Evaluating clinical reason and rationale for not delivering reperfusion therapy in ST elevation myocardial infarction patients: Insights from a comprehensive cohort.

BACKGROUND: In ST elevation myocardial infarction (STEMI), reperfusion therapy is lifesaving but is not delivered in approximately one quarter of patients. To address this care gap, we reviewed all STEMI patients that did not receive reperfusion to identify patient characteristics, in-hospital outcomes and the clinical reason or rationale for withholding reperfusion therapy. METHODS: A prospective chart review identified a consecutive cohort of STEMI patients over one-year within a defined health care region with independent data abstraction. Subsequently a trained nurse completed retrospective chart review and categorized patients by rationale for failure to receive reperfusion. RESULTS: Of 745 STEMI patients, 181 (24.3%) did not receive reperfusion. Compared to those receiving reperfusion, they were older (67.5 vs. 58.0years, p=0.001) with more comorbidities and higher in-hospital mortality (15.5% vs. 3.5% p=<0.0001). After excluding 35 patients (unavailable data) there were 146 STEMI patients for qualitative determination. Patient delay greater than 12hours from symptom onset accounted for the majority of patients (56/146, 38.4%). In 19.9% (29/146), conservative medical management with documented rationale occurred. Following angiography, primary PCI was attempted but was unsuccessful or no culprit lesion identified in 19.2% (28/146). The diagnosis of STEMI was missed or no rationale for failure to deliver therapy identified in 8.2% (12/146). Death prior to planned reperfusion occurred in 8 (8/146, 5.5%). CONCLUSIONS: Legitimate rationale exists for the majority of STEMI patients not receiving reperfusion. Ultimately, only 1.6% (12/745) of consecutive STEMI patients failed to receive reperfusion without documented rationale or due to missed diagnosis.

Paramedics assessing Elders at Risk for Independence Loss (PERIL): Derivation, Reliability and Comparative Effectiveness of a Clinical Prediction Rule.

OBJECTIVES: We conducted a program of research to derive and test the reliability of a clinical prediction rule to identify high-risk older adults using paramedics' observations. METHODS: We developed the Paramedics assessing Elders at Risk of Independence Loss (PERIL) checklist of 43 yes or no questions, including the Identifying Seniors at Risk (ISAR) tool items. We trained 1,185 paramedics from three Ontario services to use this checklist, and assessed inter-observer reliability in a convenience sample. The primary outcome, return to the ED, hospitalization, or death within one month was assessed using provincial databases. We derived a prediction rule using multivariable logistic regression. RESULTS: We enrolled 1,065 subjects, of which 764 (71.7%) had complete data. Inter-observer reliability was good or excellent for 40/43 questions. We derived a four-item rule: 1) "Problems in the home contributing to adverse outcomes?" (OR 1.43); 2) "Called 911 in the last 30 days?" (OR 1.72); 3) male (OR 1.38) and 4) lacks social support (OR 1.4). The PERIL rule performed better than a proxy measure of clinical judgment (AUC 0.62 vs. 0.56, p=0.02) and adherence was better for PERIL than for ISAR. CONCLUSIONS: The four-item PERIL rule has good inter-observer reliability and adherence, and had advantages compared to a proxy measure of clinical judgment. The ISAR is an acceptable alternative, but adherence may be lower. If future research validates the PERIL rule, it could be used by emergency physicians and paramedic services to target preventative interventions for seniors identified as high-risk.

Providing Rapid Out of Hospital Acute Cardiovascular Treatment 4 (PROACT-4).

