An Urban 9-1-1 System's Experience with Left Ventricular Assist Device Patients.

Background: Left ventricular assist devices (LVADs) are used with increasing frequency and left in place for longer periods of time. Prior publications have focused on the mechanics of troubleshooting the device itself. We aim to describe the epidemiology of LVAD patient presentations to emergency medical services (EMS), prehospital assessments and interventions, and hospital outcomes. Methods: This is a retrospective chart review of known LVAD patients that belong to a single academic center's heart failure program who activated the 9-1-1 system and were transported by an urban EMS system to one of the center's 2 emergency departments between January 2012 and December 2015. Identifying demographics were used to query the electronic medical record of the responding city fire agency and contracted transporting ambulance service. Two reviewers abstracted prehospital chief complaint, vital signs, assessments, and interventions. Emergency department and hospital outcomes were retrieved separately. Results: From January 2012 to December 2015, 15 LVAD patients were transported 16 times. The most common prehospital chief complaint was weakness (7/16), followed by chest pain (3/16). Of the 7 patients presenting with weakness, one was diagnosed with a stroke in the emergency department. Another patient was diagnosed with subarachnoid hemorrhage and expired during hospital admission. This was the only death in the cohort. The most common hospital diagnosis was GI bleed (3/16). The overall admission rate was 87.5% (14/16). Conclusions: EMS interactions with LVAD patients are infrequent but have high rates of admission and incidence of life-threatening diagnoses. The most common prehospital presenting symptoms were weakness and chest pain, and most prehospital interactions did not require LVAD-specific interventions. In addition to acquiring technical knowledge regarding LVADs, EMS providers should be aware of non-device-related complications including intracranial and GI bleeding and take this into account during their assessment.

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.

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.).

A retrospective review of the prehospital use of activated charcoal.

OBJECTIVE: We studied the complications and timing implications of prehospital activated charcoal (PAC). Appropriateness of PAC administration was also evaluated. METHODS: We retrospectively reviewed prehospital records over 32 months for overdose cases, where PAC was administered. Cases were assessed for amount and type of ingestant, clinical findings, timing of PAC, timing of transport and arrival into the emergency department (ED), and complications. Encounter duration in cases of PAC was compared with that, for all cases during the study period, where an overdose patient who did not receive activated charcoal was transported. RESULTS: Two thousand eight hundred forty-five total cases were identified. In 441 cases, PAC was given; and complications could be assessed. Two hundred eighty-one of these had complete information regarding timing of ingestion, activated charcoal administration, and transport. The average time between overdose and PAC was 49.8 minutes (range, 7-199 minutes; median, 41.0 minutes; SD, 30.4 minutes). Complications included emesis (7%), declining mental status (4%), declining blood pressure (0.4%), and declining oxygen saturation (0.4%). Four hundred seventeen cases of PAC had documentation of timing of emergency medical service (EMS) arrival on scene and arrival at the ED. Average EMS encounter time was 29 minutes (range, 10-53 minutes; median, 27.9 minutes). Two thousand forty-four poisoning patients were transported who did not receive PAC. The average EMS encounter time for this group was 28.1 minutes (range, 4-82 minutes; median, 27.3 minutes), not significantly different (P =.114). CONCLUSIONS: Prehospital activated charcoal did not appear to markedly delay transport or arrival of overdose patients into the ED and was generally safe.

Preliminary report of a mathematical model of ventilation and intrathoracic pressure applied to prehospital patients with severe traumatic brain injury.

