Sudden cardiac arrest in Israel: factors associated with successful resuscitation

Extreme temperature and out-of-hospital-cardiac-arrest. Nationwide study in a hot climate country

BACKGROUND

Out-of-hospital-cardiac arrest (OHCA) is frequently linked to environmental exposures. Climate change and global warming phenomenon have been found related to cardiovascular morbidity, however there is no agreement on their impact on OHCA occurrence. In this nationwide analysis, we aimed to assess the incidence of the OHCA events attended by emergency medical services (EMS), in relation to meteorological conditions: temperature, humidity, heat index and solar radiation.

METHODS

We analyzed all adult cases of OHCA in Israel attended by EMS during 2016-2017. In the case-crossover design, we compared ambient exposure within 72 h prior to the OHCA event with exposure prior to the four control times using conditional logistic regression in a lag-distributed non-linear model.

RESULTS

There were 12,401 OHCA cases (68.3% were pronounced dead-on-scene). The patients were on average 75.5 ± 16.2 years old and 55.8% of them were males. Exposure to 90th and 10th percentile of temperature adjusted to humidity were positively associated with the OHCA with borderline significance (Odds Ratio (OR) =1.20, 95%CI 0.97; 1.49 and OR 1.16, 95%CI 0.95; 1.41, respectively). Relative humidity below the 10th percentile was a risk factor for OHCA, independent of temperature, with borderline significance (OR = 1.16, 95%CI 0.96; 1.38). Analysis stratified by seasons revealed an adverse effect of exposure to 90th percentile of temperature when estimated in summer (OR = 3.34, 95%CI 1.90; 3.5.86) and exposure to temperatures below 10th percentile in winter (OR = 1.75, 95%CI 1.23; 2.49). Low temperatures during a warm season and high temperatures during a cold season had a protective effect on OHCA. The heat index followed a similar pattern, where an adverse effect was demonstrated for extreme levels of exposure.

CONCLUSIONS

Evolving climate conditions characterized by excessive heat and low humidity represent risk factors for OHCA. As these conditions are easily avoided, by air conditioning and behavioral restrictions, necessary prevention measures are warranted.

The influence of female gender on cardiac arrest outcomes: a systematic review of the literature

BACKGROUND

Sudden cardiac arrest is an important cause of cardiovascular mortality. The impact of gender on the outcome of cardiac arrest is not clear and data about that is limited.

OBJECTIVE

Understanding the influence of gender on cardiac arrest through a systematic review of the published literature.

METHODS

A search of all published studies in English between January 1970 and May 2013 was performed using the electronic databases PubMed and MEDLINE, using the key words 'cardiac arrest', 'outcome', and 'gender'.

RESULTS

Eleven studies were included in this review, all of which were observational studies conducted using national-based database registries of cardiac arrest. A total of 548,440 patients were enrolled in these studies with 220,646 (40.3%) of them being female patients. In general, there was a lower percentage of women in the reported studies compared to men. Women were older in age and more likely to have non-shockable rhythms as the initial rhythm. Women also had a lower rate of witnessed arrest, a lower rate of bystander resuscitation, a higher rate of survival until hospital admission and a lower rate of in-hospital survival compared to men. Women also had a more favorable one month survival and neurological outcome.

CONCLUSION

In the reported literature female gender seems to offer survival and outcome advantages following out-of-hospital cardiac arrest over male gender. This is in contrast to most other aspects of heart disease in which women tend to have a worse prognosis.

A Prospective Evaluation of Prehospital Patient Assessment by Direct In-field Observation: Failure of ALS Personnel to Measure Vital Signs

We prospectively evaluated the frequency with which advanced life support (ALS) personnel fail to attempt to measure blood pressure (BP) and/or pulse (P) during prehospital patient assessment. A single in-field observer rode on ALS rescue vehicles from 20 Emergency Medical Services (EMS) agencies throughout Arizona during a one-year study (1/89–12/89). Data were collected from urban, suburban, and rural systems. Statistical evaluation was performed by Chi Square analysis with p <0.05 considered significant.

Among 227 patient encounters, BP and/or P measurements were omitted in 84 cases (37.0%). BP and/or P were omitted in 50.0% of children (age <18 years) compared to 26.5% of adults (p=0.023). Among patients who were transported to a hospital, 19.4% had BP omitted compared to 49.1% of those not transported (p=0.00003). Seven of 58 patients in whom TVs were attempted (12.1 %) had BP omitted compared to 54 of 169 patients without IV attempts (32.0%, p=0.0055). Blood Pressure was omitted in 21.9% of patients transported Code 3 and in 24.2% of patients with Glasgow Coma Scale ≤13. Omission of BP occurred more frequently in non-urban agencies (33.9%) than in urban ones (20.0%, p=0.027).

In a statewide evaluation of prehospital patient assessment, failure to measure vital signs (VS) occurred on a frequent basis. Our data indicate that a concerning lack of attention to the most basic details of patient assessment is common. It is possible that failure to measure VS might even happen more frequently during routine patient encounters without an observer present. Medical control physicians must emphasize to EMS personnel the paramount importance of careful assessment to ensure optimal patient care.

Analysis of Prehospital Scene Time and Survival from Out-of-Hospital, Non-Traumatic, Cardiac Arrest

The purpose of this study was to determine whether shorter prehospital scene time (ST) is associated with an increased survival rate in non-traumatic, out-of-hospital, cardiac arrest (CA) in a medium-sized, metropolitan EMS system. Information was retrieved for all adult victims (age ≥18 years) of CA treated and transported by a metropolitan fire department over a 16month period (6/87–9/88). Data were retrieved from the fire department's database, hospital records, and death certificates. Statistical analysis of continuous variables was performed using the two-tailed, Student's t-test and non-parametric evaluations were performed by square analysis with p<0.05 considered significant. Two hundred ninety-eight cases were recorded of which 293 patients (98.3%) had documented ST (study group). Seventy-nine patients (27.0%) had ST <12 minutes, while 214 (73.0%) had ST≥12 minutes. Patients with ST <12 minutes were more likely to have return of spontaneous circulation in the field (26.6% vs. 15.9%, p<0.05) and also were more likely to survive than were patients with ST ≥12 minutes (13.9% vs. 6.5%, p<0.05). Mean ST for survivors was significantly less than for non-survivors (12.8 vs. 15.3 min., p<0.05).

