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.

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.

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.

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.

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

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.

Paramedic Global Impression of Change During Prehospital Evaluation and Transport for Acute Stroke.

Background and Purpose- The prehospital setting is a promising site for therapeutic intervention in stroke, but current stroke screening tools do not account for the evolution of neurological symptoms in this early period. We developed and validated the Paramedic Global Impression of Change (PGIC) Scale in a large, prospective, randomized trial. Methods- In the prehospital FAST-MAG (Field Administration of Stroke Therapy-Magnesium) randomized trial conducted from 2005 to 2013, EMS providers were asked to complete the PGIC Scale (5-point Likert scale values: 1-much improved, 2-mildly improved, 3-unchanged, 4-mildly worsened, 5-much worsened) for neurological symptom change during transport for consecutive patients transported by ambulance within 2 hours of onset. We analyzed PGIC concurrent validity (compared with change in Glasgow Coma Scale, Los Angeles Motor Scale), convergent validity (compared with National Institutes of Health Stroke Scale severity measure performed in the emergency department), and predictive validity (of neurological deterioration after hospital arrival and of final 90-day functional outcome). We used PGIC to characterize differential prehospital course among stroke subtypes. Results- Paramedics completed the PGIC in 1691 of 1700 subjects (99.5%), among whom 635 (37.5%) had neurological deficit evolution (32% improvement, 5.5% worsening) during a median prehospital care period of 33 (IQR, 27-39) minutes. Improvement was associated with diagnosis of cerebral ischemia rather than intracranial hemorrhage, milder stroke deficits on emergency department arrival, and more frequent nondisabled and independent 3-month outcomes. Conversely, worsening on the PGIC was associated with intracranial hemorrhage, more severe neurological deficits on emergency department arrival, more frequent treatment with thrombolytic therapy, and poor disability outcome at 3 months. Conclusions- The PGIC scale is a simple, validated measure of prehospital patient course that has the potential to provide information useful to emergency department decision-making. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00059332.

Impact of a New 9-1-1 Dispatch System on Call-Processing Times for Time-Critical Emergencies in the City of Los Angeles.

Objective: To determine the impact of a new emergency medical services (EMS) 9-1-1 dispatch system on call-processing times for field-confirmed time-critical emergencies. Methods: An interrupted time series study compared 9-1-1 calls for field-confirmed emergencies processed by Los Angeles Fire Department (LAFD)-telecommunicators using either the Medical Priority Dispatch System® (January 1 - September 30, 2014) or the new Los Angeles Tiered Dispatch System (January 1 - September 30, 2015). Prior to the study, authors identified seven categories of time-critical emergencies. Cases meeting inclusion criteria were systematically identified using LAFD electronic health records, and the elapsed time from call receipt to key events were obtained. The primary outcome was call-processing time (CPT), defined as time from 9-1-1 call receipt to when resources were dispatched. Results: During the study period, 12,439 incidents met inclusion criteria: 6,208 using MPDS and 6,231 using LA-TDS. Among all unique time-critical incidents, the mean CPT was 16 seconds faster using LA-TDS (M = 68.5) compared to MPDS (M = 84.4; p < 0.001). CPT was significantly (p < 0.01) lower using LA-TDS for: cardiac arrests with attempted resuscitation, patients requiring ventilation support, seizures requiring prehospital benzodiazepines, gunshot wounds with hypotension, automobile vs. pedestrian accidents, and long falls. There was no difference in CPT for drownings requiring resuscitation (p = 0.60). The elapsed time to arrival of first responders on scene improved from 370.1 seconds using MPDS to 354.8 seconds using LA-TDS (p < 0.001). Conclusion: The new Los Angeles Tiered Dispatch System significantly improved 9-1-1 call-processing times and total response times for nearly all identified time-critical emergencies under study.

Effect of New 9-1-1 System on Efficiency of Initial Resource Assignment.

