Richard O. Cummins

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.

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.

Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation.

Background Whether antiarrhythmic drugs improve the rate of successful resuscitation after out-of-hospital cardiac arrest has not been determined in randomized clinical trials. Methods We conducted a randomized, double-blind, placebo-controlled study of intravenous amiodarone in patients with out-of-hospital cardiac arrest. Patients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients). Results The treatment groups had similar clinical profiles. There was no significant difference between the amiodarone and placebo groups in the mean (±SD) duration of the resuscitation attempt (42±16 and 43±16 minutes, respectively), the number of shocks delivered (4±3 and 6±5), or the proportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66...

A Comparison of Standard-Dose and High-Dose Epinephrine in Cardiac Arrest outside the Hospital

BACKGROUND Experimental and uncontrolled clinical evidence suggests that intravenous epinephrine in doses higher than currently recommended may improve outcome after cardiac arrest. We conducted a prospective, multicenter study comparing standard-dose epinephrine with high-dose epinephrine in the management of cardiac arrest outside the hospital. METHODS Adult patients were enrolled in the study if they remained in ventricular fibrillation, or if they had asystole or electromechanical dissociation, at the time the first drug was to be administered to treat the cardiac arrest. Patients were randomly assigned to receive either 0.02 mg of epinephrine per kilogram of body weight (standard-dose group, 632 patients) or 0.2 mg per kilogram (high-dose group, 648 patients), both given intravenously. RESULTS In the standard-dose group 190 patients (30 percent) had a return of spontaneous circulation, as compared with 217 patients (33 percent) in the high-dose group; 136 patients (22 percent) in the standard-dose group and 145 patients (22 percent) in the high-dose group survived to be admitted to the hospital. Twenty-six patients (4 percent) in the standard-dose group and 31 (5 percent) in the high-dose group survived to discharge from the hospital. Ninety-two percent of the patients discharged in the standard-dose group and 94 percent in the high-dose group were conscious at the time of hospital discharge. None of the differences in outcome between the groups were statistically significant. CONCLUSIONS In this study, we were unable to demonstrate any difference in the overall rate of return of spontaneous circulation, survival to hospital admission, survival to hospital discharge, or neurologic outcome between patients treated with a standard dose of epinephrine and those treated with a high dose.

Recommended Guidelines for Reviewing, Reporting, and Conducting Research on In-Hospital Resuscitation: The In-Hospital ‘Utstein Style’ A Statement for Healthcare Professionals From the American Heart Association, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, the Australian Resuscitation Council, and the Resuscitation Councils of Southern Africa

This scientific statement is the product of the Utstein ’95 Symposium held June 23-24, 1995, at Utstein Abbey, Island of Mosteroy, Rogaland County, Norway. Draft versions were circulated for comment to participants of the Utstein ’95 Symposium; the European Resuscitation Council Executive Committee; the Emergency Cardiac Care Committee of the American Heart Association; the Executive Committees of the Heart and Stroke Foundation of Canada, the Australian Resuscitation Council, and the Resuscitation Councils of Southern Africa; and several outside reviewers. The development of this statement was authorized by the Science Advisory and Coordinating Committee of the AHA and the Executive Committee of the European Resuscitation Council. We do not know the true effectiveness of in-hospital resuscitation. Observed results of the many published studies vary greatly. Studies originate from different settings and have different patient populations. Reports suffer from nonuniform nomenclature and variable inclusion definitions. Patients differ in the extent of comorbid conditions and interventions in place at the time of cardiac arrest. These differences prevent valid interhospital and intrahospital comparisons and make determining the effectiveness of current resuscitation techniques impossible. To develop these guidelines the task force used a consensus development process that originated with the “Utstein style” for reporting outcome data from out-of-hospital resuscitation events. Task force members performed an integrated review of published studies. An initial draft was prepared, discussed, and revised at a 2-day conference. Further drafts were revised and circulated among task force members and discussed face-to-face at three subsequent meetings. The task force defined a set of data elements that are essential or desirable for documenting in-hospital cardiac arrest. Data categories are hospital variables, patient variables, arrest variables, and outcome variables. The “In-Hospital Utstein-Style Template” was developed to summarize these data and recommendations for reporting a specific set of survival rates and outcomes. The task force …

Automatic External Defibrillators for Public Access Defibrillation: Recommendations for Specifying and Reporting Arrhythmia Analysis Algorithm Performance, Incorporating New Waveforms, and Enhancing Safety A Statement for Health Professionals From the American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED Safety and Efficacy

These recommendations are presented to enhance the safety and efficacy of AEDs intended for public access. The task force recommends that manufacturers present developmental and validation data on their own devices, emphasizing high sensitivity for shockable rhythms and high specificity for nonshockable rhythms. Alternative defibrillation waveforms may reduce energy requirements, reducing the size and weight of the device. The highest levels of safety for public access defibrillation are needed. Safe and effective use of AEDs that are widely available and easily handled by nonmedical personnel has the potential to dramatically increase survival from cardiac arrest.

