Prehospital Cardiac Arrest Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical component of out-of-hospital cardiac arrest (OHCA) resuscitation. Multiple cardiac arrest airway management techniques are available to EMS clinicians including bag-valve-mask (BVM) ventilation, supraglottic airways (SGAs), and endotracheal intubation (ETI). Important goals include achieving optimal oxygenation and ventilation while minimizing negative effects on physiology and interference with other resuscitation interventions. NAEMSP recommends:Based on the skill of the clinician and available resources, BVM, SGA, or ETI may be considered as airway management strategies in OHCA.Airway management should not interfere with other key resuscitation interventions such as high-quality chest compressions, rapid defibrillation, and treatment of reversible causes of the cardiac arrest.EMS clinicians should take measures to avoid hyperventilation during cardiac arrest resuscitation.Where available for clinician use, capnography should be used to guide ventilation and chest compressions, confirm and monitor advanced airway placement, identify return of spontaneous circulation (ROSC), and assist in the decision to terminate resuscitation.

Change in out-of-hospital 12-lead ECG diagnostic classification following resuscitation from cardiac arrest

INTRODUCTION

We evaluated the incidence of change in serial 12-lead electrocardiogram (ECG) diagnostic classifications in patients resuscitated from out-of-hospital (OH) cardiac arrest (OHCA) comparing OH to emergency department (ED) ECGs.

METHODS

This retrospective case series included: 1) adults (≥ 18 years old), 2) resuscitated from OHCA, 3) ≥ 1 OH and 1 ED ECG/patient, and 4) emergency medical services (EMS) transport to the study hospital. OH and ED ECGs were classified as: 1) STEMI (ST-segment Elevation Myocardial Infarction), 2) Ischemic, and 3) Non-ischemic. Two ED physicians and one cardiologist independently classified all ECGs, then generated a consensus opinion classification for each ECG based on American Heart Association's 2018 Expert Consensus criteria. The most ischemic OH ECG classification was compared with the last ED ECG classification.

RESULTS

From 7/27/12 to 7/18/19, 176 patients were entered with a mean age of 61.2 ± 16.6 years; 102/176 (58%) were male. Overall, 504 OH and ED 12-lead ECGs were acquired (2.9 ECGs/patient). ECG classification inter-rater reliability kappa score was 0.63 ± 0.02 (substantial agreement). Overall, 86/176 (49%) changed ECG classification from the OH to ED setting; 69/86 (80%) of these ECGs changed from more to less ischemic classifications. Of 49 OH STEMI ECG classifications, 33/49 (67%) changed to a less ischemic (non-STEMI) ED ECG classification.

CONCLUSIONS

Change in 12-lead ECG classification from OH to ED setting in patients resuscitated from OHCA was common (49%). The OH STEMI classification changed to a less ischemic (non-STEMI) ED classification in 67% of cases.

Airway strategy and chest compression quality in the Pragmatic Airway Resuscitation Trial

BACKGROUND

Chest compression (CC) quality is associated with improved out-of-hospital cardiopulmonary arrest (OHCA) outcomes. Airway management efforts may adversely influence CC quality. We sought to compare the effects of initial laryngeal tube (LT) and initial endotracheal intubation (ETI) airway management strategies upon chest compression fraction (CCF), rate and interruptions in the Pragmatic Airway Resuscitation Trial (PART).

METHODS

We analyzed CPR process files collected from adult OHCA enrolled in PART. We used automated signal processing techniques and a graphical user interface to calculate CC quality measures and defined interruptions as pauses in chest compressions longer than 3 s. We determined CC fraction, rate and interruptions (number and total duration) for the entire resuscitation and compared differences between LT and ETI using t-tests. We repeated the analysis stratified by time before, during and after airway insertion as well as by successive 3-min time segments. We also compared CC quality between single vs. multiple airway insertion attempts, as well as between bag-valve-mask (BVM-only) vs. ETI or LT.

RESULTS

Of 3004 patients enrolled in PART, CPR process data were available for 1996 (1001 LT, 995 ETI). Mean CPR analysis duration were: LT 22.6 ± 10.8 min vs. ETI 25.3 ± 11.3 min (p < 0.001). Mean CC fraction (LT 88% vs. ETI 87%, p = 0.05) and rate (LT 114 vs. ETI 114 compressions per minute (cpm), p = 0.59) were similar between LT and ETI. Median number of CC interruptions were: LT 11 vs. ETI 12 (p = 0.001). Total CC interruption duration was lower for LT than ETI (LT 160 vs. ETI 181 s, p = 0.002); this difference was larger before airway insertion (LT 56 vs. ETI 78 s, p < 0.001). There were no differences in CC quality when stratified by 3-min time epochs.

CONCLUSION

In the PART trial, compared with ETI, LT was associated with shorter total CC interruption duration but not other CC quality measures. CC quality may be associated with OHCA airway management.

Bougie-assisted endotracheal intubation in the pragmatic airway resuscitation trial

OBJECTIVE

Paramedics may perform endotracheal intubation (ETI) while treating patients with out-of-hospital cardiac arrest (OHCA). The gum elastic Bougie (Bougie) is an intubation adjunct that may optimize intubation success. There are few reports of Bougie-assisted intubation in OHCA nor its association with outcomes. We compared intubation success rates and OHCA outcomes between Bougie-assisted and non-Bougie ETI in the out-of-hospital Pragmatic Airway Resuscitation Trial (PART).