BACKGROUND: Inadvertent hyperventilation is associated with poor outcomes from traumatic brain injury (TBI). Hypocapnic cerebral vasoconstriction is well described and causes an immediate and profound decrease in cerebral perfusion. The hemodynamic effects of positive-pressure ventilation (PPV) remain incompletely understood but may be equally important, particularly in the hypovolemic patient with TBI. OBJECTIVE: Preliminary report on the application of a previously described mathematical model of perfusion and ventilation to prehospital data to predict intrathoracic pressure. METHODS: Ventilation data from 108 TBI patients (76 ground transported, 32 helicopter transported) were used for this analysis. Ventilation rate (VR) and end-tidal carbon dioxide (PetCO2) values were used to estimate tidal volume (VT). The values for VR and estimated VT were then applied to a previously described mathematical model of perfusion and ventilation. This model allows input of various lung parameters to define a pressure-volume relationship, then derives mean intrathoracic pressure (MITP) for various VT and VR values. For this analysis, normal lung parameters were utilized. Separate analyses were performed assuming either fixed or variable PaCO2-PetCO2 differences. Ground and air medical patients were compared with regard to VR, PetCO2, estimated VT, and predicted MITP. RESULTS: A total of 10,647 measurements were included from the 108 TBI patients, representing about 13 minutes of ventilation per patient. Mean VR values were higher for ground patients versus air patients (21.6 vs. 19.7 breaths/min; p < 0.01). Estimated VT values were similar for ground and air patients (399 mL vs. 392 mL; p = NS) in the fixed model but not the variable (636 vs. 688 mL, respectively; p < 0.01). Mean PetCO2 values were lower for ground versus air patients (30.6 vs. 33.8 mmHg; p < 0.01). Predicted MITP values were higher for ground versus air patients, assuming either fixed (9.0 vs. 8.1 mmHg; p < 0.01) or variable (10.9 vs. 9.7 mmHg; p < 0.01) PaCO2-PetCO2 differences. CONCLUSIONS: Predicted MITP values increased with ventilation rates. Future studies to externally validate this model are warranted.

Assessment of the addition of prehospital continuous positive airway pressure (CPAP) to an urban emergency medical services (EMS) system in persons with severe respiratory distress.

BACKGROUND: The use of continuous positive airway pressure (CPAP) assisted ventilation in the emergency department(ED) has been well described. OBJECTIVES: The purpose of this study was to measure the efficacy of adding pre-hospital CPAP to an urban emergency medical service (EMS) respiratory distress protocol on persons with respiratory distress. METHODS: A historical cohort analysis of consecutive patients between 2005 and 2010. Groups were matched for severity of respiratory distress. Physiologic variables were the primary outcome obtained from first responders and upon triage in the ED. Additional outcomes included endotracheal intubation rate, hospital mortality, overall hospital length of stay(LOS), intensive care unit (ICU) admission, and ICU length of stay (ICU LOS). RESULTS: There were 410 consecutive patients with predetermined criteria for severe respiratory distress, 235 historical controls matched with 175 post-implementation patients. Average age was 67 years, 54% being male. There were significant median differences in heart and respiratory rates favoring the historical cohort (p < 0.05). There were no significant differences in intubation rate, overall hospital LOS, ICU admission rate, ICU LOS, and hospital mortality (p > 0.05).Patients that were continued on noninvasive ventilatory assistance had a significantly improved rate of intubation and ICU LOS (p < 0.05). CONCLUSIONS: The addition of CPAP to our pre-hospital respiratory distress protocol did not improve physiologic variables.There were no differences in overall and ICU LOS between groups. Persons with apparent continued ventilatory assistance appeared to have improved rates of intubation and ICU LOS [corrected].

Prehospital stroke diagnosis and treatment in ambulances and helicopters-a concept paper.

Stroke is the second common cause of death and the primary cause of early invalidity worldwide. Different from other diseases is the time sensitivity related to stroke. In case of an ischemic event occluding a brain artery, 2000000 neurons die every minute. Stroke diagnosis and treatment should be initiated at the earliest time point possible, preferably at the site or during patient transport. Portable ultrasound has been used for prehospital diagnosis for applications other than stroke, and its acceptance as a valuable diagnostic tool "in the field" is growing. The intrahospital use of transcranial ultrasound for stroke diagnosis has been described extensively in the literature. Beyond its diagnostic use, first clinical trials as well as numerous preclinical work demonstrate that ultrasound can be used to accelerate clot lysis (sonothrombolysis) in presence as well as in absence of tissue plasminogen activator. Hence, the use of transcranial ultrasound for diagnosis and possibly treatment of stroke bares the potential to add to current stroke care paradigms significantly. The purpose of this concept article is to describe the opportunities presented by recent advances in transcranial ultrasound to diagnose and potentially treat large vessel embolic stroke in the prehospital environment.

