effective. In contrast, the LUCAS device, which works predominately by compression of the sternum, is probably more effective in patients with narrower anterior–posterior diameters and a more compliant chest.

Results

These hypotheses need to be confirmed by researchers who not only have access to the lateral chest roentgenograms of patients with cardiac arrest, to determine their anterior–posterior chest diameter, but also to the type of mechanical device that was used during resuscitation efforts and their patient's survival. If the observations herein proposed are confirmed, hospitals and paramedics may ideally need to have one of each type of mechanical chest compression unit and select the one to use depending on the patient's age and anterior–posterior chest diameter.

Conclusions

The mechanism of blood flow in patients with cardiac arrest is predominantly secondary to cardiac compression in younger patients with narrow anterior chest diameters and predominately secondary to the thoracic pump mechanism in older patients with emphysema.

Mechanical Cardiopulmonary Resuscitation and Hospital Survival Among Adult Patients With Nontraumatic Out-of-Hospital Cardiac Arrest Attending the Emergency Department: A Prospective, Multicenter, Observational Study in Japan (SOS-KANTO [Survey of Survivors after Out-of-Hospital Cardiac Arrest in Kanto Area] 2012 Study)

Background

Mechanical cardiopulmonary resuscitation (mCPR) for patients with out‐of‐hospital cardiac arrest attending the emergency department has become more widespread in Japan. The objective of this study is to determine the association between the mCPR in the emergency department and clinical outcomes.

Methods and Results

In a prospective, multicenter, observational study, adult patients with out‐of‐hospital cardiac arrest with sustained circulatory arrest on hospital arrival were identified. The primary outcome was survival to hospital discharge. The secondary outcomes included a return of spontaneous circulation and successful hospital admission. Multivariate analyses adjusted for potential confounders and within‐institution clustering effects using a generalized estimation equation were used to analyze the association of the mCPR with outcomes. Between January 1, 2012 and March 31, 2013, 6537 patients with out‐of‐hospital cardiac arrest were eligible; this included 5619 patients (86.0%) in the manual CPR group and 918 patients (14.0%) in the mCPR group. Of those patients, 28.1% (1801/6419) showed return of spontaneous circulation in the emergency department, 20.4% (1175/5754) had hospital admission, 2.6% (168/6504) survived to hospital discharge, and 1.2% (75/6419) showed a favorable neurological outcome at 1 month after admission. Multivariate analyses revealed that mCPR was associated with a decreased likelihood of survival to hospital discharge (adjusted odds ratio, 0.40; 95% confidence interval, 0.20–0.78; P=0.005), return of spontaneous circulation (adjusted odds ratio, 0.71; 95% confidence interval, 0.53–0.94; P=0.018), and hospital admission (adjusted odds ratio, 0.57; 95% confidence interval, 0.40–0.80; P=0.001).

Conclusions

After accounting for potential confounders, the mCPR in the emergency department was associated with decreased likelihoods of good clinical outcomes after adult nontraumatic out‐of‐hospital cardiac arrest. Further studies are needed to clarify circumstances in which mCPR may benefit these patients.

Mechanical Ventilation During Resuscitation: How Manual Chest Compressions Affect a Ventilator's Function

INTRODUCTION

Guidelines for resuscitation recommend positive-pressure ventilation with a fixed ventilation rate as provided by an automated transport ventilator during cardiopulmonary resuscitation (CPR) with a secured airway. We investigated the influence of manual chest compressions (CC) on the accuracy of ventilator presets and the quality of CC with intermittent positive-pressure ventilation (IPPV), bilevel ventilation (BiLevel), and the novel ventilation mode chest compression synchronized ventilation (CCSV) in a simulation model.

METHODS

Ninety paramedics performed continuous CC for 2 min on a modified advanced life support mannequin with a realistic lung model. IPPV, BiLevel, and CCSV were applied in a randomized order. CCSV is a novel type of pressure-controlled ventilation with short insufflations synchronized with CC, which are stopped before decompression begins. The ventilator presets (tolerance range) were IPPV Vt = 450 (400-500) ml, PEEP = 0 hPa, f = 10/min; BiLevel Pinsp = 19 (17.1-20.9) hPa, PEEP = 5 hPa, f = 10/min; CCSV Pinsp = 60 (54-66) hPa, PEEP = 0 hPa, Tinsp = 205 ms, f = CC rate. Preset values were compared with the measured results. Values were defined as correct within a tolerance range. Quality of CC was evaluated using ERC guidelines (depth >50 mm, CC rate 100-120/min).

RESULTS

Median (25th/75th percentiles) IPPV V _t = 399 (386/411) ml, BiLevel Pinsp = 22.0 (19.7/25.6) hPa, and CCSV Pinsp = 55.2 (52.6/56.7) hPa. Relative frequency of delivering correct ventilation parameters according to ventilation mode: IPPV = 40 (0/100)% vs. BiLevel = 20 (0/100)%, p = 0.37 and vs. CCSV = 71 (50/83)%, p < 0.02. Pinsp was too high in BiLevel = 80 (0/100)% vs. CCSV = 0(0/0)%, p < 0.001. CC depth: IPPV 56 (48/63) mm, BiLevel 57 (48/63) mm, CCSV 60 (52/67) mm; CC rate: IPPV 117 (105/124)/min, BiLevel 116 (107/123)/min, CCSV 117 (107/125)/min.

