Out of hospital cardiac arrests--the experience of one hospital in Singapore

Community Socioeconomic Status and Dispatcher-Assisted Cardiopulmonary Resuscitation for Patients with Out-of-Hospital Cardiac Arrest

Few studies have investigated the association between dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) performance and the outcomes of out-of-hospital cardiac arrest (OHCA) among communities with different socioeconomic statuses (SES). A retrospective cohort study was conducted using an Utstein-style population OHCA database in Tainan, Taiwan, between January 2014 and December 2015. SES was defined based on real estate prices. The outcome measures included the achievement of return of spontaneous circulation (ROSC) and the performance of DA-CPR. Statistical significance was set at a two-tailed p-value of less than 0.05. A total of 2928 OHCA cases were enrolled in the high SES (n = 1656, 56.6%), middle SES (n = 1025, 35.0%), and low SES (n = 247, 8.4%) groups. The high SES group had a significantly higher prehospital ROSC rate, ever ROSC rate, and sustained ROSC rate and good neurologic outcomes at discharge (all p < 0.005). The low SES group, compared to the high and middle SES groups, had a significantly longer dispatcher recognition time (p = 0.004) and lower early (≤60 s) recognition rate (p = 0.029). The high SES group, but none of the DA-CPR measures, had significant associations with sustained ROSC in the multivariate regression model. The low SES group was associated with a longer time to dispatcher recognition of cardiac arrest and worse outcomes of OHCA. Strategies to promote public awareness of cardiac arrest could be tailored to neighborhood SES.

Thrombolysis as a Therapeutic Modality in Cardiac Arrest

Introduction

In recent years, thrombolysis has emerged as a potentially promising treatment for cardiac arrest. Patients with cardiac arrests from myocardial infarction or pulmonary embolism, as well as out-of-hospital cardiac arrests, were reported to have improvement in both survival and neurologic outcome after being treated with thrombolysis. This paper aims to review the available literature on the use of thrombolysis in cardiac arrest.

Method

Study of papers from PubMed literature search for all articles with terms related to thrombolysis and cardiac arrest in title or abstract.

Results

Thrombolytics are thought to act by lysing both macroscopic clots and microthrombi, particularly in the cerebral microcirculation, thus alleviating or reversing post-arrest cerebral no-reflow. Their use in cardiac arrest has been restrained by concerns over their safety after cardiopulmonary resuscitation, in particular bleeding-related complications, although these concerns seem to have been misplaced.

Conclusions

Thrombolysis for cardiac arrest is likely to be most efficacious in a pre-hospital environment, and future research should be directed to this setting.

A Six-Year Prospective Study of Out-of-Hospital Cardiac Arrest Managed by a Voluntary Ambulance Organisation

Objective

To obtain a database on the epidemiology of prehospital cardiac arrest and its management by a voluntary ambulance service, with the view for developing future strategies and service improvement.

Design

A 6-year prospective study from December 1998 to November 2004, using the Utstein-style template.

Setting

A voluntary ambulance service in Hong Kong.

Subjects and methods

Ambulance members had to complete and submit a specially designed data form after managing a cardiac arrest case, together with the ambulance run record and the automated external defibrillator (AED) computer printout, if appropriate.

Main outcome measures

Survival to hospital discharge and return of spontaneous circulation after resuscitation.

Results

A total of 72 cardiac arrests occurred during the period, with patients' age ranging from 29 to 106 years (mean 73.4). Most cardiac arrests occurred at home (46 or 63.9%). There were 58 witnessed cardiac arrests (80.5%), but bystander cardiopulmonary resuscitation (CPR) was started in only nine cases (15.5%) before the arrival of the ambulance crew. Six patients had evidence of rigor mortis or dependent lividity on ambulance arrival. For the 61 patients with electrocardiogram strips, the initial presenting rhythm on the AED was asystole in 45 (73.8%), pulseless electrical activity in 5 (8.2%), and ventricular fibrillation (VF) in 11 (18.0%). The median call-to-arrival time for VF cases (4.0 minutes) was significantly shorter than that of non-VF rhythms (8.5 minutes) [Mann-Whitney U test p=0.008]. Five patients had return of spontaneous circulation after resuscitation, but only one survived to hospital discharge.

