Systematic review of the relationship between comorbidity and out-of-hospital cardiac arrest outcomes

Survival and neurobehavioral outcomes following out-of-hospital cardiac arrest in pediatric patients with pre-existing morbidity: An analysis of the THAPCA out-of-hospital arrest data

AIM

Pre-arrest morbidity in adults who suffer out-of-hospital cardiac arrest (OHCA) is associated with increased mortality and poorer neurologic outcomes. The objective of this study was to determine if a similar association is seen in pediatric patients.

METHODS

We performed a secondary analysis of data from the Therapeutic Hypothermia after Pediatric Cardiac Arrest Out-of-Hospital trial. Study sites included 36 pediatric intensive care units across the United States and Canada. The study enrolled children between the ages of 48 hours and 18 years following an OHCA between September 1, 2009 and December 31, 2012. For our analysis, patients with (N = 151) and without (N = 142) pre-arrest comorbidities were evaluated to assess morbidity, survival, and neurologic function following OHCA.

RESULTS

No significant difference in 28-day survival was seen between groups. Dependence on technology and neurobehavioral outcomes were assessed among survivors using the Vineland Adaptive Behavior Scales-Second Edition (VABS-II), Pediatric Cerebral Performance Category (PCPC) and Pediatric Overall Performance Category (POPC). Children with pre-existing comorbidities maintained worse neurobehavioral function at twelve months, evidenced by poorer scores on POPC (p = 0.016), PCPC (p = 0.044), and VABS-II (p = 0.020). They were more likely to have a tracheostomy at hospital discharge (p = 0.034), require supplemental oxygen at three months (p = 0.039) and twelve months (p = 0.034), and be mechanically ventilated at twelve months (p = 0.041).

CONCLUSIONS

There was no difference in survival to 28 days following OHCA in children with pre-existing comorbidity compared to previously healthy children. The group with pre-existing comorbidity was more reliant on technology following arrest and exhibited worse neurobehavioral outcomes.

A review of pre-hospital extracorporeal cardiopulmonary resuscitation and its potential application in the North East of England

Patients in the UK who suffer an out-of-hospital cardiac arrest are treated with cardiopulmonary resuscitation in the pre-hospital environment. Current survival outcomes are low in out-of-hospital cardiac arrest. Extracorporeal cardiopulmonary resuscitation is a technique which is offered to patients in specialised centres which provides better blood flow and oxygen delivery than conventional chest compressions. Shortening the interval between cardiac arrest and restoration of circulation is associated with improved outcomes in extracorporeal cardiopulmonary resuscitation. Delivering extracorporeal cardiopulmonary resuscitation in the pre-hospital environment can shorten this interval, improving outcomes in out-of-hospital cardiac arrest. This article will review recently published studies and summarise studies currently being undertaken in pre-hospital extracorporeal cardiopulmonary resuscitation. It will also discuss the potential application of a pre-hospital extracorporeal cardiopulmonary resuscitation programme in the North East of England.

Comorbidities prior to out-of-hospital cardiac arrest and diagnoses at discharge among survivors

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) has a dismal prognosis with overall survival around 10%. Previous studies have shown conflicting results regarding the prevalence and significance of comorbidities in OHCA, as well as the underlying causes. Previously, 80% of sudden cardiac arrest have been attributed to coronary artery disease. We studied comorbidities and discharge diagnoses in OHCA in all of Sweden.

METHODS

We used the Swedish Registry of Cardiopulmonary Resuscitation, merged with the Inpatient Registry and Outpatient Registry to identify patients with OHCA from 2010 to 2020 and to collect all their comorbidities as well as discharge diagnoses (among those admitted to hospital). Patient characteristics were described using means, medians and SD. Survival curves were performed among hospitalised patients with acute myocardial infarction (AMI) as well as heart failure.

RESULTS

A total of 54 484 patients with OHCA were included, of whom 35 894 (66%) were men. The most common comorbidities prior to OHCA were hypertension (43.6%), heart failure (23.6%), chronic ischaemic heart disease (23.6%) and atrial fibrillation (22.0%). Previous AMI was prevalent in 14.8% of men and 10.9% of women. Among women, 18.0% had type 2 diabetes, compared with 19.6% of the men. Among hospitalised patients, 30% were diagnosed with AMI, 27% with hypertension, 20% with ischaemic heart disease and 18% with heart failure as discharge diagnoses.

