Association between a Post-Resuscitation Care Bundle and the Odds of Field Rearrest after Successful Resuscitation from Out-of-Hospital Cardiac Arrest: A Pre/Post Study.

OBJECTIVES: Rearrest after successful resuscitation from out-of-hospital cardiac arrest (OHCA) is common and is associated with worse patient outcomes. However, little is known about the effect of interventions designed to prevent rearrest. We assessed the association between a prehospital care protocol for immediate management after return of spontaneous circulation (ROSC) and rates of field rearrest and survival to discharge in patients with prehospital ROSC. METHODS: This was a retrospective study of adult patients with OHCA and field ROSC within a large EMS system before (April 2017-August 2018) and after (April 2019-February 2020) implementation of a structured prehospital post-ROSC care protocol. The protocol was introduced in September 2018 and provided on-scene stabilization direction including guidance on ventilation and blood pressure support. Field data and hospital outcomes were used to compare the frequency of field rearrest, hospital survival, and survival with good neurologic outcome before and after protocol implementation. Logistic regression was used to assess the association between the post-implementation period and these outcomes, and odds ratios were reported. The association between individual interventions on these outcomes was also explored. RESULTS: There were 2,706 patients with ROSC after OHCA in the pre-implementation period and 1,780 patients in the post-implementation period. The rate of prehospital rearrest was 43% pre-implementation vs 45% post-implementation (RD 2%, 95% CI -1, 4%). In the adjusted analysis, introduction of the protocol was not associated with decreased odds of rearrest (OR 0.87, 95% CI 0.73, 1.04), survival to hospital discharge (OR 1.01, 95% CI 0.81, 1.24), or survival with good neurologic outcome (OR 0.81, 95% CI 0.61, 1.06). Post-implementation, post-ROSC administration of saline and push-dose epinephrine increased from 11% to 25% (RD 14%, 95% CI 11, 17%) and from 3% to 12% (RD 9% 95% CI 7, 11%), respectively. In an exploratory analysis, push-dose epinephrine was associated with a decreased odds of rearrest (OR 0.68, 95% CI 0.50, 0.94). CONCLUSIONS: Introduction of a post-ROSC care protocol for patients with prehospital ROSC after OHCA was not associated with reduced odds of field rearrest. When elements of the care bundle were considered individually, push-dose epinephrine was associated with decreased odds of rearrest.

A Novel Algorithm for Improving the Prehospital Diagnostic Accuracy of ST-Segment Elevation Myocardial Infarction.

INTRODUCTION: Early detection of ST-segment elevation myocardial infarction (STEMI) on the prehospital electrocardiogram (ECG) improves patient outcomes. Current software algorithms optimize sensitivity but have a high false-positive rate. The authors propose an algorithm to improve the specificity of STEMI diagnosis in the prehospital setting. METHODS: A dataset of prehospital ECGs with verified outcomes was used to validate an algorithm to identify true and false-positive software interpretations of STEMI. Four criteria implicated in prior research to differentiate STEMI true positives were applied: heart rate <130, QRS <100, verification of ST-segment elevation, and absence of artifact. The test characteristics were calculated and regression analysis was used to examine the association between the number of criteria included and test characteristics. RESULTS: There were 44,611 cases available. Of these, 1,193 were identified as STEMI by the software interpretation. Applying all four criteria had the highest positive likelihood ratio of 353 (95% CI, 201-595) and specificity of 99.96% (95% CI, 99.93-99.98), but the lowest sensitivity (14%; 95% CI, 11-17) and worst negative likelihood ratio (0.86; 95% CI, 0.84-0.89). There was a strong correlation between increased positive likelihood ratio (r2 = 0.90) and specificity (r2 = 0.85) with increasing number of criteria. CONCLUSIONS: Prehospital ECGs with a high probability of true STEMI can be accurately identified using these four criteria: heart rate <130, QRS <100, verification of ST-segment elevation, and absence of artifact. Applying these criteria to prehospital ECGs with software interpretations of STEMI could decrease false-positive field activations, while also reducing the need to rely on transmission for physician over-read. This can have significant clinical and quality implications for Emergency Medical Services (EMS) systems.

Does Housing Status Matter in Emergency Medical Services Administration of Naloxone? A Prehospital Cross-sectional Study.

