Victorian Ambulance Cardiac Arrest Registry Research Articles

A two-point strategy to clarify prognosis in >80 year olds experiencing out of hospital cardiac arrest

Abstract Background The global population is aging, with the number of ≥80-year-olds projected to triple over the next 30 years. Rates of out-of-hospital cardiac arrest (OHCA) are also increasing within this age group. Purpose To assess predictors of survival to discharge in ≥80 year old people experiencing OHCA. Methods The Victorian Ambulance Cardiac Arrest Registry was utilised to identify OHCAs in patients aged ≥80 years between 2002-2021. Predictors of survival to discharge were defined and a prognostic score derived from this cohort. Results 77,628 patients experienced OHCA of whom 25,269 (32.6%) were ≥80 years (80-90 years=18,956; 90-100 years=6,148; >100 years=209). The number of patients ≥80 years increased over time both absolutely (p=0.002) and proportionally (p=0.028). 619 (2.4%) patients survived to discharge without change over time. Older ages had no difference in witnessed OHCA status but were less likely to have shockable rhythm (OR 0.50 (95% CI 0.44-0.57) for 90-100-year-olds, OR 0.28 (95% CI 0.12-0.63) for 90-100-year-olds). If OHCA was witnessed and there was a shockable rhythm then survival was 14%; if one factor was present survival was 5-6% and if neither factor was present, survival was 0.09%. These survival rates enabled derivation of a simplified prognostic assessment score – the ‘15/5/0’ score - highly comparable to a previously-published American cohort. Conclusions Elderly OHCA rates have increased to one-third of caseload. The most important factors predicting survival were whether the OHCA was witnessed and there was a shockable rhythm. We present a simple two-point ‘15/5/0’ prognostic score defining which patients will gain most from advanced resuscitative measures.

A two-point strategy to clarify prognosis in >80 year olds experiencing out of hospital cardiac arrest

BackgroundThe global population is aging, with the number of ≥80-year-olds projected to triple over the next 30 years. Rates of out-of-hospital cardiac arrest (OHCA) are also increasing within this age group. MethodsThe Victorian Ambulance Cardiac Arrest Registry was utilised to identify OHCAs in patients aged ≥80 years between 2002–2021. Predictors of survival to discharge were defined and a prognostic score derived from this cohort. Results77,628 patients experienced OHCA of whom 25,269 (32.6%) were ≥80 years (80–90 years = 18,956; 90–100 years = 6,148; >100 years = 209). The number of patients ≥80 years increased over time both absolutely (p = 0.002) and proportionally (p = 0.028). 619 (2.4%) patients survived to discharge without change over time. Older ages had no difference in witnessed OHCA status but were less likely to have shockable rhythm (OR 0.50 (95% CI 0.44–0.57) for 90–100-year-olds, OR 0.28 (95% CI 0.12–0.63) for 90–100-year-olds). If OHCA was witnessed and there was a shockable rhythm then survival was 14%; if one factor was present survival was 5–6% and if neither factor was present, survival was 0.09%. These survival rates enabled derivation of a simplified prognostic assessment score – the ‘15/5/0’ score - highly comparable to a previously-published American cohort. ConclusionsElderly OHCA rates have increased to one-third of caseload. The most important factors predicting survival were whether the OHCA was witnessed and there was a shockable rhythm. We present a simple two-point ‘15/5/0’ prognostic score defining which patients will gain most from advanced resuscitative measures.

Abstract 12127: The Effect of Daylight Savings Time Transitions on the Incidence of Out-of-Hospital Cardiac Arrest: An Interrupted Time Series Analysis

