Effects of early defibrillation by ambulance personnel on short- and long-term outcome of cardiac arrest survival: the Munich experiment

A Six-Year Prospective Study of Out-of-Hospital Cardiac Arrest Managed by a Voluntary Ambulance Organisation

Objective

To obtain a database on the epidemiology of prehospital cardiac arrest and its management by a voluntary ambulance service, with the view for developing future strategies and service improvement.

Design

A 6-year prospective study from December 1998 to November 2004, using the Utstein-style template.

Setting

A voluntary ambulance service in Hong Kong.

Subjects and methods

Ambulance members had to complete and submit a specially designed data form after managing a cardiac arrest case, together with the ambulance run record and the automated external defibrillator (AED) computer printout, if appropriate.

Main outcome measures

Survival to hospital discharge and return of spontaneous circulation after resuscitation.

Results

A total of 72 cardiac arrests occurred during the period, with patients' age ranging from 29 to 106 years (mean 73.4). Most cardiac arrests occurred at home (46 or 63.9%). There were 58 witnessed cardiac arrests (80.5%), but bystander cardiopulmonary resuscitation (CPR) was started in only nine cases (15.5%) before the arrival of the ambulance crew. Six patients had evidence of rigor mortis or dependent lividity on ambulance arrival. For the 61 patients with electrocardiogram strips, the initial presenting rhythm on the AED was asystole in 45 (73.8%), pulseless electrical activity in 5 (8.2%), and ventricular fibrillation (VF) in 11 (18.0%). The median call-to-arrival time for VF cases (4.0 minutes) was significantly shorter than that of non-VF rhythms (8.5 minutes) [Mann-Whitney U test p=0.008]. Five patients had return of spontaneous circulation after resuscitation, but only one survived to hospital discharge.

Conclusions

Bystander CPR and ambulance response time are two areas requiring urgent improvement in our locality. As the majority of cardiac arrests occurred at home, the cost-effectiveness of public access defibrillation for Hong Kong is unclear. However, strategic placement of AED at high incidence' locations should be seriously considered.

Role of peak current in conversion of patients with ventricular fibrillation

INTRODUCTION

Peak currents are the final arbiter of defibrillation in patients with ventricular fibrillation (VF). However, biphasic defibrillators continue to use energy in joules for electrical conversion in hopes that their impedance compensation properties will address transthoracic impedance (TTI), which must be overcome when a fixed amount of energy is delivered. However, optimal peak currents for conversion of VF remain unclear. We aimed to determine the role of peak current and optimal peak levels for conversion in collapsed VF patients.

METHODS

Adult, non-pregnant patients presenting with non-traumatic VF were included in the study. All defibrillations that occurred were included. Impedance values during defibrillation were used to calculate peak current values. The endpoint was return of spontaneous circulation (ROSC).

RESULTS

Of the 197 patients analysed, 105 had ROSC. Characteristics of patients with and without ROSC were comparable. Short duration of collapse < 10 minutes correlated positively with ROSC. Generally, patients with average or high TTI converted at lower peak currents. 25% of patients with high TTI converted at 13.3 ± 2.3 A, 22.7% with average TTI at 18.2 ± 2.5 A and 18.6% with low TTI at 27.0 ± 4.7 A (p = 0.729). Highest peak current conversions were at < 15 A and 15-20 A. Of the 44 patients who achieved first-shock ROSC, 33 (75.0%) received < 20 A peak current vs. > 20 A for the remaining 11 (25%) patients (p = 0.002).

CONCLUSION

For best effect, priming biphasic defibrillators to deliver specific peak currents should be considered.

Inhibition of nitric oxide synthases, but not inducible nitric oxide synthase, selectively worsens left ventricular function after successful resuscitation from cardiac arrest in swine

OBJECTIVES

Nitric oxide (NO) is a critical regulator of vascular tone and signal transduction in the cardiovascular system. NO is synthesized by three unique enzymes (nitric oxide synthases [NOS]): endothelial and neuronal NOS, both constitutively expressed, and inducible NOS (iNOS), which is induced by proinflammatory stimuli and subsequently produces a burst of NO. NO has been implicated as both an injurious and a beneficial mediator after cardiac arrest and resuscitation. A previous study in swine found that iNOS expression is absent in the myocardium prior to cardiac arrest and that it increases after 10 minutes of untreated ventricular fibrillation (VF), decreases somewhat during the early postresuscitation period, and then steadily increases up to 6 hours postresuscitation. Because this time course of iNOS expression mirrors that of postresuscitation myocardial dysfunction, this study was designed to test the hypothesis that selective inhibition of iNOS improves postresuscitation outcomes in swine.