CONCLUSION

When compared to IPPV and BiLevel, CCSV works best with preset values, without exceeding the upper pressure preset during simulated CPR. Quality of CC is not negatively affected by any of the ventilation patterns.

FUNDING

Parts of this study were supported by Weinmann Emergency Medical Technology GmbH + Co.KG.

Cardiocerebral and cardiopulmonary resuscitation - 2017 update

Sudden cardiac arrest is a major public health problem in the industrialized nations of the world. Yet, in spite of recurrent updates of the guidelines for cardiopulmonary resuscitation and emergency cardiac care, many areas have suboptimal survival rates. Cardiocerebral resuscitation, a non‐guidelines approach to therapy of primary cardiac arrest based on our animal research, was instituted in Tucson (AZ, USA) in 2002 and subsequently adopted in other areas of the USA. Survival rates of patients with primary cardiac arrest and a shockable rhythm significantly improved wherever it was adopted. Cardiocerebral resuscitation has three components: the community, the pre‐hospital, and the hospital. The community component emphasizes bystander recognition and chest compression only resuscitation. Its pre‐hospital or emergency medical services component emphasizes: (i) urgent initiation of 200 uninterrupted chest compressions before and after each indicated single defibrillation shock, (ii) delayed endotracheal intubation in favor of passive delivery of oxygen by a non‐rebreather mask, (iii) early adrenaline administration. The hospital component was added later. The national and international guidelines for cardiopulmonary resuscitation and emergency medical services are still not optimal, for several reasons, including the fact that they continue to recommend the same approach for two entirely different etiologies of cardiac arrest: primary cardiac arrest, often caused by ventricular fibrillation, where the arterial blood oxygenation is little changed at the time of the arrest, and secondary cardiac arrest from severe respiratory insufficiency, where the arterial blood is severely desaturated at the time of cardiac arrest. These different etiologies need different approaches to therapy.

Perspectives on implementing delayed cord clamping

Expanding evidence supports delayed cord clamping (DCC) for both term and preterm infants. This article explores issues that may be keeping early cord clamping (ECC) in place as usual practice. Professional organizations almost universally recommend DCC for preterm infants, but some reserve recommending it for term infants only in resource-poor settings. Concerns about polycythemia and jaundice persist in the literature, while years of published randomized controlled trials do not support the assumptions behind the concerns. New data suggest that DCC may improve resuscitative efforts in compromised infants. Multiple perspectives are offered for consideration when thinking about incorporating DCC into practice.

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.

Clinical evaluation of the AutoPulse automated chest compression device for out-of-hospital cardiac arrest in the northern district of Shanghai, China

INTRODUCTION

Whether the AutoPulse automated chest compression device is worthy of clinical use for out-of-hospital cardiac arrest (OHCA) remains controversial. A prospective controlled study was conducted to evaluate the effect of AutoPulse versus manual chest compression for cardiopulmonary resuscitation (CPR) of OHCA patients in the northern district of Shanghai, China.

MATERIAL AND METHODS

A total of 133 patients with OHCA who were treated at the Emergency Medical Center of the Tenth People's Hospital Affiliated with Tongji University between March 2011 and March 2012 were included. The patients were randomly assigned to the Manual CPR (n = 64) and AutoPulse CPR groups (n = 69) in accordance with the approach of chest compression received. The primary outcome measure was return of spontaneous circulation (ROSC), and the secondary outcome measures included 24-h survival rate, hospital discharge rate, and neurological prognosis at hospital discharge.

RESULTS

The ROSC rate of patients with OHCA was significantly higher in the AutoPulse CPR group than in the Manual CPR group (44.9% vs. 23.4%; p = 0.009). The 24-h survival rate of OHCA patients was significantly higher in the AutoPulse CPR group than in the Manual CPR group (39.1% vs. 21.9%; p = 0.03). The hospital discharge rate of the patients with OHCA was significantly higher in the AutoPulse CPR group than in the Manual CPR group (18.8% vs. 6.3%; p = 0.03). The proportion of patients with OHCA and a cerebral performance category score of 1 or 2 points at hospital discharge was higher in the AutoPulse CPR group than in the Manual CPR group, but the difference was not statistically significant (16.2% vs. 13.4%, p = 1.00).

CONCLUSIONS

Use of the AutoPulse increases CPR success and survival rates in patients with OHCA, but its ability to improve cerebral performance requires further evaluation.

