Mohamud Daya

Epidemiology and Outcomes From Out-of-Hospital Cardiac Arrest in Children The Resuscitation Outcomes Consortium Epistry–Cardiac Arrest

Background— Population-based data for pediatric cardiac arrest are scant and largely from urban areas. The Resuscitation Outcomes Consortium (ROC) Epistry–Cardiac Arrest is a population-based emergency medical services registry of out-of-hospital nontraumatic cardiac arrest (OHCA). This study examined age-stratified incidence and outcomes of pediatric OHCA. We hypothesized that survival to hospital discharge is less frequent from pediatric OHCA than adult OHCA. Methods and Results— This prospective population-based cohort study in 11 US and Canadian ROC sites included persons <20 years of age who received cardiopulmonary resuscitation or defibrillation by emergency medical service providers and/or received bystander automatic external defibrillator shock or who were pulseless but received no resuscitation by emergency medical services between December 2005 and March 2007. Patients were stratified a priori into 3 age groups: <1 year (infants; n=277), 1 to 11 years (children; n=154), and 12 to 19 years (adolescents; n=193). The incidence of pediatric OHCA was 8.04 per 100 000 person-years (72.71 in infants, 3.73 in children, and 6.37 in adolescents) versus 126.52 per 100 000 person-years for adults. Survival for all pediatric OHCA was 6.4% (3.3% for infants, 9.1% for children, and 8.9% for adolescents) versus 4.5% for adults (P=0.03). Unadjusted odds ratio for pediatric survival to discharge compared with adults was 0.71 (95% confidence interval, 0.37 to 1.39) for infants, 2.11 (95% confidence interval, 1.21 to 3.66) for children, and 2.04 (95% confidence interval, 1.24 to 3.38) for adolescents. Conclusions— This study demonstrates that the incidence of OHCA in infants approaches that observed in adults but is lower among children and adolescents. Survival to discharge was more common among children and adolescents than infants or adults.

Relationship Between Chest Compression Rates and Outcomes From Cardiac Arrest

Background— Guidelines for cardiopulmonary resuscitation recommend a chest compression rate of at least 100 compressions per minute. Animal and human studies have reported that blood flow is greatest with chest compression rates near 120/min, but few have reported rates used during out-of-hospital (OOH) cardiopulmonary resuscitation or the relationship between rate and outcome. The purpose of this study was to describe chest compression rates used by emergency medical services providers to resuscitate patients with OOH cardiac arrest and to determine the relationship between chest compression rate and outcome. Methods and Results— Included were patients aged ≥20 years with OOH cardiac arrest treated by emergency medical services providers participating in the Resuscitation Outcomes Consortium. Data were abstracted from monitor-defibrillator recordings during cardiopulmonary resuscitation. Multiple logistic regression analysis assessed the association between chest compression rate and outcome. From December 2005 to May 2007, 3098 patients with OOH cardiac arrest were included in this study. Mean age was 67±16 years, and 8.6% survived to hospital discharge. Mean compression rate was 112±19/min. A curvilinear association between chest compression rate and return of spontaneous circulation was found in cubic spline models after multivariable adjustment (P=0.012). Return of spontaneous circulation rates peaked at a compression rate of ≈125/min and then declined. Chest compression rate was not significantly associated with survival to hospital discharge in multivariable categorical or cubic spline models. Conclusions— Chest compression rate was associated with return of spontaneous circulation but not with survival to hospital discharge in OOH cardiac arrest.

Early versus Later Rhythm Analysis in Patients with Out-of-Hospital Cardiac Arrest

BACKGROUND In a departure from the previous strategy of immediate defibrillation, the 2005 resuscitation guidelines from the American Heart Association-International Liaison Committee on Resuscitation suggested that emergency medical service (EMS) personnel could provide 2 minutes of cardiopulmonary resuscitation (CPR) before the first analysis of cardiac rhythm. We compared the strategy of a brief period of CPR with early analysis of rhythm with the strategy of a longer period of CPR with delayed analysis of rhythm. METHODS We conducted a cluster-randomized trial involving adults with out-of-hospital cardiac arrest at 10 Resuscitation Outcomes Consortium sites in the United States and Canada. Patients in the early-analysis group were assigned to receive 30 to 60 seconds of EMS-administered CPR and those in the later-analysis group were assigned to receive 180 seconds of CPR, before the initial electrocardiographic analysis. The primary outcome was survival to hospital discharge with satisfactory functional status (a modified Rankin scale score of ≤3, on a scale of 0 to 6, with higher scores indicating greater disability). RESULTS We included 9933 patients, of whom 5290 were assigned to early analysis of cardiac rhythm and 4643 to later analysis. A total of 273 patients (5.9%) in the later-analysis group and 310 patients (5.9%) in the early-analysis group met the criteria for the primary outcome, with a cluster-adjusted difference of -0.2 percentage points (95% confidence interval, -1.1 to 0.7; P=0.59). Analyses of the data with adjustment for confounding factors, as well as subgroup analyses, also showed no survival benefit for either study group. CONCLUSIONS Among patients who had an out-of-hospital cardiac arrest, we found no difference in the outcomes with a brief period, as compared with a longer period, of EMS-administered CPR before the first analysis of cardiac rhythm. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

Out-of-hospital cardiac arrest survival improving over time: Results from the Resuscitation Outcomes Consortium (ROC).