METHODS

Thirty-two domestic swine of either sex were randomly assigned to receive one of the following treatments 15 minutes after return of spontaneous circulation (ROSC): (1) N(G) -nitro-l-arginine methyl ester (l-NAME), a global NO inhibitor; (2) aminoguanidine (AG), a selective iNOS inhibitor; or (3) saline as control. After 10 minutes of untreated VF, swine received a standard resuscitation protocol. Twenty-four-hour survival, neurological status, left ventricular (LV) function, and hemodynamic measurements were obtained.

RESULTS

Return of spontaneous circulation occurred in 28 of 32 animals (88%). Only successfully resuscitated animals were assigned to treatment groups and completed the study. There were no differences in survival or neurological outcomes between groups. There were also no differences in LV function or hemodynamic variables found between the control group and the AG group. Global inhibition of NOS with l-NAME post-ROSC increased aortic pressure and transiently decreased pulse pressure. Treatment with l-NAME also increased LV end diastolic pressure and decreased cardiac output within 30 minutes post-ROSC, which was sustained throughout the 4-hour measurements, compared to both the control and the AG groups. In addition, LV ejection fraction recovered to baseline measurements in both the control and AG groups, but failed to recover in the l-NAME group.

CONCLUSIONS

Global inhibition of NOS after cardiac arrest and resuscitation markedly worsens hemodynamic variables. Selective inhibition of iNOS after cardiac arrest and resuscitation does not prevent postresuscitation myocardial stunning. There were no significant differences in neurological outcome or survival between treatment groups.

Glucagon-like peptide-1 preserves coronary microvascular endothelial function after cardiac arrest and resuscitation: potential antioxidant effects

Glucagon-like peptide-1 (GLP-1) has protective effects in the heart. We hypothesized that GLP-1 would mitigate coronary microvascular and left ventricular (LV) dysfunction if administered after cardiac arrest and resuscitation (CAR). Eighteen swine were subjected to ventricular fibrillation followed by resuscitation. Swine surviving to return of spontaneous circulation (ROSC) were randomized to receive an intravenous infusion of either human rGLP-1 (10 pmol·kg(-1)·min(-1); n = 8) or 0.9% saline (n = 8) for 4 h, beginning 1 min after ROSC. CAR caused a decline in coronary flow reserve (CFR) in control animals (pre-arrest, 1.86 ± 0.20; 1 h post-ROSC, 1.3 ± 0.05; 4 h post-ROSC, 1.25 ± 0.06; P < 0.05). GLP-1 preserved CFR for up to 4 h after ROSC (pre-arrest, 1.31 ± 0.17; 1 h post-ROSC, 1.5 ± 0.01; 4 h post-ROSC, 1.55 ± 0.22). Although there was a trend toward improvement in LV relaxation in the GLP-1-treated animals, overall LV function was not consistently different between groups. 8-iso-PGF(2α), a measure of reactive oxygen species load, was decreased in post-ROSC GLP-1-treated animals [placebo, control (NS): 38.1 ± 1.54 pg/ml; GLP-1: 26.59 ± 1.56 pg/ml; P < 0.05]. Infusion of GLP-1 after CAR preserved coronary microvascular and LV diastolic function. These effects may be mediated through a reduction in oxidative stress.

Apoptosis is not involved in the mechanism of myocardial dysfunction after resuscitation in a rat model of cardiac arrest and cardiopulmonary resuscitation

OBJECTIVE

To investigate the presence of apoptosis after the global myocardial ischemia of cardiopulmonary resuscitation and the regional myocardial ischemia after left anterior descending coronary artery occlusion and relate it to the severity of postresuscitation myocardial dysfunction.

