Valerie J. De Maio

A Cumulative Meta-Analysis of the Effectiveness of Defibrillator-Capable Emergency Medical Services for Victims of Out-of-Hospital Cardiac Arrest

STUDY OBJECTIVE More than 1,000 patients experience sudden cardiac arrest each day. Treatment for this includes cardiopulmonary resuscitation (CPR) and emergency medical services (EMS) that provide CPR-basic life support (BLS), BLS with defibrillation (BLS-D), or advanced life support (ALS). Our previous systematic review of treatments for sudden cardiac arrest was limited by suboptimal data. Since then, debate has increased about whether bystander CPR is effective or whether attention should focus instead on rapid defibrillation. Therefore a cumulative meta-analysis was conducted to determine the relative effectiveness of differences in the defibrillation response time interval, proportion of bystander CPR, and type of EMS system on survival after out-of-hospital cardiac arrest. METHODS A comprehensive literature search was performed by using a priori exclusion criteria. We considered EMS systems that provided BLS-D, ALS, BLS plus ALS, or BLS-D plus ALS care. A generalized linear model was used with dispersion estimation for random effects. RESULTS Thirty-seven eligible articles described 39 EMS systems and included 33,124 patients. Median survival for all rhythm groups to hospital discharge was 6.4% (interquartile range, 3.7 to 10.3). Odds of survival were 1.06 (95% confidence interval [CI], 1.03 to 1.09; P <.01) per 5% increase in bystander CPR. Survival was constant if the defibrillation response time interval was less than 6 minutes, decreased as the interval increased from 6 to 11 minutes, and leveled off after 11 minutes (P <.01). Compared with BLS-D, odds of survival were as follows: ALS, 1. 71 (95% CI, 1.09 to 2.70; P =.01); BLS plus ALS, 1.47 (95% CI, 0.89 to 2.42; P =.07); and BLS with defibrillation plus ALS, 2.31 (95% CI, 1.47 to 3.62; P <.01.) CONCLUSION We confirm that greater survival after sudden cardiac arrest is associated with provision of bystander CPR, early defibrillation, or ALS. More research is required to evaluate the relative benefit of early defibrillation versus early ALS.

Improved Out-of-Hospital Cardiac Arrest Survival After the Sequential Implementation of 2005 AHA Guidelines for Compressions, Ventilations, and Induced Hypothermia: The Wake County Experience

STUDY OBJECTIVE We assess survival from out-of-hospital cardiac arrest after community-wide implementation of 2005 American Heart Association guidelines. METHODS This was an observational multiphase before-after cohort in an urban/suburban community (population 840,000) with existing advanced life support. Included were all adults treated for cardiac arrest by emergency responders. Excluded were patients younger than 16 years and trauma patients. Intervention phases in months were baseline 16; phase 1, new cardiopulmonary resuscitation 12; phase 2, impedance threshold device 6; and phase 3, full implementation including out-of-hospital-induced hypothermia 12. Primary outcome was survival to discharge. Other survival and neurologic outcomes were compared between study phases, and adjusted odds ratios with 95% confidence intervals (CIs) for survival by phase were determined by multivariate regression. RESULTS One thousand three hundred sixty-five cardiac arrest patients were eligible for inclusion: baseline n=425, phase 1 n=369, phase 2 n=161, phase 3 n=410. Across phases, patients had similar demographic, clinical, and emergency medical services characteristics. Overall and witnessed ventricular fibrillation and ventricular tachycardia survival improved throughout the study phases: respectively, baseline 4.2% and 13.8%, phase 1 7.3% and 23.9%, phase 2 8.1% and 34.6%, and phase 3 11.5% and 40.8%. The absolute increase for overall survival from baseline to full implementation was 7.3% (95% CI 3.7% to 10.9%); witnessed ventricular fibrillation/ventricular tachycardia survival was 27.0% (95% CI 13.6% to 40.4%), representing an additional 25 lives saved annually in this community. CONCLUSION In the context of a community-wide focus on resuscitation, the sequential implementation of 2005 American Heart Association guidelines for compressions, ventilations, and induced hypothermia significantly improved survival after cardiac arrest. Further study is required to clarify the relative contribution of each intervention to improved survival outcomes.