Introduction: Persons experiencing homelessness (PEH) use emergency medical services (EMS) at disproportionately high rates relative to housed individuals due to several factors including disparate access to healthcare. Limited access to care is compounded by higher rates of substance use in PEH. Despite growing attention to the opioid epidemic and housing crisis, differences in EMS naloxone administration by housing status has not been systematically examined. Our objective in this study was to describe EMS administration of naloxone by housing status in the City of Los Angeles. Methods: This was a 12-month retrospective, cross-sectional analysis of electronic patient care reports (ePCRs) for all 9-1-1 EMS incidents attended by the Los Angeles Fire Department (LAFD), the sole EMS provider agency for the City of Los Angeles during the study period, January-December 2018. During this time, the City had a population of 3,949,776 with an estimated 31,825 (0.8%) PEH. We included in the study individuals to whom LAFD personnel had administered naloxone. Housing status is a mandatory field on ePCRs. The primary study outcome was the incidence of EMS naloxone administration by housing status. We used descriptive statistics and logistic regression models to examine patterns by key covariates. Results: There were 345,190 EMS incidents during the study period. Naloxone was administered during 2,428 incidents. Of those incidents 608 (25%) involved PEH, and 1,820 (75%) involved housed individuals. Naloxone administration occurred at a rate of 19 per 1,000 PEH, roughly 44 times the rate of housed individuals. A logistic regression model showed that PEH remained 2.38 times more likely to receive naloxone than their housed counterparts, after adjusting for gender, age, and respiratory depression (odds ratio 2.38, 95% confidence interval 2.15-2.64). The most common provider impressions recorded by the EMS responders who administered naloxone were the same for both groups: overdose; altered level of consciousness; and cardiac arrest. Persons experiencing homelessness who received naloxone were more likely to be male (82% vs 67%) and younger (41.4 vs 46.2 years) than housed individuals. Conclusion: In the City of Los Angeles, PEH are more likely to receive EMS-administered naloxone than their housed peers even after adjusting for other factors. Future research is needed to understand outcomes and improve care pathways for patients confronting homelessness and opioid use.

Circadian variation in stroke onset: Differences between ischemic and hemorrhagic stroke and weekdays versus weekends.

OBJECTIVES: To delineate diurnal variation onset distinguishing ischemic from hemorrhagic stroke, wake from sleep onset, and weekdays from weekends/holidays. MATERIALS AND METHODS: We analyzed patients enrolled in the FAST-MAG trial of field-initiated neuroprotective agent in patients with hyperacute stroke within 2h of symptoms onset. Stroke onset times were analyzed in 1h, 4h, and 12h time blocks throughout the 24h day-night cycle. Patient demographic, clinical features, stroke severity, and prehospital workflow were evaluated for association with onset times. RESULTS: Among 1615 acute cerebrovascular disease patients, final diagnoses were acute cerebral ischemia in 76.5% and Intracerebral hemorrhage in 23.5%. Considering all acute cerebrovascular disease patients, frequency of wake onset times showed a bimodal pattern, with peaks on onsets at 09:00-13:59 and 17:00-18:59 and early morning (00:00-05:59) onset in only 3.8%. Circadian rhythmicity differed among stroke subtypes: in acute cerebral ischemia, a single broad plateau of elevated incidences was seen from 10:00-21:59; in Intracerebral hemorrhage, bimodal peaks occurred at 09:00 and 19:00. The ratio of Intracerebral hemorrhage to acute cerebral ischemia occurrence was highest in early morning, 02:00-06:59. Marked weekday vs weekends pattern variation was noted for acute cerebral ischemia, with a broad plateau between 09:00 and 21:59 on weekdays but a unimodal peak at 14:00-15:59 on weekends. CONCLUSIONS: Wake onset of acute cerebrovascular disease showed a marked circadian variation, with distinctive patterns of a broad elevated plateau among acute cerebral ischemia patients; a bimodal peak among intracerebral hemorrhage patients; and a weekend change in acute cerebral ischemia pattern to a unimodal peak.

Neurologic Improvement in Acute Cerebral Ischemia: Frequency, Magnitude, Predictors, and Clinical Outcomes.