METHODS

This was a secondary analysis of patients receiving ETI enrolled in the Pragmatic Airway Resuscitation Trial (PART), a multicenter clinical trial comparing intubation-first vs. laryngeal tube-first strategies of airway management in adult OHCA. The primary exposure was use of Bougie for ETI-assistance. The primary endpoint was first-pass ETI success. Secondary endpoints included overall ETI success, time to successful ETI, return of spontaneous circulation, 72-h survival, hospital survival and hospital survival with favorable neurologic status (Modified Rankin Score ≤3). We analyzed the data using Generalized Estimating Equations and Cox Regression, adjusting for known confounders.

RESULTS

Of the 3004 patients enrolled in PART, 1227 received ETI, including 440 (35.9%) Bougie-assisted and 787 (64.1%) non-Bougie ETIs. First-pass ETI success did not differ between Bougie-assisted and non-Bougie ETI (53.1% vs. 42.8%; adjusted OR 1.12, 95% CI: 0.97-1.39). ETI overall success was slightly higher in the Bougie-assisted group (56.2% vs. 49.1%; adjusted OR 1.19, 95% CI: 1.01-1.32). Time to endotracheal tube placement or abandonment was longer for Bougie-assisted than non-Bougie ETI (median 13 vs. 11 min; adjusted HR 0.63, 95% CI: 0.45-0.90). While survival to hospital discharge was lower for Bougie-assisted than non-Bougie ETI (3.6% vs. 7.5%; adjusted OR 0.94, 95% CI: 0.92-0.96), there were no differences in ROSC, 72-h survival or hospital survival or hospital survival with favorable neurologic status.

CONCLUSION

While exhibiting slightly higher ETI overall success rates, Bougie-assisted ETI entailed longer airway placement times and potentially lower survival. The role of the Bougie assistance in ETI of OHCA remains unclear.

Multimedia Evaluation of EMT-Paramedic Assessment and Management of Pediatric Respiratory Distress

BACKGROUND

The prehospital care of asthma, bronchiolitis and croup is directed by evidence-based Emergency Medical Services (EMS) protocols. Determining the appropriate intervention for these conditions requires Emergency Medical Technicians-Paramedics (EMT-Ps) to correctly differentiate asthma/bronchospasm, bronchiolitis, and croup. The diagnostic accuracy of EMT-Ps for these pediatric respiratory distress conditions is unknown.

OBJECTIVE

We hypothesized increasing provider age, years of provider experience, higher volume of pediatric cases, self-reported comfort with pediatric patients, and having children of one's own would be associated with increased accuracy in diagnosis on a validated multimedia questionnaire.

METHODS

This is a cross-sectional study of paramedics from a single EMS agency who completed a validated, case-based questionnaire between July and September 2018. The multimedia questionnaire consisted of four cases, each of which included patient videos and lung sound recordings. Paramedics were asked to assess the severity of distress and ascribe the correct diagnosis and prehospital intervention for each case. Each paramedic completed the questionnaire independently. We defined high questionnaire performance a priori as correctly identifying the diagnosis for ≥75% of cases and used multivariate regression to assess factors associated with high questionnaire performance. Provider age and EMS experience were reported in years and analyzed as continuous variables. Volume of pediatric cases was dichotomized to <1 and ≥1 case per shift and having children was dichotomized to either having children or not having children.

RESULTS

Of 514 paramedics, 420 (82%) completed the questionnaire. Overall, paramedics correctly assessed the severity of respiratory distress 92% of the time. However, they only ascribed the correct diagnosis 50% and selected the correct intervention(s) 38% of the time. Increasing age, years of experience, higher volume of pediatric cases, self-reported comfort with pediatric patients, and having children of their own were not associated with questionnaire performance.

CONCLUSION

Paramedics accurately assessed severity of distress in multimedia cases of asthma/bronchospasm, bronchiolitis and croup in children, but showed significant room for improvement in correctly identifying the diagnosis and in selecting appropriate intervention(s). Age, years of EMS experience, higher volume of clinical pediatric cases, self-reported comfort with pediatric patients, and having children of their own were not associated with questionnaire performance.

Effect of Out-of-Hospital Tranexamic Acid vs Placebo on 6-Month Functional Neurologic Outcomes in Patients With Moderate or Severe Traumatic Brain Injury

IMPORTANCE

Traumatic brain injury (TBI) is the leading cause of death and disability due to trauma. Early administration of tranexamic acid may benefit patients with TBI.

OBJECTIVE

To determine whether tranexamic acid treatment initiated in the out-of-hospital setting within 2 hours of injury improves neurologic outcome in patients with moderate or severe TBI.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blinded, randomized clinical trial at 20 trauma centers and 39 emergency medical services agencies in the US and Canada from May 2015 to November 2017. Eligible participants (N = 1280) included out-of-hospital patients with TBI aged 15 years or older with Glasgow Coma Scale score of 12 or less and systolic blood pressure of 90 mm Hg or higher.