DESIGN

Prospective animal study.

SETTING

University-affiliated animal research laboratory.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Fifteen male Sprague-Dawley rats weighing 450-550 g were randomized to: (1) 8 mins of untreated cardiac arrest followed by 6 mins of cardiopulmonary resuscitation; (2)left anterior descending coronary artery occlusion for 45 mins followed by 4 hrs of reperfusion; and (3) left anterior descending coronary artery sham group. Cardiac functions, including ejection fraction, analog differentiation of left ventricular pressure at 40 mm Hg, and rate of maximal left ventricular pressure decline were continuously measured for 4 hrs. The hearts were then harvested for the terminal transferase-mediated 2'-deoxyuridine, 5'-triphosphate nick end-labeling assay analysis.

MEASUREMENTS AND MAIN RESULTS

Myocardial function was significantly impaired after resuscitation from cardiac arrest and reperfusion from left anterior descending coronary artery occlusion(p < .01). There was no difference in the percentage of apoptotic cells between the cardiopulmonary resuscitation animals and sham-operated animals. Fewer apoptotic cells were observed in cardiac arrest/cardiopulmonary resuscitation animals in comparison to left anterior descending coronary artery occlusion animals (p < .05), even though myocardial function was more severely impaired after resuscitation (p < .01).

CONCLUSIONS

Myocardial function was significantly impaired after cardiac arrest/cardiopulmonary resuscitation and ischemia/reperfusion. However, apoptosis was not involved in the mechanism of postresuscitation myocardial dysfunction in this setting.

No fate but what we make: a case of full recovery after out-of-hospital cardiac arrest

An 80 years old man suffered a cardiac arrest shortly after arrival to his local health department. Basic Life Support was started promptly and nine minutes later, on evaluation by an Advanced Life Support team, the victim was defibrillated with a 200J shock. When orotracheal intubation was attempted, masseter muscle contraction was noticed: on reevaluation, the victim had pulse and spontaneous breathing.Thirty minutes later, the patient had been transferred to an emergency department. As he complained of chest pain, the ECG showed a ST segment depression in leads V4 to V6 and laboratory tests showed cardiac troponine I slightly elevated. A coronary angiography was performed urgently: significant left main plus three vessel coronary artery disease was disclosed.Eighteen hours after the cardiac arrest, a quadruple coronary artery bypass grafting operation was undertaken. During surgery, a fresh thrombus was removed from the middle left anterior descendent artery. Post-operative course was uneventful and the patient was discharged seven days after the procedure. Twenty four months later, he remains asymptomatic.In this case, the immediate call for the Advanced Life Support team, prompt basic life support and the successful defibrillation, altogether, contributed for the full recovery. Furthermore, the swiftness in the detection and treatment of the acute reversible cause (myocardial ischemia in this case) was crucial for long-term prognosis.

Electrical defibrillation: new technologies

Two-thirds of deaths from coronary disease occur in the pre-hospital phase and are caused by ventricular fibrillation or pulseless ventricular tachycardia, for which electrical defibrillation is the only effective treatment. The time delay between the onset of ventricular fibrillation and the administration of the first defibrillatory shock is the most important determinant for survival. To achieve the earliest defibrillation possible, rescuers others than physicians need to be able to initiate this treatment. The international scientific community strongly supports the concept of early defibrillation in the setting of a strong chain of survival. New technological developments of automated external defibrillators (AEDs) allowed the implementation of defibrillation by the first responding professional rescuer. As a consequence of the technological evolution in implantable defibrillators, much research has also been done on new defibrillation waveforms and alternative energy levels in external defibrillators. After initial animal research, human clinical investigation has shown that initial low energy (150J) nonprogressive (150J-150J-150J) impedance-adjusted biphasic waveform defibrillatory shocks for patients in out-of-hospital ventricular fibrillation are safe, acceptable and clinically effective. Reporting on outcome from cardiac arrest must be as uniform as possible to allow conclusions on performance of emergency medical service systems. The 'Utstein Style' nomenclature is a glossary of terms and a reporting guideline for uniform description of cardiac arrest, resuscitation, the emergency medical service (EMS) system and the outcome. Reports on experiences with AED programmes by traditional and non-traditional professional rescuers support the view that AEDs should not be implemented in EMS systems as an isolated intervention, but that efforts are equally needed to strengthen the other links of the chain of survival. The international scientific community (American Heart Association, International Liaison Committee on Resuscitation and European Resuscitation Council) have issued guidelines for the use of AEDs by EMS providers and first responders, and a universal treatment algorithm is proposed.