Introduction: Many studies have reported increases in the risk of acute cardiovascular events following daylight savings time (DST) transitions. We sought to investigate the effect of DST transitions on the incidence of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia. Methods: Between January 2000 and December 2020, we performed an interrupted time series analysis of the daily number of OHCA cases of medical etiology from the Victorian Ambulance Cardiac Arrest Registry. The effect of DST transition on OHCA incidence was estimated using negative binomial models and reported as either ‘immediate’ or ‘cumulative’ effects. Immediate effects were the average effects observed on the day of DST transition or each of the 6 days after DST transition. Cumulative effects were the sum of the average effects up to 6 days after the day of DST transition. Models were adjusted for population growth, temporal trends, and public holidays. Results: A total of 89,409 adult OHCA of medical etiology were included. Following the spring DST transition (i.e. shorter day), there was an immediate 13% (IRR 1.13, 95% CI: 1.02, 1.25; p=0.02) increased risk of OHCA on the day of transition (Sunday) and the cumulative risk of OHCA remained higher over the first 2 days (IRR 1.17, 95% CI: 1.02, 1.34; p=0.03) compared to non-transitional days. Following the autumn (fall) DST transition (i.e. longer day), there was a significant lagged effect on the Tuesday following transition, with a 12% (IRR 0.88, 95% CI: 0.77, 0.99; p=0.04) reduced risk of OHCA. The autumn (fall) DST transition also showed a cumulative effect on OHCA incidence, with a 30% (IRR 0.70, 95% CI: 0.51, 0.96; p=0.03) reduction in the incidence of OHCA by the end of the transitional week. Subgroups aged > 65 years and cases with initial non-shockable rhythms were most vulnerable to DST transitions. Conclusions: This study showed that there is a modest increased risk of OHCA in the 2 days following the spring DST transition and a decreased risk of OHCA in the week following the autumn DST transition. These findings should promote further research exploring strategies to reduce the risk of OHCA in vulnerable populations.

Abstract 13205: Short and Long-Term Outcomes of OHCA Patients Admitted to Wards From the Emergency Department

Introduction: The majority of research has examined out-of-hospital cardiac arrest (OHCA) patients admitted to intensive care units (ICU). Little is known about patients who are admitted to non-ICU wards. Our study aims to describe short and long term outcomes in OHCA patients admitted directly to medical wards from the emergency department. Methods: Data were obtained from the Victorian Ambulance Cardiac Arrest Registry and 12 hospitals for adult, non-traumatic OHCA cases transported to ED between 2014 and 2016. Results: Of 1578 OHCAs, 213 (13.5%) were admitted to medical or cardiac wards -only four were admitted for palliation. The majority were witnessed (38% bystander, 58% paramedic), received bystander CPR (91%, n=81/89), median downtime was 4 minutes (IQR 2-12), 179 (84%) were in a shockable rhythm, and 15 received public access defibrillation. Most had ROSC on arrival at ED (99%) and were conscious in ED (91%). Re-arrest inhospital occurred in 16 cases, the majority had a cardiac aetiology (85%) and underwent angiography (75%, 112/160 proceeded to PCI). The majority were discharged alive (n=194, 91%) and most survivors were discharged home (n=176/194, 84%) with good neurological outcomes (CPC 0-2 =94%, CPC 3= 4%). Survivors from the wards made up 30% of the overall OHCA survivors. Of survivors, 175 were alive at 12 months and 159 completed follow-up. The majority of those working prior were working at 12-months (78/92, 85%), 87% in the same role. The mean EuroQol index score for respondents was 0.77 (SD, 0.15). The mean 12-item short form Mental Component Summary score for patients was 55.0 (SD, 8.1), whereas the mean Physical Component Summary score was 49.1 (SD, 9.1). Conclusion: In our region OHCA patients admitted to wards have favourable arrest characteristics, and have good short- and long-term outcomes which are similar to regular acute coronary syndrome patients.

Daylight savings time transitions and risk of out-of-hospital cardiac arrest: An interrupted time series analysis

BackgroundMany studies have reported increases in the risk of acute cardiovascular events following daylight savings time (DST) transitions. We sought to investigate the effect of DST transition on the incidence of out-of-hospital cardiac arrest (OHCA). MethodsBetween January 2000 and December 2020, we performed an interrupted time series analysis of the daily number of OHCA cases of medical aetiology from the Victorian Ambulance Cardiac Arrest Registry. The effect of DST transition on OHCA incidence was estimated using negative binomial models, adjusted for temporal trends, population growth, and public holidays. ResultsA total of 89,409 adult OHCA of medical aetiology were included. Following the spring DST transition (i.e. shorter day), there was an immediate 13% (IRR 1.13, 95% CI: 1.02, 1.25; p = 0.02) increased risk of OHCA on the day of transition (Sunday) and the cumulative risk of OHCA remained higher over the first 2 days (IRR 1.17, 95% CI: 1.02, 1.34; p = 0.03) compared to non-transitional days. Following the autumn DST transition (i.e. longer day), there was a significant lagged effect on the Tuesday with a 12% (IRR 0.88, 95% CI: 0.77, 0.99; p = 0.04) reduced risk of OHCA. The cumulative effect following the autumn DST transition was also significant, with a 30% (IRR 0.70, 95% CI: 0.51, 0.96; p = 0.03) reduction in the incidence of OHCA by the end of the transitional week. ConclusionWe observed both harmful and protective effects from DST transitions on the risk of OHCA. Strategies to reduce this risk in vulnerable populations should be considered.

