Follow-up of 514 consecutive patients with cardiopulmonary arrest outside the hospital

Specialist Physician Approaches to Discussing Cardiopulmonary Resuscitation for Frail Older Adults: A Qualitative Study

Background: Despite the impact and importance of end-of-life discussions, little is known about how physicians discuss cardiopulmonary resuscitation (CPR) with patients and their families. The necessary components for successful communication about CPR are poorly understood and an established framework to structure these conversations is lacking. Here, we were motivated to understand how physicians approach resuscitation planning with families when older patients have limited life expectancy and a high burden of illness. Method: Qualitative analysis was conducted of semi-structured interviews of 28 physicians of varying medical sub-specialties in a tertiary care hospital. Results: Most physicians explored the surrogates’ goals and values, but few provided explicit information about the patients’ overall health status or expected long-term health outcome related to CPR and underlying illnesses. Conclusion: There is considerable heterogeneity in physicians’ approaches to CPR discussions. The principle of autonomy is dominant with less emphasis on providing adequate information for effective decision-making.

Prediction rules for estimating neurologic outcome following out-of-hospital cardiac arrest

BACKGROUND

No valid model has been developed to predict survival following out-of-hospital cardiac arrest. The purpose of this study was to develop a prediction model for meaningful survival following out-of-hospital cardiac arrest using variables available during resuscitation.

METHODS

This was a retrospective cohort study. Consecutive adult cardiac arrest patients were studied between 1994 and 2001. Variables included age, sex, race/ethnicity, arrest location, whether the arrest was witnessed, initial rhythm, whether CPR was performed, patient downtime, paramedic response time, survival to hospital discharge, and Glasgow Coma Score (GCS) at hospital discharge. Classification and Regression Tree analysis was used to develop decision rules to predict meaningful survival, as defined by the patient's discharge GCS.

RESULTS

Of the 754 patients, 16 (2%) survived with a GCS > or =13, 15 (2%) survived with a GCS = 14, and 5 (0.7%) survived with a GCS = 15. The decision rule for survival with a GCS > or = 13 incorporated whether the arrest was witnessed and the patient's age, resulting in a negative predictive value (NPV) of 99.8%. The rule for survival with a GCS > or = 14 incorporated the initial arrest rhythm, whether the arrest was witnessed, and the patient's age, resulting in a NPV of 99.6%. The rule for survival with a GCS = 15 incorporated only the interval between collapse and the initiation of life support, resulting in a NPV of 99.8%.

CONCLUSIONS

This study reports decision rules for potential meaningful survival following out-of-hospital cardiac arrest with high NPVs for each. Future studies need to be performed to prospectively validate these models.

Presentation, management, and outcome of out of hospital cardiopulmonary arrest: comparison by underlying aetiology

OBJECTIVE

To describe and compare presentation, management, and survival by aetiology of cardiopulmonary arrest.

DESIGN, SETTING, AND PATIENTS

A retrospective cohort study was undertaken of all 21 175 first out of hospital cardiopulmonary arrests in Scotland between May 1991 and March 1998.

MAIN OUTCOME MEASURE

Discharge alive from hospital.

RESULTS

Presumed cardiac disease accounted for 17 451 cases (82%), other internal aetiologies for 1814 (9%), and external aetiologies for 1910 (9%). Arrests caused by presumed cardiac disease had a better risk profile in terms of presence of a witness, bystander cardiopulmonary resuscitation, call-response interval, and use of defibrillation; 1265 (7%) of those who arrested from presumed cardiac disease were discharged alive, compared with only 77 (2%) of those with non-cardiac disorders (p < 0.001). Among those defibrillated, call-response interval was associated with survival following arrests from both presumed cardiac and non-cardiac causes (p < 0.001).

CONCLUSIONS

Out of hospital cardiopulmonary arrests from non-cardiac causes were associated with worse crude survival than arrests from cardiac causes. Improvements in call-response interval and basic life support skills in the community would improve survival irrespective of the aetiology and should therefore be encouraged.