Quality between mechanical compression on reducible stretcher versus manual compression on standard stretcher in small elevator

OBJECTIVES

Manual cardiopulmonary resuscitation (CPR) during vertical transport in small elevators using standard stretcher for out-of-hospital cardiac arrest can raise concerns with diminishing quality. Mechanical CPR on a reducible stretcher (RS-CPR) that can be shortened in the length was tested to compare the CPR quality with manual CPR on a standard stretcher (SS-CPR).

METHODS

A randomized crossover manikin simulation was designed. Three teams of emergency medical technicians were recruited to perform serial CPR simulations using two different protocols (RS-CPR and SS-CPR) according to a randomization; the first 6 minutes of manual CPR at the scene was identical for both scenarios and two different protocols during vertical transport in a small elevator followed on a basis of cross-over assignment. The LUCAS-2 Chest Compression System (Zolife AB, Lund, Sweden) was used for RS-CPR. CPR quality was measured using a resuscitation manikin (Resusci Anne QCPR, Laerdal Medical, Stavanger, Norway) in terms of no flow fraction, compression depth, and rate (median and IQR).

RESULTS

A total of 42 simulations were analyzed. CPR quality did not differ significantly at the scene. No flow fraction (%) was significantly lower when the stretcher was moving in RS-CPR then SS-CPR (36.0 (33.8-38.7) vs 44.0 (36.8-54.4), P< .01). RS-CPR showed significantly better quality than SS-CPR; 93.2 (50.6-95.6) vs 14.8 (0-20.8) for adequate depth (P< 0.01), and 97.5 (96.6-98.2) vs 68.9(43.4-78.5) for adequate rate (P< .01).

CONCLUSION

Mechanical CPR on a reducible stretcher during vertical transport showed significant improvement in CPR quality in terms of no-flow fraction, compression depth, and rate compared with manual CPR on a standard stretcher.

Hands-off Time during Automated Chest Compression Device Application in Out-of-Hospital Cardiac Arrest: A Case Series Report

INTRODUCTION

During out-of-hospital cardiac arrest (OHCA), chest compression interruptions or hands-off time (HOT) affect the prognosis. Our aim was to measure HOT due to the application of an automated chest compression device (ACD) by an advanced life support team.

MATERIALS AND METHODS

This was a prospective observational case series report since the introduction of a new method of installing the ACD. Inclusion criteria were patients over 18 years old with OHCA who were treated with an ACD (Lucas 2(TM), Physio-Control). The ACD application was indicated only for OHCA patients transported to a hospital for Extra Corporeal Life Support (ECLS). We recorded the HOT related to switching from manual to mechanical chest compressions. An ACD consists of dorsal and ventral components, which can be installed either in one or in two steps, separated from a chest compression sequence. HOT was expressed as a median number of seconds [interquartile range].

RESULTS

From January 1, 2012 to January 15, 2013, 30 patients were included. In the case of ACD application in one phase (n = 16), the median HOT was 25.3 s [19.8-30.5]. With regard to patients with an ACD application in two phases (n = 14), the median HOT was, respectively, 9.8 s [7.8-17] and 12.4 s [9.5-16.2], that is, a median global HOT of 23.6 s [19-27.6]. HOT was not different between ACD applications in one or two phases (p = 0.52). For a two phase application, the median chest compression time between the two manipulations was 14.2 s [6.4-18].

CONCLUSION

There was no significant difference between techniques in the application of the Lucas 2(TM) device in terms of HOT. The short time needed to apply the device lends itself well to use as a primary chest compression modality during cardiac arrest as well as a bridge to novel resuscitation strategies (ECLS). A further study is currently underway with a larger number of ECLS patients.

Mechanical versus manual chest compressions for cardiac arrest: a systematic review and meta-analysis

BACKGROUND

The aim of this paper was to conduct a systematic review of the published literatures comparing the use of mechanical chest compression device and manual chest compression during cardiac arrest (CA) with respect to short-term survival outcomes and neurological function.

METHODS

Databases including MEDLINE, EMBASE, Web of Science and the ClinicalTrials.gov registry were systematically searched. Further references were gathered from cross-references from articles by handsearch. The inclusion criteria for this review must be human prospective controlled studies of adult CA. Random effects models were used to assess the risk ratios and 95% confidence intervals for return of spontaneous circulation (ROSC), survival to admission and discharge, and neurological function.

RESULTS

Twelve trials (9 out-of-hospital and 3 in-hospital studies), involving 11,162 participants, were included in the review. The results of this meta-analysis indicated no differences were found in Cerebral Performance Category (CPC) scores, survival to hospital admission and survival to discharge between manual cardiopulmonary resuscitation (CPR) and mechanical CPR for out-of-hospital CA (OHCA) patients. The data on achieving ROSC in both of in-hospital and out-of-hospital setting suggested poor application of the mechanical device (RR 0.71, [95% CI, 0.53, 0.97] and 0.87 [95% CI, 0.81, 0.94], respectively). OHCA patients receiving manual resuscitation were more likely to attain ROSC compared with load-distributing bands chest compression device (RR 0.88, [95% CI, 0.80, 0.96]). The in-hospital studies suggested increased relative harm with mechanical compressions for ratio of survival to hospital discharge (RR 0.54, [95% CI 0.29, 0.98]). However, the results were not statistically significant between different kinds of mechanical chest compression devices and manual resuscitation in survival to admission, discharge and CPC scores for OHCA patients and survival to discharge for in-hospital CA patients.