BACKGROUND: Whether prehospital point-of-care (POC) troponin further accelerates the time to diagnosis in patients with chest pain (CP) is unknown. We conducted a randomized trial of POC-Troponin testing in the ambulance. METHODS AND RESULTS: Patients with chest pain presenting by ambulance were randomized to usual care (UC) or POC-Troponin; ST-elevation myocardial infarction patients or those with noncardiovascular symptoms were excluded. Pre-hospital high-sensitivity troponin was analyzed on a POC device and available to the paramedic and emergency department (ED) staff. The final diagnosis was centrally adjudicated. The primary endpoint was time from first medical contact to discharge from ED or admission to hospital. We randomized 601 patients in 19 months; 296 to UC and 305 to POC-Troponin. After ambulance arrival, the first troponin was available in 38 minutes in POC-Troponin and 139 minutes in UC. In POC-Troponin, the troponin was >0.01 ng/mL in 17.4% and >0.03 ng/mL in 9.8%. Patients spent a median of 9.0 hours from first medical contact to final disposition, and 165 (27.4%) were admitted to the hospital. The primary endpoint was shorter in patients randomized to POC-Troponin (median 8.8 hours [6.2-10.8] compared to UC (median 9.1 hours [6.7-11.2]; P=0.05). There was no difference in the secondary endpoint of repeat ED visits, hospitalizations, or death in the next 30 days. CONCLUSIONS: In this broad population of patients with CP, ambulance POC-Troponin accelerated the time to final disposition. Enhanced and more cost-effective early ED discharge of the majority of patients with CP calling 911 is an unrealized opportunity. CLINICAL TRIAL REGISTRATION: URL: https://www.ClinicalTrials.gov/. Unique identifier: NCT01634425.

Treatment choices in elderly patients with ST: elevation myocardial infarction-insights from the Vital Heart Response registry.

BACKGROUND: Management of elderly patients with ST elevation myocardial infarction (STEMI) is challenging and they are under-represented in trials. Accordingly, we analysed reperfusion strategies and their effectiveness in patients with STEMI ≥75 years compared to <75 years within a comprehensive inclusive registry. METHODS: Consecutive patients with STEMI admitted to hospital and tracked within a regional registry (2006-2011) were analysed comparing reperfusion strategy (primary percutaneous coronary intervention (PPCI), fibrinolysis and no reperfusion) between patients ≥75 vs <75 years old as well as across the reperfusion strategies in those ≥75 years. RESULTS: There were 3588 patients with STEMI with 646 (18%) ≥75 years old. Elderly patients were more likely female (46.9% vs 18.4%) and had more prior: angina (28.2% vs 17.2%), myocardial infarction (MI; 22.8% vs 13.9%), hypertension (67.6% vs 44.2%), heart failure (2.3% vs 0.3%) and atrial fibrillation (2.2% vs 0.5%) (all p<0.001). The reperfusion strategy for patients ≥75 vs <75: PPCI 45.3% vs 41.2%, fibrinolysis 24.8% vs 45.7%, and no reperfusion 29.9% vs 13.1% (p<0.001). Time from symptoms to first medical contact (median, 93 vs 78 min p=0.008) and PPCI (median, 166 vs 136 min (p<0.001) were longer for ≥75 years. In those ≥75 years outcomes by reperfusion (PPCI, fibrinolysis and none) were: in-hospital death 13.3%, 9.4% and 19.7% (p=0.018), and composite of death, recurrent-MI, cardiogenic shock and congestive heart failure 28%, 20% and 33.2% (p=0.022). CONCLUSIONS: Elderly patients have more comorbidities, worst in-hospital clinical outcomes and are less likely to receive reperfusion. Acknowledging physician selection of the reperfusion strategy; outcomes appear favourable in the elderly receiving fibrinolysis.

Validity and utility of ICD-10 administrative health data for identifying ST- and non-ST-elevation myocardial infarction based on physician chart review.

BACKGROUND: Health care administrative databases are useful for assessing the population-level burden of disease and examining issues related to access, costs and quality of care. In these databases, the diagnoses and procedures are coded with the use of the World Health Organization International Classification of Diseases (ICD). We examined the validity of 2 ICD-10 coding definitions for categorizing patients with acute myocardial infarction (MI) as having ST-elevation MI (STEMI) or non-ST-elevation MI (non-STEMI). METHODS: Charts of patients with acute MI discharged between April and June 2007 from 3 hospitals in Edmonton, were reviewed to define the acute MI subtype (i.e., STEMI v. non-STEMI). The agreement between clinician chart review and STEMI/non-STEMI classification based on the standard (ICD-10 I21.x) and the supplementary electrocardiogram (ECG) codes (R94.3x) was determined. We assessed the effect of these alternative definitions on in-hospital mortality estimates by applying them to the data for all patients with acute MI admitted to hospital in the province from April 2007 to March 2010. RESULTS: Of the 297 patients, 49.2% were identified as having STEMI based on chart review, 44.4% using the standard definition, and 44.1% using the ECG definition. Both the standard and ECG definitions provided high agreement (92% for STEMI and 100% for non-STEMI) with the chart review classification. In the larger population-level cohort (n = 15 148), use of the standard definition or the ECG definition did not affect in-hospital mortality estimates for patients with STEMI and those with non-STEMI. INTERPRETATION: The standard definition appears equivalent to the definition using supplementary ECG codes to subcategorize patients with acute MI as having STEMI or non-STEMI. These findings may be relevant for the development of later versions of ICD codes.