CONCLUSION

In summary, we find evidence that nowadays a minority of cardiac arrests are due to coronary artery disease and AMIs and its complications. Only 30% of all cases of OHCA admitted to hospital were diagnosed with AMI. Coronary artery disease is now likely in the minority with regard to causes of OHCA.

Outcomes after out-of-hospital cardiac arrest in immigrants vs natives in Denmark

AIMS

Ethnic disparities subsist in out-of-hospital cardiac arrest (OHCA) outcomes in the US, yet it is unresolved whether similar inequalities exist in European countries. This study compared survival after OHCA and its determinants in immigrants and non-immigrants in Denmark.

METHODS

Using the nationwide Danish Cardiac Arrest Register, 37,622 OHCAs of presumed cardiac cause between 2001 and 2019 were included, 95% in non-immigrants and 5% in immigrants. Univariate and multiple logistic regression was used to assess disparities in treatments, return of spontaneous circulation (ROSC) at hospital arrival, and 30-day survival.

RESULTS

Immigrants were younger at OHCA (median 64 [IQR 53-72] vs 68 [59-74] years; p < 0.05), had more prior myocardial infarction (15% vs 12%, p < 0.05), more diabetes (27% vs 19%, p < 0.05), and were more often witnessed (56% vs 53%; p < 0.05). Immigrants received similar bystander cardiopulmonary resuscitation and defibrillation rates to non-immigrants, but more coronary angiographies (15% vs 13%; p < 0.05) and percutaneous coronary interventions (10% vs 8%, p < 0.05), although this was insignificant after age-adjustment. Immigrants had higher ROSC at hospital arrival (28% vs 26%; p < 0.05) and 30-day survival (18% vs 16%; p < 0.05) compared to non-immigrants, but adjusting for age, sex, witness status, first observed rhythm, diabetes, and heart failure rendered the difference non-significant (odds ratios (OR) 1.03, 95% confidence interval (CI) 0.92-1.16 and OR 1.05, 95% CI 0.91-1.20, respectively).

CONCLUSIONS

OHCA management was similar between immigrants and non-immigrants, resulting in similar ROSC at hospital arrival and 30-day survival after adjustments.

Cardiac arrest in an emergency department in Colombia during 2011-2020: A descriptive study

Background

Cardiac arrest is a public health problem related to high morbidity and mortality. In Colombia, objective data characterize in our population has been not available. The aim of this study has been to determined the epidemiological characteristics of patients with cardiorespiratory arrest treated in an emergency room.

Methods

A retrospective observational cross-sectional cohort study was performed. We included adult patients admitted with a diagnostic of out-of-hospital cardiac arrest (OHCA) or who presented with in-hospital cardiac arrest while in the emergency department (ED).

Results

A total of 415 patients were included 232 were men, and the median age was 67 years. OHCA was presented in 383 patients. In this group, 80.2% required orotracheal intubation, 90.1% received Epinephrine, and and 52.6% received immediate resuscitation. Survival after discharge was 43.1% in patients with non-shockable rhythm registered. Return of spontaneous circulation was achieved in 49.6%. The survival after hospital discharge was 22.2%. Cerebral performance category score <=2 was 20.4%.

Conclusion

In our study, the epidemiological characteristics and outcomes of patients seen in the ED with cardiac arrest are similar to those described in the literature.

The development of a risk-adjustment strategy to benchmark emergency medical service (EMS) performance in relation to out-of-hospital cardiac arrest in Australia and New Zealand

INTRODUCTION

The aim of this study was to develop a risk adjustment strategy, including effect modifiers, for benchmarking emergency medical service (EMS) performance for out-of-hospital cardiac arrest (OHCA) in Australia and New Zealand.

METHOD

Using 2017-2019 data from the Australasian Resuscitation Outcomes Consortium (Aus-ROC) OHCA Epistry, we included adults who received an EMS attempted resuscitation for a presumed medical OHCA. Logistic regression was applied to develop risk adjustment models for event survival (return of spontaneous circulation at hospital handover) and survival to hospital discharge/30 days. We examined potential effect modifiers, and assessed model discrimination and validity.

