Pre-hospital ECPR in an Australian metropolitan setting: a single-arm feasibility assessment-The CPR, pre-hospital ECPR and early reperfusion (CHEER3) study.

INTRODUCTION: Survival from refractory out of hospital cardiac arrest (OHCA) without timely return of spontaneous circulation (ROSC) utilising conventional advanced cardiac life support (ACLS) therapies is dismal. CHEER3 was a safety and feasibility study of pre-hospital deployed extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) for refractory OHCA in metropolitan Australia. METHODS: This was a single jurisdiction, single-arm feasibility study. Physicians, with pre-existing ECMO expertise, responded to witnessed OHCA, age < 65 yrs, within 30 min driving-time, using an ECMO equipped rapid response vehicle. If pre-hospital ECPR was undertaken, patients were transported to hospital for investigations and therapies including emergent coronary catheterisation, and standard intensive care (ICU) therapy until either cardiac and neurological recovery or palliation occurred. Analyses were descriptive. RESULTS: From February 2020 to May 2023, over 117 days, the team responded to 709 "potential cardiac arrest" emergency calls. 358 were confirmed OHCA. Time from emergency call to scene arrival was 27 min (15-37 min). 10 patients fulfilled the pre-defined inclusion criteria and all were successfully cannulated on scene. Time from emergency call to ECMO initiation was 50 min (35-62 min). Time from decision to ECMO support was 16 min (11-26 min). CPR duration was 46 min (32-62 min). All 10 patients were transferred to hospital for investigations and therapy. 4 patients (40%) survived to hospital discharge neurologically intact (CPC 1/2). CONCLUSION: Pre-hospital ECPR was feasible, using an experienced ECMO team from a single-centre. Overall survival was promising in this highly selected group. Further prospective studies are now warranted.

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

AIM: Out-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. METHODS: Using 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. RESULTS: Incidence 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. CONCLUSION: The 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.

Haemodynamics as a determinant of need for pre-hospital application of a pelvic circumferential compression device in adult trauma patients.

INTRODUCTION: Pelvic ring fractures are common following high-energy blunt trauma and can lead to substantial haemorrhage, morbidity and mortality. Pelvic circumferential compression devices (PCCDs) improve position and stability of open-book type pelvic fracture, and can improve haemodynamics in patients with hypovolaemic shock. However, PCCDs may cause adverse outcomes including worsening of lateral compression fracture patterns and routine use is associated with high costs. Controversy regarding indication of PCCDs exists with some centres recommending PCCD in the setting of hypovolaemic shock compared to placement for any suspected pelvic injury. OBJECTIVE: To assess the need for PCCD application based on pre-hospital vital signs and mechanism of injury. METHODS: A retrospective cohort study was conducted in a single adult major trauma centre examining a 2-year period. Patients were sub-grouped based on initial pre-hospital and emergency department observations as haemodynamically normal (heart rate <100 bpm, systolic blood pressure ≥100 mmHg and Glasgow Coma Scale ≥13) or abnormal. Diagnostic accuracy of pre-hospital haemodynamics as a predictor of pelvic fracture requiring intervention within 24 h was assessed. RESULTS: There were 376 patients with PCCD in-situ on hospital arrival. Pelvic fractures were diagnosed in 137 patients (36.4%). Of these, 39 (28.5%) were haemodynamically normal and 98 (71.5%) were haemodynamically abnormal. The most common mechanisms of injury were motor vehicle collision (57.7%) and motorcycle collision (13.8%). Of those with fractures, 40 patients (29.2%) required pelvic intervention within 24 h of admission; of these, 8 (20%) were haemodynamically normal and 32 (80%) were haemodynamically abnormal. As a test for pelvic fracture requiring intervention within 24 h, abnormal pre-hospital haemodynamics had a sensitivity of 0.80 (95% CI 0.64-0.91), specificity of 0.32 (95% CI 0.27-0.38) and negative predictive value (NPV) of 0.93 (95% CI 0.88-0.96). Combined with absence of a major mechanism of injury, normal haemodynamics had a sensitivity 1.00, specificity 0.51 (95% CI 0.36-0.66) and NPV of 1.00 for pelvic intervention within 24 h. CONCLUSION: Normal haemodynamic status, combined with absence of major mechanism of injury can rule out requirement for urgent pelvic intervention. Ongoing surveillance is recommended to monitor for any adverse effects of this change in practice.