Electrical and mechanical recovery of cardiac function following out-of-hospital cardiac arrest.

BACKGROUND: Compression pauses may be particularly harmful following the electrical recovery but prior to the mechanical recovery from cardiopulmonary arrest. METHODS AND RESULTS: A convenience sample of patients with out-of-hospital cardiac arrest (OOHCA) were identified. Data were exported from defibrillators to define compression pauses, electrocardiogram rhythm, PetCO2, and the presence of palpable pulses. Pulse-check episodes were randomly assigned to a derivation set (one-third) and a validation set (two-thirds). Both an unweighted and a weighted receiver-operator curve (ROC) analysis were performed on the derivation set to identify optimal thresholds to predict ROSC using heart rate and PetCO2. A sequential decision guideline was generated to predict the presence of ROSC during compressions and confirm perfusion once compressions were stopped. The ability of this decision guideline to correctly identify pauses in which pulses were and were not palpated was then evaluated. A total of 145 patients with 349 compression pauses were included. The ROC analyses on the derivation set identified an optimal pre-pause heart rate threshold of >40 beats min(-1) and an optimal PetCO2 threshold of >20 mmHg to predict ROSC. A sequential decision guideline was developed using pre-pause heart rate and PetCO2 as well as the PetCO2 pattern during compression pauses to predict and rapidly confirm ROSC. This decision guideline demonstrated excellent predictive ability to identifying compression pauses with and without palpable pulses (positive predictive value 95%, negative predictive value 99%). The mean latency period between recovery of electrical and mechanical cardiac function was 78 s (95% CI 36-120 s). CONCLUSIONS: Heart rate and PetCO2 can predict ROSC without stopping compressions, and the PetCO2 pattern during compression pauses can rapidly confirm ROSC. Use of a sequential decision guideline using heart rate and PetCO2 may reduce unnecessary compression pauses during critical moments during recovery from cardiopulmonary arrest.

Pre-hospital electrocardiography by emergency medical personnel: effects on scene and transport times for chest pain and ST-segment elevation myocardial infarction patients.

OBJECTIVES: This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin. METHODS: City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI. RESULTS: There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001). CONCLUSIONS: Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.

Effects of an emergency medical services-based resource access program on frequent users of health services.

BACKGROUND: A small group of adults disproportionately and ineffectively use acute services including emergency medical services (EMS) and emergency departments (EDs). The resulting episodic, uncoordinated care is of lower quality and higher cost and simultaneously consumes valuable public safety and acute care resources. OBJECTIVE: To address this issue, we measured the impact of a pilot, EMS-based case management and referral intervention termed the San Diego Resource Access Program (RAP) to reduce EMS, ED, and inpatient (IP) visits. METHODS: This was a historical cohort study of RAP records and billing data of EMS and one urban hospital for 51 individuals sequentially enrolled in the program. The study sample consisted of adults with ≥ 10 EMS transports within 12 months and others reported by prehospital personnel with significant recent increases in transports. Data were collected over a 31-month time period from December 2006 to June 2009. Data were collected for equal pre- and postenrollment time periods based on date of initial RAP contact, and comparisons were made using the Wilcoxon signed-rank test. Overall use for subjects is reported. RESULTS: The majority of subjects were male (64.7%), homeless (58.8%), and 40 to 59 years of age (72.5%). Between the pre and post periods, EMS encounters declined 37.6% from 736 to 459 (p = 0.001), resulting in a 32.1% decrease in EMS charges from $689,743 to $468,394 (p = 0.004). The EMS task time and mileage decreased by 39.8% and 47.5%, respectively, accounting for 262 (p = 0.008) hours and 1,940 (p = 0.006) miles. The number of ED encounters at the one participating hospital declined 28.1% from 199 to 143, which correlated with a 12.7% decrease in charges from $413,410 to $360,779. The number of IP admissions declined by 9.1% from 33 to 30, corresponding to a 5.9% decrease in IP charges from $687,306 to $646,881. Hospital length of stay declined 27.9%, from 122 to 88 days. Across all services, total charges declined by $314,406. CONCLUSIONS: This pilot study demonstrated that an EMS-based case management and referral program was an effective means of decreasing EMS transports by frequent users, but had only a limited impact on use of hospital services.

