Early defibrillation in out-of-hospital sudden cardiac death: an Australian experience

Sudden cardiac death rates in an Australian population: a data linkage study

Objective The aim of the present study was to develop criteria to identify sudden cardiac death (SCD) and estimate population rates of SCD using administrative mortality and hospital morbidity records in Western Australia. Methods Four criteria were developed using place, death within 24 h, principal and secondary diagnoses, underlying and associated cause of death, and/or occurrence of a post mortem to identify SCD. Average crude, age-standardised and age-specific rates of SCD were estimated using population person-linked administrative data. Results In all, 9567 probable SCDs were identified between 1997 and 2010, with one-third aged ≥35 years having no prior admission for cardiovascular disease. SCD was more frequent in men (62.1%). The estimated average annual crude SCD rate for the period was 34.6 per 100 000 person-years with an average annual age-standardised rate of 37.8 per 100 000 person-years. Age-specific standardised rates were 1.1 per 100 000 person-years and 70.7 per 100 000 person-years in people aged 1–34 and ≥35 years, respectively. Ischaemic heart disease (IHD) was recorded as the underlying cause of death in approximately 80% of patients aged ≥35 years, followed by valvular heart disease and heart failure. IHD was the most common cause of death in those aged 1–34 years, followed by unspecified cardiomyopathy and dysrhythmias. Conclusions Administrative morbidity and mortality data can be used to estimate rates of SCD and therefore provide a suitable methodology for monitoring SCD over time. The findings highlight the magnitude of SCD and its potential for public health prevention. What is known about the topic? There is considerable variability in rates of SCD worldwide. Different data sources and varied methods of case ascertainment likely contribute to this variation. What does this paper add? The rate of SCD in Australia is low compared with international estimates from USA, Ireland, Netherlands and China. Two in every three cases of SCD aged ≥35 years had a hospitalisation history of cardiovascular disease, highlighting the opportunity for prevention. What are the implications for practitioners? High-quality person-linked administrative hospital morbidity and registered mortality data can be used to estimate rates of SCD in the population. Understanding the magnitude and distribution of SCD is imperative for developing effective public health policy and prevention measures.

Out‐of‐hospital cardiac arrest in Victoria: rural and urban outcomes

OBJECTIVE

To compare the survival rate from out-of-hospital cardiac arrest in rural and urban areas of Victoria, and to investigate the factors associated with these differences.

DESIGN

Retrospective case series using data from the Victorian Ambulance Cardiac Arrest Registry.

SETTING

All out-of-hospital cardiac arrests occurring in Victoria that were attended by Rural Ambulance Victoria or the Metropolitan Ambulance Service.

PARTICIPANTS

1790 people who suffered a bystander-witnessed cardiac arrest between January 2002 and December 2003.

RESULTS

Bystander cardiopulmonary resuscitation was more likely in rural (65.7%) than urban areas (48.4%) (P = 0.001). Urban patients with bystander-witnessed cardiac arrest were more likely to arrive at an emergency department with a cardiac output (odds ratio [OR], 2.92; 95% CI, 1.65-5.17; P < 0.001), and to be discharged from hospital alive than rural patients (urban, 125/1685 [7.4%]; rural, 2/105 [1.9%]; OR, 4.13; 95% CI, 1.09-34.91). Major factors associated with survival to hospital admission were distance of cardiac arrest from the closest ambulance branch (OR, 0.87; 95% CI, 0.82-0.92), endotracheal intubation (OR, 3.46; 95% CI, 2.49-4.80), and the presence of asystole (OR, 0.50; 95% CI, 0.38-0.67) or pulseless electrical activity (OR, 0.73; 95% CI, 0.56-0.95) on arrival of the first ambulance crew.

CONCLUSIONS

Survival rates differ between urban and rural cardiac arrest patients. This is largely due to a difference in ambulance response time. As it is impractical to substantially decrease response times in rural areas, other strategies that may improve outcome after cardiac arrest require investigation.

CPR training in households of patients with chest pain

The objectives of this study are to (1). quantify prior cardiopulmonary resuscitation (CPR) training in households of patients presenting to the Emergency Department (ED) with or without chest pain or ischaemic heart disease (IHD); (2). evaluate the willingness of household members to undertake CPR training; and (3). identify potential barriers to the learning and provision of bystander CPR. A cross-sectional study was conducted by surveying patients presenting to the ED of a metropolitan teaching hospital over a 6-month period. Two in five households of patients presenting with chest pain or IHD had prior training in CPR. This was no higher than for households of patients presenting without chest pain or IHD. Just under two in three households of patients presenting with chest pain or IHD were willing to participate in future CPR classes. Potential barriers to learning CPR included lack of information on CPR classes, perceived lack of intellectual and/or physical capability to learn CPR and concern about causing anxiety in the person at risk of cardiac arrest. Potential barriers to CPR provision included an unknown cardiac arrest victim and fear of infection. The ED provides an opportunity for increasing family and community capacity for bystander intervention through referral to appropriate training.