BACKGROUND Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death and a 2010 meta-analysis concluded that outcomes have not improved over several decades. However, guidelines have changed to emphasize CPR quality, minimization of interruptions, and standardized post-resuscitation care. We sought to evaluate whether OHCA outcomes have improved over time among agencies participating in the Resuscitation Outcomes Consortium (ROC) cardiac arrest registry (Epistry) and randomized clinical trials (RCTs). METHODS Observational cohort study of 47,148 EMS-treated OHCA cases in Epistry from 139 EMS agencies at 10 ROC sites that participated in at least one RCT between 1/1/2006 and 12/31/2010. We reviewed patient, scene, event characteristics, and outcomes of EMS-treated OHCA over time, including subgroups with initial rhythm of pulseless ventricular tachycardia or ventricular fibrillation (VT/VF). RESULTS Mean response interval, median age and male proportion remained similar over time. Unadjusted survival to discharge increased between 2006 and 2010 for treated OHCA (from 8.2% to 10.4%), as well as for subgroups of VT/VF (21.4% to 29.3%) and bystander witnessed VT/VF (23.5% to 30.3%). Compared with 2006, adjusted survival to discharge was significantly higher in 2010 for treated cases (OR = 1.72; 95% CI 1.53, 1.94), VT/VF cases (OR = 1.69; 95% CI 1.45, 1.98) and bystander witnessed VT/VF cases (OR = 1.65; 95% CI 1.36, 2.00). Tests for trend in each subgroup were significant (p < 0.001). CONCLUSIONS ROC-wide survival increased significantly between 2006 and 2010. Additional research efforts are warranted to identify specific factors associated with this improvement.

Part 7: CPR Techniques and Devices 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

A variety of CPR techniques and devices may improve hemodynamics or short-term survival when used by well-trained providers in selected patients. All of these techniques and devices have the potential to delay chest compressions and defibrillation. In order to prevent delays and maximize efficiency, initial training, ongoing monitoring, and retraining programs should be offered to providers on a frequent and ongoing basis. To date, no adjunct has consistently been shown to be superior to standard conventional (manual) CPR for out-of-hospital basic life support, and no device other than a defibrillator has consistently improved long-term survival from out-of-hospital cardiac arrest.

A Trial of an Impedance Threshold Device in Out-of-Hospital Cardiac Arrest

BACKGROUND The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. METHODS We compared the use of an active ITD with that of a sham ITD in patients with out-of-hospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability). RESULTS Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points; 95% confidence interval, -1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge. CONCLUSIONS Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

A descriptive analysis of emergency medical service systems participating in the Resuscitation Outcomes Consortium (ROC) network

Background. The optimal Emergency Medical Services (EMS) system characteristics have not been defined, resulting in substantial variability across systems. The Resuscitation Outcomes Consortium (ROC) is a United States-Canada research network that organized EMS agencies from 11 different systems to perform controlled trials in cardiac arrest andlife-threatening trauma resuscitation. Objectives. To describe EMS systems participating in ROC using a novel framework. Methods. Standardized surveys were created by ROC investigators anddistributed to each site for completion. These included separate questions for individual hospitals, EMS agencies, anddispatch centers. Results were collated andanalyzed by using descriptive statistics. Results. A total of 264 EMS agencies, 287 hospitals, and154 dispatch centers were included. Agencies were described with respect to the type (fire-based, non-fire governmental, private), transport status (transport/non-transport), andtraining level (BLS/ALS). Hospitals were described with regard to their trauma designation andthe presence of electrophysiology andcardiac catheterization laboratories. Dispatch center characteristics, including primary versus secondary public safety answering point (PSAP) status andthe use of prearrival instructions, were also described. Differences in EMS system characteristics between ROC sites were observed with multiple intriguing patterns. Rural areas andfire-based agencies had more EMS units andproviders per capita. This may reflect longer response andtransport distances in rural areas andthe additional duties of most fire-based providers. In addition, hospitals in the United States typically had catheterization laboratories, whereas Canadian hospitals generally did not. The vast majority of both primary andsecondary PSAPs use computer-aided dispatch. Conclusions. Similarities anddifferences among EMS systems participating in the ROC network were described. The framework used in this analysis may serve as a template for future EMS research.