CONCLUSIONS

The ability to achieve ROSC with mechanical devise was inferior to manual chest compression during resuscitation. The use of mechanical chest compression cannot be recommended as a replacement for manual CPR, but rather a supplemental treatment in an overall strategy for treating CA patients.

Cardiopulmonary resuscitation using electrically driven devices: a review

In the treatment of sudden cardiac arrest (SCA) immediate resuscitation with chest compressions and ventilation is crucial for survival. As manual resuscitation is associated with several drawbacks, mechanical resuscitation devices have been developed to support resuscitation teams. These devices are able to achieve better perfusion of heart and brain in laboratory settings, but real world experience showed no significant improved survival in comparison to manual resuscitation. This review will focus on two mechanical resuscitation devices, the Lund University Cardiac Assist System (LUCAS) and AutoPulse devices and the actual literature available. In conclusion, the general use of mechanical resuscitation devices cannot be recommended at the moment.

Mechanical versus manual chest compressions for out-of-hospital cardiac arrest: a meta-analysis of randomized controlled trials

Recent evidence regarding mechanical chest compressions in out-of-hospital cardiac arrest (OHCA) is conflicting. The objective of this study was to perform a meta-analysis of randomized controlled trials (RCTs) to compare the effect of mechanical versus manual chest compressions on resuscitation outcomes in OHCA. PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry were searched. In total, five RCTs with 12,510 participants were included. Compared with manual chest compressions, mechanical chest compressions did not significantly improve survival with good neurological outcome to hospital discharge (relative risks (RR) 0.80, 95% CI 0.61–1.04, P = 0.10; I² = 65%), return of spontaneous circulation (RR 1.02, 95% CI 0.95–1.09, P = 0.59; I² = 0%), or long-term (≥6 months) survival (RR 0.96, 95% CI 0.79–1.16, P = 0.65; I² = 16%). In addition, mechanical chest compressions were associated with worse survival to hospital admission (RR 0.94, 95% CI 0.89–1.00, P = 0.04; I² = 0%) and to hospital discharge (RR 0.88, 95% CI 0.78–0.99, P = 0.03; I² = 0%). Based on the current evidence, widespread use of mechanical devices for chest compressions in OHCA cannot be recommended.

Advancing resuscitation science

PURPOSE OF REVIEW

To describe an alternative approach for improving survival of patients with out-of-hospital cardiac arrest (OHCA). The survival of patients with OHCA has been poor and relatively unchanged for decades in spite of recurrent national and international guidelines. Although there are exceptions, many thought and continue to think that any change in the guidelines for cardiopulmonary resuscitation should be based on randomized controlled trials in humans. However, many factors, including the need for informed consent, the marked variability of patients, and the variability of the type and quality of bystander and advanced resuscitation efforts, all make such studies problematic. Thus, potentially life-saving procedures are often withheld for decades, resulting in unnecessary loss of life.

RECENT FINDINGS

Many improvements in public health conditions have been made using models of continuous quality improvement. When applied to resuscitation science, once baseline data are obtained, changes based on reliable experimental findings are instituted and outcomes measured. This approach has now been shown to result in significant improvement in neurologically intact survival of patients with OHCA.

SUMMARY

Following this model, we found significant improvement in survival of patients with a witnessed OHCA primary cardiac arrest.

Chest Compression Synchronized Ventilation versus Intermitted Positive Pressure Ventilation during Cardiopulmonary Resuscitation in a Pig Model

Background

Guidelines recommend mechanical ventilation with Intermitted Positive Pressure Ventilation (IPPV) during resuscitation. The influence of the novel ventilator mode Chest Compression Synchronized Ventilation (CCSV) on gas exchange and arterial blood pressure compared with IPPV was investigated in a pig model.

Methods

In 12 pigs (general anaesthesia/intubation) ventricular fibrillation was induced and continuous chest compressions were started after 3min. Pigs were mechanically ventilated in a cross-over setting with 5 ventilation periods of 4min each: Ventilation modes were during the first and last period IPPV (100% O₂, tidalvolumes = 7ml/kgKG, respiratoryrate = 10/min), during the 2nd, 3rd and 4th period CCSV (100% O₂), a pressure-controlled and with each chest compression synchronized breathing pattern with three different presets in randomized order. Presets: CCSV_A: P_insp = 60mbar, inspiratorytime = 205ms; CCSV_B: P_insp = 60mbar, inspiratorytime = 265ms; CCSV_C: P_insp = 45mbar, inspiratorytime = 265ms. Blood gas samples were drawn for each period, mean arterial (MAP) and centralvenous (CVP) blood pressures were continuously recorded. Results as median (25%/75%percentiles).