Out-of-hospital cardiac arrest outcomes in emergency departments

BackgroundThe emergency department (ED) plays an important role in out-hospital-cardiac arrest (OHCA) management. However, ED outcomes are not widely reported. This study aimed to (1) describe OHCA ED outcomes and reasons for ED deaths, and (2) whether these differed between hospitals. MethodsData were obtained from the Victorian Ambulance Cardiac Arrest Registry and 12 hospitals for adult, non-traumatic OHCA cases transported to ED between 2014 and 2016. Multivariable logistic regression was used to examine the association of level of cardiac arrest centre on ED survival in a subset of cases (non-paramedic witnessed OHCA who were unconscious on ED arrival with ROSC). ResultsOf 1547 eligible OHCA cases, 81% (N = 1254) survived ED, varying between 57% to 88% between EDs. Among non-survivors, the majority had either: cessation of resuscitation after presenting with CPR in progress (27%); withdrawal of life-sustaining treatment for non-neurological (n = 65, 22%) or neurological (16%) reasons; or a unsuccessful resuscitation following a rearrested in ED (20%). These causes of ED deaths varied between the different levels of cardiac arrest centres, and in our subset of interest (n = 952) ED survival was associated with transportation to centres with high annual OHCA volumes and with 24-hour cardiac intervention capabilities (AOR = 3.43, 95% CI 1.89–6.21). ConclusionOur study found wide variation in survival between EDs, which was associated with hospital characteristics. Such data suggests the need for a detailed review of ED deaths, particularly in non-cardiac arrest centres, and potentially the need for monitoring ED survival as a measure of quality.

Cardiac arrests in general practice clinics or witnessed by emergency medical services: a 20-year retrospective study.

To compare the frequency and outcomes of cardiac arrests in general practice clinics with those of paramedic-witnessed cardiac arrests. Retrospective study; analysis of Victorian Ambulance Cardiac Arrest Registry data, 1 January 2000 - 30 December 2019. Patients with non-traumatic cardiac arrests whom emergency medical services staff attempted to resuscitate. Survival to hospital discharge. 6363 cases of cardiac arrest were identified: 216 in general practice clinics (3.4%) and 6147 witnessed by paramedics (96.6%). The proportion of patients presenting with initial shockable rhythms was larger in clinic (126 patients, 58.3%) than paramedic-witnessed cases (1929, 31.4%). The proportion of general practice clinic cases in which defibrillation was provided in the clinic increased from 2 of 37 in 2000-2003 (5%) to 19 of 57 patients in 2016-2019 (33%); survival increased from 7 of 37 (19%) to 23 of 57 patients (40%). For patients with initial shockable rhythms, 57 of 126 in clinic cases (45%) and 1221 of 1929 people in paramedic-witnessed cases (63.3%) survived to hospital discharge; of 47 general practice patients defibrillated by clinic staff, 27 survived (57%). For patients with initial shockable rhythms, the odds of survival were greater following paramedic-witnessed events (adjusted odds ratio [aOR], 3.39; 95% CI, 2.08-5.54) or general clinic arrests with defibrillation by clinic staff (aOR, 2.23; 95% CI, 1.03-4.83) than for general practice clinic arrests in which arriving paramedics provided defibrillation. Emergency medical services should be alerted as soon as possible after people experience heart attack warning symptoms. Automated external defibrillators should be standard equipment in general practice clinics, enabling prompt defibrillation, which may substantially reduce the risk of death for people in cardiac arrest.

