Unwitnessed Out-of-Hospital Cardiac Arrest: Is Resuscitation Worthwhile?

doi:10.1016/S0196-0644(97)70114-8

Annals of Emergency Medicine

Volume 30, Issue 1, July 1997, Pages 69-75

https://doi.org/10.1016/S0196-0644(97)70114-8 Get rights and content

Abstract

Study objective: To determine the epidemiology of unwitnessed out-of-hospital cardiac arrest and the factors associated with survival after resuscitation using the Utstein style data collection. Methods: We conducted a prospective cohort study in a 525,000-population city served by a single EMS system comprising a tiered response with physicians in the field. We studied consecutive unwitnessed out-of-hospital cardiac arrests that occurred between January 1, 1994, and December 31, 1995. We determined survival from cardiac arrest to discharge from hospital and the factors associated with survival. Results: Of the 809 patients for whom resuscitation was considered, 205 (25.3%) had sustained unwitnessed arrests. Cardiac origin of arrest was verified in 52% of cases. The most common noncardiac causes of arrest were trauma, intoxication, near-drowning, and hanging. In 150 patients (73.2%) the presenting rhythm was asystole, in 28 (13.6%) it was pulseless electrical activity, and in 27 (13.2%) it was ventricular fibrillation. Resuscitation was attempted in 162 cases, 59 (36.4%) of whom demonstrated return of spontaneous circulation; 45 (27.8%) were hospitalized alive, and 8 (4.9%) were discharged. The survivors represented 6.7% of all out-of-hospital cardiac arrest survivors during the study period. Survival was most likely if patients presented with pulseless electrical activity; none of the patients with asystole of cardiac origin survived. Sex (P=.032), age (inverse relationship, P=.0004), scene of collapse (P=.042), and interval from call receipt to arrival of first responders (P=.004) were associated with survival. In a logistic-regression model, near-drowning remained an independent factor of survival (odds ratio, 15.5; 95% confidence interval, 1.2 to 200). A routine priority dispatching protocol differentiated cardiac arrest patients with survival potential from those who already had irreversible signs of death. Conclusion: This survey shows that survival after unwitnessed out-of-hospital cardiac arrest is unlikely with an initial response of basic life support alone. Withdrawal of resuscitation should be considered if an adult victim of unwitnessed cardiac arrest is found in asystole and the arrest is of obvious cardiac origin. [Kuisma M, Jaara K: Unwitnessed out-of-hospital cardiac arrest: Is resuscitation worthwhile? Ann Emerg Med July 1997;30:69-75.]

Section snippets

INTRODUCTION

Witnessed collapse, in contrast to unwitnessed collapse, has been shown to be a major determinant of survival after sudden out-of-hospital cardiac arrest.1, 2, 3 Patients who sustain unwitnessed arrests, in whom the survival rate is low despite the effort expended in resuscitation attempts, represent approximately one third of the total cardiac arrest population.² However, some subgroups among the population of unwitnessed cardiac arrest may benefit from resuscitation. In this study our goal

MATERIALS AND METHODS

Helsinki, the capital of Finland, has a population of 525,000 and a geographic area of 590 km². On workdays the population swells by approximately 10%. Approximately one third of the population is younger than 16 years (16%) or older than 65 years (13.9%).

The Helsinki 112 Dispatching Center—which receives calls for medical, fire, and rescue emergencies—dispatches 34,000 urgent medical calls annually.³ The center also serves the surrounding province of Uusimaa, increasing the population served

RESULTS

The total number of deaths from all causes in Helsinki during the study period was 1,012/100,000 inhabitants/year. Resuscitation was considered (no irreversible signs of death) for 809 out-of-hospital patients, 205 of whom (25.3%) sustained unwitnessed cardiac arrest. The mean±SD age of the patients was 56.7±21.2 years; 144 (70.2%) were men. Eight (3.9%) were younger than 16 years.