We conclude that, in our system, adult victims of CA with ST <12 minutes are more likely to survive than are patients with longer ST. In addition, the mean ST for survivors is shorter than for non-survivors. It remains unclear whether shorter ST actually has an impact on survival or is merely a reflection of a sub-group with rapid resuscitation and consequently a higher likelihood of survival. Future investigations are needed to determine whether shorter ST actually impacts the likelihood of survival from CA.

Vigilance, awareness and a phone line: 20 years of expediting CPR for enhancing survival after out-of-hospital cardiac arrest. The 'SHL'-Telemedicine experience in Israel

OBJECTIVES

The only large-scale report (1988) by the Israeli national ambulance service Magen David Adom (MDA) on the outcome of cardiac arrest victims who underwent cardiopulmonary resuscitation (CPR) by paramedics called for more frequent and more promptly initiated CPR and shorter time to arrival of paramedic care to improve survival. We report the 1987-2007 experience of resuscitation of out-of-hospital cardiac arrest victims who were 'SHL'-Telemedicine subscribers and who underwent CPR by SHL-Telemedicine mobile intensive care units (MICUs) personnel or under their instructions.

METHODS

'SHL's records of MICU reports and specifics of CPR maneuvers and outcome of resuscitated patients, as recorded by its MICU physicians, were analyzed to determine whether the system enhanced survival.

RESULTS

A total of 1810 'SHL'-Telemedicine subscribers (mean age 76+/-12 years [16-104], 67% males) were resuscitated after cardiac arrest, 597 (33%) were hospitalized and 279 (15.4%) were discharged alive. Factors associated with successful resuscitation included witnessed collapse and documented ventricular fibrillation upon MICU arrival. A history of diabetes, hyperlipidemia, stroke or advanced age adversely affected the outcome. Time from collapse to CPR initiation and duration of CPR correlated significantly with survival. Laymen instructed telephonically by the 'SHL'-Telemedicine center performed CPR on 121 patients: 13 (10%) survived to hospital discharge.

CONCLUSIONS

'SHL'-Telemedicine's policy of bi-monthly contact with its subscribers led to heightened awareness of warning signs and need for rapid summoning of medical assistance in the setting of out-of-hospital sudden cardiac arrest.

Characteristics and short-term survival of individuals with out-of-hospital cardiac arrests in the East Bohemian region

AIM

We describe survival after admission to hospital from out-of-hospital cardiac arrest (OHCA) in the East Bohemian region, according to the Utstein Style guidelines and have identified the main diagnosis including in those who died and had an autopsy.

PATIENT GROUP

Over a period of 29 months we used a questionnaire supplied to 24 rescue stations, to identify 718 individuals (511 men and 207 women, aged 16-97 years) with confirmed cardiac arrest who were considered for resuscitation.

RESULTS

Out of 560 patients in whom cardiopulmonary resuscitation for OHCA of confirmed cardiac aetiology was attempted, 350 patients (62.5%) died in the field and 61 (10.9%) died during transport. Hospital admission was achieved in 149 cases (26.6%) and, of these, 96 patients died. Fifty-three patients (9.5%) were discharged home alive, 36 (6.4%) with an intact CNS. The first monitored rhythm showed asystole in 264 cases (47.1%) followed by ventricular fibrillation in 227 cases (40.5%). The main diagnosis of coronary heart disease (CHD) was established clinically in 467 cases (83.4%). In 175 autopsy reports this diagnosis was noted in 152 cases (86.9%).

CONCLUSION

Of patients resuscitated for OHCA of cardiac aetiology, 9.5% survived to leave the acute hospital. CHD was the principle diagnosis in the entire group and this correlated with the same finding in the group of patients who received an autopsy.

Towards new models of cardiopulmonary resuscitation teaching: the role of practical scenario training on surf lifesavers' perceptions of resuscitation efficacy

INTRODUCTION

Surf lifesavers in Australia undertake numerous resuscitation scenarios in the course of their training and examination. The standard teaching and examination strategy is for the scenario to end with return of spontaneous circulation (ROSC) and then breathing. This study was performed to assess the effect of this training technique on lifesavers' expectation of successful resuscitation and to determine the effect of experience on these expectations.

METHODS

Participants were lifesavers from Surf Life Saving Sydney Northern Beaches (SLSSNB). Data was collected by questionnaire. Questionnaires were applied to newly qualified lifesavers, a random sample of patrolling lifesavers and a strategic group of lifesavers with extensive experience in resuscitation. Anticipation of ROSC was recorded on a visual analogue scale (VAS).

RESULTS

The mean VAS for the expected likelihood of successful resuscitation was 55.0+/-19.2% (95% CI: 51.3-58.6%). Published rates of ROSC range from 9 to 36.4%. Nearly 80% of our respondents expected better than 36.4% chance of ROSC. There was no difference in anticipation of ROSC between the three groups (F=0.41; 2,99df; P=0.67). Time since learning cardiopulmonary resuscitation (CPR) did not affect the expectancy of ROSC (F=0.92; 5,101df; P=0.47). Similarly, the number of resuscitations performed by an individual did not affect anticipation of successful outcome (F=0.13; 3,102df; P=0.94).

CONCLUSIONS

Surf lifesavers in the Sydney Northern Beaches branch have an exaggerated expectation of the chances of successful CPR following cardiac arrest. This expectation did not change with time since learning CPR or participation in actual resuscitations. New models for CPR education need to be investigated.

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.

The epidemiology of out-of-hospital 'sudden' cardiac arrest

It is difficult to assemble data from an out-of-hospital cardiac arrest since there is often lack of objective information. The true incidence of sudden cardiac death out-of-hospital is not known since far from all of these patients are attended by emergency medical services. The incidence of out-of-hospital cardiac arrest increases with age and is more common among men. Among patients who die, the probability of having a fatal event outside hospital decreases with age; i. e. younger patients tend to more often die unexpectedly and outside hospital. Among the different initial arrhythmias, ventricular fibrillation is the most common among patients with cardiac aetiology. The true distribution of initial arrhythmias is not known since several minutes most often elapse between collapse and rhythm assessment. Most patients with out-of-hospital cardiac arrest have a cardiac aetiology. Out-of-hospital cardiac arrests most frequently occur in the patient's home, but the prognosis is shown to be better when they occur in a public place. Witnessed arrest, ventricular fibrillation as initial arrhythmia and cardiopulmonary resuscitation are important predictors for immediate survival. In the long-term perspective, cardiac arrest in connection with acute myocardial infarction, high left ventricular ejection fraction, moderate age, absence of other heart failure signs and no history of myocardial infarction promotes better prognosis. Still there is much to learn about time trends, the influence of patient characteristics, comorbidity and hospital treatment among patients with prehospital cardiac arrest.