INTERVENTIONS

Three interventions were evaluated, with treatment initiated within 2 hours of TBI: out-of-hospital tranexamic acid (1 g) bolus and in-hospital tranexamic acid (1 g) 8-hour infusion (bolus maintenance group; n = 312), out-of-hospital tranexamic acid (2 g) bolus and in-hospital placebo 8-hour infusion (bolus only group; n = 345), and out-of-hospital placebo bolus and in-hospital placebo 8-hour infusion (placebo group; n = 309).

MAIN OUTCOMES AND MEASURES

The primary outcome was favorable neurologic function at 6 months (Glasgow Outcome Scale-Extended score >4 [moderate disability or good recovery]) in the combined tranexamic acid group vs the placebo group. Asymmetric significance thresholds were set at 0.1 for benefit and 0.025 for harm. There were 18 secondary end points, of which 5 are reported in this article: 28-day mortality, 6-month Disability Rating Scale score (range, 0 [no disability] to 30 [death]), progression of intracranial hemorrhage, incidence of seizures, and incidence of thromboembolic events.

RESULTS

Among 1063 participants, a study drug was not administered to 96 randomized participants and 1 participant was excluded, resulting in 966 participants in the analysis population (mean age, 42 years; 255 [74%] male participants; mean Glasgow Coma Scale score, 8). Of these participants, 819 (84.8%) were available for primary outcome analysis at 6-month follow-up. The primary outcome occurred in 65% of patients in the tranexamic acid groups vs 62% in the placebo group (difference, 3.5%; [90% 1-sided confidence limit for benefit, -0.9%]; P = .16; [97.5% 1-sided confidence limit for harm, 10.2%]; P = .84). There was no statistically significant difference in 28-day mortality between the tranexamic acid groups vs the placebo group (14% vs 17%; difference, -2.9% [95% CI, -7.9% to 2.1%]; P = .26), 6-month Disability Rating Scale score (6.8 vs 7.6; difference, -0.9 [95% CI, -2.5 to 0.7]; P = .29), or progression of intracranial hemorrhage (16% vs 20%; difference, -5.4% [95% CI, -12.8% to 2.1%]; P = .16).

CONCLUSIONS AND RELEVANCE

Among patients with moderate to severe TBI, out-of-hospital tranexamic acid administration within 2 hours of injury compared with placebo did not significantly improve 6-month neurologic outcome as measured by the Glasgow Outcome Scale-Extended.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01990768.

Racial disparities in out-of-hospital cardiac arrest interventions and survival in the Pragmatic Airway Resuscitation Trial

BACKGROUND

Prior studies have reported racial disparities in survival from out-of-hospital cardiac arrest (OHCA). However, these studies did not evaluate the association of race with OHCA course of care and outcomes. The purpose of this study was to evaluate racial disparities in OHCA airway placement success and patient outcomes in the multicenter Pragmatic Airway Resuscitation Trial (PART).

METHOD

We conducted a secondary analysis of adult OHCA patients enrolled in PART. The parent trial randomized subjects to initial advanced airway management with laryngeal tube or endotracheal intubation. For this analysis, the primary independent variable was patient race categorized by emergency medical services (EMS) as white, black, Hispanic, other, and unknown. We used general estimating equations to examine the association of race with airway attempt success, 72-h survival, and survival to hospital discharge, adjusting for sex, age, witness status, bystander cardiopulmonary resuscitation (CPR), initial rhythm, arrest location, and PART randomization cluster.

RESULTS

Of 3002 patients, EMS-assessed race as 1537 white, 860 black, 163 Hispanic, 90 other, and 352 unknown. Initial shockable rhythms (13.8% vs. 21.5%, p < 0.001), bystander CPR (35.6% vs. 51.4%, p < 0.001), and survival to hospital discharge (7.6% vs. 10.8%, p = 0.011) were lower for black compared to white patients. After adjustment for confounders, no difference was seen in airway success, 72-h survival, and survival to hospital discharge by race.

CONCLUSIONS

In one of the largest studies evaluating differences in prehospital airway interventions and outcomes by EMS-assessed race for OHCA patients, we found no significant adjusted differences between airway success or survival outcomes.

The impact of increased chest compression fraction on survival for out-of-hospital cardiac arrest patients with a non-shockable initial rhythm

OBJECTIVE

We evaluated the effect of chest compression fraction (CCF) on survival to hospital discharge and return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients with non-shockable rhythms.

METHODS

This is a retrospective analysis (completed in 2016) of a prospective cohort study which included OHCA patients from ten U.S. and Canadian sites (Resuscitation Outcomes Consortium Epistry and PRIMED study (2007-2011)). We included all OHCA victims of presumed cardiac aetiology, not witnessed by emergency medical services (EMS), without automated external defibrillator shock prior to EMS arrival, receiving > 1 min of CPR with CPR process measures available, and initial non-shockable rhythm. We measured CCF using the first 5 min of electronic CPR records.