Is the public equipped to act in out of hospital cardiac emergencies?

STUDY OBJECTIVE

This study aimed to determine whether the people in Australia are informed about and prepared to intervene in a cardiac emergency.

METHODS

A cross sectional telephone survey, which contained sections regarding participant demographics, cardiopulmonary resuscitation (CPR) training, knowledge of CPR, and the emergency contact number and potential barriers to performing chest compressions and mouth to mouth.

RESULTS

A total of 1489 people completed the questionnaire. Only 11% of the population had recently (<12 months) trained in CPR. When presented with a cardiac arrest scenario most participants stated that they would telephone 000. Significantly more respondents believed that they would give mouth to mouth to a family member compared with a stranger. A bleeding victim and fear of not having the skills were the most common barriers that reduced the participants perceived willingness to perform chest compressions and mouth to mouth.

CONCLUSION

This study suggests that a low percentage of the public is currently trained in CPR and also that they are unprepared to act in a cardiac emergency.

Outcomes of out-of-hospital cardiac arrest patients in Perth, Western Australia, 1996-1999

STUDY OBJECTIVE

To describe the epidemiology and survival from out-of-hospital cardiac arrest.

DESIGN

Longitudinal follow-up study from the time of paramedic attendance to 12 months later.

SETTING

Perth, Western Australia (WA), a metropolitan capital city with an adult population of approximately one million people.

METHOD

The St John Ambulance Australia (WA Ambulance Service Incorporated) cardiac arrest database was linked to the WA hospital morbidity and mortality data using probabilistic matching.

INCIDENCE

Of 3730 cardiorespiratory arrests in 1996-1999, the age standardised rate of arrests of presumed cardiac origin, where resuscitation was attempted (n=1293) was 32.9 per 100000 person-years and 7.1 per 100000 person-years for bystander-witnessed VF/VT arrests.

SURVIVAL

Survival to 28 days was 6.8% following all bystander-witnessed cardiac arrests; 10.6% following bystander-witnessed VF/VT arrests and 33% for paramedic-witnessed cardiac arrests. Logistic regression analysis showed an inverse association between ambulance response time interval and survival following all bystander-witnessed cardiac arrests (and VF/VT arrests). ONE YEAR SURVIVAL: 89% of bystander-witnessed cardiac arrest survivors and 92% of paramedic-witnessed cardiac arrests were still alive at 1 year post-arrest.

CONCLUSION

The trends in occurrence and survival following out-of-hospital cardiac arrest in Perth, WA, are similar to those found elsewhere. There is an opportunity to strengthen the chain of survival by reducing the response time interval and increasing the use of bystander cardiopulmonary resuscitation (CPR). First-responder programs and public access defibrillation will need to be considered in the light of local demographics, location and the epidemiologic features of out-of-hospital cardiac arrest.

Cardiac arrest outcomes at the Melbourne Cricket Ground and shrine of remembrance using a tiered response strategy-a forerunner to public access defibrillation

The provision of medical, paramedical and first aid services at major public events is an important concern for pre-hospital emergency medical care providers. Patient outcomes of a cardiac arrest response strategy employed at the Melbourne Cricket Ground (MCG) and the Shrine of Remembrance by St John Ambulance Australia volunteers are reported. Twenty-eight consecutive events occurring between December 1989 and December 1997 have been analysed. Included are three cardiac arrests managed at ANZAC day parades utilising the same response strategy by the same unit. The incidence of cardiac arrest at the MCG was 1:500000 attendances. Of the 28 patients, 24 (86%) left the venue alive and 20 (71%) were discharged home from hospital. In all cases the initial rhythm was ventricular fibrillation (VF). All 26 patients (93%) who were defibrillated by St John teams had this intervention within 5 min from the documented time of collapse. One patient in VF spontaneously reverted during CPR. Of the eight fatalities, four died at the scene. At major public venues and events, a co-ordinated emergency life support provision strategy, tailor made for the venue, is necessary for the delivery of prompt CPR, timely defibrillation and advanced life support.