Implantable or external defibrillators for individuals at increased risk of cardiac arrest: where cost-effectiveness hits fiscal reality

OBJECTIVES

Implantable cardioverter defibrillators (ICDs) are highly effective at preventing cardiac arrest, but their availability is limited by high cost. Automated external defibrillators (AEDs) are likely to be less effective, but also less expensive. We used decision analysis to evaluate the clinical and economic trade-offs of AEDs, ICDs, and emergency medical services equipped with defibrillators (EMS-D) for reducing cardiac arrest mortality.

METHODS

A Markov model was developed to compare the cost-effectiveness of three strategies in adults meeting entry criteria for the MADIT II Trial: strategy 1, individuals experiencing cardiac arrest are treated by EMS-D; strategy 2, individuals experiencing cardiac arrest are treated with an in-home AED; and strategy 3, individuals receive a prophylactic ICD. The model was then used to quantify the aggregate societal benefit of these three strategies under the conditions of a constrained federal budget.

RESULTS

Compared with EMS-D, in-home AEDs produced a gain of 0.05 quality-adjusted life-years (QALYs) at an incremental cost of $5225 ($104,500 per QALY), while ICDs produced a gain of 0.90 QALYs at a cost of $114,660 ($127,400 per QALY). For every $1 million spent on defibrillators, 1.7 additional QALYs are produced by purchasing AEDs (9.6 QALYs/$million) instead of ICDs (7.9 QALYs/$million). Results were most sensitive to defibrillator complication rates and effectiveness, defibrillator cost, and adults' risk of cardiac arrest.

CONCLUSIONS

Both AEDs and ICDs reduce cardiac arrest mortality, but AEDs are significantly less expensive and less effective. If financial constraints were to lead to rationing of defibrillators, it might be preferable to provide more people with a less effective and less expensive intervention (in-home AEDs) instead of providing fewer people with a more effective and more costly intervention (ICDs).

Cost-Effectiveness of a Microvolt T-Wave Alternans Screening Strategy for Implantable Cardioverter-Defibrillator Placement in the MADIT-II–Eligible Population

OBJECTIVES

This study was designed to compare the cost-effectiveness of implantable cardioverter-defibrillator (ICD) placement with and without risk stratification with microvolt T-wave alternans (MTWA) testing in the MADIT-II (Second Multicenter Automatic Defibrillator Implantation Trial) eligible population.

BACKGROUND

Implantable cardioverter-defibrillators have been shown to prevent mortality in the MADIT-II population. Microvolt T-wave alternans testing has been shown to be effective in risk stratifying MADIT-II-eligible patients.

METHODS

On the basis of published data, cost-effectiveness of three therapeutic strategies in MADIT-II-eligible patients was assessed using a Markov model: 1) ICD placement in all; 2) ICD placement in patients testing MTWA non-negative;, and 3) medical management. Outcomes of expected cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness were determined for patient lifetime.

RESULTS

Under base-case assumptions, providing ICDs only to those who test MTWA non-negative produced a gain of 1.14 QALYs at an incremental cost of 55,700 dollars when compared to medical therapy, resulting in an incremental cost-effectiveness ratio (ICER) of 48,700 dollars/QALY. When compared with a MTWA risk-stratification strategy, placing ICDs in all patients resulted in an ICER of 88,700 dollars/QALY. Most (83%) of the potential benefit was achieved by implanting ICDs in the 67% of patients who tested MTWA non-negative. Results were most sensitive to the effectiveness of MTWA as a risk-stratification tool, MTWA negative screen rate, cost and efficacy of ICD therapy, and patient risk for arrhythmic death.

