Survival by time-to-administration of amiodarone, lidocaine, or placebo in shock-refractory out-of-hospital cardiac arrest.

BACKGROUND: Amiodarone and lidocaine have not been shown to have a clear survival benefit compared to placebo for out-of-hospital cardiac arrest (OHCA). However, randomized trials may have been impacted by delayed administration of the study drugs. We sought to evaluate how timing from emergency medical services (EMS) arrival on scene to drug administration affects the efficacy of amiodarone and lidocaine compared to placebo. METHOD: This is a secondary analysis of the 10-site, 55-EMS-agency double-blind randomized controlled amiodarone, lidocaine, or placebo in OHCA study. We included patients with initial shockable rhythms who received the study drugs of amiodarone, lidocaine, or placebo before achieving return of spontaneous circulation. We performed logistic regression analyses evaluating survival to hospital discharge and secondary outcomes of survival to admission and functional survival (modified Rankin scale score ≤ 3). We evaluated the samples stratified by early (<8 min) and late administration groups (≥8 min). We compared outcomes for amiodarone and lidocaine compared to placebo and adjust for potential confounders. RESULTS: There were 2802 patients meeting inclusion criteria, with 879 (31.4%) in the early (<8 min) and 1923 (68.6%) in the late (≥8 min) groups. In the early group, patients receiving amiodarone, compared to placebo, had significantly higher survival to admission (62.0% vs. 48.5%, p = 0.001; adjusted OR [95% CI] 1.76 [1.24-2.50]), survival to discharge (37.1% vs. 28.0%, p = 0.021; 1.56 [1.07-2.29]), and functional survival (31.6% vs. 23.3%, p = 0.029; 1.55 [1.04-2.32]). There were no significant differences with early lidocaine compared to early placebo (p > 0.05). Patients in the late group who received amiodarone or lidocaine had no significant differences in outcomes at discharge compared to placebo (p > 0.05). CONCLUSIONS: The early administration of amiodarone, particularly within 8 min, is associated with greater survival to admission, survival to discharge, and functional survival compared to placebo in patients with an initial shockable rhythm.

The Association Between the Number of Prehospital Providers On-Scene and Out-of-Hospital Cardiac Arrest Outcomes.

Objective: The ideal number of emergency medical services (EMS) providers needed on-scene during an out-of-hospital cardiac arrest (OHCA) resuscitation is unknown. Our objective was to evaluate the association between the number of providers on-scene and OHCA outcomes. Methods: This was a secondary analysis of adults (≥18 years old) with non-traumatic OHCA from a 10-site North American prospective cardiac arrest registry (Resuscitation Outcomes Consortium) including a 2005-2011 cohort and a 2011-2015 cohort. The primary outcome was survival to hospital discharge. We calculated the median number of EMS providers on-scene during the first 10 minutes of the resuscitation and used multivariable logistic regression adjusting for age, sex, witness status, bystander CPR, arrest location, initial rhythm, and dispatch to EMS arrival time. Results: There were 30,613 and 41,946 patients with necessary variables in the 2005-2011 and 2011-2015 cohorts, respectively. Survival to hospital discharge (95% CI) was higher with 9 or more providers on-scene (17.2% [15.8-18.5] and 14.0% [12.6-15.4]) compared to 7-8 (14.1% [13.4-14.8] and 10.5% [9.9-11.1]), 5-6 (10.0% [9.5-10.5] and 8.5% [8.1-8.9]), 3-4 (10.5% [9.3-11.6] and 9.3% [8.5-10.1]), and 1-2 (8.6% [7.2-10.0] and 8.0% [7.1-9.0]) providers for the 2005-2011 and 2011-2015 cohorts, respectively. In multivariable logistic regressions, compared to 5-6 providers, there were no significant differences in survival to hospital discharge for 1-2 or 3-4 providers, while having 7-8 (adjusted odds ratios (aORs) 1.53 [1.39-1.67] and 1.31 [1.20-1.44]) and 9 or more (aORs 1.76 [1.56-1.98] and 1.63 [1.41-1.89]) providers were associated with improved survival in both the 2005-2011 and 2011-2015 cohorts, respectively. Conclusions: The presence of seven or more prehospital providers on-scene was associated with significantly greater adjusted odds of survival to hospital discharge after OHCA compared to fewer on-scene providers.