Optimizing ventilation in conjunction with phased chest and abdominal compression-decompression (Lifestick) resuscitation

The best method for employment of phased chest and abdominal compression-decompression (Lifestick) cardiopulmonary resuscitation (CPR) has yet to be determined. Of particular concern with using this technique is the combining of ventilation with the phased compressions and decompressions. Twenty domestic swine (50+/-1 kg) were equally divided into four groups. Following 10 min of untreated VF, CPR was begun. Group 1 received Lifestick (LS) CPR with only passive ventilation ('passive'); Group 2 received LS-CPR with synchronized positive pressure ventilations (ppv) at a chest compression ratio of 15:2 (15:2 S); Group 3 had LS-CPR with synchronized ppv at 5:1 (5:1 S); and Group 4 received LS-CPR with asynchronous ppv at 5:1 (5:1 A). Endpoints included hemodynamics, blood gases, minute ventilation, and 24 h outcome. Asynchronous ventilation (5:1 A) had significantly worse hemodynamics including aortic and right atrial systolic, aortic diastolic, and coronary perfusion pressures than the other groups (P<0.05). Passive ventilation had the poorest arterial and mixed venous blood gases (P<0.05), but did not differ from 15:2 S in minute ventilation produced (8 vs 10 l/min). No differences in outcome were seen. The ventilation technique combined with LS-CPR can make a significant difference in hemodynamics as well as ventilation. Optimizing other forms of basic and advanced cardiac life support through different ventilation methods deserves new consideration, including a re-examination of the current single rescuer recommendation of a 15:2 ratio. Optimal ventilation strategy when using the LS device at 60 compressions per min appears to be 5:1 S. Such data is important for conducting clinical trials with this new CPR adjunct.

Avoiding the futility of resuscitation

PURPOSE

To identify patients who should not have resuscitation started or continued.

DESIGN

Multi-disciplinary prospective study.

SUBJECTS

Two hundred forty-one consecutive patients with cardiopulmonary arrests from January 1995 to February 1997 were evaluated, of which 200 were studied.

METHODS

Subjects were studied for age, sex, arrest location, CPR duration, recovery from arrest, hospital discharge, 6 weeks' survival, sepsis and co-morbid conditions.

RESULTS

Overall 69 (34.5%) recovered from the arrest, 24 (12.0%) left the hospital, and 17 (8.5%) survived 6 weeks. Of inpatients, 13.7% (16/117) were alive at 6 weeks in contrast to 1.2% (1/83) of field/emergency room (ER) arrests. Sepsis did not lessen the immediate recovery rate; however, none of 25 septic patients survived hospitalization. Outcomes were not different between men and women or regular floor and ICU/CCU arrests. Age of survivors was the same as non-survivors. Survivors were resuscitated for 18.7+/-16.5 min and non-survivors 33.1+/-18.4 min (P=0.15). The initial rhythm of asystole or the presence of three or more co-morbid conditions had a negative prognosis.

CONCLUSION

CPR survival is problematic, and it is especially poor in field/BR arrests. Emergency squads should terminate CPR for pulseless patients after communicating with the ER physician. Age is not a determinant of recovery or survival. Arrest outside of the hospital, sepsis, three or more co-morbid conditions, previous CPR, asystole or resuscitation for >25 min all decrease the chance of hospital discharge and survival. Instituting or continuing CPR in a great majority of these patients is futile. Families should be so advised.

Innovative pharmacologic approaches to cardiopulmonary resuscitation

The survival rate of patients undergoing cardiopulmonary resuscitation is 5 to 15%. New cardiopulmonary resuscitation treatment approaches under investigation include the use of vasopressin as a vasopressor, amiodarone for the treatment of ventricular tachyarrhythmias, and adenosine antagonists (i.e., theophylline) for bradyasystolic rhythms. More innovative approaches include the use of thyroid hormone and endothelin.

What are we doing in cardiopulmonary resuscitation training in Europe? An analysis of a survey

This study has analysed the status of cardiopulmonary resuscitation (CPR) training in Europe in medical schools, cities in the WHO European Healthy Cities network, and hospitals in the WHO European Health Promoting Hospitals network. Three questionnaires tested by a pilot study were sent in 1996-1997: one to medical school deans, one to the WHO Health Promoting Hospitals Network coordinators and one to the focal points of the WHO Healthy Cities Network. The glossary of terms was taken from the Utstein style guidelines. The 392 medical schools returned 168 questionnaires (43%): 167 teach CPR, 165 basic CPR, 136 advanced CPR and 114 both. The 310 hospitals returned 224 questionnaires and 202 were analysed (65%); 154 train physicians, 184 nurses and 110 nursing students. The 509 cities returned 67 questionnaires (13%); 28 train police officers and 36 fire fighters. A total of 120 institutions train paramedics and 82 lay people. The training hours in basic and advanced CPR vary between medical schools and various professional groups trained in hospitals and cities. More time is devoted to training in advanced CPR than in basic CPR and more in theory than practical training. This survey can be an important incentive for European Organisations to identify priorities in their educational efforts.

Cardiac arrest in Saudi Arabia: a 7-year experience in Riyadh

All out-of-hospital and Emergency Department (ED) cardiac arrests treated at a tertiary care hospital in Riyadh, Saudi Arabia, from 1989 through 1995 were studied. Of patients arresting out-of-hospital, 3.0% received bystander cardiopulmonary resuscitation (CPR), 9.1% had some prehospital CPR, 12.1% were transported via ambulance, and 13.6% had ventricular fibrillation (VF) on ED arrival. In the witnessed arrests (80%), the estimated interval from arrest to initiation of CPR was 21.1 +/- 14.7 min. None of these variables was shown to influence outcome. Survival to hospital discharge from out-of-hospital arrest was 5.1% for adults and 7.4% for children; all had poor neurologic outcome. For patients arresting in the ED, an initial rhythm of ventricular tachycardia (VT) or VF was strongly correlated with survival. Survival from ED arrest was 30.4% in adults, 42.9% in children; all but one had normal neurologic outcome. These results are similar to those reported from large cities and EDs elsewhere. The unique set of variables influencing out-of-hospital care and transportation in Riyadh are discussed, and potential areas for improvement are noted.