RESULTS

Demographics of 12,928 adult patients were: mean age 68; male 59.9%; public location 8.5%; bystander witnessed 35.2%; bystander CPR 39.3%; median interval from 911 to defibrillator turned on 10 min:04 s; initial rhythm asystole 64.8%, PEA 26.0%, other non-shockable 9.2%; compression rate 80-120/min (69.1%); median CCF 74%; ROSC 25.6%; survival to hospital discharge 2.4%. Adjusted odds ratio (OR); 95% confidence intervals (95%CI) of survival for each CCF category were: 0-40% (2.00; 1.16, 3.32); 41-60% (0.83; 0.54, 1.24); 61-80% (1.02; 0.77, 1.35); and 81-100% (reference group). Adjusted (OR; 95%CI) of ROSC for each CCF category were: 0-40% (1.02; 0.79, 1.30); 41-60% (0.83; 0.72, 0.95); 61-80% (0.85; 0.77, 0.94); and 81-100% (reference group).

CONCLUSIONS

We observed an incremental benefit from higher CCF on the incidence of ROSC, but not survival, among non-shockable OHCA patients with CCF higher than 40%.

Innovative Approaches to Emergency Medical Services Fellowship Challenges

Introduction

Since the development of an Accreditation Council of Graduate Medical Education (ACGME)-accredited emergency medical services (EMS) fellowship, there has been little published literature on effective methods of content delivery or training modalities. Here we explore a variety of innovative approaches to the development and revision of the EMS fellowship curriculum.

Methods

Three academic, university-based ACGME-accredited EMS fellowship programs each implemented an innovative change to their existing training curricula. These changes included the following: a novel didactic curriculum delivery modality and evaluation; implementation of a distance education program to improve EMS fellows’ rural EMS experiences; and modification of an existing EMS fellowship curriculum to train a non-emergency medicine physician.

Results

Changes made to each of the above EMS fellowship programs addressed unique challenges, demonstrating areas of success and promise for more generalized implementation of these curricula. Obstacles remain in tailoring the described curricula to the needs of each unique institution and system.

Conclusion

Three separate curricula and program changes were implemented to overcome specific challenges and achieve educational goals. It is our hope that our shared experiences will enable others in addressing common barriers to teaching the EMS fellowship core content and share similar innovative approaches to educational challenges.

A centralized system for providing dispatcher assisted CPR instructions to 9-1-1 callers at multiple municipal public safety answering points

BACKGROUND

Dispatcher CPR instruction increases the odds of survival. However, many communities do not provide this lifesaving intervention, often citing the barriers of limited personnel, funding, and liability.

OBJECTIVE

Describe the implementation of a novel centralized dispatcher CPR instruction program that serves seven public safety answering points (PSAPs).

METHODS

Seven municipal PSAPs that did not previously provide dispatcher instructions implemented our program. Using a 30-min self-directed video, 84 PSAP dispatchers were trained to utilize a two-question protocol to identify and transfer suspected out-of-hospital cardiac arrest (OHCA) cases to a central communication center. At this central communication center, a trained communicator delivered CPR instructions to the caller. The 26 central communicators were trained with a 2-h in-person didactic session followed by a 2-h practice session. We collected and analyzed data from recordings of communicator-to-caller interactions.

RESULTS

169 calls were transferred to the central communication center. Of those, 106 needed CPR instructions and 56 of those callers performed chest compressions (53%). The county-wide EMS documented bystander CPR rate was 20% the prior year. The 63 remaining transferred calls were non-OHCA calls. Of the calls where CPR was needed and performed, 11 victims survived to hospital discharge (20%); the countywide survival rate was 12%.

CONCLUSIONS

Using a central communication center for instructions allowed us to train and maintain a smaller group of communicators, leading to less cost and more experience for those communicators, while limiting the burden on PSAP dispatchers.

Comparing the Accuracy of Mass Casualty Triage Systems When Used in an Adult Population

Objective: To use a previously published criterion standard to compare the accuracy of 4 different mass casualty triage systems (Sort, Assess, Lifesaving Interventions, Treatment/Transport [SALT], Simple Triage and Rapid Treatment [START], Triage Sieve, and CareFlight) when used in an emergency department-based adult population. Methods: We performed a prospective, observational study of a convenience sample of adults aged 18 years or older presenting to a single tertiary care hospital emergency department. A co-investigator with prior emergency medical services (EMS) experience observed each subject's initial triage in the emergency department and recorded all data points necessary to assign a triage category using each of the 4 mass casualty triage systems being studied. Subjects' medical records were reviewed after their discharge from the hospital to assign the "correct" triage category using the criterion standard. The 4 mass casualty triage system assignments were then compared to the "correct" assignment. Descriptive statistics were used to compare accuracy and over- and under-triage rates for each triage system. Results: A total of 125 subjects were included in the study. Of those, 53% were male and 59% were transported by private vehicle. When compared to the criterion standard definitions, SALT was found to have the highest accuracy rate (52%; 95% CI 43-60) compared to START (36%; 95% CI 28-44), CareFlight (36%; 95% CI 28-44), and TriageSieve (37%; 95% CI 28-45). SALT also had the lowest under-triage rate (26%; 95% CI 19-34) compared to START (57%; 95% CI 48-66), CareFlight (58%; 95% CI 49-66), and TriageSieve (58%; 95% CI 49-66). SALT had the highest over-triage rate (22%; 95% CI 14-29) compared to START (7%; 95% CI 3-12), CareFlight (6%; 95% CI 2-11) and TriageSieve (6%; 95% CI 2-11). Conclusion: We found that SALT triage most often correctly triaged adult emergency department patients when compared to a previously published criterion standard. While there are no target under- and over-triage rates that have been published for mass casualty triage, all 4 systems had relatively high rates of under-triage.