Relationship Between Duration of Targeted Temperature Management, Ischemic Interval, and Good Functional Outcome From Out-of-Hospital Cardiac Arrest.

OBJECTIVES: Tailoring hypothermia duration to ischemia duration may improve outcome from out-of-hospital cardiac arrest. We investigated the association between the hypothermia/ischemia ratio and functional outcome in a secondary analysis of data from the Resuscitation Outcomes Consortium Amiodarone, Lidocaine, or Placebo Study trial. DESIGN: Cohort study of out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study. SETTING: Multicenter study across North America. PATIENTS: Adult, nontraumatic, out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study who survived to hospital admission and received targeted temperature management between May 2012 and October 2015. INTERVENTIONS: Targeted temperature management in comatose survivors of out-of-hospital cardiac arrest. We defined hypothermia/ischemia ratio as total targeted temperature management time (initiation through rewarming) divided by calculated total ischemia time (approximate time of arrest [9-1-1 call or emergency medical services-witnessed] to return of spontaneous circulation). MEASUREMENTS AND MAIN RESULTS: The primary outcome was hospital survival with good functional status (modified Rankin Score, 0-3) at hospital discharge. We fitted logistic regression models to estimate the association between hypothermia/ischemia ratio and the primary outcome, adjusting for demographics, arrest characteristics, and Resuscitation Outcomes Consortium enrolling site. A total of 3,429 patients were eligible for inclusion, of whom 36.2% were discharged with good functional outcome. Patients had a mean age of 62.0 years (SD, 15.8), with 69.7% male, and 58.0% receiving lay-rescuer cardiopulmonary resuscitation. Median time to return of spontaneous circulation was 21.1 minutes (interquartile range, 16.1-26.9), and median duration of targeted temperature management was 32.9 hours (interquartile range, 23.7-37.8). A total of 2,579 had complete data and were included in adjusted regression analyses. After adjustment for patient characteristics and Resuscitation Outcomes Consortium site, a greater hypothermia/ischemia ratio was associated with increased survival with good functional outcome (odds ratio, 2.01; 95% CI, 1.82-2.23). This relationship, however, appears to be primarily driven by time to return of spontaneous circulation in this patient cohort. CONCLUSIONS: Although a larger hypothermia/ischemia ratio was associated with good functional outcome after out-of-hospital cardiac arrest in this cohort, this association is primarily driven by duration of time to return of spontaneous circulation. Tailoring duration of targeted temperature management based on duration of time to return of spontaneous circulation or patient characteristics requires prospective study.

Variation in Survival After Out-of-Hospital Cardiac Arrest Between Emergency Medical Services Agencies.

Importance: Emergency medical services (EMS) deliver essential initial care for patients with out-of-hospital cardiac arrest (OHCA), but the extent to which patient outcomes vary between different EMS agencies is not fully understood. Objective: To quantify variation in patient outcomes after OHCA across EMS agencies. Design, Setting, and Participants: This observational cohort study was conducted in the Resuscitation Outcomes Consortium (ROC) Epistry, a prospective multicenter OHCA registry at 10 sites in North America. Any adult with OHCA treated by an EMS from April 2011 through June 2015 was included. Data analysis occurred from May 2017 to March 2018. Exposure: Treating EMS agency. Main Outcomes and Measures: The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation at emergency department arrival and favorable functional outcome at hospital discharge (defined as a modified Rankin scale score ≤3). Multivariable hierarchical logistic regression models were used to adjust confounders and clustering of patients within EMS agencies, and calculated median odds ratios (MORs) were used to quantify the extent of residual variation in outcomes between EMS agencies. Results: We identified 43 656 patients with OHCA treated by 112 EMS agencies. At EMS agency level, we observed large variations in survival to hospital discharge (range, 0%-28.9%; unadjusted MOR, 1.43 [95% CI, 1.34-1.54]), return of spontaneous circulation on emergency department arrival (range, 9.0%-57.1%; unadjusted MOR, 1.53 [95% CI, 1.43-1.65]), and favorable functional outcome (range, 0%-20.4%; unadjusted MOR, 1.54 [95% CI, 1.40-1.73]). This variation persisted despite adjustment for patient-level and EMS agency-level factors known to be associated with outcomes (adjusted MOR for survival 1.56 [95% CI 1.44-1.73]; adjusted MOR for return of spontaneous circulation at emergency department arrival, 1.50 [95% CI, 1.41-1.62]; adjusted MOR for functionally favorable survival, 1.53 [95% CI, 1.37-1.78]). After restricting analysis to those who survived more than 60 minutes after hospital arrival and including hospital treatment characteristics, the variation persisted (adjusted MOR for survival, 1.49 [95% CI, 1.36-1.69]; adjusted MOR for functionally favorable survival, 1.34 [95% CI, 1.20-1.59]). Conclusions and Relevance: We found substantial variations in patient outcomes after OHCA between a large group of EMS agencies in North America that were not explained by documented patient-level and EMS agency-level variables.