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.

Effectiveness of emergency medical services for victims of out-of-hospital cardiac arrest: a metaanalysis

STUDY OBJECTIVE

To determine the relative effectiveness of differences in response time interval, proportion of bystander CPR, and type and tier of emergency medical services (EMS) system on survival after out of hospital cardiac arrest.

METHODS

We performed a comprehensive literature search, excluding EMS systems other than those of interest (systems of interest were those comprising one tier with providers of basic life support [BLS] or advanced life support [ALS] and those comprising two tiers with providers of BLS or BLS-defibrillation followed by ALS), patient population of fewer than 100 cardiac arrests, studies in which we could not determine the total number of arrests of presumed cardiac origin, and studies lacking data on survival to hospital discharge. Metaanalysis using generalized linear model with dispersion estimation for random effects was then performed.

RESULTS

Increased survival to hospital discharge was significantly associated with tier (P < .01), response time interval (P < .01), and bystander CPR (P = .04). A significant interaction was detected between response time interval and bystander CPR (P = .02). For the studies analyzed, survival was 5.2% in a one-tier EMS system or 10.5% in a two-tier EMS system. A 1-minute decrease in mean response time interval was associated with absolute increases in survival rates of .4% and .7% in a one-tier and two-tier EMS systems, respectively.

CONCLUSION

Increased survival to hospital discharge may be associated with decreased response time interval and with the use of a two-tier EMS system as opposed to a one-tier system. The data available for this analysis were suboptimal. Policymakers need more methodologically rigorous research to have more reliable and valid estimates of the effectiveness of different EMS systems.

A peer-training model for instruction of basic cardiac life support

This study evaluates a peer-training model for cardiopulmonary resuscitation (CPR) instruction for laypersons. Forty-one Norwegian factory employees were trained in CPR and given instructor training. These first trainees then trained 311 co-workers. These employees then trained 873 family members and associates at home. The reference group consists of employees in a Massachusetts commercial hotel trained in seven American Red Cross (ARC): Adult CPR classes. The Norwegian home trainees learned CPR using a cardboard training manikin and were trained by Norwegian factory employees who had learned CPR from co-workers. Trainees were evaluated using skill sheets and a Laerdal Skillmeter manikin. The performance of the Norwegians trained at home by peers did not differ from that of the ARC: Adult CPR trainees in six skills of the initial sequence of CPR. The home trainees outperformed the ARC: Adult CPR trainees in the proportion of compressions delivered correctly (P = 0.032) and ventilations delivered correctly (P = 0.015). Peer training may provide CPR instruction comparable to training in CPR classes at lower cost and with potential to reach new population segments.

One-year survival after prehospital cardiac arrest: the Utstein style applied to a rural-suburban system

To evaluate the recently published Utstein algorithm (Ann Emerg Med 1991;20:861), the authors conducted a retrospective review of all advanced life support (ALS) trip sheets and hospital records of patients with prehospital cardiac arrests between January 1988 and December 1989. Telephone follow-up was used to determine 1-year survival rates. Of 713 arrests in the 24-month study period, 601 were of presumed cardiac etiology. Approximately 599 of these charts were available for analysis. One hundred ninety-three (32.2%) of these had return of spontaneous circulation (ROSC), 36 (6.0%) survived to hospital discharge, and 24 were alive at 1-year follow-up (4.0% of total or 67% of survivors to discharge). The Utstein style was found to be a useful algorithmic format for reporting prehospital cardiac arrest data in a manner that should allow direct comparison between emergency medical service (EMS) systems. Existing prehospital record-keeping practices (trip sheets) are easily adapted to this style of data collection, although certain data for the template (eg, resuscitations not attempted and alive at 1-year) are more difficult to ascertain. Additionally, the authors report their own experience during a 2-year period, including data that suggest that the majority of patients with cardiac arrest who survive to hospital discharge are still alive at 1 year.