Helicopter Emergency Medical Services Utilization

BACKGROUND

The decision to utilize HEMS is a complex process that involves many considerations. Professional associations and agencies have published guidelines to assist providers with decision making for the utilization of helicopter transport.

STUDY OBJECTIVE

Determine if requests for HEMS align with recently published utilization guidelines.

STUDY DESIGN

A retrospective chart review was performed during a six-month period. Reviewers versed in Wisconsin HEMS Utilization, NAEMSP, and CAMTS guidelines determined if transport criteria were met. Charts were categorized according to whether or not criteria for each set of recommendations were followed.

RESULTS

514 charts were reviewed; 439 consisted of completed patient transports. CAMTS, NAEMSP, and WI HEMS guidelines satisfied 85.4%, 83.4%, and 53.1% of requests, respectively. Statistically significant differences existed when comparing rates meeting criteria between WI HEMS and CAMTS and between WI HEMS and NAEMSP guidelines (p-value <0.0001). This was true in all subgroups except STEMI, which did not show significant difference. No difference existed between rates for CAMTS and NAEMSP guidelines in any group.

CONCLUSION

Significant difference between Wisconsin HEMS utilization versus NAEMSP guidelines, and between Wisconsin HEMS utilization and CAMTS guidelines in all subgroups except STEMI patients exist. No statistically significant difference existed between NAEMSP and CAMTS guidelines.

Comparing the Accuracy of Mass Casualty Triage Systems in a Pediatric Population

INTRODUCTION

It was previously difficult to compare the accuracy of different mass casualty triage systems to one another. This pilot study is one of the first attempts to operationalize an expert panel's criterion standard definitions of triage categories in a pediatric population in order to compare accuracy between different systems.

OBJECTIVE

To compare the accuracy of 4 different mass casualty triage systems (SALT, JumpSTART, Triage Sieve, and CareFlight) when used for children.

METHODS

We observed the emergency department triage of patients less than 18 years old presenting to the only pediatric specialty hospital/Level 1 trauma center in Milwaukee County, Wisconsin. A single, certified EMS provider observed each patient's initial triage in the emergency department and recorded all findings that were necessary to categorize the patient using each of the 4 mass casualty triage systems being studied. Hospital medical records were then reviewed for each patient and assigned a criterion standard triage category based on the treatments received and final disposition. Descriptive statistics were used to compare accuracy, over-, and under-triage rates for each of the triage systems.

RESULTS

A total of 115 subjects were enrolled. Of those, 51% were male and 57% were transported by ambulance. When compared to the criterion standard definitions, SALT was found to have the highest accuracy rate (59%; 95% CI 50-68) compared to JumpSTART (57%; 95% CI 48-66), CareFlight (56%; 95% CI 47-65), and TriageSieve (56%; 95% CI 46-65). SALT also had the lowest under-triage rate (33%; 95% CI 24-42) compared to JumpSTART (39%; 95% CI 30-48), CareFlight (39%; 95% CI 30-48), and TriageSieve (39%; 95% CI 30-48). SALT had the highest over-triage rate (6%; 95% CI 2-11) compared to JumpSTART (4%; 95% CI 1-8), CareFlight (5%; 95% CI 1-9), and TriageSieve (5%; 95% CI 1-9). However, the confidence intervals for both the accuracy and under-triage rates overlapped between all triage systems. For each triage system, the most common error was designating a patient as "minimal" that, according to the criterion standard, should have been triaged as "delayed."

CONCLUSION

We found that the 4 most popular mass casualty triage systems preformed similarly in an emergency department-based pediatric population. None of the systems were extremely accurate, and each demonstrated an unacceptable amount of under-triage. Better differentiating between patients categorized as "minimal" and "delayed" may improve the accuracy of mass casualty triage systems.

Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

Emergency medical services (EMS) commonly perform endotracheal intubation (ETI) or insertion of supraglottic airways, such as the laryngeal tube (LT), on patients with out-of-hospital cardiac arrest (OHCA). The optimal method for OHCA advanced airway management is unknown.

OBJECTIVE

To compare the effectiveness of a strategy of initial LT insertion vs initial ETI in adults with OHCA.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter pragmatic cluster-crossover clinical trial involving EMS agencies from the Resuscitation Outcomes Consortium. The trial included 3004 adults with OHCA and anticipated need for advanced airway management who were enrolled from December 1, 2015, to November 4, 2017. The final date of follow-up was November 10, 2017.

INTERVENTIONS

Twenty-seven EMS agencies were randomized in 13 clusters to initial airway management strategy with LT (n = 1505 patients) or ETI (n = 1499 patients), with crossover to the alternate strategy at 3- to 5-month intervals.

MAIN OUTCOMES AND MEASURES

The primary outcome was 72-hour survival. Secondary outcomes included return of spontaneous circulation, survival to hospital discharge, favorable neurological status at hospital discharge (Modified Rankin Scale score ≤3), and key adverse events.