Advanced vs. Basic Life Support in the Treatment of Out-of-Hospital Cardiopulmonary Arrest in the Resuscitation Outcomes Consortium.

BACKGROUND: Prior observational studies suggest no additional benefit from advanced life support (ALS) when compared with providing basic life support (BLS) for patients with out-of-hospital cardiac arrest (OHCA). We compared the association of ALS care with OHCA outcomes using prospective clinical data from the Resuscitation Outcomes Consortium (ROC). METHODS: Included were consecutive adults OHCA treated by participating emergency medical services (EMS) agencies between June 1, 2011, and June 30, 2015. We defined BLS as receipt of cardiopulmonary resuscitation (CPR) and/or automated defibrillation and ALS as receipt of an advanced airway, manual defibrillation, or intravenous drug therapy. We compared outcomes among patients receiving: 1) BLS-only; 2) BLS + late ALS; 3) BLS + early ALS; and 4) ALS-first care. Using multivariable logistic regression, we evaluated the associations between level of care and return of spontaneous circulation (ROSC), survival to hospital discharge, and survival with good functional status, adjusting for age, sex, witnessed arrest, bystander CPR, shockable initial rhythm, public location, EMS response time, CPR quality, and ROC site. RESULTS: Among 35,065 patients with OHCA, characteristics were median age 68 years (IQR 56-80), male 63.9%, witnessed arrest 43.8%, bystander CPR 50.6%, and shockable initial rhythm 24.2%. Care delivered was: 4.0% BLS-only, 31.5% BLS + late ALS, 17.2% BLS + early ALS, and 47.3% ALS-first. ALS care with or without initial BLS care was independently associated with increased adjusted ROSC and survival to hospital discharge unless delivered greater than 6 min after BLS arrival (BLS + late ALS). Regardless of when it was delivered, ALS care was not associated with significantly greater functional outcome. CONCLUSION: ALS care was associated with survival to hospital discharge when provided initially or within six minutes of BLS arrival. ALS care, with or without initial BLS care, was associated with increased ROSC, however it was not associated with functional outcome.

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.

Deaths and high-risk trauma patients missed by standard trauma data sources.

BACKGROUND: Trauma registries are used to evaluate and improve trauma care, yet potentially miss certain trauma deaths and high-risk patients. We estimated the number of missed deaths and high-risk trauma patients using commonly available sources of trauma data and resulting bias in quality metrics for field trauma triage. METHODS: This was a preplanned secondary analysis of a population-based prospective cohort of injured patients transported by 44 emergency medical services agencies to 28 hospitals in seven Northwest counties from January 1, 2011 to December 31, 2011 and followed through hospitalization. We used a stratified probability sampling design for 17,633 patients, weighted to represent all 53,487 injured patients transported by emergency medical services. We compared patients meeting National Trauma Data Bank (NTDB) criteria (weighted n = 5,883), all injured patients presenting to major trauma centers (weighted n = 16,859), and all admitted patients (weighted n = 18,433), to the full sample. Outcomes included in-hospital mortality, Injury Severity Score (ISS) of 16 or higher, and critical resource use within 24 hours. RESULTS: Among 53,487 injured patients, there were 520 emergency department and in-hospital deaths, 1,745 with ISS of 16 or higher, and 923 requiring early critical resources. Compared to the full cohort, the NTDB cohort missed 62.1% of deaths, 39.2% of patients with ISS of 16 or higher, and 23.8% requiring early critical resources, especially older adults injured by falls and admitted to nontrauma hospitals. The admission cohort missed the fewest patients-23.3% of deaths, 10.5% with an ISS of 16 or higher, and 13.1% requiring early resources. Compared to triage sensitivity in the full cohort (66.2%), sensitivity estimates ranged from 63.6% (all admissions) to 93.4% (NTDB). Compared to triage specificity in the full cohort (87.8%), estimates ranged from 36.4% (NTDB) to 77.3% (all admissions). CONCLUSION: Common sources of trauma data miss substantial numbers of trauma deaths and high-risk trauma patients and can generate biased estimates for trauma system quality metrics. LEVEL OF EVIDENCE: Epidemiologic, level III.