RESULTS

Both OHCA survival outcome models included EMS agency and the Utstein variables (age, sex, location of arrest, witnessed arrest, initial rhythm, bystander cardiopulmonary resuscitation, defibrillation prior to EMS arrival, and EMS response time). The model for event survival had good discrimination according to the concordance statistic (0.77) and explained 28% of the variation in survival. The corresponding figures for survival to hospital discharge/30 days were 0.87 and 49%. The addition of effect modifiers did little to improve the performance of either model.

CONCLUSION

The development of risk adjustment models with good discrimination is an important step in benchmarking EMS performance for OHCA. The Utstein variables are important in risk-adjustment, but only explain a small proportion of the variation in survival. Further research is required to understand what factors contribute to the variation in survival between EMS.

Lower limb muscle matters in patients with hypoxic brain injury following out-of-hospital cardiac arrest

BACKGROUND

There are conflicting results regarding the association between body mass index and the prognosis of cardiac arrest patients. We investigated the association of the composition and distribution of muscle and fat with neurologic outcomes at hospital discharge in successfully resuscitated out-of-hospital cardiac arrest (OHCA) patients.

METHODS

This prospective, single-centre, observational study involved adult OHCA patients, conducted between April 2019 and June 2021. The ratio of total skeletal muscle, upper limb muscle, lower limb muscle, and total fat to body weight was measured using InBody S10, a bioimpedance analyser, after achieving the return of spontaneous circulation. Restricted cubic spline curves with four knots were used to examine the relationship between total skeletal muscle, upper limb muscle, and lower limb muscle relative to total body weight and neurologic outcome at discharge. Multivariable logistic regression analysis was performed to assess an independent association.

RESULTS

A total of 66 patients were enrolled in the study. The proportion of total muscle and lower limb muscle positively correlated with the possibility of having a good neurologic outcome. The proportion of lower limb muscle showed an independent association in the multivariable analysis (adjusted odds ratio, 2.29; 95% confidence interval, 1.06-13.98), and its optimal cut-off value calculated through receiver operating characteristic curve analysis was 23.1%, which can predict a good neurological outcome.

CONCLUSIONS

A higher proportion of lower limb muscle to body weight was independently associated with the probability of having a good neurologic outcome in OHCA patients.

The association of duration of resuscitation and long-term survival and functional outcomes after out-of-hospital cardiac arrest

AIM

Longer emergency medical system cardiopulmonary-resuscitation-to-return of-spontaneous-circulation (EMS CPR-to-ROSC) interval has been associated with worse hospital discharge outcomes after out-of-hospital cardiac arrest (OHCA). We hypothesized that this association extends post-discharge in hospital survivors. We investigated whether pre-arrest co-morbidities influence the duration of resuscitation.

METHODS

We included EMS-treated adult OHCA (January 2009 - December 2016) from British Columbia Cardiac Arrest Registry linked to provincial databases. Pre-OHCA characteristics were compared by ≤10, 10-20, and >20 min interval categories. Outcomes included survival and functional outcomes at hospital discharge and 1- and 3-year survival. We examined the relationship between CPR-to-ROSC intervals and survival using Kaplan-Meier. We examined the relationship between the CPR-to-ROSC interval (continuous variable) with all outcomes using regression models.

RESULTS

Among 10,241 OHCA, 4604 (45%) achieved ROSC, with a median CPR-to-ROSC interval of 15.5 (IQR 9.0-22.9) minutes. Diabetes, chronic kidney disease, and prior myocardial infarction were associated with longer CPR-to-ROSC intervals. 1245 (12.2%) survived to hospital discharge. Among hospital survivors, Kaplan-Meier survival at 1- and 3-years were 92% [95% CI 90-93%] and 84% [95% CI 82-86%] respectively; survival curves stratified by CPR-to-ROSC intervals were not statistically different. Longer CPR-to-ROSC interval was non-linearly associated with lower survival and functional outcomes at hospital discharge but not with post-discharge outcomes.