Comparison of Out-of-Hospital Cardiac Arrests Occurring in Schools and Other Public Locations: A 12-Year Retrospective Study

Objective: Out-of-hospital cardiac arrests (OHCA) in schools and universities are uncommon. However, these institutions must plan and prepare for such events to ensure the best outcomes. To evaluate their preparedness we assessed baseline characteristics, survival outcomes and 12-year trends for OHCA in schools/universities compared to other public locations. Methods: We conducted a retrospective analysis of OHCA in schools/universities and public locations between 2008 and 2019 using Victorian Ambulance Cardiac Arrest Registry data. Results: We included 9,037 EMS attended cases, 131 occurred in schools/universities and 8,906 in public locations. Compared to public locations, a significantly higher proportion of EMS treated cases in schools/universities received bystander cardiopulmonary resuscitation (CPR) (95.5% vs. 78.5%, p < 0.001), public access defibrillation (PAD) (26.1% vs. 9.9%, p < 0.001) and presented in shockable rhythms (69.4% vs. 50.9%, p < 0.001). Unadjusted survival to hospital discharge rates were also significantly higher in schools/universities (39.6% vs. 24.2%, p < 0.001). The long-term unadjusted trends for bystander CPR in schools/universities increased from 91.7% (2008–10) to 100% (2017–19) (p-trend = 0.025), for PAD from 4.2% (2008–10) to 47.5% (2017–19) (p-trend < 0.001) and for survival to hospital discharge from 16.7% (2008–10) to 57.5% (2017–19) (p-trend = 0.004). However, after adjustment for favorable cardiac arrest factors, such as younger age, bystander CPR and PAD, survival was similar between schools/universities and public locations. Conclusion: The majority of OHCA in schools and universities were witnessed and received bystander CPR, however less than half received PAD. Developing site-specific cardiac emergency response plans and providing age appropriate CPR training to primary, secondary and university students would help improve PAD rates.

Collateral damage: Hidden impact of the COVID-19 pandemic on the out-of-hospital cardiac arrest system-of-care

AimOut-of-hospital cardiac arrest (OHCA) during COVID-19 has been reported by countries with high case numbers and overwhelmed healthcare services. Imposed restrictions and treatment precautions may have also influenced OHCA processes-of-care. We investigated the impact of the COVID-19 pandemic period on incidence, characteristics, and survival from OHCA in Victoria, Australia. MethodsUsing data from the Victorian Ambulance Cardiac Arrest Registry, we compared 380 adult OHCA patients who received resuscitation between 16th March 2020 and 12th May 2020, with 1218 cases occurring during the same dates in 2017−2019. No OHCA patients were COVID-19 positive. Arrest incidence, characteristics and survival rates were compared. Regression analysis was performed to understand the independent effect of the pandemic period on survival. ResultsIncidence of OHCA did not differ during the pandemic period. However, initiation of resuscitation by Emergency Medical Services (EMS) significantly decreased (46.9% versus 40.6%, p = 0.001). Arrests in public locations decreased in the pandemic period (20.8% versus 10.0%; p < 0.001), as did initial shocks by public access defibrillation/first-responders (p = 0.037). EMS caseload decreased during the pandemic period, however, delays to key interventions (time-to-first defibrillation, time-to-first epinephrine) significantly increased. Survival-to-discharge decreased by 50% during the pandemic period (11.7% versus 6.1%; p = 0.002). Survivors per million person-years dropped in 2020, resulting in 35 excess deaths per million person-years. On adjusted analysis, the pandemic period remained associated with a 50% reduction in survival-to-discharge. ConclusionThe COVID-19 pandemic period did not influence OHCA incidence but appears to have disrupted the system-of-care in Australia. However, this could not completely explain reductions in survival.

Seasonal Variation in Out-of-Hospital Cardiac Arrest in Victoria 2008–2017: Winter Peak

Background: Out-of-Hospital Cardiac Arrest (OHCA) incidence and survival rates are known to vary between seasons in some locations. The winter of 2017 saw the highest ever incidence and lowest survival rate of OHCA recorded in Victoria at the time. Seasonal variation of OHCA has not previously been examined in Australia and there may be a significant effect. We aimed to describe the seasonal incidence of OHCA and examine seasonal differences in survival to discharge and 12-month quality of life outcomes. In addition, we investigated whether recent respiratory infection or pre existing respiratory disease influenced OHCA outcomes. Methods: The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify OHCA occurring in Victoria between 2008 and 2017. We examined OHCA characteristics and outcomes between seasons. We then used multivariate logistic regression, adjusting for the Utstein factors, to examine if season, recent respiratory infection or preexisting respiratory disease is associated with survival to discharge and 12-month quality of life. Results: There were 44 973 OHCA cases of which 22 209 received an attempted resuscitation (49.4%). The incidence of OHCA was highest during winter (22 per 100 000 vs. 18 per 100 000 in summer). In winter, survival to discharge was lower for OHCA patients (12.2% vs. 15.9% in summer). Both recent respiratory infection (AOR: 0.67, 95% CI: 0.52 – 0.87) and OHCA occurring during winter (AOR: 0.79 95% CI: 0.70 – 0.91) were associated with lower odds of survival to discharge. Preexisting respiratory disease was associated with lower odds of moderate to good recovery at 12 months (AOR:0.60 95% CI: 0.41 – 0.89). Conclusion: In winter the incidence of OHCA was at its highest and survival to discharge was at its lowest compared to other seasons. Recent respiratory infection was associated with lower odds of survival to discharge. Measures targeted to vulnerable groups, such as preventative public health measures for respiratory infections and the influenza vaccine may reduce the incidence of OHCA and improve survival rates.