A simulation trial of traditional dispatcher-assisted CPR versus compressions - Only dispatcher-assisted CPR

Objectives. Growing evidence indicates that it may not be essential to deliver ventilations in the first few minutes of CPR. We compared time to delivery of first compression in traditional CPR with ventilations andcompressions to compression-only CPR performed by untrained laypersons assisted by a mock 911 dispatcher. Methods. This randomized-controlled simulation study included a convenience sample of English-speaking emergency department visitors during a 6-month period. Exclusion criteria were prior CPR training or physical incapacity. A cardiac arrest scenario was presented to subjects who were then provided with one of two sets of telephone CPR instructions by a mock 911 dispatcher. One group received traditional CPR instructions (TCPR) andthe second group received compression only CPR instructions (COCPR). Subjects performed CPR on a Laerdal Resusci-Anne CPR manikin andrecording strips were analyzed for frequency andquality measures. Pre-and post-test questionnaires assessed subject fatigue andtelephone instruction understanding. The primary outcome was the time interval from 911 call to initiation of chest compressions. Analysis included Student t-test, Chi-square, andWilcoxon Rank Sum. Results. Of 377 potential subjects, 54 consented to randomization. The data from 50 subjects were analyzed. Compared to group TCPR, group COCPR initiated chest compressions faster (72 vs 117 sec, p < 0.0001), completed four cycles of CPR faster (168 vs. 250 sec, p < 0.0001), andpaused for a smaller percentage of the resuscitation (13% vs. 36%, p < 0.0001). Only 9% of ventilation opportunities in the TCPR group yielded ventilations of the correct volume. There were no differences between groups in perceived understanding of CPR instruction or fatigue. Conclusions. We have identified the potential timesavings that may occur during compressions-only CPR. Bystander resuscitation may be more efficient when ventilations are excluded from the CPR sequence.

Double Sequential External Defibrillation in Out-of-Hospital Refractory Ventricular Fibrillation: A Report of Ten Cases

Abstract Background. Ventricular fibrillation (VF) is considered the out-of-hospital cardiac arrest (OOHCA) rhythm with the highest likelihood of neurologically intact survival. Unfortunately, there are occasions when VF does not respond to standard defibrillatory shocks. Current American Heart Association (AHA) guidelines acknowledge that the data are insufficient in determining the optimal pad placement, waveform, or energy level that produce the best conversion rates from OOHCA with VF. Objective. To describe a technique of double sequential external defibrillation (DSED) for cases of refractory VF (RVF) during OOHCA resuscitation. Methods. A retrospective case series was performed in an urban/suburban emergency medical services (EMS) system with advanced life support care and a population of 900,000. Included were all adult OOHCAs having RVF during resuscitation efforts by EMS providers. RVF was defined as persistent VF following at least 5 unsuccessful single shocks, epinephrine administration, and a dose of antiarrhythmic medication. Once the patient was in RVF, EMS personnel applied a second set of pads and utilized a second defibrillator for single defibrillation with the new monitor/pad placement. If VF continued, EMS personnel then utilized the original and second monitor/defibrillator charged to maximum energy, and shocks were delivered from both machines simultaneously. Data were collected from electronic dispatch and patient care reports for descriptive analysis. Results. From 01/07/2008 to 12/31/2010, a total of 10 patients were treated with DSED. The median age was 76.5 (IQR: 65–82), with median resuscitation time of 51minutes (IQR: 45–62). The median number of single shocks was 6.5 (IQR: 6–11), with a median of 2 (IQR: 1–3) DSED shocks delivered. VF broke after DSED in 7 cases (70%). Only 3 patients (30%) had ROSC in the field, and none survived to discharge. Conclusion. This case series demonstrates that DSED may be a feasible technique as part of an aggressive treatment plan for RVF in the out-of-hospital setting. In this series, RVF was terminated 70% of the time, but no patient survived to discharge. Further research is needed to better understand the characteristics of and treatment strategies for RVF.