Objective: To determine the impact of a new dispatch system on the efficiency of first resource assignment for critical EMS patients. Methods: In December 2014, the Los Angeles Fire Department (LAFD) implemented a new, internally-developed dispatch system. An interrupted time series study compared 9-1-1 incidents processed by LAFD-telecommunicators using either the Medical Priority Dispatch System® (MPDS, January 1 - September 30, 2014), or Los Angeles Tiered Dispatch System (LA-TDS, January 1 - September 30, 2015). All incidents were assigned a Dispatch Level of Service (DLOS), based on whether a basic life support (BLS) or advanced life support (ALS) resource was dispatched, and a Field-Recommended Level of Service (RLOS), a metric based on medical necessity, required scope of practice, number and intensity of interventions, and patient severity. DLOS options included BLS or ALS, whereas RLOS options included BLS, ALS1 and ALS2, with ALS2 cases having the greatest medical need. The primary outcome was critical under-triage rate, and secondary outcomes included rates of over-triage, total resource utilization and test characteristics of each dispatch system. Results: 563,188 incidents met inclusion criteria, including 271,604 using MPDS and 291,584 using LA-TDS. During the MPDS period, 96,561 (35.6%) incidents were initially dispatched with BLS resources (including 194 (0.071% ultimately found in the field to be high-acuity RLOS ALS2), and 175,043 were dispatched with ALS resources. During the LA-TDS period, 127,827 (43.8%) were dispatched as BLS (including 154 RLOS ALS2) and 163,798 were dispatched as ALS. For the primary outcome, the critical under-triage rate was 0.20% using MPDS and 0.12% using LA-TDS (Z 4.7, p < 0.0001, RR 0.61 CI 95% 0.50-0.76), and this improvement was primarily driven by improved triage of cardiac arrest. The over-triage rate using MPDS was 44%, which decreased to 33% using LA-TDS. LA-TDS was associated with significant improvements in specificity, positive predictive value and accuracy of initial resource assignment, and is projected to have saved over 23,000 EMS resource dispatches over the 9-month study period. Conclusion: The new Los Angeles Tiered Dispatch System significantly improved the efficiency of initial 9-1-1 resource assignments by decreasing both over-triage and critical under-triage, thus sending more appropriate resources to each 9-1-1 call.

Advanced Practice Providers in the Field: Implementation of the Los Angeles Fire Department Advanced Provider Response Unit.

Background: To address the growing number of low-acuity patients in the 911-EMS system, the Los Angeles Fire Department (LAFD) launched a pilot program placing an Advanced Provider Response Unit (APRU) in the field so that a prehospital nurse practitioner (NP) could offer patients treatment/release on scene, alternative destination transport, and linkage with social services. Objective: To describe the initial 18-month experience implementing this new APRU. Methods: This is a retrospective, descriptive review of all APRU-attended patients from January 2016 to June 2017. The APRU was an ambulance staffed by an NP and a firefighter/paramedic, equipped with basic point-of-care testing capability, and linked to incidents by either being summoned by on-scene first responders or by monitoring EMS radio traffic. Descriptive statistics were used and outcome measures included counts of clients attended, treat/release rates, impact on total time in service for other LAFD resources, patient need for subsequent re-use of 911 and self-reported experience of care. Results: During its first 18 months in service, the APRU attended 812 patients, including 792 911-patient incidents. 400 of these 911-patients (50.5%) were treated and released on scene or medically cleared and transported to an alternative site for specialty care. This included 76 patients with primary psychiatric complaints who were medically-cleared and transported directly to a mental health urgent care center. An additional 18 high utilizers of 911 were attended by the APRU and connected with a social work organization, and 12 of 18 (66.7%) decreased their use of EMS in the 90-days following APRU evaluation and referral. Of the 400 911-patients that did not go to the emergency department (ED), 26 (6.5%) re-contacted 911 within 3 days: all were transported to the ED with normal vital signs and without prehospital intervention, and all were ultimately discharged home from the ED. As a result of APRU intervention, 458 other LAFD field resources were quickly placed back in service and made available for the next time-critical call. Conclusions: Advanced practice providers such as nurse practitioners can be incorporated into the prehospital setting to address a growing subset of 911-patients whose needs can be met outside of the ED.

Prime the Line! A Case Report of Air Embolism from a Peripheral IV Line in the Field.