Results

Ventilation with each CCSV mode resulted in higher PaO₂ than IPPV: PaO₂: IPPV_first: 19.6(13.9/36.2)kPa, IPPV_last: 22.7(5.4/36.9)kPa (p = 0.77 vs IPPV_first), CCSV_A: 48.9(29.0/58.2)kPa (p = 0.028 vs IPPV_first, p = 0.0001 vs IPPV_last), CCSV_B: 54.0 (43.8/64.1) (p = 0.001 vs IPPV_first, p = 0.0001 vs IPPV_last), CCSV_C: 46.0 (20.2/58.4) (p = 0.006 vs IPPV_first, p = 0.0001 vs IPPV_last). Both the MAP and the difference MAP-CVP did not decrease during twelve minutes CPR with all three presets of CCSV and were higher than the pressures of the last IPPV period.

Conclusions

All patterns of CCSV lead to a higher PaO₂ and avoid an arterial blood pressure drop during resuscitation compared to IPPV in this pig model of cardiac arrest.

Quality of continuous chest compressions performed for one or two minutes

OBJECTIVES

This study was designed to assess cardiopulmonary resuscitation quality and rescuer fatigue when rescuers perform one or two minutes of continuous chest compressions.

METHODS

This prospective crossover study included 148 lay rescuers who were continuously trained in a cardiopulmonary resuscitation course. The subjects underwent a 120-min training program comprising continuous chest compressions. After the course, half of the volunteers performed one minute of continuous chest compressions, and the others performed two minutes, both on a manikin model. After 30 minutes, the volunteers who had previously performed one minute now performed two minutes on the same manikin and vice versa.

RESULTS

A comparison of continuous chest compressions performed for one and two minutes, respectively, showed that there were significant differences in the average rate of compressions per minute (121 vs. 124), the percentage of compressions of appropriate depth (76% vs. 54%), the average depth (53 vs. 47 mm), and the number of compressions with no errors (62 vs. 47%). No parameters were significantly different when comparing participants who performed regular physical activity with those who did not and participants who had a normal body mass index with overweight/obese participants.

CONCLUSION

The quality of continuous chest compressions by lay rescuers is superior when it is performed for one minute rather than for two minutes, independent of the body mass index or regular physical activity, even if they are continuously trained in cardiopulmonary resuscitation. It is beneficial to rotate rescuers every minute when performing continuous chest compressions to provide higher quality and to achieve greater success in assisting a victim of cardiac arrest.

A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: rationale for and design of the Resuscitation Outcomes Consortium Continuous Chest Compressions Trial

The Resuscitation Outcomes Consortium is conducting a randomized trial comparing survival with hospital discharge after continuous chest compressions without interruption for ventilation versus currently recommended American Heart Association cardiopulmonary resuscitation with interrupted chest compressions in adult patients with out-of-hospital cardiac arrest without obvious trauma or respiratory cause. Emergency medical services perform study cardiopulmonary resuscitation for 3 intervals of manual chest compressions (each ~2 minutes) or until restoration of spontaneous circulation. Patients randomized to the continuous chest compression intervention receive 200 chest compressions with positive pressure ventilations at a rate of 10/min without interruption in compressions. Those randomized to the interrupted chest compression study arm receive chest compressions interrupted for positive pressure ventilations at a compression:ventilation ratio of 30:2. In either group, each interval of compressions is followed by rhythm analysis and defibrillation as required. Insertion of an advanced airway is deferred for the first ≥6 minutes to reduce interruptions in either study arm. The study uses a cluster randomized design with every-6-month crossovers. The primary outcome is survival to hospital discharge. Secondary outcomes are neurologically intact survival and adverse events. A maximum of 23,600 patients (11,800 per group) enrolled during the post-run-in phase of the study will provide ≥90% power to detect a relative change of 16% in the rate of survival to discharge, 8.1% to 9.4% with overall significance level of 0.05. If this trial demonstrates improved survival with either strategy, >3,000 premature deaths from cardiac arrest would be averted annually.

Mechanical circulatory support

The role for temporary and durable mechanical circulatory support is rapidly expanding. As the use of these technologies continues to grow, the emergency physician has an increasing opportunity to participate in the advancement of these potentially life-saving technologies. This review discusses the current role of the intra-aortic balloon pump in cardiogenic shock, describes the complications and management strategies for the critically ill patient with a left ventricular assist device, and explores the emerging role of ECMO in the emergency department for patients presenting in refractory cardiogenic shock and cardiac arrest.