CONCLUSIONS

Risk stratification with MTWA testing in MADIT-II-eligible patients improves the cost-effectiveness of ICDs. Implanting defibrillators in all MADIT-II-eligible patients, however, is not cost-effective, with one-third of patients deriving little additional benefit at great expense.

Erfolgreiche Reanimation nach Frühdefibrillation durch Pistendienst

Life-threatening incidents during leisure sport activities are not uncommon and also cardiovascular problems are occurring with ever-increasing frequency during alpine downhill skiing. Because these are emergency situations which regularly occur in distant or at least not easily accessible areas, assistance from lay persons can be the decisive factor for survival. The report describes a case of cardiopulmonary resuscitation of a skier in alpine terrain, who survived a cessation of circulation without sequelae after rapid defibrillation by maintenance personnel. A review of possibilities for improved emergency medical care in mountainous regions is also given.

In-hospital cardiac arrest

To review the current management of in-hospital cardiac arrest and to identify variables that influence outcomes, OLDMEDLINE from 1950 to 1966 and MEDLINE from 1966 to March 2005 were searched using the keywords cardiopulmonary resuscitation, cardiac arrest, in hospital, and adult. Secondary sources were derived from review publications and personal communications by one of the authors. There is no secure evidence that the ultimate outcomes after cardiopulmonary resuscitation in settings of in-hospital cardiac arrest have improved in the >40 yrs that followed the landmark report by Kouwenhoven, Jude, and Knickerbocker, which launched the modern era of cardiopulmonary resuscitation. A paucity of objective measurements preclude secure protocols for sequencing of interventions and, even more, when to initiate and discontinue cardiopulmonary resuscitation. The preparedness of both physicians and nursing professionals to implement the published guidelines has itself been questioned. Whereas early access defibrillation with automated external defibrillators may be of benefit in out-of-hospital settings, there has as yet been no secure evidence that automated external defibrillators have had a favorable impact on in-hospital cardiopulmonary resuscitation when used on infrequent occasions by first responders. This contrasts with the much greater success of advanced life support providers and especially when electrical defibrillation is promptly performed by expertly trained personnel after onset of cardiac arrest. Outcomes are therefore improved in critical care settings and especially in coronary care units in which patients are continuously monitored.

Out-of-hospital cardiac arrest and survival: an epidemiological analysis of emergency service reports in a large city in Japan

BACKGROUND

The factors that influence survival of out-of-hospital cardiac arrest in Japan have not been fully investigated.

METHODS AND RESULTS

The official emergency service record was used to investigate 1,600 patients for whom cardiopulmonary resuscitation was attempted by the city's emergency personnel. Only 45 (2.8%) patients survived for 1 month. The survival rate was 9.8% in the patients under 20 years of age, with a marked decreasing trend to 0.8% in the patients aged 80 years or older. The rate peaked at 4.8% on Sunday and bottomed out at 0.5% on Thursday, forming a distinct sine curve. The survival rate was 9.9% when an ambulance arrived at the scene within 4 min, with a steep drop to 2.5% when 4-7 min elapsed. However, the rate was not significantly different by the interval to hospital. Although bystander resuscitation did not significantly affect the survival, paramedics on board significantly improved the rate (3.5% vs 1.6%). Multivariate analysis confirmed that age, day of the week, place, interval to ambulance's arrival, and personnel on board were independently associated with the probability of survival.

CONCLUSIONS

Quick arrival of a paramedic team would improve the survival after out-of-hospital cardiac arrest. General education of lifesaving techniques would be another key factor.

Recommendations of the International Guidelines 2000 Conference on Cardiopulmonary Resuscitation and Emergency Cardiac Care: An Overview

The greatest potential for survival of sudden cardiac arrest can be achieved only by providing early intervention using evidence-based therapies that have been studied over time. Emergency cardiac care and the 2000 advanced cardiac life support guidelines encompass all therapies that have been shown to improve outcomes in patients who experience life-threatening events that involve the cardiovascular, cerebrovascular, and pulmonary systems. Early recognition of warning signs, activation of emergency medical systems within the community, basic cardiopulmonary resuscitation, early defibrillation, airway management, and intravenous medication administration are key factors in improving resuscitation outcomes.