Emergency medical services provider comfort with prehospital analgesia administration to children.

INTRODUCTION: The undertreatment of pediatric pain is a significant concern among families, clinicians, and researchers. Although some have examined prehospital pain management, the deterrents to pediatric analgesia administration by Emergency Medical Services (EMS) have not yet been examined in Canada. Problem This study describes EMS pain-management practices and prehospital provider comfort treating pediatric pain. It highlights differences in pain management between adults and children and assesses the potential barriers, misconceptions, difficulties, and needs related to provision of pediatric analgesia. METHODS: A study-specific survey tool was created and distributed to all Primary Care Paramedics (PCPs) and Advanced Care Paramedics (ACPs) over four mandatory educational seminars in the city of Edmonton (Alberta, Canada) from September through December 2008. RESULTS: Ninety-four percent (191/202) of EMS personnel for the city of Edmonton completed the survey. The majority of respondents were male (73%, 139/191), aged 26-35 (42%, 80/191), and had been in practice less than 10 years (53%, 101/191). Seventy-four percent (141/191) of those surveyed were ACPs, while 26% (50/191) were PCPs. Although the majority of respondents reported using both pain scales and clinical judgement to assess pain for adults (85%, 162/191) and adolescents (86%, 165/191), children were six times more likely than adults (31%, 59/191 vs 5%, 10/191) to be assessed by clinical judgement alone. Emergency Medical Services personnel felt more comfortable treating adults than children (P < .001), and they were less likely to treat children even if they were experiencing identical types and intensities of pain as adults (all P values <.05) and adolescents (all P values < .05). Twenty-five percent of providers (37/147) assumed pediatric patients required less analgesia due to immature nervous systems. Three major barriers to treating children's pain included limited clinical experience (34%, 37/110), difficulty in communication (24%, 26/110) and inability to assess children's pain accurately (21%, 23/110). CONCLUSION: Emergency Medical Services personnel self-report that children's pain is less rigorously measured and treated than adults' pain. Educational initiatives aimed at increasing clinical exposure to children, as well as further education regarding simple pain measurement tools for use in the field, may help to address identified barriers and discomfort with assessing and treating children.

Providing Rapid Out of Hospital Acute Cardiovascular Treatment 3 (PROACT-3).

BACKGROUND: The outcomes of acute cardiovascular symptom presentations are potentially modifiable with the use of biomarkers to accelerate accurate diagnosis. This randomized trial tested troponin and B-type natriuretic peptide before hospital guidance in patients with acute cardiovascular symptoms. METHODS: Patients with either chest pain or shortness of breath were randomized to usual care or biomarkers analyzed using a point-of-care device in the ambulance. The primary end point was time to final disposition (discharge from the emergency department or admission to hospital). The trial was stopped prematurely because of less than expected enrollment of patients of interest and no difference in the primary end point. RESULTS: We randomized 491 patients; 480 formed the final cohort. Patients were 49% male; median age 70 years; 42% had previous acute coronary syndrome; and 28% diabetes. The B-type natriuretic peptide level before hospital arrival was ≥ 100 pg/mL in 36.4%. Troponin was > 0.03 ng/mL in 13.4%; 3.6% had troponin > 0.1 ng/mL. After adjudication, 16% had acute coronary syndrome, 6.5% acute heart failure, 3.3% angina, and 74.2% another diagnosis. The primary end point was 9.2 (interquartile range, 7.3-11.1) hours in the biomarker group and 8.8 (interquartile range, 6.3-12.1) hours in the usual care group (P = 0.6). None died in the ambulance or in the emergency department: all-cause 30-day mortality was 2.1% (usual care) and 1.7% (biomarker). CONCLUSIONS: To our knowledge, this is the first randomized trial of biomarkers before hospital arrival to guide emergency management of suspected acute cardiovascular disease which showed no benefit and was terminated early because of futility. The results have important implications for the use of biomarkers in emergency management of heart disease and for the design of future randomized trials on this important topic.