Cardiocerebral Resuscitation: An Approach to Improving Survival of Patients With Primary Cardiac Arrest

Out-of-hospital cardiac arrest (OHCA) is a major public health problem. In the United States, OHCA accounts for more premature deaths than any other cause. For over a half-century, the national "Guidelines" for resuscitation have recommended the same initial treatment of primary and secondary cardiac arrests. Using this approach, the overall survival of patients with OHCA, while quite variable, was generally very poor. One reason is that the etiologies of cardiac arrests are not all the same. The vast majority of nontraumatic OHCA in adults are due to a "primary" cardiac arrest, rather than secondary to respiratory arrest. Decades of research and ongoing reviews of the literature led the University of Arizona Sarver Heart Center Resuscitation Research Group to conclude in 2003 that the national guidelines for patients with primary cardiac arrest were not optimal. Therefore, we instituted a new, nonguidelines approach to the therapy of primary cardiac arrest that dramatically improved survival. We called this approach cardiocerebral resuscitation (CCR), as it is the heart and the brain that are the most vulnerable and therefore need to be the focus of resuscitation efforts for these patients. In contrast, cardiopulmonary resuscitation should be reserved for respiratory arrests. Cardiocerebral resuscitation evolved into 3 components: the community, with emphasis for lay individuals to "Check, Call, Compress" and use an automated external defibrillator if available; the Emergency Medical Services, that emphasizes delayed intubation in favor of passive ventilation, urgent and near continuous chest compressions before and immediately after a single indicated shock, and the early administration of epinephrine; and the third component, added in 2007, the designations of hospitals in Arizona that request this designation and agree to receive patients with return of spontaneous circulation following OHCA and to institute state-of-the-art postresuscitation care that includes urgent therapeutic mild hypothermia and cardiac catheterization as a Cardiac Receiving Center. Each component of CCR is critical for optimal survival of patients with primary OHCA. In each city, county, and state where CCR was instituted, the result was a marked increase in survival of the subgroup of patients with OHCA most likely to survive, for example, those with a shockable rhythm. The purpose of this invited article on CCR is to review this alternative approach to resuscitation of patients with primary cardiac arrest and to encourage its adoption worldwide so that more lives can be saved.

Oxygenation, ventilation, and airway management in out-of-hospital cardiac arrest: a review

Recently published evidence has challenged some protocols related to oxygenation, ventilation, and airway management for out-of-hospital cardiac arrest. Interrupting chest compressions to attempt airway intervention in the early stages of OHCA in adults may worsen patient outcomes. The change of BLS algorithms from ABC to CAB was recommended by the AHA in 2010. Passive insufflation of oxygen into a patent airway may provide oxygenation in the early stages of cardiac arrest. Various alternatives to tracheal intubation or bag-mask ventilation have been trialled for prehospital airway management. Simple methods of airway management are associated with similar outcomes as tracheal intubation in patients with OHCA. The insertion of a laryngeal mask airway is probably associated with worse neurologically intact survival rates in comparison with other methods of airway management. Hyperoxemia following OHCA may have a deleterious effect on the neurological recovery of patients. Extracorporeal oxygenation techniques have been utilized by specialized centers, though their use in OHCA remains controversial. Chest hyperinflation and positive airway pressure may have a negative impact on hemodynamics during resuscitation and should be avoided. Dyscarbia in the postresuscitation period is relatively common, mainly in association with therapeutic hypothermia, and may worsen neurological outcome.

Mechanical versus manual chest compressions for cardiac arrest

BACKGROUND

This is the first update of the Cochrane review on mechanical chest compression devices published in 2011 (Brooks 2011). Mechanical chest compression devices have been proposed to improve the effectiveness of cardiopulmonary resuscitation (CPR).

OBJECTIVES

To assess the effectiveness of mechanical chest compressions versus standard manual chest compressions with respect to neurologically intact survival in patients who suffer cardiac arrest.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Studies (CENTRAL; 2013, Issue 12), MEDLINE Ovid (1946 to 2013 January Week 1), EMBASE (1980 to 2013 January Week 2), Science Citation abstracts (1960 to 18 November 2009), Science Citation Index-Expanded (SCI-EXPANDED) (1970 to 11 January 2013) on Thomson Reuters Web of Science, biotechnology and bioengineering abstracts (1982 to 18 November 2009), conference proceedings Citation Index-Science (CPCI-S) (1990 to 11 January 2013) and clinicaltrials.gov (2 August 2013). We applied no language restrictions. Experts in the field of mechanical chest compression devices and manufacturers were contacted.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster RCTs and quasi-randomised studies comparing mechanical chest compressions versus manual chest compressions during CPR for patients with atraumatic cardiac arrest.

DATA COLLECTION AND ANALYSIS

Two review authors abstracted data independently; disagreement between review authors was resolved by consensus and by a third review author if consensus could not be reached. The methodologies of selected studies were evaluated by a single author for risk of bias. The primary outcome was survival to hospital discharge with good neurological outcome. We planned to use RevMan 5 (Version 5.2. The Nordic Cochrane Centre) and the DerSimonian & Laird method (random-effects model) to provide a pooled estimate for risk ratio (RR) with 95% confidence intervals (95% CIs), if data allowed.