BACKGROUND AND OBJECTIVES: Investigations of rapid neurologic improvement (RNI) in patients with acute cerebral ischemia (ACI) have focused on RNI occurring after hospital arrival. However, with stroke routing decisions and interventions increasingly migrating to the prehospital setting, there is a need to delineate the frequency, magnitude, predictors, and clinical outcomes of patients with ACI with ultra-early RNI (U-RNI) in the prehospital and early postarrival period. METHODS: We analyzed prospectively collected data of the prehospital Field Administration of Stroke Therapy-Magnesium (FAST-MAG) randomized clinical trial. Any U-RNI was defined as improvement by 2 or more points on the Los Angeles Motor Scale (LAMS) score between the prehospital and early post-emergency department (ED) arrival examinations and classified as moderate (2-3 point) or dramatic (4-5 point) improvement. Outcome measures included excellent recovery (modified Rankin Scale [mRS] score 0-1) and death by 90 days. RESULTS: Among the 1,245 patients with ACI, the mean age was 70.9 years (SD 13.2); 45% were women; the median prehospital LAMS was 4 (interquartile range [IQR] 3-5); the median last known well to ED-LAMS time was 59 minutes (IQR 46-80 minutes), and the median prehospital LAMS to ED-LAMS time was 33 minutes (IQR 28-39 minutes). Overall, any U-RNI occurred in 31%, moderate U-RNI in 23%, and dramatic U-RNI in 8%. Any U-RNI was associated with improved outcomes, including excellent recovery (mRS score 0-1) at 90 days 65.1% (246/378) vs 35.4% (302/852), p < 0.0001; decreased mortality by 90 days 3.7% (14/378) vs 16.4% (140/852), p < 0.0001; decreased symptomatic intracranial hemorrhage 1.6% (6/384) vs 4.6% (40/861), p = 0.0112; and increased likelihood of being discharged home 56.8% (218/384) vs 30.2% (260/861), p < 0.0001. DISCUSSION: U-RNI occurs in nearly 1 in 3 ambulance-transported patients with ACI and is associated with excellent recovery and decreased mortality at 90 days. Accounting for U-RNI may be useful for routing decisions and future prehospital interventions. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov. Unique identifier: NCT00059332.

Implementation of a regional extracorporeal membrane oxygenation program for refractory ventricular fibrillation out-of-hospital cardiac arrest.

BACKGROUND: eCPR, the modality of extracorporeal membrane oxygenation (ECMO) applied in the setting of cardiac arrest, has emerged as a novel therapy which may improve outcomes in select patients with out-of-hospital cardiac arrest (OHCA). To date, implementation has been mainly limited to single academic centres. Our objective is to describe the feasibility and challenges with implementation of a regional protocol for eCPR. METHODS: The Los Angeles County Emergency Medical Services (EMS) Agency implemented a regional eCPR protocol in July 2020, which included coordination across multiple EMS provider agencies and hospitals to route patients with refractory ventricular fibrillation (rVF) OHCA to eCPR-capable centres (ECCs). Data were entered on consecutive patients with rVF with suspected cardiac aetiology into a centralized database including time intervals, field and in-hospital care, survival and neurologic outcome. RESULTS: From July 27, 2020 through July 31, 2022, 35 patients (median age 57 years, 6 (17%) female) were routed to ECCs, of whom 11 (31%) received eCPR and 3 (27%) treated with eCPR survived, all of whom had a full neurologic recovery. Challenges encountered during implementation included cost to EMS provider agencies for training, implementation, and purchase of automatic chest compression devices, maintenance of system awareness, hospital administrative support for staffing and equipment for the ECMO program, and interdepartmental coordination at ECCs. CONCLUSION: We describe the successful implementation of a regional eCPR program with ongoing patient enrolment and data collection. These preliminary findings can serve as a model for other EMS systems who seek to implement regional eCPR programs.

Quantifying the amount of greater brain ischemia protection time with pre-hospital vs. in-hospital neuroprotective agent start.

The objective of this study is to quantify the increase in brain-under-protection time that may be achieved with pre-hospital compared with the post-arrival start of neuroprotective therapy among patients undergoing endovascular thrombectomy. In order to do this, a comparative analysis was performed of two randomized trials of neuroprotective agents: (1) pre-hospital strategy: Field administration of stroke therapy-magnesium (FAST-MAG) Trial; (2) in-hospital strategy: Efficacy and safety of nerinetide for the treatment of acute ischemic stroke (ESCAPE-NA1) Trial. In the FAST-MAG trial, among 1,041 acute ischemic stroke patients, 44 were treated with endovascular reperfusion therapy (ERT), including 32 treated with both intravenous thrombolysis and ERT and 12 treated with ERT alone. In the ESCAPE-NA1 trial, among 1,105 acute ischemic stroke patients, 659 were treated with both intravenous thrombolysis and ERT, and 446 were treated with ERT alone. The start of the neuroprotective agent was sooner after onset with pre-hospital vs. in-hospital start: 45 m (IQR 38-56) vs. 122 m. The neuroprotective agent in FAST-MAG was started 8 min prior to ED arrival compared with 64 min after arrival in ESCAPE-NA1. Projecting modern endovascular workflows to FAST-MAG, the total time of "brain under protection" (neuroprotective agent start to reperfusion) was greater with pre-hospital than in-hospital start: 94 m (IQR 90-98) vs. 22 m. Initiating a neuroprotective agent in the pre-hospital setting enables a faster treatment start, yielding 72 min additional brain protection time for patients with acute ischemic stroke. These findings provide support for the increased performance of ambulance-based, pre-hospital treatment trials in the development of neuroprotective stroke therapies.

