Prehospital resuscitation in Helsinki, Finland

Regional variation and outcome of out-of-hospital cardiac arrest (ohca) in Finland - the Finnresusci study

Background

Despite the efforts of the modern Emergency Medical Service Systems (EMS), survival rates for sudden out-of-hospital cardiac arrest (OHCA) have been poor as approximately 10% of OHCA patients survive hospital discharge. Many aspects of OHCA have been studied, but few previous reports on OHCA have documented the variation between different sizes of study areas on a regional scale. The aim of this study was to report the incidence, outcomes and regional variation of OHCA in the Finnish population.

Methods

From March 1st to August 31st, 2010, data on all OHCA patients in the southern, central and eastern parts of Finland was collected. Data collection was initiated via dispatch centres whenever there was a suspected OHCA case or if a patient developed OHCA before arriving at the hospital. The study area includes 49% of the Finnish population; they are served by eight dispatch centres, two university hospitals and six central hospitals.

Results

The study period included 1042 cases of OHCA. Resuscitation was attempted on 671 patients (64.4%), an incidence of 51/100,000 inhabitants/year. The initial rhythm was shockable for 211 patients (31.4%). The survival rate at one-year post-OHCA was 13.4%. Of the witnessed OHCA events with a shockable rhythm of presumed cardiac origin (n=140), 64 patients (45.7%) were alive at hospital discharge and 47 (33.6%) were still living one year hence. Surviving until hospital admission was more likely if the OHCA occurred in an urban municipality (41.5%, p=0.001).

Conclusions

The results of this comprehensive regional study of OHCA in Finland seem comparable to those previously reported in other countries. The survival of witnessed OHCA events with shockable initial rhythms has improved in urban Finland in recent decades.

The use of undiluted amiodarone in the management of out-of-hospital cardiac arrest

INTRODUCTION

The Resuscitation 2000 Guidelines recommends amiodarone as the antiarrhythmic drug of choice in treatment of resistant ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT). Amiodarone has been associated with side-effects and difficulty of administration, due to recommended dilution, rendering it suboptimal for out-of-hospital cardiac arrest (CA) management. In the present study we report experiences and side-effects of the use of undiluted amiodarone in CA management in Helsinki Emergency Medical Service (EMS) during a 2-year period.

METHODS

On October 1, the Resuscitation 2000 Guidelines were put into practice in Helsinki EMS. Thus, in the cardiac arrest treatment protocol, after three ineffective shocks and 1 mg of adrenaline (epinephrine), a bolus of 300 mg of undiluted amiodarone (Cordarone 50 mg ml(-1), Sanofi-Synthelabo, Helsinki, Finland) was administered into a vein located as centrally as possible. The Helsinki EMS performs systematic data collection according to the Utstein Guidelines. The blood pressure levels, heart rates and the need for vasopressors, of the patients with sustained return of spontaneous circulation (ROSC), were collected from the ambulance charts.

RESULTS

During October 1, 2000 and September 30, 2002, 712 patients were considered for resuscitation and 566 were resuscitated. The initial rhythms were as follows: 32% had VF/VT, 36% had asystole and 32% had pulseless electrical activity (PEA). Of the 180 patients with VF/VT, 75 (42%) received undiluted amiodarone in addition to other resuscitative measures. Of the patients with asystole or PEA, 12 (6%) and 18 (10%), respectively, received amiodarone. The blood pressure levels and the need vasopressors after ROSC and during transportation to the hospital were similar among the patients who received and those who did not receive amiodarone.

CONCLUSIONS

The present study suggests that amiodarone can be administered undiluted without unmanageable haemodynamical side-effects in the treatment of out-of-hospital cardiac arrest. This is likely to save time and simplifies the treatment protocol in the prehospital setting.