Gender differences in scene time, transport time, and total scene to hospital arrival time determined by the use of a prehospital electrocardiogram in patients with complaint of chest pain.

BACKGROUND: Recent studies have described a gender bias against women in the setting of acute coronary syndrome (ACS). OBJECTIVES: We sought to measure the impact that a prehospital electrocardiogram (PH ECG) has on prehospital total scene time to hospital arrival time, comparing men and women with the complaint of chest pain (cCP). METHODS: This study retrospectively analyzed San Diego Emergency Medical Services (EMS) runsheets of patients with cCP before and after implementation of the PH ECG protocol. The average scene time (ST), transport time (TT), and total scene-to-arrival-at-hospital time (STH) were compared. After stratification by gender, times were compared in patients with ST-elevation myocardial infarction (STEMI) to those without STEMI. RESULTS: Of 21,742 EMS activations for patients with cCP, there were no significant differences overall. When stratified by gender, there was a significant reduction of ST (00:19:16 min vs. 00:20:48 min, p<0.001, 95% CI 00:01:17-00:01:48) and STH (00:33:22 min vs. 00:35:44 min, p<0.001, 95% CI 00:01:21-00:02:24) favoring men in cases without STEMI. In cases of STEMI, men had a significant reduction in ST (00:17:27 min vs. 00:20:29 min, p<0.001, 95% CI 00:01:24-00:04:40) and STH (00:30:30 min vs. 00:34:25 min, p<0.01, 95% CI 00:01:23-00:06:26) times compared to women. CONCLUSION: Prehospital ECG implementation led to no significant differences in pre- and post-implementation times. In cases of STEMI, men had significantly reduced scene time and scene-to-hospital time when compared to women. The precise reason for these disparities remains unknown.

A trial of an impedance threshold device in out-of-hospital cardiac arrest.

BACKGROUND: The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. METHODS: We compared the use of an active ITD with that of a sham ITD in patients with out-of-hospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability). RESULTS: Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points; 95% confidence interval, -1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge. CONCLUSIONS: Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

An open, interoperable, and scalable prehospital information technology network architecture.

Some of the most intractable challenges in prehospital medicine include response time optimization, inefficiencies at the emergency medical services (EMS)-emergency department (ED) interface, and the ability to correlate field interventions with patient outcomes. Information technology (IT) can address these and other concerns by ensuring that system and patient information is received when and where it is needed, is fully integrated with prior and subsequent patient information, and is securely archived. Some EMS agencies have begun adopting information technologies, such as wireless transmission of 12-lead electrocardiograms, but few agencies have developed a comprehensive plan for management of their prehospital information and integration with other electronic medical records. This perspective article highlights the challenges and limitations of integrating IT elements without a strategic plan, and proposes an open, interoperable, and scalable prehospital information technology (PHIT) architecture. The two core components of this PHIT architecture are 1) routers with broadband network connectivity to share data between ambulance devices and EMS system information services and 2) an electronic patient care report to organize and archive all electronic prehospital data. To successfully implement this comprehensive PHIT architecture, data and technology requirements must be based on best available evidence, and the system must adhere to health data standards as well as privacy and security regulations. Recent federal legislation prioritizing health information technology may position federal agencies to help design and fund PHIT architectures.