National Institutes of Health Stroke Scale Correlates Well with Initial Intracerebral Hemorrhage Volume.

OBJECTIVES: The US Centers for Medicare and Medicaid Services (CMS) currently publicly reports hospital-quality, risk-adjusted mortality measure for ischemic stroke but not intracerebral hemorrhage (ICH). The NIHSS, which is captured in CMS administrative claims data, is a candidate metric for use in ICH risk adjustment and has been shown to predict clinical outcome with accuracy similar to the ICH Score. Correlation between early NIHSS and initial ICH volume would further support use of the NIHSS for ICH risk adjustment. MATERIALS AND METHODS: Among 372 ICH patients enrolled in a large multicenter trial (FAST-MAG), the relation between early NIHSS and early ICH volume was assessed with correlation and linear trend analysis. RESULTS: Overall, there was strong correlation between NIHSS and ICH volume, r = 0.77 (p < 0.001), and for every 10cc increase in ICH the NIHSS increased by 4.5 points. Correlation coefficients were comparable in all subgroups, but magnitude of NIHSS increase with ICH unit volume increase was greater with left than right hemispheric ICH, with presence rather than absence of IVH, with imaging done within the first hour than second hour after last known well, with men than women, and with younger than older patients. CONCLUSION: Early NIHSS neurologic deficit severity values correlate strongly with initial ICH hematoma volume. As with ischemic stroke, lesion volume increases produce greater NIHSS change in the left than right hemisphere, reflecting greater NIHSS sensitivity to left hemisphere function. These findings provide further support for the use of NIHSS in risk-adjusted mortality measures for intracerebral hemorrhage.

SARS-CoV-2 seroprevalence among firefighters in Los Angeles, California.

OBJECTIVE: We estimate the seroprevalence of SARS-CoV-2 antibodies among a sample of firefighters in the Los Angeles (LA), California fire department in October 2020 and compare demographic and contextual factors for seropositivity. METHODS: We conducted a serological survey of firefighters in LA, California, USA, in October 2020. Individuals were classified as seropositive for SARS-CoV-2 if they tested positive for IgG, IgM or both. We compared demographic and contextual factors for seropositivity. RESULTS: All firefighters in LA, California, USA were invited to participate in our study, but only roughly 21% participated. Of 713 participants with valid serological data, 8.8% tested positive for SARS-CoV-2 antibodies, and among the 686 with complete survey data 8.9% tested positive for antibodies. Seropositivity was not associated with gender, age or race/ethnicity. Seropositivity was highest among firefighters who reported working in the vicinity of LA International Airport, which had a known outbreak in July 2020. CONCLUSIONS: Seroprevalence among firefighters in our sample was 8.8%, however, we lack a full workplace seroprevalence estimate to compare the relative magnitude against general population seroprevalence (15%). Workplace safety protocols, such as access to personal protective equipment and testing, can mitigate increased risk of infection at work, and may have eliminated differences in disease burden by geography and race/ethnicity in our sample.

Utility of Glucose Testing and Treatment of Hypoglycemia in Patients with Out-of-Hospital Cardiac Arrest.

Objective: Many emergency medical services (EMS) protocols for out-of-hospital cardiac arrests (OHCA) include point-of-care (POC) glucose measurement and administration of dextrose, despite limited knowledge of benefit. The objective of this study was to describe the incidence of hypoglycemia and dextrose administration by EMS in OHCA and subsequent patient outcomes.Methods: This was a retrospective analysis of OHCA in a large, regional EMS system from 2011 to 2017. Patients ≥18 years old with non-traumatic OHCA and attempted field resuscitation by paramedics were included. The primary outcomes were frequency of POC glucose measurement, hypoglycemia (glucose <60 mg/dl), and dextrose/glucagon administration (treatment group). The secondary outcomes included field return of spontaneous circulation (ROSC), survival to hospital discharge (SHD), and survival with good neurologic outcome.Results: There were 46,211 OHCAs during the study period of which 33,851 (73%) had a POC glucose test performed. Glucose levels were documented in 32,780 (97%), of whom 2,335 (7%) were hypoglycemic. Among hypoglycemic patients, 41% (959) received dextrose and/or glucagon. Field ROSC was achieved in 30% (286) of hypoglycemic patients who received treatment. Final outcome was determined for 1,714 (73%) of the hypoglycemic cases, of whom 120 (7%) had SHD and 66 (55%) had a good neurologic outcome. Of the 32,780 patients with a documented POC glucose result who were identified as hypoglycemic, only 27 (0.08%) received field treatment, and survived to discharge with good neurologic outcome. 48 (6%) of patients in the treatment group had SHD vs. 72 (8%) without treatment, risk difference -2.0% (95%CI -4.4%, 0.4%), p = 0.1.Conclusion: In this EMS system, POC glucose testing was common in adult OHCA, yet survival to hospital discharge with good neurologic outcome did not differ between patients treated and untreated for hypoglycemia. These results question the common practice of measuring and treating hypoglycemia in OHCA patients.