CONCLUSION

Longer CPR-to-ROSC interval was associated with lower survival at hospital discharge and was influenced by pre-arrest co-morbidities. However, these intervals were not associated with long-term survival or functional outcome among hospital survivors, suggesting early risk of longer CPR-to-ROSC intervals does not persist.

Firefighters as first-responders in out-of-hospital cardiac arrest- a retrospective study of a time-gain selective dispatch system in the Skåne Region, Sweden

AIM

To analyze the impact of a time-gain selective, first-responder dispatch system on the presence of a shockable initial rhythm (SIR), return of spontaneous circulation (ROSC) and 30-day survival after out-of-hospital cardiac arrest (OHCA).

METHOD

A retrospective observational study comprising OHCA registry data and dispatch data in the Skåne Region, Sweden (2010-2018). Data were categorized according to dispatch procedures, two ambulances (AMB-only) versus two ambulances and firefighter first-responders (DUAL-dispatch), based on the dispatcher's estimation of a time-gain. Dual dispatch was sub-categorized by arrival of first vehicle (first-responder or ambulance). Logistic regressions were used, additionally with groups matched (1:1) for age, witnessed event, bystander cardiopulmonary resuscitation and ambulance response time. Adjusted and conditional odds-ratios (aOR, cOR) with 95% confidence intervals (CI) are presented.

RESULTS

Of 3,245 eligible cases, 43% were DUAL-dispatches with first-responders first on scene (FR-first) in 72%. Despite a five-minute median reduction in response time in the FR-first group, no association with SIR was found (aOR 0.83, 95%CI 0.64-1.07) nor improved 30-day survival (aOR 1.03, 95%CI 0.72-1.47). A positive association between ROSC and the FR-first group (aOR 1.25, 95%CI 1.02-1.54) disappeared in the matched analysis (cOR 1.12, 95%CI 0.87-1.43). Time to first monitored rhythm was 7:06 minutes in the FR-first group versus 3:01 in the combined AMB-only/AMB-first groups.

CONCLUSION

In this time-gain selective first-responder dispatch system, a shorter response time was not associated with increased SIR, improved ROSC rate or survival. Process measures differed between the study groups which could account for the observed findings and requires further investigation.

Correlation between the warning symptoms and prognosis of cardiac arrest

BACKGROUND

A low survival rate in patients with cardiac arrest is associated with failure to recognize the condition in its initial stage. Therefore, recognizing the warning symptoms of cardiac arrest in the early stage may play an important role in survival.

AIM

To investigate the warning symptoms of cardiac arrest and to determine the correlation between the symptoms and outcomes.

METHODS

We included all adult patients with all-cause cardiac arrest who visited Peking University Third Hospital or Beijing Friendship Hospital between January 2012 and December 2014. Data on population, symptoms, resuscitation parameters, and outcomes were analysed.

RESULTS

Of the 1021 patients in the study, 65.9% had symptoms that presented before cardiac arrest, 25.2% achieved restoration of spontaneous circulation (ROSC), and 7.2% survived to discharge. The patients with symptoms had higher rates of an initial shockable rhythm (12.2% vs 7.5%, P = 0.020), ROSC (29.1% vs 17.5%, P = 0.001) and survival (9.2% vs 2.6%, P = 0.001) than patients without symptoms. Compared with the out-of-hospital cardiac arrest (OHCA) without symptoms subgroup, the OHCA with symptoms subgroup had a higher rate of calls before arrest (81.6% vs 0.0%, P < 0.001), health care provider-witnessed arrest (13.0% vs 1.4%, P = 0.001) and bystander cardiopulmonary resuscitation (15.5% vs 4.9%, P = 0.002); a shorter no flow time (11.7% vs 2.8%, P = 0.002); and a higher ROSC rate (23.8% vs 13.2%, P = 0.011). Compared to the in-hospital cardiac arrest (IHCA) without symptoms subgroup, the IHCA with symptoms subgroup had a higher mean age (66.2 ± 15.2 vs 62.5 ± 16.3 years, P = 0.005), ROSC (32.0% vs 20.6%, P = 0.003), and survival rates (10.6% vs 2.5%, P < 0.001). The top five warning symptoms were dyspnea (48.7%), chest pain (18.3%), unconsciousness (15.2%), paralysis (4.3%), and vomiting (4.0%). Chest pain (20.9% vs 12.7%, P = 0.011), cardiac etiology (44.3% vs 1.5%, P < 0.001) and survival (33.9% vs 16.7%, P = 0.001) were more common in males, whereas dyspnea (54.9% vs 45.9%, P = 0.029) and a non-cardiac etiology (53.3% vs 41.7%, P = 0.003) were more common in females.