260 The First Australian Multi-Source Sudden Cardiac Death Registry: Methodology and Early Findings

In 2019, the first multi-source registry of sudden cardiac arrest and death launched in Victoria, Australia. Sudden cardiac arrest / death (SCA/D) affects approximately one thousand younger Victorians per year. The Unexplained Cardiac Death Project enrols all SCA/D cases aged 1-50 years, whilst also offering family screening and access to psychological support through clinical sites and creating a genetic biorepository for whole-genome sequencing. Out of hospital cardiac arrest (OHCA) patients aged 1-50 years in Victoria, Australia are identified by either the existing Victorian Ambulance Cardiac Arrest Registry or the Victorian Institute of Forensic Medicine. Case adjudication is performed, and patients and first-degree relatives with a cardiac/unascertained cause of arrest referred to a clinical site (Royal Melbourne Hospital, St Vincent’s Hospital Melbourne, the Alfred Hospital or the Royal Children’s Hospital). Family screening is conducted, and the opportunity for index cases to contribute to a genetic biorepository offered (deceased cases have samples collected at post-mortem). To date, 509 OHCA patients aged 1-50 have been included in the registry. Of the cases enrolled, 434 (85%) died as a direct result of their cardiac arrest (377 (87%) deceased at scene). Genetic samples have been collected from 17 patients to commence the genetic biorepository. The launch of Australia’s first multi-source cardiac arrest surveillance registry highlights very high mortality in young and middle-aged OHCA patients. The registry will create a genetic biorepository of sudden cardiac arrest survivors and victims that will establish an ongoing Australian resource.

Characteristics and outcomes in patients admitted to hospital after a presumed medical out-of-hospital cardiac arrest with an initial non-shockable rhythm

Introduction: The incidence of non-shockable out-of-hospital cardiac arrest (OHCA) is increasing. Objectives/Aims: This study aims to provide a contemporary review of these patients, specifically the characteristics, aetiologies, care and outcomes of those admitted to hospital. Methods: OHCAs admitted to a large tertiary hospital located in Melbourne (Australia) between September 2010 and December 2016 were identified through the Victorian Ambulance Cardiac Arrest Registry. Excluded cases were: aged <18 years, presumed Utstein non-medical aetiologies (e.g. trauma, obvious overdose/poisoning), shockable initial rhythms and missing identification details. Results: Of the 615 OHCAs admitted, 130 were eligible (78 pulseless electrical activity [PEA] and 54 asystole). Mean age 62 years (SD=19) and 91(70%) were males. The majority were premorbidly independent (n=114,88%) and were residing at home (n=118,91%). Median downtime was 27 minutes (IQR=19-39), 79% were witnessed, 72% received bystander CPR, and 18% had ongoing CPR on ED arrival. The most common causes of arrest were cardiac related (37%, with 28% ischemic heart disease), respiratory (26%), neurological catastrophes (17%), and was unknown in 11%. Two-thirds (67%) survived to be admitted from the ED, with the majority (95%) admitted to ICU. Just over half of ICU patients received target temperature management (58%); and 13(10%) patients received angiography, with 5 undergoing cardiac intervention. Survival from ICU was 19%(n=16) and hospital discharge 15%(n=19). Good neurological outcome (cerebral performance category 1-2) was seen in 11% overall and in 79% of survivors; only three patients were discharged home (10 to rehabilitation). Organ donation was made in 17% of deaths. Conclusion: Our data shows significant heterogeneity in the causes of non-shockable OHCAs, with only one-third due to a cardiac aetiology. The vast majority of non-shockable OHCAs that survive to hospital have poor outcomes at discharge. We are currently extending this audit across other hospitals in Victoria to conduct a risk-adjusted analysis.