Prehospital Predictors of Atypical STEMI Symptoms.

Introduction: Rapid prehospital identification of patients with ST-elevation myocardial infarction (STEMI) is a critical step to reduce time to treatment. Broad screening with field 12-lead ECGs can lead to a high rate of false positive STEMI activations due to low prevalence. One strategy to reduce false positive STEMI interpretations is to limit acquisition of 12-lead ECGs to patients who have symptoms strongly suggestive of STEMI, but this may delay care in patients who present atypically and lead to disparities in populations with more atypical presentations. We sought to assess patient factors associated with atypical STEMI presentation.Methods: We retrospectively analyzed consecutive adult patients for whom Los Angeles Fire Department paramedics obtained a field 12-lead ECG from July 2011 through June 2012. The regional STEMI receiving center registry was used to identify patients with STEMI. Patients were designated as having typical symptoms if paramedics documented provider impressions of chest pain/discomfort, cardiac arrest, or cardiac symptoms, otherwise they were designated as having atypical symptoms. We utilized logistic regression to determine patient factors (age, sex, race) associated with atypical STEMI presentation.Results: Of the 586 patients who had STEMI, 70% were male, 43% White, 16% Black, 20% Hispanic, 5% Asian and 16% were other or unspecified race. Twenty percent of STEMI patients (n = 117) had atypical symptoms. Women who had STEMI were older than men (74 years [IQR 62-83] vs. 60 years [IQR 53-70], p < 0.001). Univariate predictors of atypical symptoms were older age and female sex (p < 0.0001), while in multivariable analysis older age [odd ratio (OR) 1.05 per year, [95%CI 1.04-1.07, p < 0.0001] and black race (OR vs White 2.18, [95%CI 1.20-3.97], p = 0.011) were associated with atypical presentation.Conclusion: Limiting prehospital acquisition of 12-lead ECGs to patients with typical STEMI symptoms would result in one in five patients with STEMI having delayed recognition, disproportionally impacting patients of older age, women, and Black patients. Age, not sex, may be a better predictor of atypical STEMI presentation.

Use of Naloxone in 9-1-1 Patients without Respiratory Depression in Los Angeles County, California (USA).

INTRODUCTION: Along with an increase in opioid deaths, there has been a desire to increase the accessibility of naloxone. However, in the absence of respiratory depression, naloxone is unlikely to be beneficial and may be deleterious if it precipitates withdrawal in individuals with central nervous system (CNS) depression due to non-opioid etiologies. OBJECTIVE: The aim of this study was to evaluate how effective prehospital providers were in administering naloxone. METHODS: This is a retrospective study of naloxone administration in two large urban Emergency Medical Service (EMS) systems. The proportion of patients who had a respiratory rate of at least 12 breaths per minute at the time of naloxone administration by prehospital providers was determined. RESULTS: During the two-year study period, 2,580 patients who received naloxone by prehospital providers were identified. The median (interquartile range) respiratory rate prior to naloxone administration was 12 (6-16) breaths per minute. Using an a priori respiratory rate of under 12 breaths per minute to define respiratory depression, only 1,232 (47.8%; 95% CI, 50.3%-54.2%) subjects who received naloxone by prehospital providers had respiratory depression. CONCLUSION: This study showed that EMS providers in Los Angeles County, California (USA) frequently administered naloxone to individuals without respiratory depression.

Spatiotemporal analysis of out-of-hospital cardiac arrest in the City of Los Angeles, 2011-2019.