CONCLUSION

Most patients had warning symptoms before cardiac arrest. Dyspnea, chest pain, and unconsciousness were the most common symptoms. Immediately recognizing these symptoms and activating the emergency medical system prevents resuscitation delay and improves the survival rate of OHCA patients in China.

Trends in out-of-hospital cardiac arrest incidence, patient characteristics and survival over 18 years in Perth, Western Australia

Objectives

To investigate trends in the incidence, characteristics, and survival of out-of-hospital cardiac arrests (OHCA) in the Perth metropolitan area between 2001 and 2018.

Methods

We calculated the crude incidence rate, age-standardised incidence rate (ASIR) and age- and sex-specific incidence rates (per 100,000 population) for OHCA of presumed cardiac aetiology. ASIRs were calculated using the direct method of standardisation using the 2001 Australian Population standard. Survival was assessed at return of spontaneous circulation at emergency department arrival and at 30 days. Temporal trends in patient and arrest characteristics were assessed with logistic regression, while trends in incidence were assessed using Joinpoint regression. Survival trends were assessed using binary logistic regression.

Results

A total of 18,417 OHCAs of presumed cardiac aetiology were attended by emergency medical services in Perth between 2001 and 2018. Overall, there were no significant changes in the crude or ASIR of OHCA over the study period, although OHCA incidence in 15–39 year-old males increased by 12.5% annually between 2011 and 2018. Both bystander cardiopulmonary resuscitation and bystander defibrillation increased over the study period, while the proportion of shockable arrests declined. Thirty-day OHCA survival improved significantly over time, with the odds of survival (in bystander-witnessed, initial shockable rhythm arrests) improving 12% (95% CI, 9.0% to 14.0%) annually, from 8.4% in 2001 to 44.0% in 2018.

Conclusion

Overall, there were no significant trends in OHCA incidence over the study period, although arrests in 15–39 year-old males increased significantly after 2011. There were significant improvements in 30-day survival between 2001 and 2018.

Incidence, characteristics and outcomes of out-of-hospital cardiac arrests in patients with psychiatric illness: A systematic review

Aim

To conduct a systematic literature review of the existing evidence on incidence, characteristics and outcomes after out-of-hospital cardiac arrest (OHCA) in patients with psychiatric illness.

Methods

We searched Embase, Medline, PsycINFO and Web of Science using a comprehensive electronic search strategy to identify observational studies reporting on OHCA incidence, characteristics or outcomes by psychiatric illness status. One reviewer screened all titles and abstracts, and a second reviewer screened a random 10%. Two reviewers independently performed data extraction and quality assessment.

Results

Our search retrieved 11,380 studies, 10 of which met our inclusion criteria (8 retrospective cohort studies and two nested case-control studies). Three studies focused on depression, whilst seven included various psychiatric conditions. Among patients with an OHCA, those with psychiatric illness (compared to those without) were more likely to have: an arrest in a private location; an unwitnessed arrest; more comorbidities; less bystander cardiopulmonary resuscitation; and an initial non-shockable rhythm. Two studies reported on OHCA incidence proportion and two reported on survival, showing higher risk, but lower survival, in patients with psychiatric illness.

Conclusion

Psychiatric illness in relation to OHCA incidence and outcomes has rarely been studied and only a handful of studies have reported on OHCA characteristics, highlighting the need for further research in this area. The scant existing literature suggests that psychiatric illness may be associated with higher risks of OHCA, unfavourable characteristics and poorer survival. Future studies should further investigate these links and the role of potential contributory factors such as socioeconomic status and comorbidities.

Bystander interventions and survival after exercise-related sudden cardiac arrest: a systematic review

OBJECTIVE

To evaluate the provision of bystander interventions and rates of survival after exercise-related sudden cardiac arrest (SCA).