Factors associated with return to work among survivors of out-of-hospital cardiac arrest

BackgroundAlthough out-of-hospital cardiac arrest (OHCA) is a major cause of global mortality, survival rates have increased over the last decade. As such, there is an increasing need to explore long-term functional outcomes of survivors, such as return to work (RTW). MethodologyWe analysed baseline and 12-month follow-up data from the Victorian Ambulance Cardiac Arrest Registry for patients that arrested between 2010 and 2016 who were working prior to their arrest. We also conducted more detailed RTW interviews in a subset of OHCA survivors who arrested between July and September 2017. Factors associated with RTW were assessed using multivariable logistic regression analysis. ResultsA total of 884 previously working survivors were included in the analysis, 650 (73%) of whom RTW. Male sex (AOR 1.80; 95%CI: 1.10–2.94), arrests witnessed by emergency medical services (AOR 2.72; 95%CI: 1.50–9.25), discharge directly home from hospital (AOR 4.13; 95%CI: 2.38–7.18) and favourable 12-month health-related quality of life according to the EQ-5D were associated with RTW. Increasing age (AOR 0.97; 95%CI: 0.95–0.98), traumatic arrest aetiology (AOR 0.18; 95%CI: 0.04–0.77), and labour-intensive occupations (AOR 0.44; 95%CI: 0.29–0.66) were associated with decreased odds of RTW. Of the 23 OHCA survivors that participated in the more detailed RTW telephone-interview, 87% RTW. Flexible work hours or modified duties were offered to 74% of participants. Fatigue was the most frequently reported barrier to RTW. ConclusionThis is the largest study to collectively examine factors associated with RTW among survivors of OHCA. Although larger qualitative studies are needed, our findings highlight which patients are at risk of not RTW and who may benefit from targeted rehabilitation strategies.

Long-term trends in the epidemiology of out-of-hospital cardiac arrest precipitated by suspected drug overdose

BackgroundLittle is known about the long-term trends in the incidence and outcomes of drug overdose out-of-hospital cardiac arrests (OHCA). MethodBetween 2000 and 2017, we retrospectively reviewed drug overdose OHCAs from the Victorian Ambulance Cardiac Arrest Registry. Incidence was assessed using linear regression, and the baseline characteristics and survival outcomes were assessed using nonparametric test for trend. Arrest factors associated with survival to hospital discharge were assessed using logistic regression. The 12-month functional recovery and health related quality of life for survivors was summarised using descriptive statistics. ResultsThe incidence of emergency medical services (EMS)-attended and EMS-treated cases was 5.8 and 2.0 per 100,000 person-years, respectively, with no significant changes in trend over time. Return of spontaneous circulation increased from 23% to 34% (p for trend = 0.001), event survival increased from 23% to 30% (p for trend = 0.007), and survival to hospital discharge increased from 4% to 13% (p for trend = 0.03). Age, arrest witnessed by bystander or EMS, initial shockable rhythm or pulseless electrical activity, intubation, epinephrine and sodium bicarbonate administration were independently associated with survival. The adjusted-temporal trend for survival was not significant (per year increase; OR 1.02, 95% CI: 0.98, 1.07; p = 0.244). Of the 12-month survivors, 50% of the responders reported good functional recovery, and few reported severe problems with mobility, self-care, daily activity, pain, and anxiety/depression. ConclusionAlthough the incidence of drug overdose OHCA remained unchanged between 2000 and 2017, the rates of survival have significantly improved.

Trends in survival from out-of-hospital cardiac arrests defibrillated by paramedics, first responders and bystanders