Minimizing pre- and post-defibrillation pauses increases the likelihood of return of spontaneous circulation (ROSC).

BACKGROUND: The three-phase model of ventricular fibrillation (VF) arrest suggests a period of compressions to "prime" the heart prior to defibrillation attempts. In addition, post-shock compressions may increase the likelihood of return of spontaneous circulation (ROSC). The optimal intervals for shock delivery following cessation of compressions (pre-shock interval) and resumption of compressions following a shock (post-shock interval) remain unclear. OBJECTIVE: To define optimal pre- and post-defibrillation compression pauses for out-of-hospital cardiac arrest (OOHCA). METHODS: All patients suffering OOHCA from VF were identified over a 1-month period. Defibrillator data were abstracted and analyzed using the combination of ECG, impedance, and audio recording. Receiver-operator curve (ROC) analysis was used to define the optimal pre- and post-shock compression intervals. Multiple logistic regression analysis was used to quantify the relationship between these intervals and ROSC. Covariates included cumulative number of defibrillation attempts, intubation status, and administration of epinephrine in the immediate pre-shock compression cycle. Cluster adjustment was performed due to the possibility of multiple defibrillation attempts for each patient. RESULTS: A total of 36 patients with 96 defibrillation attempts were included. The ROC analysis identified an optimal pre-shock interval of <3s and an optimal post-shock interval of <6s. Increased likelihood of ROSC was observed with a pre-shock interval <3s (adjusted OR 6.7, 95% CI 2.0-22.3, p=0.002) and a post-shock interval of <6s (adjusted OR 10.7, 95% CI 2.8-41.4, p=0.001). Likelihood of ROSC was substantially increased with the optimization of both pre- and post-shock intervals (adjusted OR 13.1, 95% CI 3.4-49.9, p<0.001). CONCLUSIONS: Decreasing pre- and post-shock compression intervals increases the likelihood of ROSC in OOHCA from VF.

Integration of pre-hospital electrocardiograms and ST-elevation myocardial infarction receiving center (SRC) networks: impact on Door-to-Balloon times across 10 independent regions.

OBJECTIVES: The aim of this study was to evaluate the rate of timely reperfusion for ST-elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PPCI) in regional STEMI Receiving Center (SRC) networks. BACKGROUND: The American College of Cardiology Door-to-Balloon (D2B) Alliance target is a >75% rate of D2B

Asphyxiation due to dry ice in a walk-in freezer.

BACKGROUND: Exposure to a high concentration of environmental carbon dioxide (CO2) can result in poisoning through direct toxicity and by displacing atmospheric oxygen (O2). Dry ice undergoes sublimation to a gaseous state at -78.5 degrees C (-109.3 degrees F), which is heavier than air and can accumulate in dependent areas. CASE REPORT: We report the case of a 59-year-old man found in cardiac arrest shortly after entering a recently repaired walk-in freezer that contained dry ice. First responders and bystanders did not recognize the proximate hazardous environment but were fortunately uninjured. A careful Emergency Department history coupled with rapid case investigation by the Medical Examiner's Office led to the determination of the cause of death and the elimination of the ongoing hazard. CONCLUSION: This case illustrates the lethal consequences of improper storage of dry ice and the need to consider toxic environmental exposure as a cause of sudden cardiac arrest.

Prehospital transport time intervals for acute stroke patients.