DESIGN

Systematic review.

DATA SOURCES

MEDLINE, EMBASE, PubMed, CINAHL, SPORTDiscus, Cochrane Library and grey literature sources were searched from inception to November/December 2020.

STUDY ELIGIBILITY CRITERIA

Observational studies assessing a population of exercise-related SCA (out-of-hospital cardiac arrests that occurred during exercise or within 1 hour of cessation of activity), where bystander cardiopulmonary resuscitation (CPR) and/or automated external defibrillator (AED) use were reported, and survival outcomes were ascertained.

METHODS

Among all included studies, the median (IQR) proportions of bystander CPR and bystander AED use, as well as median (IQR) rate of survival to hospital discharge, were calculated.

RESULTS

A total of 29 studies were included in this review, with a median study duration of 78.7 months and a median sample size of 91. Most exercise-related SCA patients were male (median: 92%, IQR: 86%-96%), middle-aged (median: 51, IQR: 39-56 years), and presented with a shockable arrest rhythm (median: 78%, IQR: 62%-86%). Bystander CPR was initiated in a median of 71% (IQR: 59%-87%) of arrests, whereas bystander AED use occurred in a median of 31% (IQR: 19%-42%) of arrests. Among the 19 studies that reported survival to hospital discharge, the median rate of survival was 32% (IQR: 24%-49%). Studies which evaluated the relationship between bystander interventions and survival outcomes reported that both bystander CPR and AED use were associated with survival after exercise-related SCA.

CONCLUSION

Exercise-related SCA occurs predominantly in males and presents with a shockable ventricular arrhythmia in most cases, emphasising the importance of rapid access to defibrillation. Further efforts are needed to promote early recognition and a rapid bystander response to exercise-related SCA.

Gastrointestinal bleeding is associated with higher in-hospital mortality, longer length of stay and higher cost in patients with in-hospital cardiac arrest

Background

In-hospital cardiac arrest (IHCA) carries a high mortality and significant morbidity in survivors. Gastrointestinal bleeding (GIB) can complicate cardiac arrests. We aim to study the association between GIB and the in-hospital outcomes of patients with IHCA.

Methods and results

The National Inpatient Sample 2016–2018 databases were used. IHCA were identified using ICD-10-PCS code for cardiopulmonary resuscitation. Other diagnoses including GIB were identified using ICD-10-CM codes. Multivariate logistic regression was used to study the effect of GIB on in-hospital mortality. Gamma regression with log link was used to determine the effect of GIB on length of stay and cost of admission. In patients with IHCA, GIB as a secondary diagnosis is associated with an increased in hospital mortality (unadjusted 74.2% vs 68.3%, adjusted OR 1.17, 95% confidence interval [CI] 1.09–1.25, p < 0.001), longer length of stay (unadjusted median 16 vs 10 days, IQR 9–27 vs 5–17 days, exponentiated coefficient 1.45, 95% CI 1.36–1.54, p < 0.001 for survivors; unadjusted median 4 vs 3 days, IQR 1–10 vs 1–7 days, exponentiated coefficient 1.27, 95% CI 1.22–1.34, p < 0.001 for patients who died in hospital), and higher cost for hospital stay (unadjusted median $226065 vs $151459, IQR $117551–434003 vs $76197–287846, exponentiated coefficient 1.40, 95% CI 1.32–1.49, p < 0.001 for survivors; unadjusted median $87996 vs $77056, IQR $42566–186677 vs $34066–149009, exponentiated coefficient 1.26, 95% CI 1.20–1.32, p < 0.001 for patients who died in hospital) adjusted for baseline characteristics and other comorbidities.

Conclusions

In patients with IHCA, GIB as a secondary diagnosis is associated with a higher in-hospital mortality, longer length of stay and higher cost for the admission.