OBJECTIVE: The goal of this analysis is to spatiotemporally identify and categorize areas in a large urban city according to Out-of-Hospital Cardiac Arrest (OHCA) rates and No Bystander CPR (NBCPR) risk levels. STUDY AREA AND PARTICIPANTS: The study comprised all cardiac arrests within the administrative geographic boundary of the City of Los Angeles. The final sample included 15,904 cases that were geolocated within 985 census tracts. MAIN OUTCOMES AND MEASURES: The primary outcome was stratification of census tracts into risk levels of OHCA and NBCPR by observed spatiotemporal patterns. RESULTS: Of 985 census tracts in the analytical sample, 182 census tracts (18.5%) were identified as having higher risk of OHCA and NBCPR. This assessment resulted in 129 census tracts in Tier 3 (moderate risk), 36 in Tier 2 (moderate-high risk), and 17 in Tier 1 (highest risk). Census tracts in Tiers 2 and 3 had higher amounts incident OHCA, while those in tier 1 had more OHCA events with NBCPR. These areas were largely contiguous and located in the Central and South areas of Los Angeles. CONCLUSIONS: Using a novel three-tiered neighborhood risk classification tool, specific neighborhoods have been identified in the second largest city in the U.S. with consistently high or accelerating rates of OHCA and low bystander CPR. Further study of bystander response and community-based public health campaigns are needed in these communities.

Comparison of Emergency Medical Dispatch Systems for Performance of Telecommunicator-Assisted Cardiopulmonary Resuscitation Among 9-1-1 Callers With Limited English Proficiency.

Importance: Increasing bystander cardiopulmonary resuscitation (CPR) among racial/ethnic minority groups and culturally underserved populations is a key strategy in improving health care disparities in out-of-hospital cardiac arrest. Objective: To ascertain whether implementation of the Los Angeles Tiered Dispatch System (LA-TDS) was associated with improved performance of telecommunicator-assisted CPR (T-CPR) among 9-1-1 callers with limited English proficiency in the City of Los Angeles. Design, Setting, and Participants: This cohort study compared emergency medical services-treated, nontraumatic out-of-hospital cardiac arrest calls using the Medical Priority Dispatch System (MPDS) from January 1 to March 31, 2014, with calls using LA-TDS from January 1 to March 31, 2015. Trained data abstractors evaluated all 9-1-1 audio recordings for the initiation of T-CPR and the elapsed time to predefined events. Data were analyzed between January and December 2017. Main Outcomes and Measures: The primary outcome was the prevalence of T-CPR among 9-1-1 callers with limited English proficiency for field-confirmed nontraumatic cardiac arrests. Additional outcomes included T-CPR among callers with English proficiency and the elapsed time until key events in the call. Results: Of the 1027 emergency medical services calls during the study periods, 597 met the inclusion criteria. A total of 289 calls (48%) were made using MPDS (263 callers with English proficiency, and 26 callers with limited English proficiency), and 308 calls (52%) were made using LA-TDS (273 callers with English proficiency, and 35 callers with limited English proficiency). No differences between MPDS and LA-TDS cohorts were found in age, sex, known comorbidities, arrest location (private vs public), or witnessed status. The prevalence of T-CPR among callers with limited English proficiency was significantly greater using LA-TDS (69%) vs MPDS (28%) (odds ratio [OR], 5.66; 95% CI, 1.79-17.85; P = .003). For callers with English proficiency, the prevalence of T-CPR improved from 55% using MPDS to 67% using LA-TDS (OR, 1.66; 95% CI, 1.15-2.41; P = .007). With LA-TDS, callers with limited English proficiency had a significant decrease in time to recognition of cardiac arrest (OR, 0.59; 95% CI, 0.41-0.84; P = .005) and dispatch of resources (OR, 0.71; 95% CI, 0.54-0.94; P = .02). Conclusions and Relevance: The LA-TDS compared with MPDS was associated with increased performance of T-CPR for out-of-hospital cardiac arrests involving 9-1-1 callers with limited English proficiency. Further studies are needed in communities with a predominance of people with limited English proficiency to characterize bystander response, promote activation of the chain of survival, and clarify the precise elements of LA-TDS that can improve T-CPR performance.

The relationship of large city out-of-hospital cardiac arrests and the prevalence of COVID-19.