Comparison of alfentanil and morphine in the prehospital treatment of patients with acute ischaemic-type chest pain

Patients with acute myocardial ischaemic pain would benefit from rapid pain relief. The clinical usefulness of alfentanil, which has a rapid onset of action, was therefore assessed as the initial pain relieving opioid in patients suffering from acute myocardial ischaemic pain. The effects of alfentanil were compared with those of morphine in the prehospital treatment of 40 haemodynamically stable patients suffering from acute ischaemic-type chest pain. After initial assessment, the patients were given either 0.5 mg alfentanil or 5 mg morphine intravenously in a randomized double-blind fashion. The dose was repeated 2 minutes later if severe pain persisted. Arterial pressure, heart rate, respiratory rate and pain expressed on a visual analogue scale was measured before and at 2, 4, 6, 10 and 15 minutes after administration of drugs. After randomization, four patients were excluded. Sixteen patients received alfentanil and 20 patients morphine. Pain relief was faster (p < 0.005) in the alfentanil group than in the morphine group. Alfentanil was found to provide effective analgesia during the follow-up period of 15 minutes. No haemodynamic or respiratory side effects occurred. It is concluded that alfentanil is an effective analgesic in the prehospital treatment of myocardial ischaemic pain.

Estimating the effect of bystander-initiated cardiopulmonary resuscitation in Japan

Low incidence of bystander-initiated cardiopulmonary resuscitation (CPR) is allegedly responsible for poor survival from out-of-hospital cardiac arrest (OHCA) in Japan. This study was conducted to determine significant predictors for survival after collapse-witnessed OHCA of presumed cardiac etiology to investigate the impact of bystander-initiated CPR. Logistic regression analysis of OHCA of presumed cardiac etiology was performed on retrospective data sets from three Japanese suburban communities. All arrest incidents were witnessed and occurred prior to the arrival of EMS personnel. Outcome measure was survival to discharge. Initial electrocardiogram (ECG) rhythm (ventricular fibrillation (VF) or not), interval from collapse to CPR (within 5 min or not), and initial ECG rhythm/collapse-to-CPR interval interaction were significantly associated with survival. Patient age (70 years or less/over 70 years), interval from collapse to EMS response, and bystander-initiated CPR were significantly associated with VF in an initial ECG. The effectiveness of bystander-initiated CPR for OHCA can be successfully predicted based on the interval from collapse to CPR and initial ECG rhythm. The increase in the proportion of bystander-initiated CPR from the present level of 20-50% would be expected to rescue another 1800 victims of OHCA per year in Japan.

Thrombolytic treatment of acute myocardial infarction after out-of-hospital cardiac arrest

OBJECTIVE

To investigate the safety and efficacy of thrombolytic treatment for an acute myocardial infarction (AMI) immediately after resuscitation in the out-of-hospital setting.

DESIGN

Retrospective.

SETTING

A middle-sized urban city (population 540000) served by a single emergency medical system using a tiered response with physicians in field.

PATIENTS AND METHODS

Sixty-eight patients with an initial diagnosis of AMI who received thrombolytic treatment in an out-of-hospital setting after cardiac arrest and cardiopulmonary resuscitation (CPR) between January 1st 1994 and December 31st 1998. An ECG and the myocardial enzymes (CK, CK-MB, Troponin-T) were used to diagnose AMI. Myocardial reperfusion was assessed by resolution of the ST-segment elevation. Side effects and complications were studied. The quality of secondary survival was evaluated. The Utstein style was used for a uniform style of reporting the cardiac arrest data.

RESULTS

The accuracy of prehospital diagnosis was found to be excellent. Retrospective analysis revealed that thrombolytic therapy had been appropriately administered in 64 (94%) of the 68 patients actually treated. Reperfusion was achieved in 71% of the patients. Haemorrhagic complications were few, and included intracranial haemorrhage (one patient), gastrointestinal bleeding (two patients), bleeding from the puncture site (one patient) and epistaxis (one patient). The incidence of hypotension during streptokinase infusion was 22%. Sixty-three (93%) of the patients were admitted alive to the hospital, with 36 subsequently surviving to discharge.

CONCLUSIONS

Thrombolytic treatment is a safe and effective treatment in AMI even after out-of-hospital cardiopulmonary resuscitation.