RESULTS

Among 3004 enrolled patients (median [interquartile range] age, 64 [53-76] years, 1829 [60.9%] men), 3000 were included in the primary analysis. Rates of initial airway success were 90.3% with LT and 51.6% with ETI. Seventy-two hour survival was 18.3% in the LT group vs 15.4% in the ETI group (adjusted difference, 2.9% [95% CI, 0.2%-5.6%]; P = .04). Secondary outcomes in the LT group vs ETI group were return of spontaneous circulation (27.9% vs 24.3%; adjusted difference, 3.6% [95% CI, 0.3%-6.8%]; P = .03); hospital survival (10.8% vs 8.1%; adjusted difference, 2.7% [95% CI, 0.6%-4.8%]; P = .01); and favorable neurological status at discharge (7.1% vs 5.0%; adjusted difference, 2.1% [95% CI, 0.3%-3.8%]; P = .02). There were no significant differences in oropharyngeal or hypopharyngeal injury (0.2% vs 0.3%), airway swelling (1.1% vs 1.0%), or pneumonia or pneumonitis (26.1% vs 22.3%).

CONCLUSIONS AND RELEVANCE

Among adults with OHCA, a strategy of initial LT insertion was associated with significantly greater 72-hour survival compared with a strategy of initial ETI. These findings suggest that LT insertion may be considered as an initial airway management strategy in patients with OHCA, but limitations of the pragmatic design, practice setting, and ETI performance characteristics suggest that further research is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02419573.

Self-Assessment Feedback Form Improves Quality of Out-of-Hospital CPR

Objective: Various continuous quality improvement (CQI) approaches have been used to improve quality of cardiopulmonary resuscitation (CPR) delivered at the scene of out-of-hospital cardiac arrest. We evaluated a post-event, self-assessment, CQI feedback form to determine its impact on delivery of CPR quality metrics. Methods: This before/after retrospective review evaluated data from a CQI program in a midsized urban emergency medical services (EMS) system using CPR quality metrics captured by Zoll Medical Inc. X-series defibrillator ECG files in adult patients (≥18 years old) with non-traumatic out-of-hospital cardiac arrest. Two 9-month periods, one before and one after implementation of the feedback form on December 31, 2013 were evaluated. Metrics included the mean and percentage of goal achievement for chest compression depth (goal: >5 centimeters [cm]; >90%/episode), rate (goal: 100-120 compressions/minute [min]), chest compression fraction (goal: ≥75%), and preshock pause (goal: <10 seconds [sec]). The feedback form was distributed to all EMS providers involved in the resuscitation within 72 hours for self-review. Results: A total of 439 encounters before and 621 encounters after were evaluated including basic life support (BLS) and advanced life support (ALS) providers. The Before Group consisted of 408 patients with an average age of 61 ± 17 years, 61.8% male. The After Group consisted of 556 patients with an average age of 61 ± 17 years, 58.3% male. Overall, combining BLS and ALS encounters, the mean CPR metric values before and after were: chest compression depth (5.0 cm vs. 5.5 cm; p < 0.001), rate (109.6/min vs 114.8/min; p < 0.001), fraction (79.2% vs. 86.4%; p < 0.001), and preshock pause (18.8 sec vs. 11.8 sec; p < 0.001), respectively. Overall, the percent goal achievement before and after were: chest compression depth (48.5% vs. 66.6%; p < 0.001), rate (71.8% vs. 71.7%, p = 0.78), fraction (68.1% vs. 91.0%; p < 0.001), and preshock pause (24.1% vs. 59.5%; p < 0.001), respectively. The BLS encounters and ALS encounters had similar statistically significant improvements seen in all metrics. Conclusion: This post-event, self-assessment CQI feedback form was associated with significant improvement in delivery of out-of-hospital CPR depth, fraction and preshock pause time.

Antiarrhythmic Drugs for Nonshockable-Turned-Shockable Out-of-Hospital Cardiac Arrest: The ALPS Study (Amiodarone, Lidocaine, or Placebo)

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) commonly presents with nonshockable rhythms (asystole and pulseless electric activity). It is unknown whether antiarrhythmic drugs are safe and effective when nonshockable rhythms evolve to shockable rhythms (ventricular fibrillation/pulseless ventricular tachycardia [VF/VT]) during resuscitation.

METHODS

Adults with nontraumatic OHCA, vascular access, and VF/VT anytime after ≥1 shock(s) were prospectively randomized, double-blind, to receive amiodarone, lidocaine, or placebo by paramedics. Patients presenting with initial shock-refractory VF/VT were previously reported. The current study was a prespecified analysis in a separate cohort that initially presented with nonshockable OHCA and was randomized on subsequently developing shock-refractory VF/VT. The primary outcome was survival to hospital discharge. Secondary outcomes included discharge functional status and adverse drug-related effects.