Aminophylline in undifferentiated out-of-hospital asystolic cardiac arrest

PRIMARY OBJECTIVE

To determine if the introduction of intravenous aminophylline, a nonspecific adenosine receptor antagonist, into the resuscitation algorithm of asystole will increase return of spontaneous circulation when used in undifferentiated prehospital cardiac arrest.

METHODS

An urban, prehospital, prospective, randomized, double-blind, placebo-controlled trial of nonpregnant normothermic adults suffering nontraumatic out-of-hospital asystolic cardiac arrest. Subjects were treated in accordance with published advanced cardiac life support guidelines and standard pharmacotherapy. They were randomly assigned to receive either placebo or aminophylline along with the initial boluses of atropine and epinephrine. Cardiac rhythms and carotid pulses were monitored throughout the resuscitation.

RESULTS

Eighty-two patients were entered into the trial. Forty-five patients were assigned to the placebo group and 37 received aminophylline. Nine of 45 controls (20%; 95% CI 10-35%) achieved return of spontaneous circulation compared to ten of 37 (27%; 95% CI 14-44%) in the aminophylline group.

CONCLUSIONS

We were not able to show a statistically significant improvement in return of spontaneous circulation when aminophylline was given during the early resuscitation phase of undifferentiated asystolic cardiac arrest in the prehospital setting with this sample size.

Outcome from out-of-hospital cardiac arrest caused by nonventricular arrhythmias: contribution of successful resuscitation to overall survivorship supports the current practice of initiating out-of-hospital ACLS

STUDY OBJECTIVE

Studies indicate that ventricular tachycardia (VT) and ventricular fibrillation (VF) are no longer the most common rhythms initially documented in out-of-hospital sudden cardiac death. Although the outcome from asystole and rhythms designated as pulseless electrical activity (PEA) is reported as poor (approximately 1% survival), resuscitative efforts for these patients are still encouraged. The purpose of this study was to determine the potential contribution that this patient group makes to overall survivorship.

METHODS

During this 2-year prospective study, all patients in cardiopulmonary arrest who were transported to the study institution after out-of-hospital Advanced Cardiac Life Support (ACLS) interventions were considered eligible for inclusion. Patients younger than 18 years of age and those in posttraumatic arrest were excluded. Age, sex, first-documented arrest rhythm, presence of a witness to the arrest, performance of bystander CPR, survival to hospital discharge, and functional status at discharge were recorded.

RESULTS

A total of 197 patients met the inclusion criteria. The initial rhythm was VF/VT in 59 (30%; 95% confidence interval [CI], 24% to 37%) and asystole/PEA in 138 (70%; 95% CI, 64% to 76%). There was 1 hospital survivor in the VT/VF group; 9 patients (7%; 95% CI, 4% to 13%) in the asystole/PEA group survived to hospital discharge. Of the asystole/PEA survivors, 100% (95% CI, 66% to 100%) had a witnessed arrest and 56% (95% CI, 21% to 86%) received bystander CPR. Fifty-six percent (95% CI, 21% to 86%) of the asystole/PEA survivors were discharged at a functional level equivalent to that preceding arrest.

CONCLUSION

In this study, patients in asystole/PEA comprised 90% of the survivors. The outcome for patients with asystole/PEA whose arrest was witnessed and who received bystander CPR may be greater than previously estimated and supports the current practice of initiating aggressive out-of-hospital ACLS in this patient group.

The impact of paramedics on out-of-hospital cardiac arrests in a rural community

OBJECTIVE

To determine whether paramedics influence the outcome of cardiac arrest patients in a rural area.

METHODS

Retrospective analysis of cardiorespiratory arrest patients in rural southeast Alaska from 1987 to 1996.

RESULTS

Paramedics treated 37 patients and advanced life support emergency medical technicians (EMT-IIIs) treated 34 patients. Demographics/CPR variables of the two groups were similar. Return of spontaneous circulation (ROSC) was 46% (17/37) for the paramedic-treated patients and 18% (6/34) for the EMT-III-treated patients (p = 0.01). Intensive care unit (ICU) admission was 38% (14/37) for the paramedic-treated patients and 15% (5/34) for the EMT-III-treated patients (p < 0.03). Discharge from the hospital neurologically intact was 20% (7/35) for the paramedic-treated patients and 9% (3/34) for the EMT-III-treated patients (p = NS). Two patients in the paramedic-treated group had ROSC and survived in the local hospital ICU for several days before being transferred to a tertiary care hospital in another state and were lost to follow-up for the discharge-from-hospital-neurologically-intact category but were included in the ROSC and ICU admission analysis.

CONCLUSION

In this rural setting, a paramedic on the scene significantly improved the ROSC (paramedics = 46% vs 18% for EMT-III, p = 0.01) and survival to ICU admission (38% vs 15%, p = 0.03). The presence of a paramedic on the scene increased survival to hospital discharge neurologically intact (20% vs 9%), although this was not statistically significant.

Circumstances and causes of out-of-hospital cardiac arrest in sudden death survivors

OBJECTIVE

To study the circumstances and medical profile of out-of-hospital sudden cardiac arrest (SCA) patients in whom resuscitation was attempted by the ambulance service, and to identify causes of SCA in survivors and factors that influence resuscitation success rate.

METHODS

During a five year period (1991-95) all cases of out-of-hospital SCA between the ages of 20 and 75 years and living in the Maastricht area in the Netherlands were studied. Information was gathered about the circumstances of SCA, as well as medical history for all patients in whom resuscitation was attempted by the ambulance personnel. Causes of SCA in survivors were studied and logistic regression analysis was performed to identify factors associated with survival.