Epidemiology of Out-of Hospital Pediatric Cardiac Arrest due to Trauma

Abstract Objective. To determine the epidemiology and survival of pediatric out-of-hospital cardiac arrest (OHCA) secondary to trauma. Methods. The CanAm Pediatric Cardiac Arrest Study Group is a collaboration of researchers in the United States and Canada sharing a common goal to improve survival outcomes for pediatric cardiac arrest. This was a prospective, multicenter, observational study. Twelve months of consecutive data were collected from emergency medical services (EMS), fire, and inpatient records from 2000 to 2003 for all OHCAs secondary to trauma in patients aged ≤18 years in 36 urban and suburban communities supporting advanced life support (ALS) programs. Eligible patients were apneic and pulseless and received chest compressions in the field. The primary outcome was survival to discharge. Secondary measures included return of spontaneous circulation (ROSC), survival to hospital admission, and 24-hour survival. Results. The study included 123 patients. The median patient age was 7.3 years (interquartile range [IQR] 6.0–17.0). The patient population was 78.1% male and 59.0% African American, 20.5% Hispanic, and 15.7% white. Most cardiac arrests occurred in residential (47.1%) or street/highway (37.2%) locations. Initial recorded rhythms were asystole (59.3%), pulseless electrical activity (29.1%), and ventricular fibrillation/tachycardia (3.5%). The majority of cardiac arrests were unwitnessed (49.5%), and less than 20% of patients received chest compressions by bystanders. The median (IQR) call-to-arrival interval was 4.9 (3.1–6.5) minutes and the on-scene interval was 12.3 (8.4–18.3) minutes. Blunt and penetrating traumas were the most common mechanisms (34.2% and 25.2%, respectively) and were associated with poor survival to discharge (2.4% and 6.5%, respectively). For all OHCA patients, 19.5% experienced ROSC in the field, 9.8% survived the first 24 hours, and 5.7% survived to discharge. Survivors had triple the rate of bystander cardiopulmonary resuscitation (CPR) than nonsurvivors (42.9% vs. 15.2%). Unlike patients sustaining blunt trauma or strangulation/hanging, most post–cardiac arrest patients who survived the first 24 hours after penetrating trauma or drowning were discharged alive. Drowning (17.1% of cardiac arrests) had the highest survival-to-discharge rate (19.1%). Conclusions. The overall survival rate for OHCA in children after trauma was low, but some trauma mechanisms are associated with better survival rates than others. Most OHCA in children is preventable, and education and prevention strategies should focus on those overrepresented populations and high-risk mechanisms to improve mortality.

Variability in discharge instructions and activity restrictions for patients in a children's ED postconcussion

Objective The objective of this study was to describe discharge instructions given to school-aged patients evaluated in a children’s emergency department (ED) following concussion. Methods This was a retrospective cohort study of children 6 to 18 years evaluated in a dedicated children’s ED at a level I trauma center in 2008 following acute head trauma regardless of mechanism, identified by any of 27 International Classification of Disease, Ninth Revision diagnoses for head injury, concussion, or skull fracture. Included were those presentations consistent with the Zurich definition for concussion. Excluded were hospital admission, death before admission, evidence of intoxication, or structural abnormality on imaging. Univariate and multivariate analyses determined adjusted odds ratios (ORs) for receipt of concussion-specific discharge instructions and activity restrictions. Results Of 350 eligible patients, the 218 included patients were mostly male (68%) with mean age 12.8 (SD, 3.4) years. Injury characteristics included sports-related, 42%; fall, 23%; loss of consciousness, 33%; headache, 75%; dizziness, 29%; amnesia, 25%; and vomiting, 19%. Most patients underwent imaging (81%). Discharge characteristics included concussion stated in final diagnosis, 31%; concussion-specific instructions, 62%; and activity restrictions, 34%. Concussion-specific discharge instructions were more likely for loss of consciousness (OR, 1.7; 95% confidence interval [CI], 1.22–2.36), and activity restrictions were more likely for sport-related injury (OR, 1.31; 95% CI, 1.02–1.76) and amnesia (OR, 1.42; 95% CI, 1.01–1.98). Conclusions Most children meeting diagnostic criteria for concussion were discharged without concussion-specific diagnoses or activity restrictions. Given the risks associated with untimely return to both physical and cognitive activity after concussion, improved awareness and standardization of disposition are imperative for the management of these young patients in the ED.