Pre-hospital management of anaphylaxis in one Canadian Urban Centre.

STUDY AIM: Anaphylaxis requires prompt recognition and management to improve patient outcomes. This study examined the diagnosis and treatment of anaphylactic reactions by the Emergency Medical Services (EMS) in a Canadian urban centre. METHODS: Electronic patient care records (ePCRs), identifying allergy-related calls in the Edmonton-Zone for the year 2011, were retrospectively reviewed to confirm anaphylaxis diagnosis and record treatments. Data were abstracted and entered into the REDCap electronic platform. Descriptive and multivariable analyses were performed. Pre-hospital management included any care provided by paramedic personnel and/or first-aid treatment received prior to EMS arrival. RESULTS: From 481 identified allergy-related case records, 136 (28%) met guideline criteria for anaphylaxis. Seventy-six (56%) of these confirmed cases were deemed high acuity by medical dispatchers. Self-medication and bystander first-aid was recorded in 60 (44%) anaphylactic events; 34 (25%) received epinephrine. Paramedics administered epinephrine in an additional 49 cases (36%); only 7% received all three primary pre-hospital anaphylaxis treatments: epinephrine, corticosteroids, and antihistamines. Factors associated with pre-hospital epinephrine administration included: previous episode of anaphylaxis (adjusted odds ratio [aOR]=4.9, 95% confidence interval [CI]: 1.30, 19.21); administration of corticosteroids by bystanders or EMS personnel (aOR=3.8, 95% CI: 1.36, 10.65); and transport severity (aOR=3.2, 95% CI: 1.21, 8.36). CONCLUSION: Paramedics in this region demonstrated higher use of epinephrine than reported elsewhere; however, almost half of all patients meeting anaphylaxis criteria did not receive pre-hospital epinephrine. Instead, more patients received antihistamines. Efforts to improve adherence to anaphylaxis protocols and guidelines appear warranted.

Bridging the gap for nonmetropolitan STEMI patients through implementation of a pharmacoinvasive reperfusion strategy.

BACKGROUND: Timely primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in ST-elevation myocardial infarction (STEMI). However, universal access is limited outside metropolitan centres and portends worse outcomes for rural patients. This study evaluates the outcomes of STEMI patients treated in a metropolitan and nonmetroplitan setting within Vital Heart Response, an integrated reperfusion program developed to reduce reperfusion delay in Central and Northern Alberta. METHODS: From October 2006 to March 2011, data on consecutive STEMI patients was prospectively recorded. Clinical characteristics, in-hospital management, and outcomes grouped by site of presentation are described. RESULTS: There were 1990 metropolitan and 1602 nonmetropolitan STEMI patients. Metropolitan were older (62.7 vs 60.4 years; P < 0.001) and had more: angina (21.2% vs 16.5%; P < 0.001), dyslipidemia (45.3% vs 39.6%; P = 0.001), and hypertension (49.9% vs 46.6%; P = 0.047). The reperfusion strategy for metropolitan and nonmetropolitan: primary PCI (57.4% vs 22.9%; P < 0.001), fibrinolysis (26.3% vs 61.2%; P < 0.001), and no reperfusion (16.3% vs 15.9%; P = 0.855). First medical contact to reperfusion was delayed in nonmetropolitan with fibrinolysis and PCI, 8 and 125 minutes. A rescue PCI or coronary angiography within 24 hours was completed in 41.4% and 46.2%, respectively. Nonmetropolitan patients had fewer deaths (4.1% vs 6.8%; P = 0.001) with no difference in the composite outcome (death, reinfraction, congestive heart failure, cardiogenic shock) (16.8% vs 15.1%; P = 0.161) or major bleeding (7.9% vs 8.0%; P = 0.951). CONCLUSIONS: Systematic application of a pharmacoinvasive strategy appears to be safe and effective for patients in whom a delay in mechanical reperfusion is anticipated.