RESULTS

Of 288 SCA patients in whom cardiopulmonary resuscitation (CPR) and advanced life support were applied, 47 (16%) were discharged alive from the hospital. Their mean (SD) age was 58 (11) years, 37 (79%) were men, and 24 (51%) had a history of cardiac disease. Acute myocardial infarction was diagnosed in 24 (51%) of the survivors; seven with and 17 without a history of cardiac disease. Ventricular fibrillation (VF) or ventricular tachycardia (VT) as the first documented rhythm was significantly positively associated with survival (odds ratio (OR) 5.7, 95% confidence interval (CI) 2.1 to 15.9). A time interval of less than four minutes between the moment of collapse and the start of resuscitation, and an ambulance delay time of less than eight minutes were significantly positively associated with survival (OR 3.3, 95% CI 1.3 to 8.6, and OR, 3.6, 95% CI 1.3 to 10.5, respectively). A history of cardiac disease was negatively associated with survival (OR 0.46, 95% CI 0.21 to 0.98).

CONCLUSIONS

Acute myocardial infarction was the underlying mechanism of SCA in most of the survivors, especially in those without a history of cardiac disease. CPR within four minutes, an ambulance delay time less than eight minutes, and VT or VF diagnosed by the paramedics were positively associated with success.

The psychological consequences of cardiopulmonary resuscitation training for family members of patients at risk for sudden death

OBJECTIVES

The purpose of this study was to determine psychological consequences of teaching cardiopulmonary resuscitation (CPR) to family members of patients at risk for sudden death.

METHODS

Patient-family pairs (n = 337) were randomized into one of four groups: control, CPR only, CPR with cardiac risk factor education, and CPR with a social support intervention. Only family members received CPR training. Data on emotional state and psychosocial adjustment to illness were collected at baseline, 2 weeks, and 3 and 6 months following CPR training.

RESULTS

There were no significant differences in the emotional states of family members across the four groups. However, significant differences in psychosocial adjustment and emotional states occurred in patients across treatment groups following CPR training. Patients whose family members learned CPR with the social support intervention reported better psychosocial adjustment and less anxiety and hostility than patients in the other groups. Control patients reported better psychosocial adjustment and less emotional distress than patients in the CPR-only and CPR-education groups.

CONCLUSIONS

These findings support tailoring family CPR training so that instruction does not result in negative psychological states in patients. The findings also illustrate the efficacy of a simple intervention that combines CPR training with social support.

Unwitnessed out-of-hospital cardiac arrest: is resuscitation worthwhile?

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.

Out-of-hospital cardiac arrests: an 8-year New York City experience

A retrospective study was conducted to determine the outcome of out-of-hospital cardiac arrests by one prehospital system in New York City from January, 1986, through December, 1993. The results were recorded consistent with the Utstein Style. Of 481 attempted patient resuscitations 406 were of cardiac etiology, with 382 patients having arrested prior to EMS arrival; their overall survival rate was 2.1% (8/382). Cardiac arrests were witnessed in 246 patients. Of the witnessed arrest patients found in ventricular fibrillation (96/246), the overall survival rate was 7.3% (7/96). Of the 7 survivors who were discharged from the hospital, 71.4% (5/7) had a good cerebral performance/good overall performance. Of 24 patients who arrested in the presence of EMS, the survival rate was 12.5% (3/24). This study confirms a poor survival rate for patients suffering out-of-hospital cardiac arrests in New York City.

Prehospital cardiac arrest in Leicestershire: targeting areas for improvement

OBJECTIVE

To identify the impact of advanced life support skills on outcome for prehospital cardiac arrest in a defined population and to assess the value of certain physiological variables in predicting the outcome in those successfully resuscitated in the accident and emergency (A&E) department; to identify areas for improvement in the outcome of such patients.

DESIGN

Prospective 12 month study.

SETTING

Leicestershire, United Kingdom.

MAIN OUTCOME MEASURE

Survival to hospital discharge and status at 6 months.

RESULTS

266 patients were identified as having suffered a prehospital cardiac arrest; of these, 86 had their resuscitation attempt terminated in the community by a general practitioner and 180 were transferred to the A&E department of the Leicester Royal Infirmary. Of the latter, 159 were felt to be of cardiac aetiology, and 19 were eventually discharged from hospital. All survivors had experienced a witnessed cardiac arrest, ventricular fibrillation (VF) being identified as the initial rhythm. After adjusting for age and sex using logistic regression, the Glasgow coma score (GCS) was found to be associated with subsequent mortality (chi 2 = 18.22 on 2 df, P < 0.0001). Compared to a baseline GCS of 9-15, the relative odds of death for a GCS of 3 were 25.3 (95% confidence interval 4.3 to 149-9), while a GCS of 4-8 gave a relative odds of death of 12-18 (95% CI 1.8 to 80.2). No significant association was found between postarrest arterial pH and mortality.

CONCLUSIONS

The immediate GCS on admission is a predictor of outcome and it is important to monitor its trend in the first 24 h. Multidisciplinary audit and joint guidelines with other specialties are important in optimising the care of these patients.

Quality of bystander cardiopulmonary resuscitation influences outcome after prehospital cardiac arrest

To evaluate the influence of quality of bystander cardiopulmonary resuscitation (CPR) on outcome in prehospital cardiac arrest we consecutively included patients with prehospital cardiac arrest treated by paramedics in a community run ambulance system in Oslo, Norway from 1985 to 1989. Good CPR was defined as palpable carotid or femoral pulse and intermittent chest expansion with inflation attempts. Outcome measure was hospital discharge rate. One hundred and forty-nine of 334 patients (45%) received bystander CPR. The discharge rate after good BCPR (23%) was higher than after no good BCPR (1%, P < 0.0005) or after no BCPR (6%, P < 0.0005). There was no difference between no good and no BCPR (P = 0.1114). There were no differences in paramedic response interval between the groups, but the mean interval from start of unconsciousness to initiation of CPR (arrest-CPR interval) was significantly shorter in the group receiving good bystander CPR (2.5 min, 95% confidence interval (CI): 1.7-3.3 min) than no good CPR (6.6 min, CI: 5.2-8.0 min) or no bystander CPR (7.8 min, CI: 7.2-8.4 min). Bystanders started CPR more frequently in public than in the patient's home (58 vs. 34%, P < 0.0005). Good bystander CPR was associated with a shorter arrest-CPR interval and improved hospital discharge rate as compared to no good BCPR or no BCPR.