BackgroundAlthough survival from out-of-hospital cardiac arrest (OHCA) is increasing, little is known about the long-term trends in survival for patients defibrillated by first responders and bystanders. MethodsBetween 2000 and 2017, we included adult non-traumatic OHCA with an initial shockable rhythm from the Victorian Ambulance Cardiac Arrest Registry. Adjusted logistic regression analyses were used to assess trends in survival to hospital discharge according to whether the patient was initially shocked by paramedics, first responders or bystanders. ResultsOf the 10,451 initial shockable arrests, 796 (7.6%) and 526 (5.0%) were initially shocked by first responders and bystanders, respectively. Between 2000–02 and 2015–17, the proportion of cases initially shocked by first responders and bystanders increased from 3.8% to 8.2% and from 2.0% to 11.2%, respectively. Over the same period, survival to hospital discharge increased from 11.6% to 28.8% for cases initially shocked by paramedics, from 10.5% to 37.8% for cases initially shocked by first responders, and from 6.7% to 55.5% for cases initially shocked by bystanders (p trend <0.001 for all). In the adjusted analyses, patients initially shocked by first responders (AOR 1.40, 95% CI: 1.18, 1.67; p < 0.001) and bystanders (AOR 2.11, 95% CI: 1.72, 2.59; p < 0.001) were more likely to survive to hospital discharge than those initially shocked by paramedics. The odds of survival increased year-on-year by 8.1% for patients shocked by paramedics (p < 0.001), 6.1% for patients shocked by first responders (p = 0.004), and 11.8% for patients shocked by bystanders (p < 0.001). ConclusionOHCA patients initially defibrillated by bystanders yielded the largest improvements in survival over time.

A descriptive analysis of the epidemiology and management of paediatric traumatic out-of-hospital cardiac arrest

AimPaediatric traumatic out-of-hospital cardiac arrest (OHCA) is a rare event with few survivors. We examined long-term trends in the incidence and outcomes of paediatric traumatic OHCA and explored the frequency and timing of intra-arrest interventions. MethodsWe retrospectively analysed data from the Victorian Ambulance Cardiac Arrest Registry for cases involving traumatic OHCA in patients aged ≤16 years arresting between January 2000 to December 2017. Trends were assessed using linear regression and a non-parametric test for trend. ResultsA total of 292 cases were attended by emergency medical services (EMS), of which 166 (56.9%) received an attempted resuscitation. The overall incidence of EMS-attended cases was 1.4 cases per 100,000 person-years, with no significant changes over time. Unadjusted outcomes also remained unchanged, with 23.5% achieving return of spontaneous circulation and 3.7% surviving to hospital discharge. The frequency of trauma-specific interventions increased between 2000–2005 and 2012–2017, including needle thoracostomy from 10.5% to 51.0% (p trend <0.001), crystalloid administration from 31.6% to 54.9% (p trend = 0.004) and blood administration from 0.0% to 6.3% (p trend = 0.01). The median time from emergency call to the delivery of interventions were: 12.9 min (IQR: 8.5, 20.0) for cardiopulmonary resuscitation, 19.7 min (IQR: 10.7, 39.6) for external haemorrhage control, 29.8 min (IQR: 22.0, 35.4) for crystalloid administration and 31.5 min (IQR: 21.0, 38.0) for needle thoracostomy. ConclusionThe incidence and outcomes of paediatric traumatic OHCA remained unchanged over an 18 year period. Early correction of reversible causes by reducing delays to the delivery of trauma-specific interventions may yield additional survivors.

Exercise-related out-of-hospital cardiac arrest in Victoria, Australia

BackgroundCharacteristics and outcomes of exercise-related out-of-hospital cardiac arrests (OHCA) are not well described in Australia. MethodsThis was a retrospective observational study of non-exercise-related aetiology and exercise-related OHCAs from the Victorian Ambulance Cardiac Arrest Registry between 2008 and 2016, including 12-month quality of life data from 2010 to 2016. Exercise-related OHCA was defined as taking place during or within 1 h of at least moderate intensity exercise. Descriptive statistics and adjusted logistic regression analyses were performed. ResultsDuring the study period there were 482 exercise-related and 33,358 non-exercise-related OHCAs. Jogging/running were the most frequent precipitating sports. The incidence rate of exercise-related OHCA was low (<1 per 100,000 person-years). Compared to non-exercise-related aetiology, exercise-related OHCAs were younger (mean 54 versus 70 years, p < 0.001) and more likely to present in an initial shockable rhythm (85% versus 18%, p < 0.001). Bystander CPR, and bystander or EMS defibrillation at any time, were more common among exercise-related arrests (93% versus 38%, p < 0.001 and 91% versus 24%, p < 0.001, respectively). A public access defibrillator was used in 24% of shockable exercise-related OHCAs compared with 4% of non-exercise-related OHCAs (p < 0.001). After adjustment for arrest characteristics, exercise-related OHCAs were more likely to survive to hospital discharge (50% versus 14%, p < 0.001; adjusted odds ratio [AOR] = 1.56, 95% confidence interval [CI] 1.25–1.96, p < 0.001) and survive to 12-months with good functional recovery (72% versus 62%, p = 0.012; AOR = 1.57, 95% CI 1.08–2.28, p = 0.018). ConclusionsExercise-related OHCAs were associated with better short- and long-term prognoses compared to non-exercise-related OHCAs. The underlying factors associated with this survival benefit warrant further investigation.