Response Time Threshold for Predicting Outcomes of Patients with Out-of-Hospital Cardiac Arrest

Ambulance response time is a prognostic factor for out-of-hospital cardiac arrest (OHCA), but the impact of ambulance response time under different situations remains unclear. We evaluated the threshold of ambulance response time for predicting survival to hospital discharge for patients with OHCA. A retrospective observational analysis was conducted using the emergency medical service (EMS) database (January 2015 to December 2019). Prehospital factors, underlying diseases, and OHCA outcomes were assessed. Receiver operating characteristic (ROC) curve analysis with Youden Index was performed to calculate optimal cut-off values for ambulance response time that predicted survival to hospital discharge. In all, 6742 cases of adult OHCA were analyzed. After adjustment for confounding factors, age (odds ratio [OR] = 0.983, 95% confidence interval [CI]: 0.975-0.992, p < 0.001), witness (OR = 3.022, 95% CI: 2.014-4.534, p < 0.001), public location (OR = 2.797, 95% CI: 2.062-3.793, p < 0.001), bystander cardiopulmonary resuscitation (CPR, OR = 1.363, 95% CI: 1.009-1.841, p=0.044), EMT-paramedic response (EMT-P, OR = 1.713, 95% CI: 1.282-2.290, p < 0.001), and prehospital defibrillation using an automated external defibrillator ([AED] OR = 3.984, 95% CI: 2.920-5.435, p < 0.001) were statistically and significantly associated with survival to hospital discharge. The cut-off value was 6.2 min. If the location of OHCA was a public place or bystander CPR was provided, the threshold was prolonged to 7.2 min and 6.3 min, respectively. In the absence of a witness, EMT-P, or AED, the threshold was reduced to 4.2, 5, and 5 min, respectively. The adjusted OR of EMS response time for survival to hospital discharge was 1.217 (per minute shorter, CI: 1.140-1299, p < 0.001) and 1.992 (<6.2 min, 95% CI: 1.496-2.653, p < 0.001). The optimal response time threshold for survival to hospital discharge was 6.2 min. In the case of OHCA in public areas or with bystander CPR, the threshold was prolonged, and without witness, the optimal response time threshold was shortened.

Cardiac arrest in older adult patients

PURPOSE OF REVIEW

To describe the epidemiology, prognostication, and treatment of out- and in-hospital cardiac arrest (OHCA and IHCA) in elderly patients.

RECENT FINDINGS

Elderly patients undergoing cardiac arrest (CA) challenge the appropriateness of attempting cardiopulmonary resuscitation (CPR). Current literature suggests that factors traditionally associated with survival to hospital discharge and neurologically intact survival after CA cardiac arrest in general (e.g. presenting ryhthm, bystander CPR, targeted temperature management) may not be similarly favorable in elderly patients. Alternative factors meaningful for outcome in this special population include prearrest functional status, comorbidity load, the specific age subset within the elderly population, and CA location (i.e., nursing versus private home). Age should therefore not be a standalone criterion for withholding CPR. Attempts to perform CPR in an elderly patient should instead stem from a shared decision-making process.

SUMMARY

An appropriate CPR attempt is an attempt resulting in neurologically intact survival. Appropriate CPR in elderly patients requires better risk classification. Future research should therefore focus on the associations of specific within-elderly age subgroups, comorbidities, and functional status with neurologically intact survival. Reporting must be standardized to enable such evaluation.

Association between prehospital prognostic factors on out-of-hospital cardiac arrest in different age groups

Background

The prognosis of out-of-hospital cardiac arrest (OHCA) is very poor. While several prehospital factors are known to be associated with improved survival, the impact of prehospital factors on different age groups is unclear. The objective of the study was to access the impact of prehospital factors and pre-existing comorbidities on OHCA outcomes in different age groups.

Methods

A retrospective observational analysis was conducted using the emergency medical service (EMS) database from January 2015 to December 2019. We collected information on prehospital factors, underlying diseases, and outcome of OHCAs in different age groups. Kaplan-Meier type survival curves and multivariable logistic regression were used to analyze the association between modifiable pre-hospital factors and outcomes.