Cost-effectiveness of in-home automated external defibrillators for individuals at increased risk of sudden cardiac death

BACKGROUND/OBJECTIVE

In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment.

DESIGN

Markov decision model employing a societal perspective.

PATIENTS

Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%).

INTERVENTION

Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS.

RESULTS

Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is 216,000 dollars. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are 132,000 dollars, 104,000 dollars, and 88,000 dollars, respectively.

CONCLUSIONS

The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive.

Therapie bedrohlicher Herzrhythmusst�rungen

Tachyarrhythmias represent a frequent problem in intensive care medicine. However, considerable uncertainty prevails among physicians regarding optimal pharmacotherapy, due also to numerous negative study results on chronic antiarrhythmic therapy. Moreover, in an emergency situation, the physician faces the dilemma of treating a potentially life-threatening arrhythmia as quickly as possible while simultaneously ensuring adequate diagnostic work-up, which will be decisive for long-term therapy once the patient has survived the crisis. The differential diagnosis between supraventricular and ventricular tachycardias is primarily facilitated by knowledge of a few salient points from the patient's history and 12-lead electrocardiography. This overview presents the most important principles for treating these arrhythmias. Interventional therapy principles (overstimulation, ablation) play an increasing role in these considerations. New insights on the pathogenesis of "malignant" arrhythmias and implementation of new concepts such as defibrillation by lay responders with the automatic external defibrillator will substantially influence emergency treatment of tachyarrhythmias in the coming years.

Immediate and 1-Year Survival of Out-of-Hospital Cardiac Arrest Victims in Southern New Jersey:. 1995-2000

Most studies report the out-of-hospital cardiac arrest (OHCA) survival to hospital discharge. One-year survival and neurological outcomes in southern New Jersey in 1996-2000 were analyzed using a retrospective data review. There were 1,597 cases of OHCA. Initial survival ranged between 15% in 2000 and 19% in 1997. Survival to hospital discharge, taken as a percent of the initial survivors, decreased from 44% in 1997 to 22% in 2000. In relation to all OHCA victims, survival to discharge decreased from 7.2% to 2.4%, respectively. On discharge from the hospital 19-50% of people had the diagnosis of anoxic brain damage. In ventricular fibrillation, survival to discharge was 41%, 46.7%, 40.7%, 37.5%, and 17.4%, respectively, from 1996 to 2000. The response time increased from 6.6 to 8.1 minutes. Correlation coefficient between in-hospital survival and response time was -0.73. The percent of people discharged with neurological damage increased from 38% to 50%. Initial survival was 29.2% in shockable and 7.5% in nonshockable rhythm (P < 0.001). Survival to discharge was 11.3% versus 1.6%, and survival to 1 year was 9.6% versus 0.7%, respectively (P < 0.001 for all). Overall, the neurologically favorable 1-year survival rate was 2.3% of all OHCA victims. One-year survival of OHCA victims without neurological deficits is low. In southern New Jersey the survival rate did not improve over the 5-year study. Not only initial (prehospital) mortality, but also "delayed" (in-hospital mortality) increases with increase of response time.

Analysis of clinical outcomes following in-hospital adult cardiac arrest

AIMS

The outcome of in-hospital resuscitation following cardiac arrest depends on many factors related to the patient, the environment and the extent of resuscitation efforts. The aim of the present study was to determine predictors of successful resuscitation and survival to -hospital discharge following in-hospital cardiac arrest and to assess functional outcomes of survivors (cerebral performance scores).

METHODS

Medical records of adult patients sustaining in-hospital cardiac arrest between June 2001 and January 2003 were reviewed. Successful resuscitation was defined as the return of spontaneous circulation at the completion of resuscitative efforts, irrespective of degree of inotropic/vasopressor support. Thirty demographic and clinical variables were analysed to determine predictors of successful resuscitation and in-hospital survival.