Conclusions

Bystander CPR and ambulance response time are two areas requiring urgent improvement in our locality. As the majority of cardiac arrests occurred at home, the cost-effectiveness of public access defibrillation for Hong Kong is unclear. However, strategic placement of AED at high incidence' locations should be seriously considered.

Outcome Predictors of Patients in Out-Of-Hospital Cardiac Arrests with Pre-Hospital Defibrillation in Hong Kong

Objective

To report the epidemiology, outcomes and the predictors of survival in patients with out-of-hospital cardiac arrest (OHCA) with pre-hospital shockable cardiac rhythms in Hong Kong.

Methods

It was a prospective study based on data from the cardiac arrest registry of emergency departments (ED) in two regional hospitals in Hong Kong from 1st August 2010 to 31st January 2012. All non-traumatic patients aged 18 years or above presented with OHCA with shockable pre-hospital cardiac rhythm and received pre-hospital defibrillation were included. The characteristics of patients, pre-hospital data, management and outcomes were recorded in a standardised form compatible with Utstein template at the time of patient consultation. Binominal logistic regression was applied to evaluate the relationship between survival to admission (STA) and patients' variables.

Results

A total of 135 patients fulfilled the inclusion criteria. The mean age was 67.0 years old. The STA rate was 34.8% and the survival to discharge (STD) rate was 6.7%. Factors independently associated with better prognosis in terms of STA were presence of bystander cardiopulmonary resuscitation (CPR) (OR 5.76, 95% CI=1.08-30.5), restoration of spontaneous circulation (ROSC) before arrival to ED (OR 43.94, 95% CI= 4.19-460.43) and short time from calling emergency medical services (EMS) to first defibrillation (OR 0.82, 95% CI=0.70-0.96).

Conclusion

STA rate for adults presenting with shockable OHCA in our study was 34.8%. Patients with shockable OHCA with bystander CPR, short call-to-shock time and achieved ROSC before arrival to ED are significantly associated with higher STA rate.

Prehospital Predictors of Initial Shockable Rhythm in Out-of-Hospital Cardiac Arrest: Findings From the Taichung Sudden Unexpected Death Registry (THUNDER)

OBJECTIVE

To identify the incidence and prehospital predictors of ventricular tachycardia/ventricular fibrillation (VT/VF) as the initial arrhythmia in patients with out-of-hospital cardiac arrest (OHCA) in central Taiwan.

PATIENTS AND METHODS

The Taichung Sudden Unexpected Death Registry program encompasses the Taichung metropolitan area in central Taiwan, with a population of 2.7 million and 17 destination hospitals for patients with OHCA. We performed a detailed analysis of demographic characteristics, circumstances of cardiac arrest, and emergency medical service records using the Utstein Style.

RESULTS

From May 1, 2013, through April 30, 2014, resuscitation was attempted in 2013 individuals with OHCA, of which 384 were excluded due to trauma and noncardiac etiologies. Of the 1629 patients with presumed cardiogenic OHCA, 7.9% (n=129) had initial shockable rhythm; this proportion increased to 18.8% (61 of 325) in the witnessed arrest subgroup. Male sex (odds ratio [OR], 2.45; 95% CI, 1.46-4.12; P<.001), age younger than 65 years (OR, 2.39, 95% CI, 1.58-3.62; P<.001), public location of arrest (OR, 4.61; 95% CI, 2.86-7.44; P<.001), and witnessed status (OR, 3.98; 95% CI, 2.62-6.05; P<.001) were independent predictors of VT/VF rhythm.