Impact of cardiopulmonary resuscitation duration on survival from paramedic witnessed out-of-hospital cardiac arrests: An observational study.

BACKGROUND: Resuscitation guidelines often recommend ongoing cardiopulmonary resuscitation (CPR) efforts to hospital for out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) personnel. In this study, we examine the relationship between EMS CPR duration and survival to hospital discharge in EMS witnessed OHCA patients. METHODS: Between January 2003 and December 2011, 1035 adult EMS witnessed arrests of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. CPR duration was defined as the total sum of prehospital CPR time in minutes. Adjusted logistic regression analyses were used to assess the impact of EMS CPR duration on survival to hospital discharge. RESULTS: 382 (37.3%) patients were discharged alive. The median CPR duration was 12 min (95% CI: 11-13) overall, but was higher in non-survivors compared to survivors (24 min vs. 2 min, p<0.001). The 99th percentile CPR duration in patients surviving to hospital discharge differed by the initial rhythm of arrest: 32 min (95% CI: 27-44) overall, 32 min (95% CI: 23-44) for ventricular fibrillation and pulseless ventricular tachycardia (VF/VT), 34 min (95% CI: 30-34) for pulseless electrical activity (PEA), and 28 min (95% CI: 21-28) for asystole. There were no survivors after 44 min for all rhythms. After adjusting for prehospital confounders, every minute increase in CPR duration was associated with a 13% reduction in the odds of survival to hospital discharge (OR 0.87, 95% CI: 0.84-0.89, p<0.001). The multivariable model predicted no chance of survival at or after a CPR duration of 48 min for VF/VT patients, 47 min for PEA patients and 45 min for asystole patients. CONCLUSION: Resuscitation efforts exceeding 32 min yielded less than 1% of survivors from EMS witnessed OHCA. On the basis of this data, EMS witnessed OHCA patients may benefit from ongoing CPR efforts up to 48 min in duration.

Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: epidemiology, survival to hospital discharge and 12-month functional recovery.

BACKGROUND: Despite immediate resuscitation, survival rates following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) are reportedly low. We sought to compare survival and 12-month functional recovery outcomes for OHCA occurring before and after EMS arrival. METHODS: Between 1st July 2008 and 30th June 2013, we included 8648 adult OHCA cases receiving an EMS attempted resuscitation from the Victorian Ambulance Cardiac Arrest Registry, and categorised them into five groups: bystander witnessed cases±bystander CPR, unwitnessed cases±bystander CPR, and EMS witnessed cases. The main outcomes were survival to hospital and survival to hospital discharge. Twelve-month survival with good functional recovery was measured in a sub-group of patients using the Extended Glasgow Outcome Scale (GOSE). RESULTS: Baseline and arrest characteristics differed significantly across groups. Unadjusted survival outcomes were highest among bystander witnessed cases receiving bystander CPR and EMS witnessed cases, however outcomes differed significantly between these groups: survival to hospital (46.0% vs. 53.4% respectively, p<0.001); survival to hospital discharge (21.1% vs. 34.9% respectively, p<0.001). When compared to bystander witnessed cases receiving bystander CPR, EMS witnessed cases were associated with a significant improvement in the risk adjusted odds of survival to hospital (OR 2.02, 95% CI: 1.75-2.35), survival to hospital discharge (OR 6.16, 95% CI: 5.04-7.52) and survival to 12 months with good functional recovery (OR 5.56, 95% CI: 4.18-7.40). CONCLUSION: When compared to OHCA occurring prior to EMS arrival, EMS witnessed arrests were associated with significantly higher survival to hospital discharge rates and favourable neurological recovery at 12-month post-arrest.

The significance of pre-arrest factors in out-of-hospital cardiac arrests witnessed by emergency medical services: a report from the Victorian Ambulance Cardiac Arrest Registry.