BACKGROUND: Though variable, many major metropolitan cities reported profound and unprecedented increases in out-of-hospital cardiac arrest (OHCA) in early 2020. This study examined the relative magnitude of those increases and their relationship to COVID-19 prevalence. METHODS: EMS (9-1-1 system) medical directors for 50 of the largest U.S. cities agreed to provide the aggregate, de-identified, pre-existing monthly tallies of OHCA among adults (age >18 years) occurring between January and June 2020 within their respective jurisdictions. Identical comparison data were also provided for corresponding time periods in 2018 and 2019.  Equivalent data were obtained from the largest cities in Italy, United Kingdom and France, as well as Perth, Australia and Auckland, New Zealand. FINDINGS: Significant OHCA escalations generally paralleled local prevalence of COVID-19. During April, most U.S. cities (34/50) had >20% increases in OHCA versus 2018-2019 which reflected high local COVID-19 prevalence. Thirteen observed 1·5-fold increases in OHCA and three COVID-19 epicenters had >100% increases (2·5-fold in New York City). Conversely, cities with lesser COVID-19 impact observed unchanged (or even diminished) OHCA numbers. Altogether (n = 50), on average, OHCA cases/city rose 59% during April (p = 0·03). By June, however, after mitigating COVID-19 spread, cities with the highest OHCA escalations returned to (or approached) pre-COVID OHCA numbers while cities minimally affected by COVID-19 during April (and not experiencing OHCA increases), then had marked OHCA escalations when COVID-19 began to surge locally. European, Australian, and New Zealand cities mirrored the U.S. experience. INTERPRETATION: Most metropolitan cities experienced profound escalations of OHCA generally paralleling local prevalence of COVID-19.  Most of these patients were pronounced dead without COVID-19 testing. FUNDING: No funding was involved. Cities provided de-identified aggregate data collected routinely for standard quality assurance functions.

Prehospital Needle Decompression Improves Clinical Outcomes in Helicopter Evacuation Patients With Multisystem Trauma: A Multicenter Study.

BACKGROUND: The utility of prehospital thoracic needle decompression (ND) for tension physiology in the civilian setting continues to be debated. We attempted to provide objective evidence for clinical improvement when ND is performed and determine whether technical success is associated with provider factors. We also attempted to determine whether certain clinical scenarios are more predictive than others of successful improvement in symptoms when ND is performed. METHODS: Prehospital ND data acquired from one air ambulance service serving 79 trauma centers consisted of 143 patients (n = 143; ND attempts = 172). Demographic and clinical outcome data were retrospectively reviewed. Patients were stratified by prehospital characteristics and indications. Objective outcomes were measured as improvement in vital signs, subjective patient assessment, and physical examination findings. Univariate analysis was performed using chi-square for variable proportions and unpaired Student's t-test for variable means; p < .05 was considered statistically significant. RESULTS: The success rate of ND performed for hypoxia (70.5%) was notably higher than ND performed for hemodynamic instability (20.3%; p < .01) or cardiac arrest (0%; p < .01). Compared to vital sign parameters, clinical examination findings as part of the indication for ND did not reliably predict technical success (p > .52 for all indications). No difference was observed comparing registered nurse versus paramedic (p = .23), diameter of catheter (p > .13 for all), or length of catheter (p = .12). CONCLUSION: Prehospital ND should be considered in the appropriate clinical setting. Outcomes are less reliable in cases of cardiopulmonary arrest or hypotension with respiratory symptoms; however, this should not deter prehospital providers from attempting ND when clinically indicated. Additionally, the success rate of prehospital ND does not appear to be related to catheter type or the role of the performing provider.

Emergency Medical Services Utilization by Homeless Patients.

BACKGROUND: Homelessness is a rapidly growing issue throughout the United States and has important public health implications. Los Angeles, like other large urban cities, has seen a recent increase in homelessness. However, little is known about emergency medical service (EMS) utilization by those experiencing homelessness. Objective: Describe the utilization of emergency medical services by homeless patients. Methods: This is a 12-month retrospective review of electronic health records of all 911-incidents attended by the Los Angeles Fire Department (LAFD) from January to December 2018. The City of Los Angeles is 480 square miles and has a population of 3,949,776 with a homeless population of 31,285 (0.8% of city population). The primary outcome is the frequency of EMS 911-calls for homeless patients. Secondary outcomes include call characteristics. Results: There were 355,411 911-incidents during the study period. Homeless patients were involved in 36,122 (10.2%) incidents. Incidents for the homeless population occurred at a rate of 1155 per 1000 homeless residents or 14 times the rate of housed residents. Of the 217,972 calls resulting in transport to the emergency department, 28,917 (13.3%) were for homeless patients. This translates into a rate of 924 per 1000 homeless patients, which is 19 times higher than housed patients. Homeless patients were younger (mean 46.1 v 52.6 years) and more likely to be male (71% v 49.1%). Acuity was lower in the homeless group, 31.4% v 42.5% received advanced life support. Conclusion: In the City of Los Angeles, people experiencing homelessness demonstrated disproportionately high use of EMS services and ambulance transports, were more frequently younger, male, and had lower acuity conditions when compared with housed patients.