Role of Guideline Adherence in Improving Field Triage.

OBJECTIVE: To compare the sensitivity of current field triage practices for identifying high-risk trauma patients to strict guideline adherence, including changes in triage specificity, ambulance transport patterns, and trauma center volumes. METHODS: This was a pre-planned secondary analysis of an out-of-hospital prospective cohort of injured children and adults transported by 44 EMS agencies to 28 trauma and non-trauma hospitals in 7 Northwest U.S. counties from January 1, 2011 through December 31, 2011. Outcomes included Injury Severity Score (ISS) ≥16 (primary) and early critical resource use. Strict adherence of the triage guidelines was based on evidence in the EMS chart for patients meeting any current field triage criteria, calculated with and without strict interpretation of the age criterion (<15 or >55 years). Due to the probability sampling nature of the cohort, strata and weights were included in all analyses. RESULTS: 17,633 injured patients were transported by EMS (weighted to represent 53,487 transported patients), including 3.1% with ISS ≥16 and 1.7% requiring early critical resources. Field triage sensitivity for identifying patients with ISS ≥16 increased from the current 66.2% (95% CI 60.2-71.7%) to 87.3% (95% CI 81.9-91.2%) for strict adherence without age and to 91.0% (95% CI 86.4-94.2%) for strict adherence with age. Specificity decreased with increasing adherence, from 87.8% (current) to 47.6% (strict adherence without age) and 35.8% (strict adherence with age). Areas under the curve (AUC) were 0.78, 0.73, and 0.72, respectively. Results were similar for patients requiring early critical resources. We estimate the number of triage-positive patients transported each year by EMS to an individual major trauma center (on average) to increase from 1,331 (current) to 5,139 (strict adherence without age) and to 6,256 (strict adherence with age). CONCLUSIONS: The low sensitivity of current triage practices would be expected to improve with strict adherence to current triage guidelines, with a commensurate decrease in triage specificity and an increase in the number of triage-positive patients transported to major trauma centers.

Evaluation of Rural vs Urban Trauma Patients Served by 9-1-1 Emergency Medical Services.

Importance: Despite a large rural US population, there are potential differences between rural and urban regions in the processes and outcomes following trauma. Objectives: To describe and evaluate rural vs urban processes of care, injury severity, and mortality among injured patients served by 9-1-1 emergency medical services (EMS). Design, Setting, and Participants: This was a preplanned secondary analysis of a prospective cohort enrolled from January 1 through December 31, 2011, and followed up through hospitalization. The study included 44 EMS agencies transporting to 28 hospitals in 2 rural and 5 urban counties in Oregon and Washington. A population-based, consecutive sample of 67 047 injured children and adults served by EMS (1971 rural and 65 076 urban) was enrolled. Among the 53 487 patients transported by EMS, a stratified probability sample of 17 633 patients (1438 rural and 16 195 urban) was created to track hospital outcomes (78.9% with in-hospital follow-up). Data analysis was performed from June 12, 2015, to May 20, 2016. Exposures: Rural was defined at the county level by 60 minutes or more driving proximity to the nearest level I or II trauma center and/or rural designation in the Centers for Medicare & Medicaid Services ambulance fee schedule by zip code. Main Outcomes and Measures: Mortality (out-of-hospital and in-hospital), need for early critical resources, and transfer rates. Results: Of the 53 487 injured patients transported by EMS (17 633 patients in the probability sample), 27 535 were women (51.5%); mean (SD) age was 51.6 (26.1) years. Rural vs urban sensitivity of field triage for identifying patients requiring early critical resources was 65.2% vs 80.5%, and only 29.4% of rural patients needing critical resources were initially transported to major trauma centers vs 88.7% of urban patients. After accounting for transfers, 39.8% of rural patients requiring critical resources were cared for in major trauma centers vs 88.7% of urban patients. Overall mortality did not differ between rural and urban regions (1.44% vs 0.89%; P = .09); however, 89.6% of rural deaths occurred within 24 hours compared with 64% of urban deaths. Rural regions had higher transfer rates (3.2% vs 2.7%) and longer transfer distances (median, 97.4 km; interquartile range [IQR], 51.7-394.5 km; range, 47.8-398.6 km vs 22.5 km; IQR, 11.6-24.6 km; range, 3.5-97.4 km). Conclusions and Relevance: Most high-risk trauma patients injured in rural areas were cared for outside of major trauma centers and most rural trauma deaths occurred early, although overall mortality did not differ between regions. There are opportunities for improved timeliness and access to major trauma care among patients injured in rural regions.