CONCLUSION

The proportion of patients with OHCA presenting with VT/VF was generally low in this East Asian population. Of the prehospital factors associated with VT/VF, public location of OHCA was the strongest predictor of VT/VF in this population, which may affect planning and deployment of emergency medical services in central Taiwan.

Bystander-initiated CPR in an Asian metropolitan: does the socioeconomic status matter?

OBJECTIVES

To determine the association of neighborhood socioeconomic status (SES) with bystander-initiated cardiopulmonary resuscitation (CPR) and patient outcomes of out of hospital cardiac arrests (OHCAs) in an Asian metropolitan area.

METHODS

We performed a retrospective study in a prospectively collected cohort from the Utstein registry of adult non-traumatic OHCAs in Taipei, Taiwan. Average real estate value was assessed as the first proxy of SES. Twelve administrative districts in Taipei City were categorized into low versus high SES areas to test the association. The primary outcome was bystander-initiated CPR, and the secondary outcome was patient survival status. Factors associated with bystander-initiated CPR were adjusted for in multivariate analysis. The mean household income was assessed as the second proxy of SES to validate the association.

RESULTS

From January 1, 2008 to December 30, 2009, 3573 OHCAs received prehospital resuscitation in the community. Among these, 617 (17.3%) cases received bystander CPR. The proportion of bystander CPR in low-SES vs. high-SES areas was 14.5% vs. 19.6% (p<0.01). Odds ratio of receiving bystander-initiated CPR in low-SES areas was 0.72 (95% confidence interval: [0.60-0.88]) after adjusting for age, gender, witnessed status, public collapse, and OHCA unrecognized by the online dispatcher. Survival to discharge rate was significantly lower in low-SES areas vs. high-SES areas (4.3% vs. 6.8%; p<0.01). All results above remained consistent in the analyses by mean household income.

CONCLUSIONS

Patients who experienced an OHCA in low-SES areas were less likely to receive bystander-initiated CPR, and demonstrated worse survival outcomes.

C ARDIAC A RREST AND R ESUSCITATION E PIDEMIOLOGY IN S INGAPORE (CARE I S TUDY )

OBJECTIVES

To describe the epidemiology of out-of-hospital cardiac arrest (OHCA) in Singapore, the emergency medical services (EMS) response, and to identify possible areas for improvement.

METHODS

This prospective observational study constitutes phase I of the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Included were all patients with nontraumatic OHCA conveyed by the national emergency ambulance service. Patient characteristics, cardiac arrest circumstances, EMS response, and outcomes were recorded according to the Utstein style.

RESULTS

From October 1, 2001, to April 30, 2002, 548 patients were enrolled into the study. Mean (standard deviation [SD]) age was 62.2 (17.9) years, with a male predominance (65.6%). A total of 59.8% of collapses occurred at home, 35.3% of arrests were not witnessed, and bystander cardiopulmonary resuscitation was present for 20.6%. Mean (SD) time from collapse to call received by EMS was 10.6 (13.1) minutes. Mean (SD) EMS response time was 10.2 (4.3) minutes. Mean (SD) time from call to defibrillation was 16.7 (7.2) minutes. Mean (SD) on-scene time was 9.9 (4.5) minutes. First presenting rhythm at the scene was asystole in 54.5%, pulseless electrical activity 22.9%, ventricular fibrillation 19.6%, and ventricular tachycardia 0.4%. Of all cardiac arrests, 351 had resuscitation attempted and were of cardiac origin. Among these patients, 17.9% had return of spontaneous circulation, 8.5% survived to hospital admission, and 2.0% survived to discharge.

CONCLUSION

CARE I establishes the baseline for the evaluation of incremental introduction of prehospital Advanced Cardiac Life Support interventions planned for future phases. Continuing efforts should be made to strengthen all chains of survival. This represents the most comprehensive OHCA study yet conducted in Singapore.