Effect of extreme temperatures on drugs for prehospital ACLS

Advanced cardiac life support drugs undergo a wide range of temperature exposures in the prehospital setting. Although manufacturers place temperature restrictions for drug stability on their products, it has been shown that these limits are often exceeded in the prehospital environment. We exposed four different drugs to temperatures of -20 degrees C (-6 degrees F) and 70 degrees C (150 degrees F) and subsequently performed assays to determine their respective chemical stability compared with that of control samples. We determined that no significant difference in chemical structure occurred between the standard sample and the four drugs exposed to extreme temperatures (P > .05). This information has obvious implications in making further recommendations for drug storage. More work to determine bioactivity of temperature-exposed drugs may show results with implications for success in prehospital cardiac resuscitation.

Prehospital cardiac arrest survival and neurologic recovery

Many studies of prehospital defibrillation have been conducted but the effects of airway intervention are unknown and neurologic follow-up has been incomplete. A non-randomized cohort prospective study was conducted to determine the effectiveness of defibrillation in prehospital cardiac arrest. Two ambulance companies in the study area developed a defibrillation protocol and they formed the experimental group. A subgroup of these patients received airway management with an esophageal obturator airway (EOA) or endotracheal intubation (ETT). The control group was composed of patients who suffered a prehospital cardiac arrest and did not receive prehospital defibrillation. All survivors were assessed for residual deficits using the Sickness Impact Profile (SIP) and the Dementia Rating Scale (DRS). A total of 221 patients were studied over a 32-month period. Both the experimental group (N = 161) and the control group (N = 60) were comparable with respect to age, sex distribution, and ambulance response time. Survival to hospital discharge was 2/60 (3.3%) in the control group and 12/161 (6.3%) in the experimental group. This difference is not statistically significant. Survival in the experimental group by airway management technique was basic airway support (3/76 3.9%), EOA (3/67 4.5%), and ETT (6/48 12.5%). The improved effect on survival by ETT management was statistically significant. Survivors had minor differences in memory, work, and recreation as compared to ischemic heart disease patients as measured by the SIP and DRS. No effect of defibrillation was found on survival to hospital discharge. However, endotracheal intubation improved survival in defibrillated patients. Survivors had a good functional outcome.

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.

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.

Nontraumatic prehospital cardiac arrest ages 1 to 39 years

Clinical and autopsy records were retrospectively reviewed for 105 patients between the ages of 1 and 39 years who came in to the emergency department with nontraumatic cardiac arrest. There were 65 male (62%) and 40 female patients (38%). Forty-eight percent of the patients were resuscitated. Long-term survival rate was 23%. The most common presenting rhythm was ventricular fibrillation (45%). Cardiac diseases constituted the most common cause of arrest (38%). Atherosclerotic coronary artery disease represented 50% of all cardiac causes. The second most common etiology was overdose or toxic exposure (21%). Witnessed arrest and an etiology of primary cardiac dysrhythmia for arrest were statistically significant factors related to favorable outcome. Asystole as the initial cardiac rhythm was a negative prognostic indicator. Age, sex, race, bystander cardiopulmonary resuscitation, and paramedic response time were not significant prognostic factors for long-term survival.

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.

Brain resuscitation

Optimal neurological outcome after cardiac arrest requires careful attention to the details of both intracranial and extracranial homeostasis. A high index of suspicion regarding the potential causes and complications of cardiac arrest facilitates discovery and treatment of problems before they adversely impact upon neurological outcome. The future is bright for resuscitation research since our fundamental understanding of cerebral ischemia and its consequences has dramatically improved. This knowledge can hopefully be transferred to clinical useful modes of therapy.