RESULTS

In 105 patients with cardiac arrest, 46 patients (44%) were successfully resuscitated and 22 (21%) survived to hospital discharge. Predictors of successful resuscitation included a primary cardiac admission diagnosis, monitoring at the time of the arrest, a longer duration of resuscitation and the absence of the need for endotracheal intubation. Patients with ventricular tachycardia/fibrillation were more likely to survive to hospital discharge than those with asystolic or pulseless electrical activity (45 vs 12 vs 20%, P = 0.01). The sole independent predictor of survival to hospital discharge was the absence of the need for endotracheal intubation (odds ratio 0.14, 95% confidence interval 0.02-0.88, P < 0.01). The majority of survivors (73%) had normal cerebral performance scores.

CONCLUSIONS

Identification of predictors of successful resuscitation following cardiac arrest is important for risk stratification. Ongoing appraisal of in-hospital cardiac arrests through a multicentre registry could improve clinical outcomes.

Advances for treating in-hospital cardiac arrest: safety and effectiveness of a new automatic external cardioverter-defibrillator

OBJECTIVES

The purpose of this study was to prospectively analyze the performance and safety of a new programmable, fully automatic external cardioverter-defibrillator (AECD) in a European multicenter trial. BACKGROUND Although, the response time to cardiac arrest (CA) is a major determinant of mortality and morbidity, in-hospital strategies have not significantly changed during the last 30 years.

METHODS

Patients (n = 117) at risk of CA in monitored wards (n = 51) and patients undergoing electrophysiologic testing or implantable cardioverter-defibrillator (ICD) implantation (n = 66) were enrolled. The accuracy of the automatic response of the device to any change of rhythm (lasting >1 s and >4 beats) was confirmed by reviewing the simultaneously recorded Holter data and the programmed parameters.

RESULTS

During 1,240 h, 1,988 episodes of rhythm changes were documented. A total of 115 episodes lasted > or =10 s or needed treatment (pacing, n = 32; ICD, n = 51; AECD, n = 35) for termination. The device detected ventricular tachyarrhythmias with a sensitivity of 100% and specificity of 97.6% (true negatives, n = 1,454; true positives, n = 499; false positives, n = 35; false negatives, n = 0). The false positives were all caused by T-wave oversensing during ventricular pacing. There were no complications or adverse events. The mean response time was 14.4 s for those episodes needing a full charge of the capacitor.

CONCLUSIONS

This new AECD is safe and effective in detecting, monitoring, and treating spontaneous arrhythmias. This fully automatic device shortens the response time to treatment, and it is likely that it will significantly improve the outcome of patients with in-hospital CA.

Prehospital ACLS--does it work?

Cardiac disease is the most common cause of death in the United States, and sudden cardiac arrest frequently claims the lives of men and women during their most productive years. It is believed that much better survival rates can be achieved for victims of cardiac arrest through optimizing the "chain of survival" as described by the American Heart Association. The relative and incremental benefit of full prehospital ACLS over basic life support and defibrillation is unproven, however. This is an important issue in this era of cost containment. Some of the ongoing studies including the OPALS study may clarify the cost effectiveness and relative efficacy of rapid defibrillation and full ACLS programs for victims of prehospital cardiac arrest [6].

Acute myocardial infarction: does pre-hospital treatment increase survival?

The aim of this study was to assess the impact of a mobile emergency care unit (MECU) staffed with an anaesthetist, in terms of increased survival among patients with acute myocardial infarction (MI). The setting was an urban area with 330 000 inhabitants. This was a quasi-experimental before-and-after-study including consecutive emergency calls during September to November 1996 (Period 1, without the MECU) and September to November 1997 (Period 2, including the MECU). Fifty-four ambulance patients had their MI diagnosis confirmed at hospital during Period 1, and another 54 in Period 2. The 28-day mortality was collected from relevant registers. Twenty-four (44%) of Period 2 patients were transported by the MECU. MECU patients had lower systolic blood pressure (SBP) than other patients, both before and after hospital admission. Nitroglycerine treatment was relatively frequent in MECU patients, and cardioversion, anaesthesia and intubation was applied exclusively in these patients. After arrival at hospital, MECU patients had thrombolysis relatively often (46% versus 23% in other Period 2 patients) but percutaneous transluminal coronary angioplasty (PTCA) relatively infrequently (21% vs 30%). The total mortality was significantly lower in Period 2 than in Period 1 patients (11% vs 21%, <0.025), irrespective of differences in the distribution of age, gender, pulse and SBP, measured at hospital. Also, the more specific MECU use, alone and in combination with subsequent PTCA treatment, was found to be associated with prolonged survival. Pre-hospital treatment by an MECU staffed by an anaesthetist and/or having a PTCA seems to be associated with prolonged survival in acute MI patients. It must be underscored that these observations have been based on quasi-experimental rather than randomized experimental data.