Recommended guidelines for reviewing, reporting, and conducting research on in-hospital resuscitation: The in-hospital 'Utstein style'

This scientific statement is the product of the Utstein ’95 Symposium held June 23-24, 1995, at Utstein Abbey, Island of Mosteroy, Rogaland County, Norway. Draft versions were circulated for comment to participants of the Utstein ’95 Symposium; the European Resuscitation Council Executive Committee; the Emergency Cardiac Care Committee of the American Heart Association; the Executive Committees of the Heart and Stroke Foundation of Canada, the Australian Resuscitation Council, and the Resuscitation Councils of Southern Africa; and several outside reviewers. The development of this statement was authorized by the Science Advisory and Coordinating Committee of the AHA and the Executive Committee of the European Resuscitation Council. We do not know the true effectiveness of in-hospital resuscitation. Observed results of the many published studies vary greatly. Studies originate from different settings and have different patient populations. Reports suffer from nonuniform nomenclature and variable inclusion definitions. Patients differ in the extent of comorbid conditions and interventions in place at the time of cardiac arrest. These differences prevent valid interhospital and intrahospital comparisons and make determining the effectiveness of current resuscitation techniques impossible. To develop these guidelines the task force used a consensus development process that originated with the “Utstein style” for reporting outcome data from out-of-hospital resuscitation events. Task force members performed an integrated review of published studies. An initial draft was prepared, discussed, and revised at a 2-day conference. Further drafts were revised and circulated among task force members and discussed face-to-face at three subsequent meetings. The task force defined a set of data elements that are essential or desirable for documenting in-hospital cardiac arrest. Data categories are hospital variables, patient variables, arrest variables, and outcome variables. The “In-Hospital Utstein-Style Template” was developed to summarize these data and recommendations for reporting a specific set of survival rates and outcomes. The task force …

The location of collapse and its effect on survival from cardiac arrest

Survival from cardiac arrest is higher when the collapse occurs outside the home. Of 781 patients collapsing at home, 101 (13%) survived to hospital discharge. This compared with 66 survivors among 248 (27%) patients arresting outside the home (P less than .001). Patients collapsing outside the home were younger and more frequently were men. Cardiac arrests outside the home were more often witnessed, more likely to have bystander CPR, less often preceded by symptoms, and the collapsing rhythm was more frequently ventricular fibrillation. Mean time to CPR was shorter. Multivariate logistic regression showed that the effect of location on survival was still statistically significant, although diminished, after adjusting for the above variables (P less than .01). We speculate that comorbidity, underlying etiology, and activity level may explain the remaining difference. Because 76% of arrests occur in the home, efforts to increase the frequency of bystander-CPR through targeted and dispatcher-assisted CPR programs are warranted.

Recommended Guidelines for Uniform Reporting of Pediatric Advanced Life Support: The Pediatric Utstein Style

This consensus document is an attempt to provide an organized method of reporting pediatric ALS data in out-of-hospital, emergency department, and in-hospital settings. For this methodology to gain wide acceptance, the task force encourages development of a common data set for both adult and pediatric ALS interventions. In addition, every effort should be made to ensure that consistent definitions are used in all age groups. As health care changes, we will all be challenged to document the effectiveness of what we currently do and show how new interventions or methods of treatment improve outcome and/or reduce cost. Only through collaborative research will we obtain the necessary data. For these reasons, and to improve the quality of care and patient outcomes, it is the hope of the task force that clinical researchers will follow the recommendations in this document. It is recognized that further refinements of this statement will be needed; these recommendations will improve only when researchers, clinicians, and EMS personnel use them, work with them, and modify them. Suggestions, recommendations, and other comments aimed at improving the reporting of pediatric resuscitation should be sent to Arno Zaritsky, MD, Eastern Virginia Medical School, Childrens Hospital of The Kings Daughter, Division of Critical Care Medicine, 601 Childrens Lane, Norfolk, VA 23507.

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.