Pre-CPR conditions and the final outcome of CPR. The Cerebral Resuscitation Study Group

Outcome of cardiac arrest (CA) is very much influenced by pre-CPR conditions. To assess the importance of these pre-CPR factors, an analysis of the Belgian CPCR registry was made according to some pre-CPR conditions. In this registry, several variables related to pre-arrest, arrest, CPR and post CPR period have been recorded in 4548 patients. The pre-CPR conditions studied were: age, witnessed event or not, pre-arrest health state, underlying disease, site of cardiac arrest, type of respiratory arrest and type of cardiac arrest. Age did not influence outcome significantly. The importance of witnessing is very significant. Severe pre-arrest disability reduces chances on long-term survival (LTS) to half and overall health status longterm survivors is clearly less. Intoxication and metabolic origin of CA have good prognosis (LTS, 21%). Trauma/exsanguination, drowning, SIDS and sepsis have bad prognosis (LTS, 1-3%). Cardiac (LTS, 12%) and respiratory (LTS, 14%) origin have similar outcome, although significant difference exists in occurrence of cerebral failure, suggesting that post-ischemic encephalopathy is more severe in respiratory than in cardiac origin. The most frequent site of CA, the home of the patient, has poor outcome results (LTS, 5%). Gasping is significantly related to successful outcome. In the out-of-hospital setting the type of CA was 25% VF (LTS, 77%), 65% asystole (LTS, 4%) and 10% EMD (LTS, 3%). Outcome of the subgroup out-of-hospital, witnessed, VF is comparable to other reports. This sub-group seems to us the most appropriate for clinical trials.

Out-of-hospital cardiac arrest: a six-year experience in a suburban-rural system

All out-of-hospital cardiac arrest advanced life support (ALS) trip sheets were collected from January 1980 through December 1985 for this suburban-rural system. Information was extracted according to a uniform reporting format. In our study, 18% of patients with early CPR (less than four minutes) and early ALS (less than ten minutes) survived to hospital discharge, compared with 7% with early CPR and late ALS, 6% with late CPR and early ALS, and 3% with both occurring late. Although 75% of the survivors had ventricular tachyarrhythmias as initial rhythms, bradyasystolic arrests were not uniformly lethal, even with long CPR and ALS times. This study supports the need for early CPR in the prehospital care of potential sudden-death victims. We recommend, with qualification, this reporting format to emergency medical services systems to describe their cardiac arrest experience.

Cerebral resuscitation after cardiac arrest using hetastarch hemodilution, hyperbaric oxygenation and magnesium ion

This study was done to investigate the effects of hemodilution, hyperbaric oxygenation, and magnesium sulfate on cerebral resuscitation. Sixteen mongrel dogs were anesthetized, and monitored via pulmonary artery catheter, arterial catheter and electrocardiogram. A left lateral thoracotomy was done. Ventricular fibrillation was obtained by application of a 6-volt AC current. Mechanical ventilation was stopped. Total arrest time was 12 min. All dogs were cardiac resuscitated within 6 min using internal massage, ventilation, bicarbonate, epinephrine and internal defibrillation. The animals were then randomized into three groups. Group I represented controls, and were not treated. Group II dogs received normvolemic hemodilution using hetastarch (Hespan) containing magnesium sulfate (2000 mg/l), resulting in a hematocrit of 20%-30%. Group III dogs received the above hemodilution plus compression in a hyperbaric oxygen chamber to 2 atmospheres absolute. Critical care management and hourly neurologic scoring was performed for 7 days by blinded observers. All dogs at the time of death underwent autopsies for gross study. Data analysis revealed no statistical difference among the three groups with respect to survival time, cardiac function or neurologic scoring.