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.).

Prospective Validation of the National Field Triage Guidelines for Identifying Seriously Injured Persons.

BACKGROUND: The national field trauma triage guidelines have been widely implemented in US trauma systems, but never prospectively validated. We sought to prospectively validate the guidelines, as applied by out-of-hospital providers, for identifying high-risk trauma patients. STUDY DESIGN: This was an out-of-hospital prospective cohort study from January 1, 2011 through December 31, 2011 with 44 Emergency Medical Services agencies in 7 counties in 2 states. We enrolled injured patients transported to 28 acute care hospitals, including 7 major trauma centers (Level I and II trauma hospitals) and 21 nontrauma hospitals. The primary exposure term was Emergency Medical Services' use of one or more field triage criteria in the national field triage guidelines. Outcomes included Injured Severity Score ≥16 (primary) and critical resource use within 24 hours of emergency department arrival (secondary). RESULTS: We enrolled 53,487 injured children and adults transported by Emergency Medical Services to an acute care hospital, 17,633 of which were sampled for the primary analysis; 13.9% met field triage guidelines, 3.1% had Injury Severity Score ≥16, and 1.7% required early critical resources. The sensitivity and specificity of the field triage guidelines were 66.2% (95% CI, 60.2-71.7%) and 87.8% (95% CI, 87.7-88.0%) for Injury Severity Score ≥16 and 80.1% (95% CI, 65.8-89.4%) and 87.3% (95% CI 87.1-87.4%) for early critical resource use. Triage guideline sensitivity decreased with age, from 87.4% in children to 51.8% in older adults. CONCLUSIONS: The national field triage guidelines are relatively insensitive for identifying seriously injured patients and patients requiring early critical interventions, particularly among older adults.

Improving early identification of the high-risk elderly trauma patient by emergency medical services.

STUDY OBJECTIVE: We sought to (1) define the high-risk elderly trauma patient based on prognostic differences associated with different injury patterns and (2) derive alternative field trauma triage guidelines that mesh with national field triage guidelines to improve identification of high-risk elderly patients. METHODS: This was a retrospective cohort study of injured adults ≥65 years transported by 94 EMS agencies to 122 hospitals in 7 regions from 1/1/2006 through 12/31/2008. We tracked current field triage practices by EMS, patient demographics, out-of-hospital physiology, procedures and mechanism of injury. Outcomes included Injury Severity Score≥16 and specific anatomic patterns of serious injury using abbreviated injury scale score ≥3 and surgical interventions. In-hospital mortality was used as a measure of prognosis for different injury patterns. RESULTS: 33,298 injured elderly patients were transported by EMS, including 4.5% with ISS≥16, 4.8% with serious brain injury, 3.4% with serious chest injury, 1.6% with serious abdominal-pelvic injury and 29.2% with serious extremity injury. In-hospital mortality ranged from 18.7% (95% CI 16.7-20.7) for ISS≥16 to 2.9% (95% CI 2.6-3.3) for serious extremity injury. The alternative triage guidelines (any positive criterion from the current guidelines, GCS≤14 or abnormal vital signs) outperformed current field triage practices for identifying patients with ISS≥16: sensitivity (92.1% [95% CI 89.6-94.1%] vs. 75.9% [95% CI 72.3-79.2%]), specificity (41.5% [95% CI 40.6-42.4%] vs. 77.8% [95% CI 77.1-78.5%]). Sensitivity decreased for individual injury patterns, but was higher than current triage practices. CONCLUSIONS: High-risk elderly trauma patients can be defined by ISS≥16 or specific non-extremity injury patterns. The field triage guidelines could be improved to better identify high-risk elderly trauma patients by EMS, with a reduction in triage specificity.

Post-discharge outcomes after resuscitation from out-of-hospital cardiac arrest: A ROC PRIMED substudy.