In 162 of the 205 cases, resuscitation was attempted, and 59 of the 162 (36.4%) demonstrated ROSC. Forty-five

DISCUSSION

Survival of unwitnessed out-of-hospital cardiac arrest was low (4.9% of patients were discharged alive from the hospital) as expected, although not so near zero as the rates in most studies (Table 3). The survivors represented a small subset of all survivors of out-of-hospital cardiac arrest (6.7%), in accordance with the findings of most previous studies.2, 3, 7, 8 In only one study have the survivors of unwitnessed cardiac arrest been reported to represent a remarkable proportion of all

Acknowledgements

We thank Per Rosenberg, MD, PhD, for valuable comments; Anneli Ojajärvi, MSc, for statistical review; and the Laerdal Foundation and Finnish Society of Intensive Care for financial support.

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Unwitnessed out-of-hospital cardiac arrest is associated with low survival chances because of the delayed activation of the emergency medical system in most cases. Automated cardiac arrest detection and alarming using biosensor technology would offer a potential solution to provide early help. We developed and validated an algorithm for automated circulatory arrest detection using wrist-derived photoplethysmography from patients with induced circulatory arrests.
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The automated detection of induced circulatory arrests using wrist-derived photoplethysmography is feasible with good sensitivity and low false positives. These promising findings warrant further development of this wearable technology to enable automated cardiac arrest detection and alarming in a home setting.
Dutch Heart Foundation (Hartstichting).
Cardiac arrest with initial arrest rhythm of pulseless electrical activity: Do rhythm characteristics correlate with outcome?
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Citation Excerpt :
To our knowledge, this is the only study exploring the association of cardiac rhythm characteristics and outcome after PEA cardiac arrest. Pulseless electrical activity is a disease with high mortality and diverse etiologies [4-10]. Often, a standardized treatment algorithm is deployed that is the same for each patient in PEA regardless of the etiology, particularly in the prehospital setting, due to the time critical nature of the disease and lack of a clear identifiable etiology during resuscitation [13].
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This is a retrospective review of patients with PEA out-of-hospital cardiac arrest with first documented cardiac rhythm of PEA from January 2010 to September 2013. Demographic, arrest and initial rhythm characteristics, and patient outcome were abstracted via systematic chart review. The initial 20 seconds of each rhythm strip were used to ascertain electrical rate and QRS width. Primary outcome was survival to hospital discharge. Four hundred fourteen patients were eligible for the study. One hundred fifty-two patients did not have sufficient data for analysis. Two hundred sixty-two patients were included in the final analysis with mean age, 66 years. There were 23 (8.8%) survivors and 17 (6.5%) neurologically intact survivors. Mean heart rate was 58 (confidence interval, 54-63) beats per minute, and mean QRS interval was 100 (confidence interval, 95-106) milliseconds. Twenty-nine point seven percent of patients had wide QRS complexes, and 70.3% were narrow. There was no difference in survival in patients based on heart rate (13.1% vs 7.4%, P = .16) or QRS interval (8.7% vs 7.7%, P = .79).
In this single emergency medical services agency study, neither PEA electrical rate nor QRS width correlated with survival or neurologic outcome.
Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms
2013, Resuscitation
Citation Excerpt :
Historically, the relative success of defibrillation at correcting shockable forms of cardiac arrest has resulted in a strong emphasis on the treatment of patients with both ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). In contrast, due to their poor prognoses both pulseless electrical activity (PEA) and asystole are often considered non-survivable rhythms.1–5 The nature of cardiac care and resuscitation has been shifting over the last 50 years and EMS systems have observed a steady decrease in the incidence of shockable rhythms (VF and pulseless VT) in cardiac arrest.
Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.
To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.
Secondary analysis of data in Epistry – Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.
A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p = 0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60–1.30).
For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.