Venous air embolisms are rare but a cause of potentially life-threatening events with associated cardiovascular, pulmonary and neurologic effects. We report the first prehospital case of a venous air embolism in a 31-year-old male who became hemodynamically unstable after a peripheral intravenous catheter with unprimed tubing was placed by paramedics in the prehospital setting and diagnosed in the emergency department. We highlight the clinical presentation, diagnosis and emergency management of venous air embolisms.

Critical Medication Shortages: Effective Strategies to Maintain Continuous Medication Availability for Emergency Medical Services.

Objective: Critical shortages of generic injectable medications are an ongoing challenge for Emergency Medical Services (EMS) systems. Mitigation strategies have been proposed to address the issue, but a limited amount of data exists quantifying the scope of the problem or describing strategies being used to ensure access to essential medications for prehospital care. In this study, we sought to quantify specific medication shortages and to determine the most frequently employed mitigation strategies to maintain medication availability in a large, regional EMS system. Methods: A survey was distributed to the 30 public advanced life support (ALS) provider agencies in Los Angeles County (LAC) to assess the prevalence of specific medication shortages and types of shortage mitigation strategies implemented. Survey responses were reviewed and presented using descriptive statistics. Results: Survey responses were received from 29 of 30 (97%) provider agencies. All but one of the responding agencies reported being impacted by medication shortages. Strategies to maintain the supply of medications included use of alternative vendors 20/28 (71%), rotating medications from low to high volume units (54%), utilizing expired medication FDA-approved extensions (50%), substituting medications (43%), borrowing medications from the LAC EMS Agency (39%) or other EMS provider agencies (32%), utilizing expired medications with medical director approval (29%), diluting medications to obtain desired concentration (18%), reducing minimum periodic automatic replacement (PAR) levels (14%), and using alternate medication concentrations/formulations (14%). The medications most frequently reported to have shortages included epinephrine (0.1 mg/mL), morphine, dextrose 10%, and normal saline. None of the provider agencies self-reported adverse events due to the shortages. Conclusions: Critical medication shortages remain a problem for many EMS systems. EMS medical directors need to implement multiple mitigation strategies to maintain supply of critical medications for prehospital patient care.

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.

Association Between Hyperacute Stage Blood Pressure Variability and Outcome in Patients With Spontaneous Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Increased blood pressure (BP) variability, in addition to high BP, may contribute to adverse outcome in intracerebral hemorrhage. However, degree and association with outcome of BP variability (BPV) in the hyperacute period, 15 minutes to 5 hours after onset, have not been delineated. METHODS: Among consecutive patients with intracerebral hemorrhage enrolled in the FAST-MAG trial (Field Administration of Stroke Therapy-Magnesium), BPs were recorded by paramedics in the field and during the first 24 hours of hospital course. BP was analyzed in the hyperacute period, from 0 to 4-6 hours, and in the acute period, from 0 to 24-26 hours after onset. BPV was analyzed by SD, coefficient of variation, and successive variation. RESULTS: Among 386 patients with intracerebral hemorrhage, first systolic BP at median 23 minutes (interquartile range, 14-38.5) after onset was median 176 mm Hg, second systolic BP on emergency department arrival at 57 minutes (interquartile range, 45-75) after onset was 178 mm Hg, and systolic BP 24 hours after arrival was 138 mm Hg. Unfavorable outcome at 3 months (modified Rankin Scale, 3-6) occurred in 270 (69.9%). Neither mean nor maximum systolic BP was associated with outcome in multivariable analysis. However, all 3 parameters of BPV, in both the hyperacute and the acute stages, were associated with poor outcome. In the hyperacute phase, BPV was associated with poor outcome with adjusted odds ratios of 3.73 for the highest quintile of SD, 4.78 for the highest quintile of coefficient of variation, and 3.39 for the highest quintile of successive variation. CONCLUSIONS: BPV during the hyperacute first minutes and hours after onset in patients with intracerebral hemorrhage was independently associated with poor functional outcome. Stabilization of BPV during this vulnerable period, in the pre-hospital and early emergency department course, is a potential therapeutic target for future clinical trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059332.