Results of the first five years of the prehospital automatic external defibrillation project in Singapore in the “Utstein style”

In 1994, all emergency medical services (EMS) ambulance officers in Singapore were trained to perform pre-hospital defibrillation with semi-automated external defibrillators (AED). All non-traumatic cardiac arrest patients over 10 years old were included, excluding those who were obviously dead and children below 36 kg. The data were collected by the ambulance officers according to the Utstein guidelines. From 1 February 1994 to 31 January 1999; resuscitation was attempted in 968 non-trauma cardiac arrests. Fifteen percent of the cases were of non-cardiac origin. The overall survival rate was 40/968 (4.1%, 95% CI 2.9-5.6%). Of 968 patients, 22/136 (16.2%, 95% CI 10.4-23.5%), 18/622 (2.9%, 95% CI 1.7-4.5%) and 0/210 (0%, 95% CI 0-1.7%) survived in the EMS witnessed, bystander witnessed and un-witnessed groups, respectively (P < 0.001). Within the EMS witnessed group, those with an initial rhythm of VF/VT had a higher survival rate (30.6%) than those without VF/VT (4.1%). P < 0.001, OR = 10.3, 95% CI 2.9-36.9. Similarly, the VF/VT survival rate in the bystander witnessed group (4.5%) was higher than the non-VF/VT (1.0%) (P = 0.011, OR = 4.4, 95% CI 1.3-15.4). The survival rate of patients with bystander witnessed VF/VT arrest who received bystander CPR was 9.4% compared to 1.0% in those who did not (P = 0.037, OR = 4.4, 95% CI 1.01-20.1). Our survival rate of bystander witnessed VF/VT arrest is comparable to large metropolitan cities in the USA. The determinants of survival include EMS witnessed arrest and VF/VT arrest. Increased quantity and quality of bystander CPR rate may improve the outcome in bystander witnessed cardiac arrest.

Impact of community-wide deployment of biphasic waveform automated external defibrillators on out-of-hospital cardiac arrest in Taipei

OBJECTIVES

To determine the impact and outcome of out-of-hospital cardiac arrests (OHCA) while using automated external defibrillators (AED) with biphasic waveforms and its effectiveness when using the Utstein Style community-wide in Taipei.

MATERIAL AND METHODS

A one-year study was conducted to collect OHCA patients with AED utilization prospectively in Taipei City. All events and variables were recorded in the Utstein Style. Electrocardiography and voice records recovered from AED data cards were analysed. The endpoints were survival outcomes.

RESULTS

Of 653 OHCA patients with AED utilization, only 80 (12.6%) patients with 635 true arrests presented with ventricular fibrillation or tachycardia (VF/VT) as the initial rhythm. The interval between call-to-shock was 5 min longer than call-to-EMS arrival (9.3 min versus 4.0 min). Fourteen (25%) of the 55 witnessed VF/VT arrests survived to home discharge. Ninety-seven percent of shockable rhythms were successfully terminated with less than three shocks. For all OHCA patients, initial rhythm of VF/VT (OR 3.4; 95% CI = 1.2-9.4), witnessed status (OR 4.7; 95% CI = 1.3-16.6), and presence of organised rhythm irrespective of pulse during prehospital resuscitation (OR 9.2; 95% CI = 3.2-26.8) demonstrated an independent association with survival to home discharge. For VF/VT arrests, witnessed status, shorter call-to-shock time, high successful rate of the first shock, fewer averaged number of shocks delivered for each patient, and presence of an organised rhythm during prehospital resuscitation showed a likelihood to predict to predict discharged survival in univariate analysis.

CONCLUSIONS

Low frequency of VF arrests is unique to certain eastern populations but without a reduction of AED shock efficacy with biphasic waveform. Besides initial VF and witnessed status, a prehospital post-shock organized rhythm irrespective of pulse appears to be correlated to survival. Certain circumstances in a congested metropolitan city consume time to deliver shocks even after EMS arrival, and might require bystander or public access defibrillation.