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We used the Coronary Heart Disease Policy Model, a Markov model of the US population between 35 and 84 years of age, and US Census projections to model the age structure of the population between 2010 and 2040.
Assuming no substantive changes in risks factors or treatments, incident coronary heart disease is projected to increase by approximately 26%, from 981,000 in 2010 to 1,234,000 in 2040, and prevalent coronary heart disease by 47%, from 11.7 million to 17.3 million. Mortality will be affected strongly by the aging population; annual coronary heart disease deaths are projected to increase by 56% over the next 30 years, from 392,000 to 610,000. Coronary heart disease-related health care costs are projected to rise by 41% from $126.2 billion in 2010 to $177.5 billion in 2040 in the United States. It may be possible to offset the increase in disease burden through achievement of Healthy People 2010/2020 objectives or interventions that substantially reduce obesity, blood pressure, or cholesterol levels in the population.
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2011, Journal of Pediatrics
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We used a simulation model to combine several data sources to project the lifetime costs and cardiovascular outcomes for a cohort of 15-year-old U.S. adolescents under different BP approaches and conducted cost-effectiveness analysis. We obtained BP distributions from the National Health and Nutrition Examination Survey 1999–2004 and used childhood-to-adult longitudinal correlation analyses to simulate the tracking of BP. We then used the coronary heart disease policy model to estimate lifetime coronary heart disease events, costs, and quality-adjusted life years (QALY).
Among screen-and-treat strategies, finding and treating the adolescents at highest risk (eg, left ventricular hypertrophy) was most cost-effective ($18000/QALY [boys] and $47000/QALY [girls]). However, all screen-and-treat strategies were dominated by population-wide strategies such as salt reduction (cost-saving [boys] and $650/QALY [girls]) and increasing physical education ($11000/QALY [boys] and $35000/QALY [girls]).
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Out-of-Hospital Unwitnessed Cardiopulmonary Collapse and No-Bystander CPR: A Practical Addition to Resuscitation Termination Guidelines
2008, Journal of Emergency Medicine
Citation Excerpt :
In 2004, Haukoos et al. reported that unwitnessed arrest could predict lack of survival with a Glasgow Coma Score above 12, which supports the data presented in this study (12). A prospective Finnish study also showed unlikely survival to hospital discharge after unwitnessed cardiopulmonary collapse in an EMS system that included physician responders in the field (7). From the opposite perspective, the data we report are consistent with multiple studies that show increased survival when cardiopulmonary collapse is witnessed and there is bystander CPR (7–10,19–24).
Cardiopulmonary resuscitation (CPR) provides possible survival from otherwise fatal cardiopulmonary collapse. Termination guidelines have been developed for use when resuscitation has no potential benefit for a victim. The purpose of this prospective cohort study was to determine if unwitnessed collapse combined with no-bystander cardiopulmonary resuscitation would support a decision to terminate attempted resuscitation. There were 541 patients analyzed during 6 months, with functional neurological survival the outcome of interest. There were no functional neurological survivors at hospital discharge among the 180 victims in the unwitnessed, no-bystander CPR subgroup (95% confidence interval [CI] 0.0%–2.1%). Functional neurological survival for witnessed collapse, bystander CPR was 6.0% (95% CI 2.8%–12.5%), for witnessed collapse, no-bystander CPR was 3.8% (95% CI 1.9%–7.7%), and for unwitnessed collapse, bystander CPR 1.3% (95% CI 0.2%–6.9%). With confirmation by further studies, unwitnessed collapse and lack of bystander CPR may be a practical addition to resuscitation termination guidelines.

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^☆: From the Helsinki City Emergency Medical Services, Helsinki, Finland.

^☆☆: Supported by the Laerdal Foundation and the Finnish Society of Intensive Care.

^★: Reprint no. 47/1/81675

^★★: Address for reprints: Markku Kuisma, MD, MQ Helsinki City EMS, Agricolankatu 15 A, FIN00530 Helsinki, Finland

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Unwitnessed Out-of-Hospital Cardiac Arrest: Is Resuscitation Worthwhile?☆,☆☆,★,★★

Abstract

Section snippets

INTRODUCTION

MATERIALS AND METHODS

RESULTS

DISCUSSION

Acknowledgements

Am J Emerg Med

Ann Emerg Med

Ann Emerg Med

Lancet

Resuscitation

Resuscitation

Am J Emerg Med

Resuscitation

Ann Emerg Med