Los Angeles Motor Scale to Identify Large Vessel Occlusion: Prehospital Validation and Comparison With Other Screens.

BACKGROUND AND PURPOSE: Prehospital scales have been developed to identify patients with acute cerebral ischemia (ACI) because of large vessel occlusion (LVO) for direct routing to Comprehensive Stroke Centers (CSCs), but few have been validated in the prehospital setting, and their impact on routing of patients with intracranial hemorrhage has not been delineated. The purpose of this study was to validate the Los Angeles Motor Scale (LAMS) for LVO and CSC-appropriate (LVO ACI and intracranial hemorrhage patients) recognition and compare the LAMS to other scales. METHODS: The performance of the LAMS, administered prehospital by paramedics to consecutive ambulance trial patients, was assessed in identifying (1) LVOs among all patients with ACI and (2) CSC-appropriate patients among all suspected strokes. Additionally, the LAMS administered postarrival was compared concurrently with 6 other scales proposed for paramedic use and the full National Institutes of Health Stroke Scale. RESULTS: Among 94 patients, age was 70 (±13) and 49% female. Final diagnoses were ACI in 76% (because of LVO in 48% and non-LVO in 28%), intracranial hemorrhage in 19%, and neurovascular mimic in 5%. The LAMS administered by paramedics in the field performed moderately well in identifying LVO among patients with ACI (C statistic, 0.79; accuracy, 0.72) and CSC-appropriate among all suspected stroke transports (C statistic, 0.80; accuracy, 0.72). When concurrently performed in the emergency department postarrival, the LAMS showed comparable or better accuracy versus the 7 comparator scales, for LVO among ACI (accuracies LAMS, 0.70; other scales, 0.62-0.68) and CSC-appropriate (accuracies LAMS, 0.73; other scales, 0.56-0.73). CONCLUSIONS: The LAMS performed in the field by paramedics identifies LVO and CSC-appropriate patients with good accuracy. The LAMS performs comparably or better than more extended prehospital scales and the full National Institutes of Health Stroke Scale.

Prehospital use of magnesium sulfate as neuroprotection in acute stroke.

BACKGROUND: Magnesium sulfate is neuroprotective in preclinical models of stroke and has shown signals of potential efficacy with an acceptable safety profile when delivered early after stroke onset in humans. Delayed initiation of neuroprotective agents has hindered earlier phase 3 trials of neuroprotective agents. METHODS: We randomly assigned patients with suspected stroke to receive either intravenous magnesium sulfate or placebo, beginning within 2 hours after symptom onset. A loading dose was initiated by paramedics before the patient arrived at the hospital, and a 24-hour maintenance infusion was started on the patient's arrival at the hospital. The primary outcome was the degree of disability at 90 days, as measured by scores on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability). RESULTS: Among the 1700 enrolled patients (857 in the magnesium group and 843 in the placebo group), the mean (±SD) age was 69±13 years, 42.6% were women, and the mean pretreatment score on the Los Angeles Motor Scale of stroke severity (range, 0 to 10, with higher scores indicating greater motor deficits) was 3.7±1.3. The final diagnosis of the qualifying event was cerebral ischemia in 73.3% of patients, intracranial hemorrhage in 22.8%, and a stroke-mimicking condition in 3.9%. The median interval between the time the patient was last known to be free of stroke symptoms and the start of the study-drug infusion was 45 minutes (interquartile range, 35 to 62), and 74.3% of patients received the study-drug infusion within the first hour after symptom onset. There was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the magnesium group and those in the placebo group (P=0.28 by the Cochran-Mantel-Haenszel test); mean scores at 90 days did not differ between the magnesium group and the placebo group (2.7 in each group, P=1.00). No significant between-group differences were noted with respect to mortality (15.4% in the magnesium group and 15.5% in the placebo group, P=0.95) or all serious adverse events. CONCLUSIONS: Prehospital initiation of magnesium sulfate therapy was safe and allowed the start of therapy within 2 hours after the onset of stroke symptoms, but it did not improve disability outcomes at 90 days. (Funded by the National Institute of Neurological Disorders and Stroke; FAST-MAG ClinicalTrials.gov number, NCT00059332.).