Long term outcome after out-of-hospital cardiac arrest with physician staffed emergency medical services: the Utstein style applied to a midsized urban/suburban area

OBJECTIVE

To test the effect of a physician staffed advanced cardiac life support (ALS) system on patient outcome following out-of-hospital cardiac arrest.

DESIGN

Observational study.

SETTING

Two tier basic life support (BLS) and physician staffed ALS services in the midsized urban/suburban area of Heidelberg, Germany.

PATIENTS

All patients suffering out-of-hospital cardiac arrest of cardiac aetiology between January 1992 and December 1994 and who were covered by ALS services.

INTERVENTIONS

Physician staffed ALS services.

MAIN OUTCOME MEASURES

Return of spontaneous circulation, hospital discharge, and one year survival, according to the Utstein style.

RESULTS

Of 330 000 inhabitants, 755 suffered from cardiac arrest covered by the Heidelberg ALS services. In 512 patients, cardiopulmonary resuscitation had been initiated. Of 338 patients with cardiac aetiology, return of spontaneous circulation was achieved in 164 patients (49%), 48 (14%) were discharged alive, and 40 (12%) were alive one year later; most of these patients showed good neurological outcome. Thus, 4.85 patients with cardiac aetiology were saved by the ALS services and discharged alive per 100 000 inhabitants a year. Ventricular fibrillation or tachycardia was detected in 106 patients (31%), other cardiac rhythms in 40 (12%), and asystole in 192 (57%). Hospital discharge rates (and one year survival) in these subgroups were 34.0% (29.2%), 12.5% (7.5%), and 3.6% (3.1%), respectively. Discharge rates increased if cardiac arrest was witnessed (bystander, 20.0%; BLS/ALS personnel, 21.4%; non-witnessed arrest, 3.3%; p < 0.01), and if the time period between the alarm and the arrival of the ALS unit was four minutes or less (</= 4 minutes, 30.6%; 4-8 minutes, 10.4%; > 8 minutes, 8. 1%; p < 0.001). In 69 patients with bystander witnessed cardiac arrest with ventricular fibrillation, the discharge rate was 37.7%; 21 patients were alive after one year.

CONCLUSIONS

A two tier BLS and physician staffed ALS system is associated with good long term outcome of patients suffering from out-of-hospital cardiac arrest of cardiac aetiology in a midsized urban/suburban area. Further studies, however, are required to assess whether having a physician in the ALS unit is an independent determinant for improved long term outcome.

A comparison of standard cardiopulmonary resuscitation and active compression-decompression resuscitation for out-of-hospital cardiac arrest. French Active Compression-Decompression Cardiopulmonary Resuscitation Study Group

BACKGROUND

We previously observed that short-term survival after out-of-hospital cardiac arrest was greater with active compression-decompression cardiopulmonary resuscitation (CPR) than with standard CPR. In the current study, we assessed the effects of the active compression-decompression method on one-year survival.

METHODS

Patients who had cardiac arrest in the Paris metropolitan area or in Thionville, France, more than 80 percent of whom had asystole, were assigned to receive either standard CPR (377 patients) or active compression-decompression CPR (373 patients) according to whether their arrest occurred on an even or odd day of the month, respectively. The primary end point was survival at one year. The rate of survival to hospital discharge without neurologic impairment and the neurologic outcome were secondary end points.

RESULTS

Both the rate of hospital discharge without neurologic impairment (6 percent vs. 2 percent, P=0.01) and the one-year survival rate (5 percent vs. 2 percent, P=0.03) were significantly higher among patients who received active compression-decompression CPR than among those who received standard CPR. All patients who survived to one year had cardiac arrests that were witnessed. Nine of 17 one-year survivors in the active compression-decompression group and 2 of 7 in the standard group, respectively, initially had asystole or pulseless electrical activity. In 12 of the 17 survivors who had received active compression-decompression CPR, neurologic status returned to base line, as compared with 3 of 7 survivors who had received standard CPR (P=0.34).