Demographic, Belief, and Situational Factors Influencing the Decision to Utilize Emergency Medical Services Among Chest Pain Patients

BACKGROUND Empirical evidence suggests that people value emergency medical services (EMS) but that they may not use the service when experiencing chest pain. This study evaluates this phenomenon and the factors associated with the failure to use EMS during a potential cardiac event. METHODS AND RESULTS Baseline data were gathered from a randomized, controlled community trial (REACT) that was conducted in 20 US communities. A random-digit-dial survey documented bystander intentions to use EMS for cardiac symptoms in each community. An emergency department surveillance system documented the mode of transport among chest pain patients in each community and collected ancillary data, including situational factors surrounding the chest pain event. Logistic regression identified factors associated with failure to use EMS. A total of 962 community members responded to the phone survey, and data were collected on 875 chest pain emergency department arrivals. The mean proportion of community members intending to use EMS during a witnessed cardiac event was 89%; the mean proportion of patients observed using the service was 23%, with significant geographic differences (range, 10% to 48% use). After controlling for covariates, non-EMS users were more likely to try antacids/aspirin and call a doctor and were less likely to subscribe to (or participate in) an EMS prepayment plan. CONCLUSIONS The results of this study indicate that indecision, self-treatment, physician contact, and financial concerns may undermine a chest pain patients intention to use EMS.

Receiving Hospital Characteristics Associated with Survival after Out-of-Hospital Cardiac Arrest

AIM Survival after out-of-hospital cardiac arrest (OOHCA) varies between regions, but the contribution of different factors to this variability is unknown. This study examined whether survival to hospital discharge was related to receiving hospital characteristics, including bed number, capability of performing cardiac catheterization and hospital volume of OOHCA cases. MATERIAL AND METHODS Prospective observational database of non-traumatic OOHCA assessed by emergency medical services was created in 8 US and 2 Canadian sites from December 1, 2005 to July 1, 2007. Subjects received hospital care after OOHCA, defined as either (1) arriving at hospital with pulses, or (2) arriving at hospital without pulses, but discharged or died > or =1 day later. RESULTS A total of 4087 OOHCA subjects were treated at 254 hospitals, and 32% survived to hospital discharge. A majority of subjects (68%) were treated at 116 (46%) hospitals capable of cardiac catheterization. Unadjusted survival to discharge was greater in hospitals performing cardiac catheterization (34% vs. 27%, p=0.001), and in hospitals that received > or =40 patients/year compared to those that received <40 (37% vs. 30%, p=0.01). Survival was not associated with hospital bed number, teaching status or trauma center designation. Length of stay (LOS) for surviving subjects was shorter at hospitals performing cardiac catheterization (p<0.01). After adjusting for all variables, there were no independent associations between survival or LOS and hospital characteristics. CONCLUSIONS Some subsets of hospitals displayed higher survival and shorter LOS for OOHCA subjects but there was no independent association between hospital characteristics and outcome.

Chest compression rates and survival following out-of-hospital cardiac arrest.

Objective:Guidelines for cardiopulmonary resuscitation recommend a chest compression rate of at least 100 compressions/min. A recent clinical study reported optimal return of spontaneous circulation with rates between 100 and 120/min during cardiopulmonary resuscitation for out-of-hospital cardiac arrest. However, the relationship between compression rate and survival is still undetermined. Design:Prospective, observational study. Setting:Data is from the Resuscitation Outcomes Consortium Prehospital Resuscitation IMpedance threshold device and Early versus Delayed analysis clinical trial. Participants:Adults with out-of-hospital cardiac arrest treated by emergency medical service providers. Interventions:None. Measurements Main Results:Data were abstracted from monitor-defibrillator recordings for the first five minutes of emergency medical service cardiopulmonary resuscitation. Multiple logistic regression assessed odds ratio for survival by compression rate categories (<80, 80–99, 100–119, 120–139, ≥140), both unadjusted and adjusted for sex, age, witnessed status, attempted bystander cardiopulmonary resuscitation, location of arrest, chest compression fraction and depth, first rhythm, and study site. Compression rate data were available for 10,371 patients; 6,399 also had chest compression fraction and depth data. Age (mean ± SD) was 67 ± 16 years. Chest compression rate was 111 ± 19 per minute, compression fraction was 0.70 ± 0.17, and compression depth was 42 ± 12 mm. Circulation was restored in 34%; 9% survived to hospital discharge. After adjustment for covariates without chest compression depth and fraction (n = 10,371), a global test found no significant relationship between compression rate and survival (p = 0.19). However, after adjustment for covariates including chest compression depth and fraction (n = 6,399), the global test found a significant relationship between compression rate and survival (p = 0.02), with the reference group (100–119 compressions/min) having the greatest likelihood for survival. Conclusions:After adjustment for chest compression fraction and depth, compression rates between 100 and 120 per minute were associated with greatest survival to hospital discharge.