An analysis of excess mortality not predicted to occur by APACHE III in an Australian level III intensive care unit

The APACHE III derived standardized mortality ratio has been suggested as a statistic to measure intensive care unit (ICU) effectiveness. From 1991 data collected on 519 consecutive admissions to the Royal Adelaide Hospital ICU a standardized mortality ratio of 1.25 was calculated. Of the 174 deaths only 95 had a prediction of death greater than 0.5. As part of a quality assurance study we undertook a retrospective case note audit to try to identify factors that were associated with the low mortality prediction (< 0.5) in hospital deaths. Firstly we analysed the patient population that died to determine the factors that were different between patients who had a mortality prediction of greater than 0.5 versus those who had a mortality prediction of less than 0.5. Next we analysed the patient population with a mortality prediction of less than 0.5 and compared actual survivors with patients who died in hospital. Amongst low mortality prediction patients admitted to the Royal Adelaide Hospital ICU we identified age, a history of acute myocardial infarction, presentation to ICU after a cardiac arrest or with an elevated creatinine and the development of acute renal failure and septicaemia during the ICU admission as being associated with in-hospital mortality. We also documented that late hospital deaths on the ward after ICU discharge occurred more frequently with low predicted hospital mortality ICU patients. Factors other than the APACHE III score may be associated with hospital deaths of ICU patients.

Out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA), with its high fatality rate, is a significant public health issue. The aetiology of OHCA is reviewed, and management strategies are discussed, including the "chain of survival", the Utstein method of data collection, and recent developments in advanced cardiac life support emphasising defibrillation.

Cardiopulmonary resuscitation training for family members of patients on cardiac rehabilitation programmes in Scotland

Existing cardiopulmonary resuscitation (CPR) training programmes have failed to reach those most likely to witness a cardiac arrest, such as families of cardiac patients. In 1993, the Scottish Health Service Advisory Committee suggested that CPR training could be offered as part of cardiac rehabilitation programmes. A survey was carried out to identify the current extent and nature of such training and factors influencing its provision. Questionnaires were mailed to all the 45 Scottish cardiac rehabilitation programmes on the British Heart Foundation's register. A 93% response rate was achieved. Only 37% of programmes provided information to families about attending a CPR course and 37% actually provided CPR training The numbers trained by these programmes were very small. Hospital programmes were significantly more likely than community programmes to provide CPR training (chi2 = 6.65, P < 0.01) as were those which included an exercise component (chi2 = 7.63, P < 0.01). Reasons for not providing training ranged from lack of resources and lack of staff training, to not having considered it. CPR training is provided as part of cardiac rehabilitation programmes to a limited extent. Ways of recruiting and increasing the number of family members of cardiac patients who are trained in CPR need to be found.

Out-of-hospital cardiac arrests in Amsterdam and its surrounding areas: results from the Amsterdam resuscitation study (ARREST) in 'Utstein' style

The purpose of this study was to describe the chain of survival in Amsterdam and its surroundings and to suggest areas for improvement. To ensure accurate data, collection was made by research personnel during the resuscitation, according to the Utstein recommendations. Between June 1, 1995 and August 1, 1997 all consecutive cardiac arrests were registered. Patient characteristics, resuscitation characteristics and time intervals were analyzed in relation to survival. From the 1046 arrests with a cardiac etiology and where resuscitation was attempted, 918 cases were not witnessed by EMS personnel. The analysis focussed on these 918 patients of whom 686 (75%) died during resuscitation, 148 (16%) died during hospital admission and 84 patients (9%) survived to hospital discharge. Patient and resuscitation characteristics associated with survival were: age, VF as initial rhythm, witnessed arrest and bystander CPR. EMS arrival time was significantly shorter for survivors (median 9 min) compared to non-survivors (median 11 min). In 151 cases the police was also alerted and arrived 5 min (median) earlier than EMS personnel. Using the OPC/CPC good functional health was observed in 50% of the survivors and moderate performance in 29%. All links in the chain of survival must be strengthened, but equipping the police with semi-automatic defibrillators may be the most useful intervention to improve survival.

Bystander-initiated cardiopulmonary resuscitation out-of-hospital. A first description of the bystanders and their experiences

At present there are about 1 million trained cardiopulmonary resuscitation (CPR) rescuers in Sweden. CPR out-of-hospital is initiated about 2000 times a year in Sweden. However, very little is known about the bystanders' experiences and reactions. The aim of this study was to describe bystander-initiated CPR, the circumstances, the bystander and his experiences. All CPR bystanders in Sweden who reported their resuscitation attempts between 1990 and 1994 were approached with a phone interview and a postal questionnaire, resulting in 742 questionnaires. Bystander-initiated CPR most frequently took place in public places such as the street. The rescuer most frequently had problems with mouth-to-mouth ventilation (20%) and vomiting (18%). More than half (53%) of the rescuers experienced CPR without problems. Ninety-two percent of the bystanders had no hesitation because of fear of contracting the acquired immunodeficiency syndrome (AIDS) virus. Ninety-three percent of the rescuers regarded their intervention as a mainly positive experience. Of 425 interviewed rescuers, 99.5% were prepared to start CPR again.