IMPORTANCE: Assessment of morbidity is an important component of evaluating interventions for patients with out-of-hospital cardiac arrest (OHCA). OBJECTIVE: We evaluated among survivors of OHCA cognition, functional status, health-related quality of life and depression as functions of patient and emergency medical services (EMS) factors. DESIGN: Prospective cohort sub-study of a randomized trial. SETTING: The parent trial studied two comparisons in persons with non-traumatic OHCA treated by EMS personnel participating in the Resuscitation Outcomes Consortium. PARTICIPANTS: Consenting survivors to discharge. MAIN OUTCOME MEASURES: Telephone assessments up to 6 months after discharge included neurologic function (modified Rankin score, MRS), cognitive impairment (Adult Lifestyle and Function Mini Mental Status Examination, ALFI-MMSE), health-related quality of life (Health Utilities Index Mark 3, HUI3) and depression (Telephone Geriatric Depression Scale, T-GDS). RESULTS: Of 15,794 patients enrolled in the parent trial, 729 (56% of survivors) consented. About 644 respondents (88% of consented) completed ≥ 1 assessment. Likelihood of assessment was associated with baseline characteristics and study site. Most respondents had MRS ≤ 3 (82.7%), no cognitive impairment (82.7% ALFI-MMSE ≥ 17), no severe impairment in health (71.6%, HUI3 ≥ 0.7) and no depression (90.1% T-GDS≤10). Outcomes did not differ by trial intervention or time from hospital discharge. CONCLUSIONS AND RELEVANCE: The majority of patients in this large cohort who survived cardiac arrest and were interviewed had no, mild or moderate health impairment. Concern about poor quality of life is not a valid reason to abandon efforts to improve an EMS system's response to cardiac arrest.

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.

Survival advantage from ventricular fibrillation and pulseless electrical activity in women compared to men: the Oregon Sudden Unexpected Death Study.

OBJECTIVE: Studies evaluating a possible survival advantage from sudden cardiac arrest (SCA) in women have produced mixed results possibly due to a lack of comprehensive analyses. We hypothesized that race, socioeconomic status (SES), and elements of the lifetime clinical history influence gender effects and need to be incorporated within analyses of survival. METHODS: Cases of SCA were identified from the ongoing, prospective, multiple-source Oregon Sudden Unexpected Death Study (population approximately one million). Subjects included were age ≥18 years who underwent attempted resuscitation by EMS providers. Pearson's chi-square tests and independent samples t tests or analysis of variance were used for univariate comparisons. We evaluated gender and race differences in survival adjusted for age, circumstances of arrest, disease burden, and socioeconomic status using a logistic regression model predicting survival. RESULTS: A total of 1,296 cases had resuscitation attempted (2002-2007; mean age 65 years, male 67%). Women were older than men (68 vs. 63 years, p < 0.0001) and were more likely to have return of spontaneous circulation (41% vs. 33%, p = 0.004). Women were more likely to present with pulseless electrical activity (PEA) and asystole (p < 0.0001), and overall, PEA was more common among African Americans (p = 0.04). Higher survival to hospital discharge was observed in women compared to men presenting with ventricular fibrillation/tachycardia (34% vs. 24%, p = 0.02) or with PEA (10% vs. 3%, p = 0.007). In a multivariate model adjusting for age, race, presenting arrhythmia, arrest circumstances, arrest location, disease burden, and SES, women were more likely than men to survive to hospital discharge [odds ratio 1.85; 95% confidence interval (1.12-3.04)]. CONCLUSIONS: Despite older age, higher prevalence of SCA in the home, and higher rates of PEA, women had a survival advantage from ventricular fibrillation and pulseless electrical activity.

Out-of-hospital decision making and factors influencing the regional distribution of injured patients in a trauma system.

