Elsevier

Resuscitation

Volume 82, Issue 7, July 2011, Pages 830-834
Resuscitation

Clinical paper
Out-of-hospital cardiac arrests in young adults in Melbourne, Australia

https://doi.org/10.1016/j.resuscitation.2011.03.008Get rights and content

Abstract

Background

Characteristics and outcomes of out-of-hospital cardiac arrest (OHCA) in young adults are not well described in Australia.

Methods

A 10-year retrospective case review of all OHCA in young adults (aged 16–39) and not witnessed by EMS, was performed using data from the Victorian Ambulance Cardiac Arrest Registry (VACAR).

Results

Between 2000 and 2009 there were 30,006 adult cardiac arrests of which 3912 (13%) were in this age group. The median (IQR) age was 30 (25–35) years for both sexes with a 3:1 male to female ratio. Overdose was the most common precipitant (33.5%) followed by presumed cardiac (20%). Bystander CPR occurred in 21.2%, EMS median response time was 7 min and resuscitation was attempted in 36% of OHCAs. The presenting rhythm was asystole in 84.6%, PEA in 8.8% and VF/VT in 6.6%. Survival to hospital discharge, for all cause OHCA where resuscitation was attempted, was similar for young adult and older adults (8.8% vs 8.4%, p = 0.2). However, for presumed cardiac aetiology OHCA, young adults had a greater proportion of survivors (14.8% vs 9.0%, p < 0.001). Cardiac arrest with shockable rhythm (VF/pulseless VT) had a survival rate of 31.2% for young adults compared to 18.5% for older adults (p < 0.001).

Conclusion

Survival to hospital discharge rates from OHCA due to a ‘presumed cardiac’ precipitant in young adults is much better than older adults, however, all cause OHCA survival is similar. Multi agency novel upstream preventive strategies aimed at tackling drug overdose may reduce this aetiology of OHCA and save lives.

Introduction

Amongst patients suffering from out of-hospital cardiac arrest, young adults represent a minority. However, these victims suffer from the catastrophe when they are in a very active phase of life and have a long life expectancy.

The definition of ‘young’ is arbitrary, sometimes indicating children and including adults up to their mid to late 30s.1 The aetiology of and survival from cardiac arrest in the young adult age group is likely to be different to that of older adults where ischemic heart disease is more common.2 There has been much attention towards structural heart abnormalities, cardiac electrical disorders and the importance of correct diagnosis of genetic cardiac disorders so appropriate family screening of at-risk individuals and initiation of preventive strategies, such as implantable defibrillator therapy can be arranged.3 However, little is published on the epidemiology, characteristics and outcomes of out of hospital cardiac arrests in young adults which may help in the appropriate allocation of attention and resources in this important group in society. This paper describes the characteristics and outcomes of out-of-hospital cardiac arrest (OHCA) occurring in young adult patients in Melbourne, Australia.

Section snippets

Methods

The study setting was Melbourne, Australia which had a population at the time of the last census (2006) of 3.59 million, of whom 1,279,980 (35.6%) were aged between 16 and 39 years of age with an equal male female distribution.

The emergency medical service comprises ambulance paramedics who have some advanced life support skills (laryngeal mask airway, intravenous epinephrine) and mobile intensive care ambulance (MICA) paramedics who are authorized to perform endotracheal intubation and

Ethics approval

VACAR has been classified as a quality assurance project by the ethics committee at the Department of Health. The collection of cardiac arrest data by VACAR was approved by the ethics committees of Melbourne hospitals receiving cardiac arrests by ambulance. This study was approved by the Research Committee of Ambulance Victoria and Monash University Human Research Ethics Committee.

Statistical analysis

All data were entered into an Access software cardiac arrest registry database (version 2003, Microsoft, Redmond, WA, USA). Statistical calculations were performed on STATA software (version 10.0 Stata Corporation, College Station, TX, USA). Young adults aged 16–39 years were compared to older adults (aged >40 years). Chi-square analyses were used for categorical variables. Continuous variables were compared using the t-test (normal distribution) or Mann–Whitney.

Factors affecting paramedic's

Results

Between the years 2000–2009 there were 30,006 OHCAs of which 3912 (13%) were in young adults aged 16–39 years of age; this represents an incidence of 31 per 100,000 young adults per year. Table 2 describes the Utstein data elements characterizing OHCA in young adults (16–39 years of age) compared to all adults (>39 years of age) in OHCA attended.

Drug overdose was the most common precipitating cause for young adult OHCA; the incidence was 10 per 100,000 young adults per year. The incidence of

Discussion

This is the largest study to date describing out-of-hospital cardiac arrest in young adults. We found drug overdose was the most common clinically discernable cause of OHCA in this age group, that when compared to older adults less had witnessed arrests, less received bystander CPR and that less received attempted resuscitation by paramedics. Survival to hospital discharge for all cause OHCA was similar but where the precipitant was ‘presumed cardiac’ was much better in the young adult group.

Limitations

This study has a number of limitations due to its retrospective nature. Little is reported on quality of life outcomes for this age group of survivors in the literature. VACAR has commenced quality of life follow up of all OHCA survivors but this data was not available for the time periods described in this study.

There are challenges in using the Utstein template7 for out-of-hospital cardiac arrest (OHCA) reporting around defining the aetiology of cardiac arrest based on clinical information

Conclusions

Survival to hospital discharge rates from OHCA due to a ‘presumed cardiac’ precipitant in young adults is much better than older adults, however, all cause OHCA survival is similar. Drug overdose is the most common cause of young adult cardiac arrest in Melbourne with a poor outcome, therefore multi agency novel upstream preventive strategies aimed at tackling drug overdose may reduce this aetiology of OHCA and save lives.

Conflict of interest statement

No conflict of interest to declare.

Acknowledgement

Dr Conor Deasy was supported by a Monash University overseas PhD student scholarship during this project. Ambulance Victoria provided in kind support with data extraction.

References (17)

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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2011.03.008.

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On behalf of the VACAR Steering Committee.

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