Methodology-dependent variation in documentation of outcome predictors in out-of-hospital cardiac arrest

OBJECTIVE

To identify variation in outcome predictor documentation in out-of-hospital cardiac arrest associated with two different methods of data collection: concurrent questioning of personnel following a resuscitation attempt and archival report review.

METHODS

All patients > or = 18 years old who had out-of-hospital cardiac arrests, verified using the New York City 911 telephone system, between October 1, 1990, and April 1, 1991, were eligible for inclusion. The authors reviewed the first 200 cases of presumed primary cardiac arrest involving a resuscitation attempt among 3,243 consecutive ambulance call reports for cardiac arrest occurring during the study period. This archival data set was compared with data for the same 200 cases gathered through direct interview of field personnel by trained paramedics. The two data sets had been compiled independently by different individuals, using the same data collection instrument, which conformed to the Utstein template.

RESULTS

Comparison of the data obtained from ambulance records with the data obtained from interviews of prehospital personnel revealed several areas of variance. Of note was a significantly lower proportion of bystander-witnessed ventricular fibrillation (VF) in the data set gathered from written reports (7% vs 18%; 95% CI for the difference 4-18%; p = 0.001).

CONCLUSION

differences in methods of collection of out-of-hospital cardiac arrest data are associated with a more than twofold variation in the reported incidences of witnessed cardiac arrests manifesting as VF. Methodology-dependent variation in this important "denominator" may produce substantially different estimates of survival within the same cohort of patients.

Methodology for data collection to study prehospital cardiac arrest in New York City: the PHASE methodology. PreHospital Arrest Survival Evaluation Group

STUDY OBJECTIVE

To describe an effective methodology for the investigation of prehospital cardiac arrest in large cities.

DESIGN

Observational cohort study.

SETTING

New York City emergency medical services system.

PARTICIPANTS

All cardiac arrests dispatched by the 911 system between October 1, 1990, and March 31, 1991.

INTERVENTIONS

Trained paramedics performed immediate postarrest interviews with prehospital and hospital care providers using a standardized data collection instrument.

RESULTS

Of 3,239 consecutive, confirmed cardiac arrests in which resuscitation was attempted, 2,329 (72%) were of cardiac etiology. Information was sought for 15 of the 17 core events and times recommended by the Utstein Consensus Conference Data were obtained in more than 98% of cases for all except one of these core events and times. One core time yielded data in 96% of cases. All patients were followed until death or discharge home. None were lost to follow-up.

CONCLUSION

Concurrent, interactive acquisition of prehospital cardiac arrest data in a large urban setting captured over 98% of the core data recommended for completion of the Utstein template. This methodology may be a suitable means of investigating prehospital cardiac arrest in large cities.

Out-of-hospital cardiac arrest in an Oriental metropolitan city

To investigate the epidemiology of out-of-hospital cardiac arrest in Taipei City, Taiwan, a prospective chart review and follow-up study was conducted by collecting the prehospital cardiac arrest record from 10 designated responsible emergency departments (EDs) from August 1, 1992 through May 31, 1993. Cases with the restoration of spontaneous circulation (ROSC) were followed up until discharged from hospital. The information gathered included age, sex, bystander cardiopulmonary resuscitation, response time (time elapsed from receiving the call to arrival on the scene), advanced cardiac life support (ACLS) time (time elapsed from receiving the call to arrival at the ED), initial cardiac rhythm in the ED, ROSC, survival to discharge from the hospital, underlying disease, past history, personal history, and neurological outcome at discharge. Of 638 out-of-hospital cardiac arrests, 554 (86.7%) were nontraumatic. Response time, ACLS time, ROSC rates, and survival rates were 7.4 minutes, 21.6 minutes, 15.8%, and 1.4%, respectively. In comparing the trauma and nontrauma group, there were significant differences in age, sex, response time, and ACLS time. Between cases of patients who had ROSC and those who died, the data were statistically significant, P = .0143, showing that ACLS time was shorter in the ROSC group (19.5 v 21.9 minutes). In analysis of underlying disease, definite and probable cardiac-origin sudden deaths were found in only 120 patients, which may extend the annual sudden cardiac death rates to be 0.0053%. In conclusion, the low resuscitation and survival rates in this country were because of delayed initiation of both basic life support and ACLS.(ABSTRACT TRUNCATED AT 250 WORDS)

Case definition in survival studies of out-of-hospital cardiac arrest

The purpose of this investigation was to determine problems with case definition and selection biases in studies of survival from out-of-hospital cardiac arrest, by comparing characteristics of subjects with cardiac arrest who entered the emergency medical services (EMS) system and those who did not enter the system. Data for 143 prehospital cardiac arrest patients in Johnson County, Iowa, were obtained from death certificates and EMS reports. Approximately one half of cardiac arrest patients entered the EMS system. Mean total number of causes of death listed on death certificates was significantly higher in subjects who did not enter the EMS system. Several factors, including age, sex, and number of causes of death listed on death certificates were significant univariate factors in whether a cardiac arrest victim entered the EMS system, but multivariate logistic regression indicated age by itself was the most significant factor. These results indicate there are possible initial biases determining who will enter the EMS system, which affects the generalizability of previous studies.

Predicting survival from out-of-hospital cardiac arrest: a graphic model

STUDY OBJECTIVE

To develop a graphic model that describes survival from sudden out-of-hospital cardiac arrest as a function of time intervals to critical prehospital interventions.

PARTICIPANTS

From a cardiac arrest surveillance system in place since 1976 in King County, Washington, we selected 1,667 cardiac arrest patients with a high likelihood of survival: they had underlying heart disease, were in ventricular fibrillation, and had arrested before arrival of emergency medical services (EMS) personnel.

METHODS

For each patient, we obtained the time intervals from collapse to CPR, to first defibrillatory shock, and to initiation of advanced cardiac life support (ACLS).

RESULTS

A multiple linear regression model fitting the data gave the following equation: survival rate = 67%-2.3% per minute to CPR-1.1% per minute to defibrillation-2.1% per minute to ACLS, which was significant at P < .001. The first term, 67%, represents the survival rate if all three interventions were to occur immediately on collapse. Without treatment (CPR, defibrillatory shock, or definitive care), the decline in survival rate is the sum of the three coefficients, or 5.5% per minute. Survival rates predicted by the model for given EMS response times approximated published observed rates for EMS systems in which paramedics respond with or without emergency medical technicians.