MAIN RESULTS

Two new studies were included in this update. Six trials in total, including data from 1166 participants, were included in the review. The overall quality of included studies was poor, and significant clinical heterogeneity was observed. Only one study (N = 767) reported survival to hospital discharge with good neurological function (defined as a Cerebral Performance Category score of one or two), demonstrating reduced survival with mechanical chest compressions when compared with manual chest compressions (RR 0.41, 95% CI 0.21 to 0.79). Data from four studies demonstrated increased return of spontaneous circulation, and data from two studies demonstrated increased survival to hospital admission with mechanical chest compressions as compared with manual chest compressions, but none of the individual estimates reached statistical significance. Marked clinical heterogeneity between studies precluded any pooled estimates of effect.

AUTHORS' CONCLUSIONS

Evidence from RCTs in humans is insufficient to conclude that mechanical chest compressions during cardiopulmonary resuscitation for cardiac arrest are associated with benefit or harm. Widespread use of mechanical devices for chest compressions during cardiac events is not supported by this review. More RCTs that measure and account for the CPR process in both arms are needed to clarify the potential benefit to be derived from this intervention.

Sudden cardiac death--historical perspectives

Sudden cardiac death (SCD) is an unexpected death due to cardiac causes that occurs in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease. It is believed to be involved in nearly a quarter of human deaths, with ventricular fibrillation being the most common mechanism. It is estimated that more than 7 million lives per year are lost to SCD worldwide. Historical perspectives of SCD are analyzed with a brief description on how the developments in the management of sudden cardiac arrest evolved over time.

Neurologic complications of cardiac arrest

Cardiac arrest is a common and serious medical emergency affecting upwards of 450000 Americans on an annual basis. It causes a substantial strain on the physical and financial resources of the medical system. The optimal management of patients requires the close collaboration of multiple specialists, including first responders, intensivists, cardiologists, and neurologists. The role of the neurologist for the post-arrest patient is to assist in management to minimize brain injury as well as to prognosticate long-term outcomes to help guide therapy decisions of families and physicians. This review focuses on epidemiologic data, current management recommendations, clinical and ancillary testing to suggest long-term prognosis, and common complications of cardiac arrest. Particular attention has been paid to updates, including therapeutic hypothermia, since this topic was last reviewed in 1993.

Role of manual and mechanical chest compressions during resuscitation efforts throughout cardiac arrest

The previously published randomized trials of mechanical versus manual resuscitation of patients with cardiac arrest are inconclusive, but a recent systematic review concluded: "There is no evidence that mechanical cardiopulmonary resuscitation devices improve survival; to the contrary they may worsen neurological outcome." However, in our view, none of the randomized trials to date are definitive as the manual groups with primary cardiac arrest have not been treated optimally; that is, with minimally interrupted manual chest compressions, as advocated with cardiocerebral resuscitation. Since the mechanical chest compression devices work on different principles, it is possible that, while they may not be as effective and may even be worse in some subsets of patients, they may be preferable in others. Nevertheless, there are situations where manual chest compressions are not practical and, in these, mechanical devices may well be preferable. The Thumper® (Michigan Instruments, MI, USA) and the LUCAS™ (Jolife AB, Lund, Sweden) devices produce sternal compressions at 100 per min. By contrast, the AutoPulse® (ZOLL Circulation, CA, USA) produces chest compressions at a rate of only 80 per min. Since chest compression rate, as reviewed in this article, is important, one would guess that the devices that can produce a faster rate would be more effective. On the other hand, it could be that sternal compressions with manual or mechanical devices may be more or less effective depending on the arrested patient's chest configuration. We speculate that in the subset of patients with barrel chests, where sternal compressions are less likely to be operative, the AutoPulse might be more effective, but less effective in thin-chested individuals, where direct cardiac compression is the major mechanism of forward blood flow in the manual, Thumper and LUCAS methods. The original LUCAS device had the potential of active decompression as well as compression. To market in the USA, holes had to be placed in the 'suction cup'. It would be informative to know whether the original LUCAS device is more effective than the device in which the active decompression has been deactivated.

Virtual arterial blood pressure feedback improves chest compression quality during simulated resuscitation

INTRODUCTION

Quality chest compressions (CC) are the most important factor in successful cardiopulmonary resuscitation. Adjustment of CC based upon an invasive arterial blood pressure (ABP) display would be theoretically beneficial. Additionally, having one compressor present for longer than a 2-min cycle with an ABP display may allow for a learning process to further maximize CC. Accordingly, we tested the hypothesis that CC can be improved with a real-time display of invasively measured blood pressure and with an unchanged, physically fit compressor.

METHODS

A manikin was attached to an ABP display derived from a hemodynamic model responding to parameters of CC rate, depth, and compression-decompression ratio. The area under the blood pressure curve over time (AUC) was used for data analysis. Each participant (N=20) performed 4 CPR sessions: (1) No ABP display, exchange of compressor every 2 min; (2) ABP display, exchange of compressor every 2 min; (3) no ABP display, no exchange of the compressor; (4) ABP display, no exchange of the compressor. Data were analyzed by ANOVA. Significance was set at a p-value<0.05.