BACKGROUND: The decision-making processes used for out-of-hospital trauma triage and hospital selection in regionalized trauma systems remain poorly understood. The objective of this study was to assess the process of field triage decision making in an established trauma system. METHODS: We used a mixed methods approach, including emergency medical services (EMS) records to quantify triage decisions and reasons for hospital selection in a population-based, injury cohort (2006-2008), plus a focused ethnography to understand EMS cognitive reasoning in making triage decisions. The study included 10 EMS agencies providing service to a four-county regional trauma system with three trauma centers and 13 nontrauma hospitals. For qualitative analyses, we conducted field observation and interviews with 35 EMS field providers and a round table discussion with 40 EMS management personnel to generate an empirical model of out-of-hospital decision making in trauma triage. RESULTS: A total of 64,190 injured patients were evaluated by EMS, of whom 56,444 (88.0%) were transported to acute care hospitals and 9,637 (17.1% of transports) were field trauma activations. For nontrauma activations, patient/family preference and proximity accounted for 78% of destination decisions. EMS provider judgment was cited in 36% of field trauma activations and was the sole criterion in 23% of trauma patients. The empirical model demonstrated that trauma triage is driven primarily by EMS provider "gut feeling" (judgment) and relies heavily on provider experience, mechanism of injury, and early visual cues at the scene. CONCLUSIONS: Provider cognitive reasoning for field trauma triage is more heuristic than algorithmic and driven primarily by provider judgment, rather than specific triage criteria.

Predicting survival after out-of-hospital cardiac arrest: role of the Utstein data elements.

STUDY OBJECTIVE: Survival after out-of-hospital cardiac arrest depends on the links in the chain of survival. The Utstein elements are designed to assess these links and provide the basis for comparing outcomes within and across communities. We assess whether these measures sufficiently predict survival and explain outcome differences. METHODS: We used an observational, prospective data collection, case-series of adult persons with nontraumatic out-of-hospital cardiac arrest from December 1, 2005, through March 1, 2007, from the multisite, population-based Resuscitation Outcomes Consortium Epistry-Cardiac Arrest. We used logistic regression, receiver operating curves, and measures of variance to estimate the extent to which the Utstein elements predicted survival to hospital discharge and explained outcome variability overall and between 7 Resuscitation Outcomes Consortium sites. Analyses were conducted for all emergency medical services-treated cardiac arrests and for the subset of bystander-witnessed patient arrests because of presumed cardiac cause presenting with ventricular fibrillation or ventricular tachycardia. RESULTS: Survival was 7.8% overall (n=833/10,681) and varied from 4.6% to 14.7% across Resuscitation Outcomes Consortium sites. Among bystander-witnessed ventricular fibrillation or ventricular tachycardia, survival was 22.1% overall (n=323/1459) and varied from 12.5% to 41.0% across sites. The Utstein elements collectively predicted 72% of survival variability among all arrests and 40% of survival variability among bystander-witnessed ventricular fibrillation. The Utstein elements accounted for 43.6% of the between-site survival difference among all arrests and 22.3% of the between-site difference among the bystander-witnessed ventricular fibrillation subset. CONCLUSION: The Utstein elements predict survival but account for only a modest portion of outcome variability overall and between Resuscitation Outcomes Consortium sites. The results underscore the need for ongoing investigation to better understand characteristics that influence cardiac arrest survival.

Is it possible to safely triage callers to EMS dispatch centers to alternative resources?

OBJECTIVES: To develop guidelines allowing emergency medical services (EMS) dispatchers to safely match callers to an EMS response or, alternatively, to a nontraditional resource. METHODS: This was a prospective cohort study of callers to an urban EMS dispatch center and an associated review of EMS patient care forms and emergency department (ED) patient care records. The following five "nature codes" (patient chief complaints) were included: back pain, fall, bleeding or laceration, sick, and trauma. Callers included in the study had been assigned the lowest severity level (Alpha), according to existing dispatch criteria. An a priori list of EMS and ED "important findings," indicating need for an EMS response, was used as the outcome variable. Classification and regression tree (CART) analysis was used to develop a decision rule to further identify a low-risk subgroup of patients who could potentially be served by alternative resources. RESULTS: From November 1, 1998, to May 31, 1999, 656 subjects were entered into the study, including 263 males (40%) and 389 females (59%). The mean age was 51 years (range, 0-101 years). One hundred twenty-five (19%) callers had an important EMS finding, including the administration of comfort medications, morphine, benzodiazepines, and droperidol. Forty-six subjects (7%) had an important ED finding. When EMS and ED findings were combined, 158 subjects (24%) had an "important finding." Using CART analysis, having an age <12 years predicted a subset of patients who did not have an important finding suggesting the need for an EMS response. Using cross-validation, this decision rule had a 99% sensitivity, 13% specificity, and 98% negative predictive value. CONCLUSION: The authors were able to use a demographic variable (age) to predict a population of callers to a 911 dispatch center triaged to the lowest acuity category, who have a very low risk of having an EMS or ED important finding. The decision rule developed here is preliminary, requiring further validation.