Influence of early defibrillation on the survival rate and quality of life after CPR in prehospital emergency medical service in a German metropolitan area

Early defibrillation by emergency medical personnel has been shown to improve survival in patients suffering from out-of-hospital cardiac arrest with ventricular fibrillation. Due to organisational differences it is difficult to compare results in various studies. Comparison of studies has been simplified by introduction of the Utstein template. After introduction of an early defibrillation program in Hamburg, we compared the patients being treated with early defibrillation by emergency medical technicians (EMTs) with patients being defibrillated by physicians in an out-of-hospital emergency service in a prospective study. All patients suffered from non EMT-witnessed ventricular fibrillation of cardiac origin. During 1 year, 103 patients were analyzed with respect to survival rate and quality of life. Of the 53 patients in the early defibrillation group (G1) 11 regained a palpable pulse at physicians' arrival, whereas all patients of the control group (G2) showed ventricular fibrillation. More patients treated with early defibrillation regained sinus rhythm without antiarrhythmics in the prehospital phase (G1: n=43 (86%); G2: n=32 (60%); P<0.05) and had a shorter in-hospital stay (G1: median, 23 days; range 5-51 days; G2: median 39, range 15-88 days; P<0.05). Twelve patients in G1 and 16 in G2 were discharged from hospital. The survival rate was similar in both groups (after 6 months G1: n=12; G2: n=14, after 12 months G1: n=10; G2: n=13 and after 24 months G1: n=9; G2: n=10), and the quality of life according to Glasgow-Pittsburgh Cerebral Performance Category (CPC) and Overall Performance Category (OPC) scores also was comparable between groups. We conclude that early defibrillation provides a higher incidence of return of a spontaneous circulation, a reduced need for antiarrhythmics and shorter in-hospital treatment times in patients with out-of-hospital ventricular fibrillation.

Part 9: pediatric basic life support. European Resuscitation Council

The epidemiology and outcome of pediatric cardiopulmonary arrest and the priorities, techniques, and sequence of pediatric resuscitation assessments and intervention differ from those of adults. Current guidelines have been updated after extensive multinational evidence-based review and discussion over several years. Areas of controversy in current guidelines and recommendations made by consensus are detailed. A large degree of uniformity exists in the current guidelines advocated by the AHA, Council on Latin American Resuscitation, Heart and Stroke Foundation of Canada, European Resuscitation Council, Australian Resuscitation Council, and Resuscitation Council of Southern Africa. Differences are currently based on local and regional preferences, training networks, and customs rather than scientific controversy. Unresolved issues with potential for future universal application are highlighted.

Resuscitation in Europe: a tale of five European regions

AIM

To describe cardiac arrest data from five emergency medical services (EMS) systems in Europe with regard to survival from an out-of-hospital cardiac arrest.

METHODS

Based on recommendations from various countries in Europe EMS systems were approached with regard to survival from out-of-hospital cardiac arrest. Five EMS systems were asked to report their cardiac arrest data according to the Utstein style.

RESULTS

The five selected EMS systems were: Bonn (Germany), Göttingen (Germany), Helsinki (Finland), Reykjavik (Iceland) and Stavanger (Norway). For patients with a bystander witnessed arrest of cardiac aetiology the percentage of patients being discharged alive from hospital in these regions were: 21, 33, 23, 23 and 35. The corresponding percentages for patients fulfilling criteria as above and being found in ventricular fibrillation were: 32, 42, 32, 27 and 55.

CONCLUSIONS

Many EMS systems in Europe show extremely good results in terms of survival after an out-of-hospital cardiac arrest. Some of the results should be interpreted with caution since they were based on relatively small sample sizes. Furthermore, the results from one of the regions (Stavanger) was unit based and not community based.