Guidelines for discontinuing prehospital CPR in the emergency department--a review

We provide information that we believe should allow the establishment of rational guidelines for discontinuing, with physician supervision, unsuccessful prehospital CPR. Goldberg has advocated that CPR be terminated only after evidence of brain or cardiac death has persisted for more than one hour of adequately applied advanced CPR. This recommendation was made for inhospital resuscitation and does not reflect the limited capabilities of basic and advanced CPR techniques to sustain life outside the hospital. In addition, White and associates have demonstrated that after resuscitation from prolonged cardiac arrest, cerebral cortical blood flow is reduced severely. This state of hypoperfusion may last up to 18 hours. Because this condition can result in extensive neurologic damage, it may explain the poor survival rates after prolonged resuscitation. We propose that CPR be terminated in the ED when, despite adequate rescue attempts (intubation, defibrillation, IV medications, CCCM en route) by those responding at the scene of cardiac arrest, intrinsic cardiac activity has not been achieved in patients brought to the hospital with asystole or bradyarrhythmia. Additionally patients who have had advanced prehospital CPR for more than 45 minutes without generation of any intrinsic cardiac activity are not resuscitatable by current standard techniques, and CPR may be discontinued. These criteria must not be used for victims of hypothermia before a core temperature of 35 C to 36.1 C is achieved by active core rewarming during CPR. The available data suggest that if these criteria are implemented, many unproductive hospital-based resuscitative efforts can be eliminated without jeopardizing potential survivors.(ABSTRACT TRUNCATED AT 250 WORDS)

Prehospital endotracheal tube airway or esophageal gastric tube airway: a critical comparison

This study compares two similar groups of patients in cardiopulmonary arrest with ventricular fibrillation (VF). In the survival study group of 296 patients, 148 patients received an endotracheal tube airway (ETA) and 148 patients received an esophageal gastric tube airway (EGTA), the improved version of the esophageal obturator airway (EOA). Survival rates, both short term (ETA = 35.8%, EGTA = 39.1%) and long term (ETA = 11.5%, EGTA = 16.2%), and neurological sequelae of survivors showed no statistically significant difference between the two groups (P greater than .05). In addition, we found that success and complication rates of intubation were similar. Training time was longer for the ETA. We conclude that both airways have a place in the prehospital setting.

Extended training of ambulance staff in England

It has been widely demonstrated that it is possible to teach ambulance staffs to carry out the extended trained skills of endotracheal intubation, intravenous infusion and ventricular defilbrillation. So far in England only a few health authorities have been able to develop courses i advanced ambulance aid. Data on the costs of this training in six authorities presently operating such courses were collected, together with the costs of operating vehicles crewed by extended trained staff. Training and operating costs vary according to the different organisation of the training schemes and the way in which the extended trained staff are deployed on operational duties. Total costs vary between 235 pounds and 878 pounds per trained person per year. The experience of different health authorities in the U.K. and in the U.S.A. operating ambulance services with extended trained staff is then examined to try to identify the benefits of reduced mortality and morbidity which accrued from the introduction of the improved service. Most of this experience is concerned with reduced mortality from the treatment of out-of-hospital cardio-pulmonary arrest, and the estimates of the life-saving potential of the service varied from one area to another. The most conservative estimate was that one fully equipped, permanently available vehicle staffed by extended trained personnel would save 3-4 lives per year. Although there is very little evidence available of reduced mortality and morbidity from trauma and other sudden serious illness, some experience indicated a further 1 or 2 lives could be saved per vehicle per year.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac arrest under age 40: etiology and prognosis

Between January 1979 and December 1982, 84 patients between the ages of 1 and 39 years presented to the emergency department in a state of cardiac arrest. There were 58 male patients (69%) and 26 female patients (31%) in the group. Presenting rhythms were ventricular fibrillation (37%), asystole (37%), idioventricular rhythm (14%), heart block (4%), bradycardia (4%), ventricular tachycardia (3%), and electromechanical dissociation (3%). Thirty-two percent had bystander CPR. Of 21 patients initially resuscitated (25%), only four (5%) survived to discharge from the hospital. All survivors were neurologically intact. Seventy-five of the 80 patients who died (90%) underwent autopsy. Cause of death in the five remaining patients was inferred from clinical history. Etiologies of the cardiac arrests were the following: toxic exposure or ingestion (26%), atherosclerotic heart disease (23%), undetermined (11%), pulmonary embolism (6%), hemorrhage (6%), epilepsy (2%), cardiomyopathy (7%), myocarditis (2%), pneumonia (4%), and one case each of airway obstruction, asthma, peptic disease, and septic shock. Diverse etiologies should lead to a diagnostic search for reversible conditions in young patients. The prognosis for hospital discharge is poorer in the young population than is reported in our overall cardiac arrest population; however, numbers of neurologically intact survivors are similar in the young and the overall cardiac arrest population.