Analysis of clinical outcomes following in-hospital adult cardiac arrest

AIMS

The outcome of in-hospital resuscitation following cardiac arrest depends on many factors related to the patient, the environment and the extent of resuscitation efforts. The aim of the present study was to determine predictors of successful resuscitation and survival to -hospital discharge following in-hospital cardiac arrest and to assess functional outcomes of survivors (cerebral performance scores).

METHODS

Medical records of adult patients sustaining in-hospital cardiac arrest between June 2001 and January 2003 were reviewed. Successful resuscitation was defined as the return of spontaneous circulation at the completion of resuscitative efforts, irrespective of degree of inotropic/vasopressor support. Thirty demographic and clinical variables were analysed to determine predictors of successful resuscitation and in-hospital survival.

RESULTS

In 105 patients with cardiac arrest, 46 patients (44%) were successfully resuscitated and 22 (21%) survived to hospital discharge. Predictors of successful resuscitation included a primary cardiac admission diagnosis, monitoring at the time of the arrest, a longer duration of resuscitation and the absence of the need for endotracheal intubation. Patients with ventricular tachycardia/fibrillation were more likely to survive to hospital discharge than those with asystolic or pulseless electrical activity (45 vs 12 vs 20%, P = 0.01). The sole independent predictor of survival to hospital discharge was the absence of the need for endotracheal intubation (odds ratio 0.14, 95% confidence interval 0.02-0.88, P < 0.01). The majority of survivors (73%) had normal cerebral performance scores.

CONCLUSIONS

Identification of predictors of successful resuscitation following cardiac arrest is important for risk stratification. Ongoing appraisal of in-hospital cardiac arrests through a multicentre registry could improve clinical outcomes.

Resuscitation for patients with out-of-hospital cardiac arrest: Singapore

AIM

To evaluate characteristics and outcome of out-of-hospital cardiac arrest (OHCA) patients presenting to the Emergency Department (ED), and to examine factors that could be used to determine to prolong or abort resuscitation for these patients.

METHOD

All OHCA patients presenting to the ED were studied over a three-month period from November 2001 through January 2002. Patient with traumatic cardiac arrest were excluded. Data were collected from the ambulance case records, ED resuscitation charts, and the ED Very High Frequency (VHF) radio case-log sheet. Information collected included the patient's demographic characteristics, timings (time from call to ambulance arrival on scene, time from arrival at scene to departure from scene, time from scene to arrival in the ED) recorded in the pre-hospital setting, the outcome of the resuscitation, and the final outcome for patients who survived ED resuscitation.

RESULTS

Ninety-three non-traumatic patients with an OHCA were studied during the three-month period. Of the 93 patients, 15 (16.1%) survived ED resuscitation, and one survived to hospital discharge. There were no statistically significant differences for age, race, or gender with regards to the outcome of the resuscitation. The initial cardiac rhythms were asystole (65), pulseless electrical activity (21), and ventricular fibrillation (7). Fourteen (15%) received bystander cardiopulmonary resuscitation (CPR). All seven patients with return of spontaneous circulation (ROSC) on arrival in the ED survived ED resuscitation. The ambulance took an average of 11.80 +/- 3.36 minutes for the survivors and 11.8 +/- 4.22 minutes for the non-survivors from the time of call to get to these patients. The average of the scene times was 12.5 +/- 4.61 minutes for the survivors and 12.0 +/- 4.02 minutes for the non-survivors. Transport time from the scene to the ED took an average of 39.1 +/- 8.32 minutes for the survivors and 37.2 +/- 9.00 minutes for the non-survivors.

CONCLUSION

The survival rate for patients with OHCA after ED resuscitation is similar to the results from other studies. There is a need to increase the awareness and delivery of basic life support by public education. Automatic External Defibrillators (AED) should be available widely to ensure that the chance of early defibrillation is increased. Prolonged resuscitation efforts appear to be futile for OHCA patients if the time from cardiac arrest until arrival in the ED is > or = 30 minutes coupled with no ROSC, and if continuous asystole has been documented for > 10 minutes.