Adiposity and Outcome After Ischemic Stroke: Obesity Paradox for Mortality and Obesity Parabola for Favorable Functional Outcomes.

BACKGROUND AND PURPOSE: A survival advantage among individuals with higher body mass index (BMI) has been observed for diverse acute illnesses, including stroke, and termed the obesity paradox. However, prior ischemic stroke studies have generally tested only for linear rather than nonlinear relations between body mass and outcome, and few studies have investigated poststroke functional outcomes in addition to mortality. METHODS: We analyzed consecutive patients with acute ischemic stroke enrolled in a 60-center acute treatment trial, the NIH FAST-MAG acute stroke trial. Outcomes at 3 months analyzed were (1) death; (2) disability or death (modified Rankin Scale score, 2-6); and (3) low stroke-related quality of life (Stroke Impact Scale

The Effect of Early Treatment with Intravenous Magnesium Sulfate on the Incidence of Cardiac Comorbidities in Hospitalized Stroke Patients.

BACKGROUND: Cardiac adverse events are common among patients presenting with acute stroke and contribute to overall morbidity and mortality. Prophylactic measures for the reduction of cardiac adverse events in hospitalized stroke patients have not been well understood. We sought to investigate the effect of early initiation of high-dose intravenous magnesium sulfate on cardiac adverse events in stroke patients. METHODS: This is a secondary analysis of the prehospital Field Administration of Stroke Therapy-Magnesium (FAST-MAG) randomized phase-3 clinical trial, conducted from 2005-2013. Consecutive patients with suspected acute stroke and a serum magnesium level within 72 hours of enrollment were selected. Twenty grams of magnesium sulfate or placebo was administered in the ambulance starting with a 15-minute loading dose intravenous infusion followed by a 24-hour maintenance infusion in the hospital. RESULTS: Among 1126 patients included in the analysis of this study, 809 (71.8%) patients had ischemic stroke, 277 (24.6%) had hemorrhagic stroke, and 39 (3.5%) with stroke mimics. The mean age was 69.5 (SD13.4) and 42% were female. 565 (50.2%) received magnesium treatment, and 561 (49.8%) received placebo. 254 (22.6%) patients achieved the target, and 872 (77.4%) did not achieve the target, regardless of their treatment group. Among 1126 patients, 159 (14.1%) had at least one CAE. Treatment with magnesium was not associated with fewer cardiac adverse events. A multivariate binary logistic regression for predictors of CAEs showed a positive association of older age and frequency of CAEs (R = 1.04, 95% CI 1.03-1.06, p < 0.0001). Measures of early and 90-day outcomes did not differ significantly between the magnesium and placebo groups among patients who had CAEs. CONCLUSION: Treatment of acute stroke patients with magnesium did not result in a reduction in the number or severity of cardiac serious adverse events.

A Prehospital Acute Stroke Trial has Only Modest Impact on Enrollment in Concurrent, Post-arrival-Recruiting Stroke Trials.

BACKGROUND: Because "time is brain," acute stroke trials are migrating to the prehospital setting. The impact upon enrollment in post-arrival trials of earlier recruitment in a prehospital trial requires delineation. METHODS: We analyzed all patients recruited into acute and prevention stroke trials during an 8-year period when an academic medical center (AMC) was participating in a prehospital treatment trial - the NIH Field Administration of Stroke Treatment - Magnesium (FAST-MAG) study. RESULTS: During the study period, in addition to FAST-MAG, the AMC participated in 33 post-arrival stroke trials: 27 for acute cerebral ischemia, one for intracerebral hemorrhage, and 5 secondary prevention trials. Throughout the study period, the AMC was recruiting for at least 3 concurrent post-arrival acute trials. Among 199 patients enrolled in acute stroke trials, 98 (49%) were in FAST-MAG and 101 (51%) in concurrent, post-arrival acute trials. Among FAST-MAG patients, 67% were not eligible for any concurrent acute, post-arrival trial. Of 134 patients eligible for post-arrival acute trials, 101 (76%) were enrolled in post-arrival trials and 32 (24%) in FAST-MAG. Leading reasons FAST-MAG patients were ineligible for post-arrival acute trials were: NIHSS too low (23.4%), intracranial hemorrhage (17.9%), IV tPA used in standard management (9.0%), NIHSS too high (7.1%), and age too high (5.2%). CONCLUSIONS: A prehospital hyperacute stroke trial with wide entry criteria reduced only modestly, by one-fourth, enrollment into concurrently active, post-arrival stroke trials. Simultaneous performance of prehospital and post-arrival acute and secondary prevention stroke trials in research networks is feasible.