CONCLUSION

The model is useful in planning community EMS programs, comparing EMS systems, and showing how different arrival times within a system affect survival rate.

Survival from out-of-hospital cardiac arrest: effects of patient age and presence of 911 Emergency Medical Services phone access

The purpose of this investigation was to determine factors associated with survival from out-of-hospital cardiac arrest, including effects of 911 Emergency Medical Services telephone access and the age of patient. Subjects included 1,753 prehospital cardiac arrest patients in Iowa. Patient survival status and other variables were compared for patients with access to a 911 service with those who did not, and for different age categories, using univariate associations and multivariate logistic regression analysis. The presence of 911 telephone access was significantly associated with survival from out-of-hospital cardiac arrest (9.18% versus 5.35% survival for 911 versus no 911 groups, respectively). This association was partially the result of the significant association of 911 with decreased time from collapse to call for help, decreased time to cardiopulmonary resuscitation (CPR), and decreased time to first shock (if in ventricular fibrillation [VF]). Younger age was significantly associated with survival in univariate analyses (8.94% versus 6.26% survival for younger versus older age groups, respectively), but this was not an independent association, which is indicated by the lack of significance of age in the multivariate model.

Incidence of cardiac arrest: a neglected factor in evaluating survival rates

STUDY OBJECTIVES

To add to our understanding of survival rates in out-of-hospital cardiac arrest studies, we examined the incidence of cardiac arrest in the published literature. We specifically estimated if incidence rates are uniform between communities and if any relationship exists between incidence and the reported survival rates.

DESIGN

A retrospective study of nearly 100 cardiac arrest peer-reviewed articles from 1970 to 1989 was performed to identify reports that included rates for incidence and survival or provided sufficient data for the calculation of these rates.

MEASUREMENTS AND MAIN RESULTS

We were able to obtain reported or calculated incidence and survival rates for 20 communities. Statistical analysis was performed to compare incidence rates between communities and examine the relationship across these 20 studies between incidence rates and reported survival rates. Incidence rates ranged significantly from 35.7 to 128.3 per 100,000, with a mean of 62. Survival rates ranged significantly from 1.6% to 20.7%. Incidence rates in these communities were negatively related to survival rates; that is, as the incidence rate increased, the survival rate decreased. We determined the regression curve that describes this inverse relationship. This nomogram can be used to identify survival/incidence rate combinations that are significantly above or below average.

CONCLUSION

The marked variations in incidence and inverse relationship between incidence and survival could be due to true variation in risk among the populations reported (ie, some populations may be older or sicker than others). Also, different research methodologies may create artifactual differences among studies as standards for designing studies, terminology, and reporting data have not been uniform. Therefore, these findings may reflect methodological differences and true epidemiological differences among communities. Future reports should include a method, such as an incidence/survival nomogram, to analyze survival rates while taking into account the community incidence rate of cardiac arrest. Further analysis of incidence and survival is necessary to improve intersystem comparisons, a prerequisite to sound decisions about cardiac arrest treatment, health policy, and allocation of resources.

Comparison of standard and high-dose adrenaline in the resuscitation of asystole and electromechanical dissociation

Sixty-eight adults with cardiac arrest (asystole and electromechanical dissociation) were randomly allocated for treatment with standard (1 mg) or high-dose epinephrine (5 mg). If the first dose of adrenaline (1 or 5 mg) failed, standardized advanced life-support was applied in all cases. High-dose adrenaline was associated with higher initial resuscitation success rates (16 of 28) than standard-dose adrenaline (6 of 40), whereas hospital discharge rates were not significantly different between the groups. Blood pressure was significantly higher in the high-dose adrenaline group in comparison to the standard dose at 1 and 5 min after resuscitation. Although high-dose adrenaline appears to improve cardiac resuscitation success, the duration of global cerebral ischaemia seems to determine the ultimate outcome.

Outcome of CPR in a large metropolitan area--where are the survivors?

STUDY OBJECTIVES

Survival from out-of-hospital cardiac arrest in cities with populations of more than 1 million has not been studied adequately. This study was undertaken to determine the overall survival rate for Chicago and the effect of previously reported variables on survival, and to compare the observed survival rates with those previously reported.

DESIGN

Consecutive prehospital arrest patients were studied prospectively during 1987.

SETTING

The study area was the city of Chicago, which has more than 3 million inhabitants in 228 square miles. The emergency medical services system, with 55 around-the-clock ambulances and 550 paramedics, is single-tiered and responds to more than 200,000 emergencies per year.

TYPE OF PARTICIPANTS

We studied 3,221 victims of out-of-hospital cardiac arrest on whom paramedics attempted resuscitation.

MEASUREMENTS AND MAIN RESULTS

Ninety-one percent of patients were pronounced dead in emergency departments, 7% died in hospitals, and 2% survived to hospital discharge. Survival was significantly greater with bystander-witnessed arrest, bystander-initiated CPR, paramedic-witnessed arrest, initial rhythm of ventricular fibrillation, and shorter treatment intervals.

CONCLUSIONS

The overall survival rates were significantly lower than those reported in most previous studies, all based on smaller communities; they were consistent with the rates reported in the one comparable study of a large city. The single factor that most likely contributed to the poor overall survival was the relatively long interval between collapse and defibrillation. Logistical, demographic, and other special characteristics of large cities may have affected the rates. To improve treatment of cardiac arrest in large cities and maximize the use of community resources, we recommend further study of comparable metropolitan areas using standardized terms and methodology. Detailed analysis of each component of the emergency medical services systems will aid in making improvements to maximize survival of out-of-hospital cardiac arrest.

Prehospital cardiac arrest: the impact of witnessed collapse and bystander CPR in a metropolitan EMS system with short response times

OBJECTIVE

Numerous studies have shown initiation of bystander CPR to significantly improve survival from prehospital cardiac arrest. However, in emergency medical services (EMS) systems with very short response times, bystander CPR has not been shown to impact outcome. The purpose of this study was to determine the effect of bystander CPR on survival from out-of-hospital cardiac arrest in such a system.

DESIGN

Prehospital, hospital, and death certificate data from a medium-sized metropolitan area were retrospectively analyzed for adult, nontraumatic cardiac arrest during a 16-month period.