Prehospital trauma death review in the State of Victoria, Australia: a study protocol

IntroductionRegionalised trauma systems have been shown to improve outcomes for trauma patients. However, the evaluation of these trauma systems has been oriented towards in-hospital care. Therefore, the epidemiology and care...

Long-term functional recovery and health-related quality of life of elderly out-of-hospital cardiac arrest survivors

IntroductionUnderstanding the prognosis of elderly out-of-hospital cardiac arrest (OHCA) patients is vital to informing resuscitation and advanced care planning decisions. However, short-term outcomes such as survival to hospital discharge do not account for post-arrest quality of life. We describe the 12-month functional recovery and health-related quality of life (HR-QOL) of elderly OHCA survivors, including those arresting in aged care facilities. MethodsWe conducted a retrospective analysis of Victorian Ambulance Cardiac Arrest Registry data for all OHCA survivors to hospital discharge aged ≥65 years between 1 January 2010 and 30 June 2016. The influence of age on functional recovery and independent living was assessed using multivariable logistic regression. ResultsDuring the study period, 20,103 elderly OHCAs were attended, 9016 (44.9%) of whom received a resuscitation attempt. In total, 876 (9.7%) patients survived to hospital discharge and 777 were alive 12 months post-arrest. Of these, 651 participated in 12-month follow-up (response rate 83.8%). Most (60.6%) resided at home without additional care and 66.6% reported a good functional recovery, however both measures decreased with increasing age (p < 0.001). Mental HR-QOL increased with increasing age and was significantly better than the age- and sex-matched Australian population. Each 10-year increase in age was associated with a 40.8% (95%CI 25.6–53.0%) reduction in the odds of good functional recovery, and a 65.8% (95%CI 55.8–73.5%) reduction in the odds of living independently. Of the 2575 OHCAs in an aged care facility, 2.2% survived to hospital discharge, however no patient reported a good 12-month functional recovery. ConclusionsMost elderly OHCA survivors resided independently with good functionality 12 months post-arrest. However, increasing age was associated with less favourable outcomes. New strategies are needed with regard to resuscitation in aged care facilities.

Warning symptoms preceding out-of-hospital cardiac arrest: Do patient delays matter?

BackgroundAlthough increasing patient delays between symptom onset and activation of emergency medical services (EMS) can lead to poorer outcomes following acute myocardial infarction, its effect in out-of-hospital cardiac arrest (OHCA) populations is unclear. MethodsBetween 1st January 2003 and 31st December 2011, we included adult patients with anginal warning symptoms and subsequent EMS witnessed OHCA of presumed cardiac aetiology from the Victorian Ambulance Cardiac Arrest Registry. Multivariable logistic regression was used to assess the impact of patient delay time (i.e. symptom onset to EMS call time) on survival to hospital discharge. ResultsA total of 1056 EMS witnessed OHCA were screened, of which 515 (48.8%) reported chest pain or anginal equivalent symptoms. The median patient delay time was 25min (interquartile range [IQR] 9–89min), and did not differ across survivors and non-survivors. However, patients in lowest quartile of patient delay (≤8min) also experienced significantly higher rates of non-shockable arrest rhythms and circulatory compromise. A total of 16 baseline and clinical characteristics were tested in a multivariable model of survival to hospital discharge, of which, only six were retained in the final model, including: age, dyspnoea, vomiting, shockable arrest rhythm, systolic blood pressure, and patient delay time. Every 30min increase in patient delay time was independently associated with a 2.3% (95% CI: 0.4%, 4.1%; p=0.02) reduction in the odds of survival to hospital discharge. Among patients with ST-segment deviation on the pre-arrest ECG, every 30min increase in patient delay time was associated with a 3.4% reduction in the odds of survival (OR 0.966, 95% CI: 0.937, 0.996; p=0.03). ConclusionIncreasing delays in activating EMS before the onset OHCA may be associated with reduced survival. Future research could explore whether increasing public awareness of the warning symptoms leads to earlier medical contact for OHCA.