CONCLUSIONS

Active compression-decompression CPR performed during advanced life support significantly improved long-term survival rates among patients who had cardiac arrest outside the hospital.

Epidemiology and survival rate of out-of-hospital cardiac arrest in north-east Italy: The F.A.C.S. study. Friuli Venezia Giulia Cardiac Arrest Cooperative Study

The results of the first epidemiological, prospective, multicentric study on cardiac arrest in a geographical Italian region are reported. On 708 consecutive cardiac arrests, 438 underwent cardiopulmonary resuscitation (CPR). Of these, 344 were identified of cardiac aetiology. The underlying initial rhythm was: 166 asystole (48.3%), 104 ventricular fibrillation (30.2%), 74 pulseless electrical activity (21.5%). The best outcome occurred in patients whose cardiac arrest was witnessed by the EMS (49% return of spontaneous circulation (ROSC), 21% hospital discharge). When cardiac arrest was witnessed by lay people, 20.5% had ROSC and 4.4% were discharged alive from the hospital. When it was unwitnessed ROSC and hospital discharge were 8.6 and 1.7%, respectively. Ventricular fibrillation was highly predictive of outcome. Both ROSC and hospital discharge correlated inversely with the delay of the first defibrillation. Overall, the highest probability of survival was achieved when CPR interventions were started within the first minutes after collapse. Basic Life Support (BLS) manoeuvres began after 9 min of untreated cardiac arrest were still followed by a ROSC, but none of these patients survived. The incidence of prehospital cardiac arrest in our population was estimated to be in proportion of 0.95/1000 per year with a survival rate of 6.7%.

Paediatric cardiac arrest and resuscitation provided by physician-staffed emergency care units

BACKGROUND

Most paediatric cardiac arrest studies have been conducted in the USA, where paramedics provide prehospital emergency care. We wanted to study the outcome of paediatric cardiac arrest patients in an emergency medical system which is based on physician staffed emergency care units.

METHODS

We analysed retrospectively the files of 100 prehospital cardiac arrest patients from Southern Finland during a 10-year study period. The patients were less than 16 years of age.

RESULTS

Fifty patients were declared dead on the scene (DOS) without attempted resuscitation, and cardiopulmonary resuscitation (CPR) was initiated in 50 patients. The sudden infant death syndrome was the most common cause of arrest in the DOS patients (68%) as well as in those receiving CPR (36%). Asystole was the initial cardiac rhythm in 70% of the patients in whom CPR was attempted. Resuscitation was successful in 13 patients, 8 of whom were ultimately discharged. Six of the patients survived with mild or no disability and 4 of them had near-drowning aetiology. In multivariate analysis, the short duration of CPR (< or = 15 min) was the only factor significantly associated with better survival.

CONCLUSIONS

Although prehospital care was provided by physicians, the overall rate of survival was found to be equally poor as reported from systems with paramedics. The only major difference between physician- and paramedic-staffed emergency care units is the ability of physicians to refrain from resuscitation already on the scene when prognosis is poor.

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.

Out-of-hospital cardiac arrests in Helsinki: Utstein style reporting

OBJECTIVE

To determine the epidemiology of out-of-hospital cardiac arrests and survival after resuscitation and to apply the Utstein style of reporting to data collection.

DESIGN

Prospective cohort study.

SETTING

A middle-sized urban city (population 516,000) served by a single emergency medical services system.

PATIENTS

Consecutive prehospital cardiac arrests occurring between 1 January and 31 December 1994.

INTERVENTION

Advanced cardiac life support according to the recommendations of American Heart Association.

MAIN OUTCOME MEASURES

Survival from cardiac arrest to hospital discharge, and factors associated with survival.