Decline in coronary heart disease mortality. Old questions and new facts

By 1979, mortality rates for coronary heart disease had declined for 14 consecutive years in the United States. Preliminary data indicate a continued decline. This review of reports published in the last five years documents the consistency of most data with the following hypotheses: (1) Reductions in population levels of hypertension and cigarette smoking have contributed to the decline in mortality from coronary heart disease. (2) Improved medical care for acute myocardial infarction has also contributed to the decline. Data are lacking to specify the contributions of changes in other risk factors, emergency medical services, medical care of chronic coronary heart disease, or other changes in the physical and social environment. Long-term, simultaneous surveillance of mortality, morbidity, medical care, and risk factors should be supported in five to 10 centers around the United States.

The problem of cardiac arrest in the community

Out-of-hospital cardiac arrests constitute 350,000 cases yearly in the United States and 60,000 in the United Kingdom. Prompt resuscitation (CPR) by lay persons and fast defibrillation by paramedics have had epidemiologic consequences on both sides of the Atlantic. In Seattle there are 20.6 and in Brighton 10.0 long-term life-saves yearly per 100,000 persons. In Piedmont Virginia, coronary deaths fell 16% for persons 30-69 years old and 25% for those of all ages; prehospital life-saves accounted for 23% and 8% of each respective reduction. Since CPR by lay persons now triples the long-term survival rate when coupled with prehospital defibrillation, favorable benefit-to-cost ratios can be effected by adding advanced life support and citizen CPR to an extant ambulance system. Meticulous direct and indirect medical control by the physician assures the highest quality of CPR and early cardiac care (ECC). Diagnostic procedures like electro-provocation identify high-risk patients. Changes of behavior and diet, new drugs, new operations, and external and implantable automated devices reduce sudden deaths. In the future, automated defibrillation by first responders and trained lay persons (including members of families of high-risk patients) should increase the number of early survivors who become candidates for long-term therapy with drugs, operations, and devices.

Survivors of out-of-hospital cardiac arrest: morbidity and long-term survival

Sudden cardiac death accounts for two thirds of death due to coronary artery disease. Advanced cardiac life support can now be brought directly to patients with out-of-hospital cardiac arrest, and in this country, as many as 30% of such patients can be discharged from the hospital annually. Certain clinical and resuscitation-related factors are predictive of mortality and morbidity. The best clinical predictors of long-term survival are absence of previous history of myocardial infarction, lack of congestive heart failure during hospitalization, and age less than 60 years. Resuscitation-related predictors of long-term survival are a short time collapse to cardiopulmonary resuscitation (CPR), and a short time from collapse to CPR combined with a short time to provision of definitive care. The majority of cardiac arrest survivors are able to resume previous levels of function.

Intrapulmonary epinephrine during prolonged cardiopulmonary resuscitation: improved regional blood flow and resuscitation in dogs

Blood flow to vital organs was measured at five-minute intervals during 20 minutes of cardiopulmonary resuscitation (CPR) and ventricular fibrillation in two groups of anesthetized dogs (n = 15 per group). The relationship between organ blood flow and restoration of circulation after 20 minutes was assessed with no additional treatment in Group I and with intrapulmonary epinephrine in Group II. Cardiac output and organ blood flow did not vary significantly in Group I. In Group II, intrapulmonary epinephrine significantly improved blood flow to the myocardium, the brain, and the adrenals. A mean myocardial blood flow of less than 0.13 mL/min/g resulted in no survival, while a flow of greater than 0.16 mL/min/g resulted in survival. These studies show that a critical level of myocardial blood flow is required to restore ability of the heart to function as a pump after prolonged CPR, and that a drug that increases flow improves resuscitation efforts.