Results

A total of 4188 witnessed adult OHCAs were analyzed. For the age group 1 (age ≦75 years old), after adjustment for confounding factors, EMS response time (odds ratio [OR] = 0.860, 95% confidence interval [CI]: 0.811–0.909, p < 0.001), public location (OR = 1.843, 95% CI: 1.179–1.761, p < 0.001), bystander CPR (OR = 1.329, 95% CI: 1.007–1.750, p = 0.045), attendance by an EMT-Paramedic (OR = 1.666, 95% CI: 1.277–2.168, p < 0.001), and prehospital defibrillation by automated external defibrillator (AED)(OR = 1.666, 95% CI: 1.277–2.168, p < 0.001) were prognostic factors for survival to hospital discharge in OHCA patients. For the age group 2 (age > 75 years old), age (OR = 0.924, CI:0.880–0.966, p = 0.001), EMS response time (OR = 0.833, 95% CI: 0.742–0.928, p = 0.001), public location (OR = 4.290, 95% CI: 2.450–7.343, p < 0.001), and attendance by an EMT-Paramedic (OR = 2.702, 95% CI: 1.704–4.279, p < 0.001) were independent prognostic factors for survival to hospital discharge in OHCA patients.

Conclusions

There were variations between younger and older OHCA patients. We found that bystander CPR and prehospital defibrillation by AED were independent prognostic factors for younger OHCA patients but not for the older group.

Relative long-term survival in out-of-hospital cardiac arrest: Is it really improving?

AIM

To describe the long-term survival of out-of-hospital cardiac arrest (OHCA) patients and to determine whether survival is improving in comparison to the general age- and sex-matched population.

METHODS

We utilised the St John Western Australia (WA) OHCA database to retrospectively identify patients aged ≥16 years who experienced an OHCA within the Perth metropolitan area between 1998 and 2017 and survived for at least 30-days post arrest. Patients were excluded if their primary residence was not WA, they did not have an emergency medical services attempted resuscitation (or bystander defibrillation) or did not have an arrest of medical aetiology. Relative survival ratios stratified by decade of arrest were calculated by dividing observed survival of the study cohort by the expected survival of an age- and sex-matched cohort estimated from the Australian Bureau of Statistics life tables for WA.

RESULTS

The OHCA patients who initially survived to 30-days experienced a modest reduction in long-term survival, with 84% (95% CI, 78-90) of patients surviving to 10-years relative to the age- and sex-matched general population. The 10-year relative survival increased from 76% (95% CI, 67-85) to 92% (95% CI, 84-100) between the first (1998-2007) and second (2008-2017) decade of our study.

CONCLUSION

Relative long-term survival prospects for initial OHCA survivors are moderately lower than that of the general population, however these differences have reduced over time and may be approaching those of the general population.

Association between prehospital prognostic factors and out-of-hospital cardiac arrest: Effect of rural-urban disparities

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and a highly variable survival rate. Few studies have focused on outcomes in rural and urban groups while also evaluating underlying diseases and prehospital factors for OHCAs.

OBJECTIVE

To investigate the relationship between the patient's underlying disease and outcomes of OHCAs in urban areas versus those in rural areas.

METHODS

We reviewed the emergency medical service (EMS) database for information on OHCA patients treated between January 2015 and December 2019, and collected data on pre-hospital factors, underlying diseases, and outcomes of OHCAs. Univariate and multivariate logistic regression analyses were used to evaluate the prognostic factors for OHCA.

RESULTS

Data from 4225 OHCAs were analysed. EMS response time was shorter and the rate of attendance by EMS paramedics was higher in urban areas (p < 0.001 for both). Urban area was a prognostic factor for >24-h survival (odds ratio [OR] = 1.437, 95% confidence interval [CI]: 1.179-1.761). Age (OR = 0.986, 95% CI: 0.979-0.993). EMS response time (OR = 0.854, 95% CI: 0.811-0.898), cardiac arrest location (OR = 2.187, 95% CI: 1.707-2.795), attendance by paramedics (OR = 1.867, 95% CI: 1.483-2.347), and prehospital defibrillation (OR = 2.771, 95% CI: 2.154-3.556) were independent risk factors for survival to hospital discharge, although the influence of an urban area was not significant (OR = 1.211, 95% CI: 0.918-1.584).

CONCLUSIONS

Compared with rural areas, OHCA in urban areas are associated with a higher 24-h survival rate. Shorter EMS response time and a higher probability of being attended by paramedics were noted in urban areas. Although shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics were associated with a higher rate of survival to hospital discharge, urban area was not an independent prognostic factor for survival to hospital discharge in OHCA patients.