BACKGROUND: The significance of pre-arrest factors in out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical services (EMS) is not well established. The purpose of this study was to assess the association between prodromal symptoms and pre-arrest clinical observations on the arresting rhythm and survival in EMS witnessed OHCA. METHODS: Between 1st January 2003 and 31st December 2011, 1056 adult EMS witnessed arrests of a presumed cardiac aetiology were identified from the Victorian Ambulance Cardiac Arrest Registry. Pre-arrest prodromal features and clinical characteristics were extracted from the patient care record. Backward elimination logistic regression was used to identify pre-arrest factors associated with an initial shockable rhythm and survival to hospital discharge. RESULTS: The median age was 73.0 years, 690 (65.3%) were male, and the rhythm of arrest was shockable in 465 (44.0%) cases. The most commonly reported prodromal symptoms prior to arrest were chest pain (48.8%), dyspnoea (41.8%) and altered consciousness (37.8%). An unrecordable systolic blood pressure was observed in 34.4%, a respiratory rate <13 or >24min(-1) was present in 43.1%, and 45.5% had a Glasgow coma score <15. In the multivariable analysis, the following pre-arrest factors were significantly associated with survival: age, public location, aged care facility, chest pain, arm or shoulder pain, dyspnoea, dizziness, vomiting, ventricular tachycardia, pulse rate, systolic blood pressure, respiratory rate, Glasgow coma score, aspirin and inotrope administration. CONCLUSION: Pre-arrest factors are strongly associated with the arresting rhythm and survival following EMS witnessed OHCA. Potential opportunities to improve outcomes exist by way of early recognition and management of patients at risk of OHCA.

Public access defibrillation­results from the Victorian Ambulance Cardiac Arrest Registry.

AIM: To assess the impact of automated external defibrillator (AED) use by bystanders in Victoria, Australia on survival of adults suffering an out-of-hospital cardiac arrest (OHCA) in a public place compared to those first defibrillated by emergency medical services (EMS). METHODS: We analysed data from the Victorian Ambulance Cardiac Arrest Registry for individuals aged >15 years who were defibrillated in a public place between 1 July 2002 and 30 June 2013, excluding events due to trauma or witnessed by EMS. RESULTS: Of 2270 OHCA cases who arrested in a public place, 2117 (93.4%) were first defibrillated by EMS and 153 (6.7%) were first defibrillated by a bystander using a public AED. Use of public AEDs increased almost 11-fold between 2002/2003 and 2012/2013, from 1.7% to 18.5%, respectively (p < 0.001). First defibrillation occurred sooner in bystander defibrillation (5.2 versus 10.0 min, p < 0.001). Unadjusted survival to hospital discharge for bystander defibrillated patients was significantly higher than for those first defibrillated by EMS (45% versus 31%, p < 0.05). Multivariable logistic regression analysis showed that first defibrillation by a bystander using an AED was associated with a 62% increase in the odds of survival to hospital discharge (adjusted odds ratio 1.62, 95% CI: 1.12­2.34, p = 0.010) compared to first defibrillation by EMS. CONCLUSION: Survival to hospital discharge is improved in patients first defibrillated using a public AED prior to EMS arrival in Victoria, Australia. Encouragingly, bystander AED use in Victoria has increased over time. More widespread availability of AEDs may further improve outcomes of OHCA in public places.

Outcomes following out-of-hospital cardiac arrest with an initial cardiac rhythm of asystole or pulseless electrical activity in Victoria, Australia.