Sudden death and acute myocardial infarction in a metropolitan area, 1970-1980. The Minnesota Heart Survey

To determine the causes of the nationwide decline in deaths due to coronary heart disease, the Minnesota Heart Survey enumerated coronary deaths among persons 30 to 74 years old in Minneapolis-St. Paul. The survey also ascertained rates of hospitalization and case fatality during hospitalization for acute myocardial infarction. For deaths occurring between 1970 and 1978 that were due to coronary heart disease, the rates outside the hospital declined by 43 per cent in men and 40 per cent in women, and the rates in hospital emergency rooms increased by 311 per cent in men and 200 per cent in women. In both these years about two thirds of all such deaths occurred outside hospital wards. Between 1970 and 1980, hospitalization rates for acute infarction in persons 30 to 74 years old declined 8 per cent among men and 26 per cent among women, and case fatality in the hospital in persons 45 to 74 years old declined 29 per cent in men and 27 per cent in women. These changes are probably due to the combined influence of changes in risk factors in the population and improved care of patients with acute myocardial infarction before and during hospitalization.

Resuscitation time in ventricular fibrillation--a prognostic indicator

Length of resuscitation in prehospital ventricular fibrillation patients was studied to define its relationship to survival. Five hundred sixty-five patients presenting with the initial rhythm of ventricular fibrillation to the Milwaukee County Paramedic System between January 1978 and April 1982 were resuscitated successfully. Pediatric patients and patients with trauma, poisoning, and drowning were excluded. Of the 565 resuscitated patients, 262 (46%) were discharged alive and 303 (54%) died during hospitalization. For all 565 patients the resuscitation time and times from arrival of paramedics until the first sustained pulse were plotted against survival to define a curve. The curve demonstrated rapidly declining survival rates for resuscitation time up to 20 minutes; thereafter, survival declined more gradually with respect to resuscitation time. The mean resuscitation time for those eventually discharged alive was 12.6 minutes, which was statistically shorter (P less than .0001) than the mean resuscitation time of 23.9 minutes for those who eventually died. The overall survival curve of witnessed arrest patients was not statistically different from that of unwitnessed patients. The survival curve of those patients receiving bystander cardiopulmonary resuscitation (CPR) was similar to the curve of those who received no CPR. We conclude that resuscitation time is a heretofore undefined significant predictor of survival of resuscitated prehospital ventricular fibrillation patients.

Epidemiology of cardiac arrest and resuscitation in children

A surveillance system identified all out-of-hospital cardiac patients under the age of 18 who received emergency care in suburban King County, Washington. The etiology, cardiac rhythm, and outcome were identified for each case. During a 6 1/2-year period, 119 cardiac arrests occurred (annual incidence, 12.7/100,000 among individuals less than 18). Sudden infant death was the most common etiology (32%), and drowning was the second most common (22%). The most common rhythm was asystole, accounting for 66% of all rhythms. Six percent of patients treated with basic EMT care were discharged, compared with 7% of patients treated with EMT and paramedic care. In contrast to resuscitation from cardiac arrest in adults, the likelihood of successful resuscitation in children is very poor. This is due to different etiologies and the higher proportion of asystole seen in pediatric cardiac arrest as compared with adults.