Retrospective validation of a protocol to limit unnecessary transport of assisted-living residents who fall

Abstract Objective. Emergency medical services (EMS) often transports patients who suffer simple falls in assisted-living facilities (ALFs). An EMS “falls protocol” could avoid unnecessary transport for many of these patients, while ensuring that patients with time-sensitive conditions are transported. Our objective was to retrospectively validate an EMS protocol to assist decision making regarding the transport of ALF patients with simple falls. Methods. We conducted a retrospective cohort study of patients transported to the emergency department from July 2010 to June 2011 for a chief complaint of “fall” within a subset of ALFs served by a specific primary care group in our urban EMS system (population 900,000). The primary outcome, “time-sensitive intervention” (TSI), was met by patients who had wound repair or fracture, admission to the ICU, OR, or cardiac cath lab, death during hospitalization, or readmission within 48 hours. EMS and primary care physicians developed an EMS protocol, a priori and by consensus, to require transport for patients needing TSI. The protocol utilizes screening criteria, including history and exam findings, to recommend transport versus nontransport with close primary care follow-up. The EMS protocol was retrospectively applied to determine which patients required transport. Protocol performance was estimated using sensitivity, specificity, and negative predictive value (NPV). Results. Of 653 patients transported across 30 facilities, 644 had sufficient data. Of these, 197 (31%) met the primary outcome. Most patients who required TSI had fracture (73) or wound repair (92). The EMS protocol identified 190 patients requiring TSI, for a sensitivity of 96% (95% CI: 93–98%), specificity of 54% (95% CI: 50–59%), and NPV of 97% (95% CI: 94–99%). Of 7 patients with false negatives, 3 were readmitted (and redischarged) after another fall, 3 sustained hip fractures that were surgically repaired, and 1 had a lumbar compression fracture and was discharged. Conclusions. In this cohort, two-thirds of patients with falls in ALFs did not require TSI. An EMS protocol may have sufficient sensitivity to safely allow for nontransport of these patients with falls in ALFs. Prospective validation of the protocol is necessary to test this hypothesis.

Impact of the privacy rule on the study of out-of-hospital pediatric cardiac arrest.

Introduction. The Privacy Rule, a follow-up to the Health Insurance Portability andAccountability Act, limits distribution of protected health information. Compliance with the Privacy Rule is particularly challenging for prehospital research, because investigators often seek data from multiple emergency medical services (EMS) andreceiving hospitals. Objective. To describe the impact of the Privacy Rule on prehospital research andto present strategies to optimize data collection in compliance with the Privacy Rule. Methods. The CanAm Pediatric Cardiopulmonary Arrest Study Group has previously conducted a multicentered observational study involving children with out-of-hospital cardiac arrest. In the current study, we used a survey to assess site-specific methods of compliance with the Privacy Rule andthe extent to which such strategies were successful. Results. The previously conducted observational study included collection of data from a total of 66 EMS agencies (range of 1–37 per site). Data collection from EMS providers was complicated by the lack of a systematic approval mechanism for the research use of EMS records andby incomplete resuscitation records. Agencies approached for approval to release EMS data for study purposes included Department of Health Institutional Review Boards, Fire Commissioners, andCommissioners of Health. The observational study included collection of data from a total of 164 receiving hospitals (range of 1–63 per site). Data collection from receiving hospitals was complicated by the varying requirements of receiving hospitals for the release of patient survival data. Conclusions. Obtaining complete EMS andhospital data is challenging but is vital to the conduct of prehospital research. Obtaining approval from city or state level IRBs or Privacy Boards may help optimize data collection. Uniformity of methods to adhere to regulatory requirements would ease the conduct of prehospital research.