RESULTS

The average AUC for cycles without ABP display was 5201 mm Hgs (95% confidence interval (CI) of 4804-5597 mm Hgs), and for cycles with ABP display 6110 mm Hgs (95% CI of 5715-6507 mm Hgs) (p<0.0001). The average AUC increase with ABP display for each participant was 20.2±17.4% 95 CI (p<0.0001).

CONCLUSIONS

Our study confirms the hypothesis that a real-time display of simulated ABP during CPR that responds to participant performance improves achieved and sustained ABP. However, without any real-time visual feedback, even fit compressors demonstrated degradation of CC quality.

Cardio pump reloaded: in-hospital resuscitation during transport

High-quality chest compressions are crucial during resuscitation if a positive outcome is to be achieved. Sometimes a patient must be transported within the hospital while chest compressions are being performed. We compared different chest compression devices [animax mono (AM), AutoPulse(®) (AP) and LUCAS2™ (L2)] with manual chest compression using a manikin during transport from a fifth floor ward to the cardiac catheterization laboratory in the basement. Chest compressions were interrupted for 10.7 s to set up the AM, 15.3 s for the L2 and 23.5 s for the AP. The use of a mechanical device reduced transport times from 144.5 s when manual compressions were underway, to 126.8, 111.1 and 98.5 s with the AM, L2 and AP, respectively (p < 0.05). Transfer to the laboratory gurney required little or no interruption in chest compressions with the L2 (0.8 s) and AP (no interruption), compared with 10.3 s with the AP and 3.3 s for manual compressions. Manual compression frequency was 124 min(-1), compared with 100.4 min(-1) for the AM, 99.9 min(-1) for the L2 and 79.7 min(-1) for the AP. Compression depth did not change during transport in any group. Mechanical compression devices are suitable for use during transport, but are not clearly superior to manual compressions. Devices maintain the same compression depth, but fell short of current guidelines, as did manual compressions. Some interruptions occurred while the devices were set up. Further, patient studies are necessary to determine the clinical utility of these devices.

Signal integral for optimizing the timing of defibrillation

OBJECTIVE

The possibility of successful defibrillation decreases with an increased duration of ventricular fibrillation (VF). Futile electrical shocks are inversely correlated with myocardial contractile function and long-term survival. Previous studies have demonstrated that various ECG waveform analyses predict the success of defibrillation. This study investigated whether the absolute amplitude of pre-shock VF waveform is likely to predict the success of defibrillation.

METHODS

ECG recordings of 350 out-of-hospital cardiac arrest (OOHCA) patients were obtained from the automated external defibrillator (AED) and analyzed by the method of signal integral. Successful defibrillation was defined as organized rhythm with heart rate ≥40beat/min commencing within one min of post-shock period and persisting for a minimum of 30s.

RESULTS

Signal integral was significantly greater in successful defibrillation than unsuccessful defibrillation (81.76±32.3mV vs. 34.9±15.33mV, p<0.001). The intersection of the sensitivity and specificity curve provided a threshold value of 51mV. The corresponding values of sensitivity, specificity, positive predictive and negative predictive values for successful defibrillation were 90%, 86%, 80% and 93%, respectively. The receiver operator curve further revealed that signal integral predicted the likelihood of successful defibrillation (area under the curve=0.949).

CONCLUSIONS

Signal integral predicted successful electrical shocks on patients with ventricular fibrillation and have potential to optimize the timing of defibrillation and reduce the number of electrical shocks.

A randomized trial of video self-instruction in cardiopulmonary resuscitation for lay persons

Background

Cardiopulmonary resuscitation (CPR) improves outcomes after cardiac arrest. Much of the lay public is untrained in CPR skills. We evaluated the effectiveness of a compression-only CPR video self-instruction (VSI) with a personal manikin in the lay public.

Methods

Adults without prior CPR training in the past year or responsibility to provide medical care were randomized into one of three groups: 1) Untrained before testing, 2) 10-minute VSI in compressions-only CPR (CPR Anytime, American Heart Association, Dallas, TX), or 3) 22-minute VSI in compressions and ventilations (CPR Anytime). CPR proficiency was assessed using a sensored manikin. The primary outcome was composite skill competence of 90% during five minutes of skill demonstration. Evaluated were alternative cut-points for skill competence and individual components of CPR. 488 subjects (143 in untrained group, 202 in compressions-only group and 143 in compressions and ventilation group) were required to detect 21% competency with compressions-only versus 7% with untrained and 34% with compressions and ventilations.

Results

Analyzable data were available for the untrained group (n = 135), compressions-only group (n = 185) and the compressions and ventilation group (n = 119). Four (3%) achieved competency in the untrained group (p-value = 0.57 versus compressions-only), nine (4.9%) in the compressions-only group, and 12 (10.1%) in the compressions and ventilations group (p-value 0.13 vs. compressions-only). The compressions-only group had a greater proportion of correct compressions (p-value = 0.028) and compressions with correct hand placement (p-value = 0.0004) compared to the untrained group.

Conclusions

VSI in compressions-only CPR did not achieve greater overall competency but did achieve some CPR skills better than without training.