BACKGROUND: While internationally reported survival from out-of-hospital cardiac arrest (OHCA) is improving, much of the increase is being observed in patients presenting to emergency medical services (EMS) in shockable rhythms. The purpose of this study was to assess survival and 12-month functional recovery in patients presenting to EMS in asystole or pulseless electrical activity (PEA). METHODS: The Victorian Ambulance Cardiac Arrest Registry was searched for adult OHCA patients presenting in non-shockable rhythms in Victoria, Australia between 1st July 2003 and 30th June 2013. We excluded patients defibrillated prior to EMS arrival and arrests witnessed by EMS. Twelve-month quality-of-life interviews were conducted on survivors who arrested between 1st January 2010 and 31st December 2012. The main outcome measures were survival to hospital discharge and 12-month functional recovery measured by the Extended Glasgow Outcome Scale (GOSE). RESULTS: A total of 38,378 non-shockable OHCA attended by EMS were included, of which 88.0% were asystole and 11.6% were PEA. Of the patients receiving resuscitation, survival to hospital discharge was 1.1% for asystole and 5.9% for PEA (p<0.001), with no significant improvement observed over the 10 year study period. In survivors with 12-month follow-up data, the combined rate of death, vegetative state or lower severe disability was 66.7% (95% CI 41.0-80.0%) for asystole and 44.7% (95% CI 30.2-59.9%) for PEA. CONCLUSION: Survival outcomes following OHCA with initial rhythms of asystole or PEA did not improve over the 10-year study period. Our findings indicate high rates of death within 12 months, and unfavourable functional recovery for survivors.

The impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest in Victoria, Australia: implications for Utstein-style outcome reports.

BACKGROUND: Success rates from cardiopulmonary resuscitation (CPR) are often quantified by Utstein-style outcome reports in populations who receive an attempted resuscitation. In some cases, evidence of futility is ascertained after a partial resuscitation attempt has been administered, and these cases reduce the overall effectiveness of CPR. We examine the impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia. METHODS: Between 2002 and 2012, 34,849 adult OHCA cases of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. Resuscitation attempts lasting ≤10min in cases which died on scene were defined as a partial resuscitation. We used logistic regression to identify factors associated with a partial resuscitation attempt in the emergency medical service (EMS) treated population. Survival outcomes with and without partial resuscitations were compared across included years. RESULTS: The proportion of partial resuscitations in the overall EMS treated population increased significantly from 8.6% in 2002 to 18.8% in 2012 (p for trend<0.001), and were largely supported by documented evidence of irreversible death. Partial resuscitations were independently associated with older age, female gender, initial non-shockable rhythm, prolonged downtime, and lower skill level of EMS personnel. Selectively excluding partial resuscitations increased event survival by 7.6% (95% CI 4.1-11.2%), and survival to hospital discharge increased by 3.1% (95% CI 0.5-5.7%) in 2012 (p<0.001 for both). CONCLUSION: In our EMS system, evidence of futility was often identified after the commencement of a partial resuscitation attempt. Excluding these events from OHCA outcome reports may better reflect the overall effectiveness of CPR.

Direction of first bystander call for help is associated with outcome from out-of-hospital cardiac arrest.

BACKGROUND: Preventable bystander delays following out-of-hospital cardiac arrest (OHCA) are common, and include bystanders inappropriately directing their calls for help. METHODS: We retrospectively extracted Utstein-style data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) for adult OHCA occurring in Victoria, Australia, between July 2002 and June 2012. Emergency medical service (EMS) witnessed events were excluded. Cases were assigned into two groups on the basis of the first bystander call for help being directed to EMS. Study outcomes were: likelihood of receiving EMS treatment; survival to hospital, and; survival to hospital discharge. RESULTS: A total of 44499 adult OHCA cases attended by EMS were identified, of which first bystander calls for help were not directed to EMS in 2842 (6.4%) cases. Calls to a relative, friend or neighbour accounted for almost 60% of the total emergency call delays. Patient characteristics and survival outcomes were consistently less favourable when calls were directed to others. First bystander call to others was independently associated with older age, male gender, arrest in private location, and arrest in a rural region. The risk-adjusted odds of treatment by EMS (OR 1.33, 95% CI 1.20-1.48), survival to hospital (OR 1.64, 95% CI 1.37-1.96) and survival to hospital discharge (OR 1.64, 95% CI 1.13-2.36) were significantly improved if bystanders called EMS first. CONCLUSION: The frequency of inappropriate bystander calls following OHCA was low, but associated with a reduced likelihood of treatment by EMS and poorer survival outcomes.