Use of atropine for brady-asystolic prehospital cardiac arrest

The efficacy of atropine in treating prehospital cardiac arrest patients developing asystole slow pulseless idioventricular rhythms (PIVR) was evaluated in a controlled, prospective study. Twenty-one prehospital cardiac-arrested patients developing asystole or PIVR (less than 40) were divided into atropine-treated or non-atropine (control) groups. Control group patients received treatment including bicarbonate, epinephrine, calcium, isoproterenol, dexamethasone, and transthoracic pacing. Atropine-treated patients received 1 mg atropine intravenously with a repeat dose at one minute if no rhythm change occurred. These patients then received the same therapy as the control group. In both groups, rhythm changes were treated as appropriate for the specific circumstances. No differences in mortality or effected rhythm changes were observed. Ten of the 11 controls and eight of 10 atropine patients developed rhythms other than asystole or PIVR less than 40. However, only two patients in each group were successfully resuscitated in the emergency department and only one control group patient was discharged alive. Our findings are not in agreement with those of previous authors who have advocated the use of atropine in cardiac arrest patients with these arrhythmias. We question the usefulness of atropine in this setting. More study is necessary in order to clearly define its role in the resuscitation of patients who have sustained brady-asystolic arrests.

Criteria for cessation of CPR in the emergency department

Specific criteria have been proposed for the cessation of cardiopulmonary resuscitation (CPR) in the emergency department. Using these criteria and others, we developed a survey which was completed by 78 physicians practicing emergency medicine. The physicians surveyed did not make decisions to cease CPR that were consistent with any such criteria which might guide them in clinical decision making. In this survey, the type of residency training, the size of city in which the physician practiced, and the number of years an individual had practiced emergency medicine significantly correlated with how he made the decision to cease CPR. Based on a review of the current literature, and due to the fact that considerable and variable ethical and psychological factors weigh in each clinical circumstance, the authors recommend that no criteria be followed for ceasing CPR.

Treatment of out-of-hospital cardiac arrests with rapid defibrillation by emergency medical technicians

The survival rate for patients with out-of-hospital cardiac arrest is low in communities where emergency service is provided solely by emergency medical technicians. We trained such technicians in a suburban community of 79,000 to recognize and treat out-of-hospital ventricular fibrillation with up to three defibrillatory shocks without the use of medications or special airway protection. Outcomes from cardiac arrest due to underlying heart disease were determined during two periods: two years with standard care by emergency medical technicians and one year with defibrillator-trained technicians. During the period with standard care, four of 100 patients with cardiac arrest were resuscitated and discharged alive from the hospital, as compared with 10 of 54 patients during the period with defibrillator-trained technicians (P less than 0.01). In 12 of 38 patients with ventricular fibrillation, a stable perfusing cardiac rhythm followed defibrillatory shocks given by defibrillator technicians. The enhanced survival after cardiac arrest is encouraging, and further trials of defibrillation by emergency medical technicians are warranted.

Out-of-hospital cardiac arrest: a review of major studies and a proposed uniform reporting system

The scientific literature from January 1970 to June 1979 was reviewed for articles reporting outcomes from out-of-hospital cardiac arrest treated by paramedic programs. Only articles appearing in refereed professional journals and reporting 25 or more attempted resuscitations were included. A total of 21 articles from 15 U.S. locations were found. Four separate case definitions were distinguished. Methods and reporting formats varied considerably. Few studies used an experimental or quasi-experimental design, or control or comparison groups. The range of attempted resuscitations varied from 26 to 1.106 patients. Patients admitted to hospital varied between 22 per cent and 65 per cent (mean 38 per cent, S.D. +/- 12.4 per cent). Patients discharged alive varied from 3.5 per cent to 31 per cent (mean 17.2 per cent, S.D. +/- 7.1 per cent). Post discharge survival was either not reported or reported in different formats. A simplified reporting format is proposed using factors known to be associated with successful resuscitation: 1) underlying heart disease etiology; 2) witnessed arrest; 3) cardiac rhythm of ventricular fibrillation/ventricular tachycardia; 4) hospital admission and discharge and, when possible, by time from collapse to initiation of CPR and definitive care. Uniform reporting of outcomes will improve comparability and accurate measurement of the impact of emergency programs on out-of-hospital cardiac arrest.