RESULTS

Four hundred and twelve patients were considered for resuscitation. The overall incidence of out-of-hospital cardiac arrest was 79.8/100,000 inhabitants/year. Fifty seven patients (16.6%) survived to discharge when resuscitation was attempted. 32.5% survived when cardiac arrest was bystander witnessed and was of cardiac origin with ventricular fibrillation as the initial rhythm. When asystole or pulseless electrical activity was the first rhythm recorded, discharge rates were 6.2 and 2.7% respectively. The cause of cardiac arrest was cardiac in 66.5%, and ventricular fibrillation was the initial rhythm in 65.0% of bystander witnessed cardiac arrests of cardiac origin. 22.1% of patients received bystander initiated cardiopulmonary resuscitation. The mean time intervals from the receipt of the call to the arrival of a first response advanced life support unit and mobile intensive care unit at the patient's side and to the return of spontaneous circulation were 7.0 and 10.3 and 12.6 and 16.7 min respectively. In the logistic regression model bystander witnessed arrest, age, ventricular fibrillation as initial rhythm, and the call-to-arrival interval of the first response unit were independent factors relating to survival. Utstein style reporting with modification of time zero was found to be an appropriate form of data collection in this emergency medical services system.

CONCLUSIONS

After implementation of major changes in the emergency medical services system during the 1980s survival from out-of-hospital cardiac arrest markedly increased. However, early access, which has turned out to be the weakest link in the chain of survival, should receive major attention in the near future. Utstein style reporting with a modified time zero was found to be appropriate, although laborious, protocol for data collection.

The effect of experience of on-site physicians on survival from prehospital cardiac arrest

Outcome from prehospital cardiac arrest was studied 1 year before (Period I) and after (Period II) a reorganisation of the work and the simultaneous change of all physicians participating in the care of prehospital patients in the emergency medical service system in Helsinki. There were 444 patients during Period I and 395 patients during Period II. Resuscitation was initiated in 279 patients during Period I and in 323 patients (P < 0.001) during Period II. The number of patients with ventricular fibrillation who suffered a witnessed cardiac arrest due to presumed heart disease was 120 and 130, respectively. During Period I, 70 of these patients were successfully resuscitated and admitted to hospital, 41 (34%) survived to discharge home from hospital. Corresponding figures during Period II were 79 and 33 (25%, NS). Compared with Period I, a larger proportion of the successfully resuscitated patients either died in hospital or were discharged to an institution during Period II (P < 0.05).

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.

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 fire department first-responder automated defibrillation

STUDY OBJECTIVE

To examine the effect of fire department first-responder defibrillation on time to defibrillation in a mid-sized community with two tiers of emergency medical services (EMS) ambulance response.

DESIGN

Retrospective cohort.

SETTING

The study area was the region of Hamilton-Wentworth, which has more than 445,000 inhabitants and covers 1,136 km2 (438 square miles).

TYPE OF PARTICIPANTS

We studied 297 victims of out-of-hospital cardiac arrest presenting to the EMS system between May 1, 1990, and April 30, 1991.

MEASUREMENTS AND MAIN RESULTS

The mean defibrillation interval was decreased from 11.96 minutes to 8.50 minutes (P < .001) by the introduction of fire first-responder defibrillation. Survival was significantly greater with bystander-witnessed arrest, initial rhythm of ventricular fibrillation, and presence of a pulse on arrival in the emergency department.

CONCLUSION

In our EMS system, fire first-responders were able to provide defibrillation in significantly shorter times than ambulance attendants. Other EMS systems should review their response times and consider instituting first-responder defibrillation as one means of reducing defibrillation intervals.

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.