RESULTS

Of 37 889 patients with OHCA, 3026 with initial VF/VT and 1063 with initial nonshockable-turned-shockable rhythms were treatment-eligible, were randomized, and received their assigned drug. Baseline characteristics among patients with nonshockable-turned-shockable rhythms were balanced across treatment arms, except that recipients of a placebo included fewer men and were less likely to receive bystander cardiopulmonary resuscitation. Active-drug recipients in this cohort required fewer shocks, supplemental doses of their assigned drug, and ancillary antiarrhythmic drugs than recipients of a placebo (P<0.05). In all, 16 (4.1%) amiodarone, 11 (3.1%) lidocaine, and 6 (1.9%) placebo-treated patients survived to hospital discharge (P=0.24). No significant interaction between treatment assignment and discharge survival occurred with the initiating OHCA rhythm (asystole, pulseless electric activity, or VF/VT). Survival in each of these categories was consistently higher with active drugs, although the trends were not statistically significant. Adjusted absolute differences (95% confidence interval) in survival from nonshockable-turned-shockable arrhythmias with amiodarone versus placebo were 2.3% (-0.3, 4.8), P=0.08, and for lidocaine versus placebo 1.2% (-1.1, 3.6), P=0.30. More than 50% of these survivors were functionally independent or required minimal assistance. Drug-related adverse effects were infrequent.

CONCLUSIONS

Outcome from nonshockable-turned-shockable OHCA is poor but not invariably fatal. Although not statistically significant, point estimates for survival were greater after amiodarone or lidocaine than placebo, without increased risk of adverse effects or disability and consistent with previously observed favorable trends from treatment of initial shock-refractory VF/VT with these drugs. Together the findings may signal a clinical benefit that invites further investigation.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01401647.

Does an individualized feedback mechanism improve quality of out-of-hospital CPR?

BACKGROUND

Despite its prevalence, survival from out-of-hospital cardiac arrest remains low. High quality CPR has been associated with improved survival in cardiac arrest patients. In early 2014, a program was initiated to provide feedback on CPR quality to prehospital providers after every treated cardiac arrest.

OBJECTIVE

To assess whether individualized CPR feedback was associated with improved CPR quality measures in the prehospital setting.

METHODS

This before and after retrospective review included all treated adult out-of-hospital cardiac arrest in patients in an urban community. Data was compared prior to and after the initiation of the CPR feedback program. We compared the percent of encounters reaching the system defined benchmarks as well as the average values for compression fraction, compression rate, compression depth, and pre-shock pause in the before period compared to the after period.

RESULTS

There were 159 encounters in the before period and 117 in the after. Compared to the before group, the after group had higher average compression rates (111.2/min vs 113.8/min; p=0.042), increased compression depths (4.9cm vs 5.6cm; p<0.001), and increased rates of benchmark achievement for compression depth greater than 5cm (48.1% vs 72.6%; p<0.001). No significant difference was noted in pre-shock pause (21.4s vs 14.7s; p=0.068). Additionally, no difference was noted between groups for compression fraction, though goal achievement was high in both groups.

CONCLUSION

We found that individual CPR feedback is associated with marginally improved quality of CPR in the prehospital setting. Further investigation with larger samples is warranted to better quantify this effect.

Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest

BACKGROUND

Antiarrhythmic drugs are used commonly in out-of-hospital cardiac arrest for shock-refractory ventricular fibrillation or pulseless ventricular tachycardia, but without proven survival benefit.

METHODS

In this randomized, double-blind trial, we compared parenteral amiodarone, lidocaine, and saline placebo, along with standard care, in adults who had nontraumatic out-of-hospital cardiac arrest, shock-refractory ventricular fibrillation or pulseless ventricular tachycardia after at least one shock, and vascular access. Paramedics enrolled patients at 10 North American sites. The primary outcome was survival to hospital discharge; the secondary outcome was favorable neurologic function at discharge. The per-protocol (primary analysis) population included all randomly assigned participants who met eligibility criteria and received any dose of a trial drug and whose initial cardiac-arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia was refractory to shock.

RESULTS

In the per-protocol population, 3026 patients were randomly assigned to amiodarone (974), lidocaine (993), or placebo (1059); of those, 24.4%, 23.7%, and 21.0%, respectively, survived to hospital discharge. The difference in survival rate for amiodarone versus placebo was 3.2 percentage points (95% confidence interval [CI], -0.4 to 7.0; P=0.08); for lidocaine versus placebo, 2.6 percentage points (95% CI, -1.0 to 6.3; P=0.16); and for amiodarone versus lidocaine, 0.7 percentage points (95% CI, -3.2 to 4.7; P=0.70). Neurologic outcome at discharge was similar in the three groups. There was heterogeneity of treatment effect with respect to whether the arrest was witnessed (P=0.05); active drugs were associated with a survival rate that was significantly higher than the rate with placebo among patients with bystander-witnessed arrest but not among those with unwitnessed arrest. More amiodarone recipients required temporary cardiac pacing than did recipients of lidocaine or placebo.

CONCLUSIONS

Overall, neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT01401647.).

Design and implementation of the Resuscitation Outcomes Consortium Pragmatic Airway Resuscitation Trial (PART)

Airway management is an important component of resuscitation from out-of-hospital cardiac arrest (OHCA). The optimal approach to advanced airway management is unknown. The Pragmatic Airway Resuscitation Trial (PART) will compare the effectiveness of endotracheal intubation (ETI) and Laryngeal Tube (LT) insertion upon 72-h survival in adult OHCA. Encompassing United States Emergency Medical Services agencies affiliated with the Resuscitation Outcomes Consortium (ROC), PART will use a cluster-crossover randomized design. Participating subjects will include adult, non-traumatic OHCA requiring bag-valve-mask ventilation. Trial interventions will include (1) initial airway management with ETI and (2) initial airway management with LT. The primary and secondary trial outcomes are 72-h survival and return of spontaneous circulation. Additional clinical outcomes will include airway management process and adverse events. The trial will enroll a total of 3000 subjects. Results of PART may guide the selection of advanced airway management strategies in OHCA.