Characteristics of paediatricpediatric concussion patients utilisingutilizing emergency department services prior to initial concussion clinic evaluation

Objective To evaluate characteristics of paediatric concussion patients utilising the emergency department (ED) prior to initial concussion clinic evaluation. Design Prospective cohort. Setting Clinics of an American urban/suburban family practice (12/2014–04/2015). Subjects Consented concussion patients 8–18 years presenting to clinic within 3 days of injury (n=195; age=14.3, SD=2.1 years; female=42.3%). Intervention Participants completed a systematic evaluation at initial clinic visit and survey at 4-6 weeks (73.8% follow-up). Criterion variables included demographics, prior head injury, time of injury (TOI) factors, total symptom severity, Immediate Postconcussion Assessment and Cognitive Test (ImPACT) composites, one-month persistent symptoms, one-month Paediatric Quality of Life (PedsQL). Outcome measures ED visit before clinic evaluation (yes/no) served as the dependent variable. Results ED visits were reported for 12.8% (n=25) of participants. Amnesia (36.0% vs. 10.1%; p<0.001), loss of consciousness (LOC) (20.8% vs. 6.7%; p=0.021), confusion (40.0% vs. 20.0%; p<0.0255), difficulty remembering (52.0% vs. 26.5%; p<0.0091), paresthesias (16.0% vs. 4.7%; p<0.0282), and CT imaging (60.0% vs. 0.6%; p<0.0001) were greater for the ED group. Initial symptom severity and ImPACT composite scores, and one-month outcomes of persistent symptoms and PedsQL, were no different for the ED group. Conclusions Paediatric patients presenting to concussion clinic with 72 hours of injury who first visited an ED, have more dramatic symptoms at the TOI, yet do not appear to have any worse initial symptom severity, ImPACT scores, or one-month persistent symptoms or PedsQL than those who presented first to clinic. Future study should evaluate these relationships in larger samples. Competing interests The current study is funded in part by the National Operating Committee on Standards for Athletic Equipment. Ms. Fonseca is employed at the study setting. Ms. Phillips is employed at the study setting. Dr. Bloom is employed at the study setting.

Football Equipment Removal Improves Chest Compression and Ventilation Efficacy

Abstract Objective: Airway access recommendations in potential catastrophic spine injury scenarios advocate for facemask removal, while keeping the helmet and shoulder pads in place for ensuing emergency transport. The anecdotal evidence to support these recommendations assumes that maintaining the helmet and shoulder pads assists inline cervical stabilization and that facial access guarantees adequate airway access. Our objective was to determine the effect of football equipment interference on performing chest compressions and delivering adequate ventilations on patient simulators. We hypothesized that conditions with more football equipment would decrease chest compression and ventilation efficacy. Methods: Thirty-two certified athletic trainers were block randomized to participate in six different compression conditions and six different ventilation conditions using human patient simulators. Data for chest compression (mean compression depth, compression rate, percentage of correctly released compressions, and percentage of adequate compressions) and ventilation (total ventilations, mean ventilation volume, and percentage of ventilations delivering adequate volume) conditions were analyzed across all conditions. Results: The fully equipped athlete resulted in the lowest mean compression depth (F5,154 = 22.82; P < 0.001; Effect Size = 0.98) and delivery of adequate compressions (F5,154 = 15.06; P < 0.001; Effect Size = 1.09) compared to all other conditions. Bag-valve mask conditions resulted in delivery of significantly higher mean ventilation volumes compared to all 1- or 2-person pocketmask conditions (F5,150 = 40.05; P < 0.001; Effect Size = 1.47). Two-responder ventilation scenarios resulted in delivery of a greater number of total ventilations (F5,153 = 3.99; P = 0.002; Effect Size = 0.26) and percentage of adequate ventilations (F5,150 = 5.44; P < 0.001; Effect Size = 0.89) compared to one-responder scenarios. Non-chinstrap conditions permitted greater ventilation volumes (F3,28 = 35.17; P < 0.001; Effect Size = 1.78) and a greater percentage of adequate volume (F3,28 = 4.85; P = 0.008; Effect Size = 1.12) compared to conditions with the chinstrap buckled or with the chinstrap in place but not buckled. Conclusions: Chest compression and ventilation delivery are compromised in equipment-intense conditions when compared to conditions whereby equipment was mostly or entirely removed. Emergency medical personnel should remove the helmet and shoulder pads from all football athletes who require cardiopulmonary resuscitation, while maintaining appropriate cervical spine stabilization when injury is suspected. Further research is needed to confirm our findings supporting full equipment removal for chest compression and ventilation delivery.