BACKGROUND: Recognizing factors that cause prehospital stroke delays may improve time of presentation to the Emergency Department (ED) and allow earlier treatment of acute stroke patients. STUDY OBJECTIVES: To determine the impact of stroke recognition by emergency medical dispatchers (EMD) and paramedics (PM) on ED arrival time in a large urban Emergency Medical Services system. METHODS: Retrospective study of patients aged 18 years or more identified as having acute stroke by EMD, PM, or stroke neurologists from January 1, 2005 to December 31, 2005. Data were acquired from computer-assisted dispatch records, paramedic assessments, ICD-9 (International Classification of Diseases, 9(th) Revision) databases, and a hospital stroke registry. Paramedic time to scene, scene time, and total run time were computed for patients with final hospital diagnosis of stroke and grouped into missed strokes and identified strokes by EMD and PM. Time intervals were compared between missed and identified strokes as well as between incidents where EMD and PM agreed or disagreed. RESULTS: A total of 1067 patients were eligible for the study; 22 were excluded for missing data. For true strokes, EMD and PM were in agreement 27.3% of the time. The median RT was 2.5 min shorter when there was agreement between the providers than when there was disagreement (36.5 min; interquartile range [IQR] 30-43 vs. 39 min.; IQR 33-45, respectively). CONCLUSIONS: Prehospital scene time and run times for acute strokes are less when there is diagnostic concordance between dispatchers and paramedics. Time intervals did not differ between missed and recognized strokes.

Accuracy of stroke recognition by emergency medical dispatchers and paramedics--San Diego experience.

BACKGROUND: Prehospital personnel in Emergency Medical Service (EMS) systems have varying levels of accuracy in stroke recognition. Identifying the accuracy of emergency medical dispatcher using Medical Priority Dispatch Systems (MPDS) stroke protocol and paramedics may help understand the accuracy of stroke recognition in about 3000 emergency medical dispatch systems and prehospital systems world wide. OBJECTIVE: Our aim was to assess the accuracy of stroke identification in emergency medical dispatchers (EMD) with high compliance to MPDS protocol and paramedics using Cincinnati Prehospital Stroke Scale (CSS). METHODS: This was a retrospective observational study. Data was acquired from a computer assisted dispatch (CAD) system, a computerized paramedic record database and discharge diagnosis from billing records or stroke registry containing all stroke assessments of patients who presented to the participating study hospitals within 12 hours of symptom onset. We included patients 18 years or older, identified as having stroke by EMD and city agency paramedics. We excluded patients taken to hospitals not participating in the study, patients with a dispatch determinant of Stroke (card 28) not transported by City EMS agency (SDMSE) to participating hospitals, patients in the stroke registry not transported by SDMSE or patients with no final outcome data. A stroke neurologist or hospital discharge diagnosis of stroke (physician diagnosis) was used to determine the sensitivity and predictive values of EMD and paramedic recognition of stroke. RESULTS: Of 882 patients with a dispatch determinant of stroke using MPDS Stroke protocol, 367 had a final discharge diagnosis of stroke. This gives a sensitivity of 83% and a positive predictive value of 42% for EMD using MPDS Stroke protocol. Of 477 patients with a paramedic assessment of stroke using CSS, 193 had a final discharge diagnosis of stroke. This gives a sensitivity of 44% and a PPV of 40% for paramedics using CSS. CONCLUSIONS: In our EMS system, EMD using MPDS Stroke protocol with a high compliance has a higher sensitivity than paramedics using CSS.

Serum troponin I measurement of subjects exposed to the Taser X-26.

The Taser is a high-voltage, low-amperage conducted energy device used by many law enforcement agencies as a less lethal force weapon. The objective of this study was to evaluate for a rise in serum troponin I level after deployment of the Taser on law enforcement training volunteers. A prospective, observational cohort study was performed evaluating serum troponin I levels in human subjects 6 h after an exposure to the Taser X-26. Outcome measures included abnormal elevation in serum troponin I level (> 0.2 ng/mL). There were 66 subjects evaluated. The mean shock duration was 4.36 s (range 1.2-5 s). None of the subjects had a positive troponin I level 6 h after exposure. It was concluded that human volunteers exposed to a single shock from the Taser did not develop an abnormal serum troponin I level 6 h after shock, suggesting that there was no myocardial necrosis or infarction.