A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: rationale for and design of the Resuscitation Outcomes Consortium Continuous Chest Compressions Trial

The Resuscitation Outcomes Consortium is conducting a randomized trial comparing survival with hospital discharge after continuous chest compressions without interruption for ventilation versus currently recommended American Heart Association cardiopulmonary resuscitation with interrupted chest compressions in adult patients with out-of-hospital cardiac arrest without obvious trauma or respiratory cause. Emergency medical services perform study cardiopulmonary resuscitation for 3 intervals of manual chest compressions (each ~2 minutes) or until restoration of spontaneous circulation. Patients randomized to the continuous chest compression intervention receive 200 chest compressions with positive pressure ventilations at a rate of 10/min without interruption in compressions. Those randomized to the interrupted chest compression study arm receive chest compressions interrupted for positive pressure ventilations at a compression:ventilation ratio of 30:2. In either group, each interval of compressions is followed by rhythm analysis and defibrillation as required. Insertion of an advanced airway is deferred for the first ≥6 minutes to reduce interruptions in either study arm. The study uses a cluster randomized design with every-6-month crossovers. The primary outcome is survival to hospital discharge. Secondary outcomes are neurologically intact survival and adverse events. A maximum of 23,600 patients (11,800 per group) enrolled during the post-run-in phase of the study will provide ≥90% power to detect a relative change of 16% in the rate of survival to discharge, 8.1% to 9.4% with overall significance level of 0.05. If this trial demonstrates improved survival with either strategy, >3,000 premature deaths from cardiac arrest would be averted annually.

A consensus-based gold standard for the evaluation of mass casualty triage systems

INTRODUCTION

Accuracy and effectiveness analyses of mass casualty triage systems are limited because there are no gold standard definitions for each of the triage categories. Until there is agreement on which patients should be identified by each triage category, it will be impossible to calculate sensitivity and specificity or to compare accuracy between triage systems.

OBJECTIVE

To develop a consensus-based, functional gold standard definition for each mass casualty triage category.

METHODS

National experts were recruited through the lead investigators' contacts and their suggested contacts. Key informant interviews were conducted to develop a list of potential criteria for defining each triage category. Panelists were interviewed in order of their availability until redundancy of themes was achieved. Panelists were blinded to each other's responses during the interviews. A modified Delphi survey was developed with the potential criteria identified during the interview and delivered to all recruited experts. In the early rounds, panelists could add, remove, or modify criteria. In the final rounds edits were made to the criteria until at least 80% agreement was achieved.

RESULTS

Thirteen national and local experts were recruited to participate in the project. Six interviews were conducted. Three rounds of voting were performed, with 12 panelists participating in the first round, 12 in the second round, and 13 in the third round. After the first two rounds, the criteria were modified according to respondent suggestions. In the final round, over 90% agreement was achieved for all but one criterion. A single e-mail vote was conducted on edits to the final criterion and consensus was achieved.

CONCLUSION

A consensus-based, functional gold standard definition for each mass casualty triage category was developed. These gold standard definitions can be used to evaluate the accuracy of mass casualty triage systems after an actual incident, during training, or for research.

Resuscitation Outcomes Consortium-Amiodarone, Lidocaine or Placebo Study (ROC-ALPS): Rationale and methodology behind an out-of-hospital cardiac arrest antiarrhythmic drug trial

BACKGROUND

Despite their wide use, whether antiarrhythmic drugs improve survival after out-of-hospital cardiac arrest (OHCA) is not known. The ROC-ALPS is evaluating the effectiveness of these drugs for OHCA due to shock-refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/VT).

METHODS

ALPS will randomize 3,000 adults across North America with nontraumatic OHCA, persistent or recurring VF/VT after ≥1 shock, and established vascular access to receive up to 450 mg amiodarone, 180 mg lidocaine, or placebo in the field using a double-blind protocol, along with standard resuscitation measures. The designated target population is all eligible randomized recipients of any dose of ALPS drug whose initial OHCA rhythm was VF/VT. A safety analysis includes all randomized patients regardless of their eligibility, initial arrhythmia, or actual receipt of ALPS drug. The primary outcome of ALPS is survival to hospital discharge; a secondary outcome is functional survival at discharge assessed as a modified Rankin Scale score ≤3.

RESULTS

The principal aim of ALPS is to determine if survival is improved by amiodarone compared with placebo; secondary aim is to determine if survival is improved by lidocaine vs placebo and/or by amiodarone vs lidocaine. Prioritizing comparisons in this manner acknowledges where differences in outcome are most expected based on existing knowledge. Each aim also represents a clinically relevant comparison between treatments that is worth investigating.

CONCLUSIONS

Results from ALPS will provide important information about the choice and value of antiarrhythmic therapies for VF/VT arrest with direct implications for resuscitation guidelines and clinical practice.