Paramedic Initiation of Neuroprotective Agent Infusions: Successful Achievement of Target Blood Levels and Attained Level Effect on Clinical Outcomes in the FAST-MAG Pivotal Trial (Field Administration of Stroke Therapy - Magnesium).

BACKGROUND AND PURPOSE: Paramedic use of fixed-size lumen, gravity-controlled tubing to initiate intravenous infusions in the field may allow rapid start of neuroprotective therapy for acute stroke. In a large, multicenter trial, we evaluated its efficacy in attaining target serum levels of candidate neuroprotective agent magnesium sulfate and the relation of achieved magnesium levels to outcome. METHODS: The FAST-MAG phase 3 trial (Field Administration of Stroke Therapy - Magnesium) randomized 1700 patients within 2 hours of onset to paramedic-initiated, a 15-minute loading intravenous infusion of magnesium or placebo followed by a 24-hour maintenance dose. The drug delivery strategy included fixed-size lumen, gravity-controlled tubing for field drug administration, and a shrink-wrapped ambulance kit containing both the randomized field loading and hospital maintenance doses for seamless continuation. RESULTS: Among patient randomized to active treatment, magnesium levels in the first 72 hours were assessed 987 times in 572 patients. Mean patient age was 70 years (SD±14 years), and 45% were women. During the 24-hour period of active infusion, mean achieved serum level was 3.91 (±0.8), consistent with trial target. Mg levels were increased by older age, female sex, lower weight, height, body mass index, and estimated glomerular filtration rate, and higher blood urea nitrogen, hemoglobin, and higher hematocrit. Adjusted odds for clinical outcomes did not differ by achieved Mg level, including disability at 90 days, symptomatic hemorrhage, or death. CONCLUSIONS: Paramedic infusion initiation using gravity-controlled tubing permits rapid achievement of target serum levels of potential neuroprotective agents. The absence of association of clinical outcomes with achieved magnesium levels provides further evidence that magnesium is not biologically neuroprotective in acute stroke.

Field Validation of the Los Angeles Motor Scale as a Tool for Paramedic Assessment of Stroke Severity.

BACKGROUND AND PURPOSE: The Los Angeles Motor Scale (LAMS) is a 3-item, 0- to 10-point motor stroke-deficit scale developed for prehospital use. We assessed the convergent, divergent, and predictive validity of the LAMS when performed by paramedics in the field at multiple sites in a large and diverse geographic region. METHODS: We analyzed early assessment and outcome data prospectively gathered in the FAST-MAG trial (Field Administration of Stroke Therapy-Magnesium phase 3) among patients with acute cerebrovascular disease (cerebral ischemia and intracranial hemorrhage) within 2 hours of onset, transported by 315 ambulances to 60 receiving hospitals. RESULTS: Among 1632 acute cerebrovascular disease patients (age 70±13 years, male 57.5%), time from onset to prehospital LAMS was median 30 minutes (interquartile range 20-50), onset to early postarrival (EPA) LAMS was 145 minutes (interquartile range 119-180), and onset to EPA National Institutes of Health Stroke Scale was 150 minutes (interquartile range 120-180). Between the prehospital and EPA assessments, LAMS scores were stable in 40.5%, improved in 37.6%, and worsened in 21.9%. In tests of convergent validity, against the EPA National Institutes of Health Stroke Scale, correlations were r=0.49 for the prehospital LAMS and r=0.89 for the EPA LAMS. Prehospital LAMS scores did diverge from the prehospital Glasgow Coma Scale, r=-0.22. Predictive accuracy (adjusted C statistics) for nondisabled 3-month outcome was as follows: prehospital LAMS, 0.76 (95% confidence interval 0.74-0.78); EPA LAMS, 0.85 (95% confidence interval 0.83-0.87); and EPA National Institutes of Health Stroke Scale, 0.87 (95% confidence interval 0.85-0.88). CONCLUSIONS: In this multicenter, prospective, prehospital study, the LAMS showed good to excellent convergent, divergent, and predictive validity, further establishing it as a validated instrument to characterize stroke severity in the field.