Moving toward uniform reporting and terminology

Researchers interested in performing research on prehospital cardiac arrest should carefully review the presentations from the session "Moving Toward Uniform Reporting and Terminology." Although each presentation concentrates on specific research topics, taken together they suggest the next evolutionary steps we should take to conduct such research. We will base these further steps on the following insights. First, all future articles on prehospital cardiac arrest must share a common nomenclature and template for reporting outcomes. The Utstein style has not solved this problem completely, but it is the critical first step. Over the coming years, we must, through continued use, progressively refine the Utstein style. Second, we can no longer depend on research that comes from a single EMS system. Although we have gained important insights from such studies in the past, our expectations of greater validity and generalizability are rising and pushing us toward multicenter, cooperative studies. The International Brain Resuscitation clinical trials and the numerous studies on thrombolytic therapy demonstrate the directions we must head. Third, we must abandon our narrow focus on the pre-hospital experience. Although some studies have avoided this problem, the preponderance of clinical studies on prehospital cardiac arrest fails to gather information on the prearrest condition of the patient, the actual decisions and action taken around the event (witness Kellermann's discussion of death criteria and rules for stopping resuscitation efforts), and the clinical experience after successful resuscitations. Fourth, we can no longer be satisfied with simple statistics on dichotomous (yes/no) survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Variation in the quality of cardiopulmonary resuscitation

During instruction in basic cardiopulmonary resuscitation (CPR) skills, cardiac massage and mouth-to-mouth ventilation are applied without interruption for no longer than a few minutes. The aim of this study was to see if the quality of technique during the first 2 min of CPR reflects the resuscitators ability to perform CPR over a 15 min period. Assessments were done with a resuscitation mannequin from which recordings of several variables were made at 2, 5, 10, and 15 min after the start of CPR. 60 lay volunteers who had received CPR training were studied, and six variables that describe the quality of CPR technique were recorded and scored with a predefined scoring system. No deterioration in CPR skills was seen during 15 min. We conclude that the initial 2 min assessment reflects the resuscitators ability to perform CPR over a longer period.

Comparison of standard external CPR, open-chest CPR, and cardiopulmonary bypass in a canine myocardial infarct model

STUDY OBJECTIVES

After cardiac arrest, open-chest CPR (OCCPR) and cardiopulmonary bypass (CPB) have demonstrated higher resuscitation rates when compared individually with standard external CPR (SECPR). We compared all three techniques in a canine myocardial infarct ventricular fibrillation model.

TYPE OF PARTICIPANTS

Twenty-six mongrel dogs were block-randomized to receive SECPR and advanced life support (nine), CPB (nine), or OCCPR (eight).

DESIGN AND INTERVENTIONS

All dogs received left anterior descending coronary artery occlusion followed by four minutes of ventricular fibrillation without CPR and eight minutes of Thumper CPR. At 12 minutes, dogs received one of three resuscitation techniques. After resuscitation, all animals received four hours of intensive care. Animals that were resuscitated had histochemical determination of ischemic and necrotic myocardial areas.

MEASUREMENTS

Intravascular pressures were measured and coronary perfusion pressure was calculated during baseline, cardiac arrest, resuscitation, and postresuscitation periods. Percent necrotic myocardium, percent ischemic myocardium, and necrotic-to-ischemic ratios were determined for resuscitated animals. Epinephrine dosage and number of countershocks were determined for each group.

MAIN RESULTS

Nine of nine CPB and six of nine OCCPR, compared with two of eight SECPR animals, were resuscitated (P less than .01). Three of nine CPB and OCCPR and two of eight SECPR dogs survived to four hours (P = NS). Coronary perfusion pressure two minutes after institution of technique was significantly higher with CPB (75 +/- 37 mm Hg) and OCCPR (56 +/- 31 mm Hg) than in SECPR animals (16 +/- 16 mm Hg, P less than .04). Epinephrine required for resuscitation was significantly less with CPB (0.10 +/- 0.02 mg/kg) than for SECPR (0.28 +/- 0.11 mg/kg, P less than .002). The ratio of necrotic to ischemic myocardium at four hours was significantly lower with CPB (0.15 +/- 0.31) and OCCPR (0.39 +/- 0.25) than for SECPR (1.16 +/- 0.31, P less than .02).

CONCLUSION

OCCPR and CPB produce higher coronary perfusion pressures and improved resuscitation rates from ventricular fibrillation when compared with SECPR in this canine myocardial infarct cardiac arrest model. CPB and OCCPR yielded similar resuscitation results, although less epinephrine was required with CPB.