RESULTS

A total of 298 patients met study criteria. One hundred ninety-five arrests (65.4%) were witnessed, and 103 (34.6%) were unwitnessed. Twenty-five witnessed victims (12.8%) were discharged alive, whereas no unwitnessed victims survived (P less than .001). Patients suffering a witnessed episode of ventricular fibrillation/tachycardia (VF/VT) were more likely to survive (21.9%) than were other patients (2.0%, P less than .0001). Among witnessed patients, initiation of bystander CPR was associated with a significant improvement in survival (20.0%) compared with the no-bystander CPR group (9.2%, P less than .05). Bystander CPR was also associated with improved outcome when witnessed patients with successful prehospital resuscitation were evaluated as a group; 18 had bystander CPR, of whom 13 (72.2%) survived compared with only 12 of 38 patients with no bystander CPR (31.6%, P less than .01).

CONCLUSION

Our data revealed improved survival rates when bystander CPR was initiated on victims of witnessed cardiac arrest in an EMS system with short response times.

Survival rates from out-of-hospital cardiac arrest: recommendations for uniform definitions and data to report

Survival rates for out-of-hospital cardiac arrest vary widely among locations. We surveyed the definitions used in published studies of out-of-hospital cardiac arrest. Data from 74 studies involving 36 communities showed survival rates ranging from 2% to 44%. There were five different case definitions and 11 different definitions of survivors. The absence of uniform definitions prevents meaningful intersystem comparisons, prohibits explorations of hypotheses about effective interventions, and interferes with the efforts of quality assurance. The most satisfactory numerator for a survival rate appears to be survival to hospital discharge; the most appropriate denominator appears to be witnessed adult cardiac arrest of presumed heart disease etiology, with ventricular fibrillation as the initial identified rhythm. Proposed definitions for the data emergency medical services systems should report as they examine their cardiac arrest survival rates are presented.

The effectiveness of bystander CPR in an animal model

Several clinical studies have yielded conflicting results in examining the effectiveness of bystander CPR (BCPR). The purpose of this pilot study was to determine the effectiveness of BCPR in an animal model of cardiac arrest and resuscitation. Ten swine were instrumented for hemodynamic and regional blood flow measurements with tracer microspheres. After two minutes of ventricular fibrillation (VF), the animals received eight minutes of either BCPR (five) or no-bystander CPR (NBCPR; five). Defibrillation was then attempted in both groups. If unsuccessful, CPR was begun and epinephrine 0.02 mg/kg was administered. Defibrillation was attempted again three and one-half minutes after epinephrine administration. Regional myocardial and cerebral blood flows were measured 30 seconds and five and one-half minutes after initiation of BCPR and one minute after epinephrine administration. In the BCPR group, myocardial blood flow was initially 29.0 +/- 33.2 and decreased to 15.0 +/- 21.5 mL/min/100 g during the last two and one-half minutes of BCPR. Cortical cerebral blood flow was initially 2.0 +/- 2.8 and fell to 0.6 +/- 0.8 mL/min/100 g during the last two and one-half minutes of BCPR. There were no statistical differences in myocardial blood flow and cerebral blood flow between the initial or late stages of BCPR (P greater than .14). There were no statistical differences in myocardial blood flow and cerebral blood flow between BCPR and NBCPR groups after epinephrine administration (P greater than .09).(ABSTRACT TRUNCATED AT 250 WORDS)

Prehospital resuscitation in Helsinki, Finland

Helsinki, a city of 500,000 inhabitants, is served by a two-tiered emergency medical system with basic emergency medical technicians in ordinary ambulances and one physician-staffed prehospital emergency care unit. All 266 patients with prehospital cardiopulmonary resuscitation during 1987 were studied. Two hundred twelve patients with presumed heart disease and a witnessed arrest were analyzed further. Their response times for basic life support and advanced life support were 5.5 and 10.7 minutes, respectively. The initial cardiac rhythm in 144 patients (68%) was ventricular fibrillation. In 79 of these patients, cardiopulmonary resuscitation was successful, and 39 patients (27%) were discharged from hospital. The patients who survived had shorter response times for basic life support and their arrest locations was more often outside home, compared with the nonsurvivors. The results seem comparable with emergency medical systems in the United States, but a need to reduce response times is identified.

Initiation of resuscitation in patients with prehospital bradyasystolic cardiac arrest in Helsinki

The factors influencing the decision to initiate resuscitation in prehospital cardiac arrest patients encountered in bradyasystole due to presumed heart disease were studied. For this purpose, the characteristics and circumstances of arrest of the patients encountered in asystole and electromechanical dissociation, seen by a physician-staffed prehospital emergency care unit in a tiered emergency medical system, were reviewed. During the study period, resuscitation was initiated in 83 bradyasytolic patients. The characteristics of these patients were compared with those of 72 patients in asystole or electromechanical dissociation declared dead on the scene without resuscitation. The presence of EMD was the most important factor influencing the decision to resuscitate (P less than 0.001), even if the arrest was unwitnessed, while the patient's age was of less importance. For the patients with a witnessed arrest, the delay before treatment was initiated also affected the decision. Successful resuscitation and survival of the patients was similar to earlier reports. The results provide guidelines in the decision making of initiation of resuscitation when developing our emergency care system into one with non-physicians as advanced life support providers.

Cardiac arrest and resuscitation: a tale of 29 cities

Published reports of out-of-hospital cardiac arrest give widely varying results. The variation in survival rates within each type of system is due, in part, to variation in definitions. To determine other reasons for differences in survival rates, we reviewed published studies conducted from 1967 to 1988 on 39 emergency medical services programs from 29 different locations. These programs could be grouped into five types of prehospital systems based on the personnel who deliver CPR, defibrillation, medications, and endotracheal intubation; the five systems were three types of single-response systems (basic emergency medical technician [EMT], EMT-defibrillation [EMT-D], and paramedic) and two double-response systems (EMT/paramedic and EMT-D/paramedic). Reported discharge rates ranged from 2% to 25% for all cardiac rhythms and from 3% to 33% for ventricular fibrillation. The lowest survival rates occurred in single-response systems and the highest rates in double-response systems, although there was considerable variation within each type of system. Hypothetical survival curves suggest that the ability to resuscitate is a function of time, type, and sequence of therapy. Survival appears to be highest in double-response systems because CPR is started early. We speculate that early CPR permits definitive procedures, including defibrillation, medications, and intubation, to be more effective.