Mode of hospital presentation in patients with non-ST-elevation myocardial infarction: implications for strategic management.

INTRODUCTION: Contemporary non-ST-elevation myocardial infarction-acute coronary syndrome guidelines emphasize early-risk stratification and optimizing therapy including an invasive strategy in high-risk patients. To assess the feasibility of initiating this strategy in the prehospital environment, we examined how such patients are transported to hospital, their risk profile, and the proportion potentially eligible for such a strategy. METHODS: Consecutive patients with ST-segment elevation myocardial infarction admitted in Edmonton were studied between September and November 2008 and divided according to their mode of transport to hospital: emergency medical services (EMS) versus self-presenting. Baseline characteristics, GRACE Risk Score, blinded core laboratory electrocardiogram analysis, cardiac biomarkers, in-hospital procedures, and outcomes were analyzed. RESULTS: Thirty-five percent (93/263) of patients presented via EMS and often to percutaneous coronary intervention hospitals, that is, 64.5% versus 44.1% (P = .0016). They were older (75 vs 62 years, P < .001), more often female (43% vs 28.1%, P < .001), diabetic (34.4% vs 22.9%, P = .045), and hypertensive (72.0% vs 57.1%, P = .017) and had higher GRACE Risk Scores (median 166 vs 130, P < .001). Electrocardiogram analysis revealed more baseline Q waves (38.8% vs 25.5%, P = .031) and ST depression ≥2 mm (P = .027) in EMS-transported patients. Fewer EMS patients underwent cardiac catheterization (60.2% vs 88.2%, P < .001), and a paradoxical relationship existed between catheterization rates and GRACE Risk Score in the total cohort (low-risk: 93.4% vs high-risk: 59.3%, P < .001). The composite of death/re-myocardial infarction/congestive heart failure/shock was greater in EMS patients (unadjusted odds ratio 3.96, 95% CI 1.80-8.69, P = .001); these differences were attenuated after GRACE Risk Score adjustment. CONCLUSION: Regional strategies using risk-based triage, early medical therapy, and timely triage to percutaneous coronary intervention centers represents an unrealized opportunity to enhance ST-segment elevation myocardial infarction care.

The pre-hospital fibrinolysis experience in Europe and North America and implications for wider dissemination.

OBJECTIVES: The primary objective of this report was to describe the infrastructures and processes of selected European and North American pre-hospital fibrinolysis (PHL) programs. A secondary objective is to report the outcome data of the PHL programs surveyed. BACKGROUND: Despite its benefit in reducing mortality in patients with ST-segment elevation myocardial infarction, PHL remained underused in North America. Examination of existing programs may provide insights to help address barriers to the implementation of PHL. METHODS: The leading investigators of PHL research projects/national registries were invited to respond to a survey on the organization and outcomes of their affiliated PHL programs. RESULTS: PHL was successfully deployed in a wide range of geographic territories (Europe: France, Sweden, Vienna, England, and Wales; North America: Houston, Edmonton, and Nova Scotia) and was delivered by healthcare professionals of varying expertise. In-hospital major adverse outcomes were rare with mortality of 3% to 6%, reinfarction of 2% to 5%, and stroke of <2%. CONCLUSIONS: Combining formal protocols for PHL for some patients with direct transportation of others to a percutaneous coronary intervention hospital for primary percutaneous coronary intervention would allow for tailored reperfusion therapy for patients with ST-segment elevation myocardial infarction. Insights from a variety of international settings may promote widespread use of PHL and increase timely coronary reperfusion worldwide.

Temporal trends in patient and treatment delay among men and women presenting with ST-elevation myocardial infarction.

BACKGROUND: over the last decade, there have been major changes in the treatment of ST-elevation myocardial infarction (STEMI). Whether these have resulted in changes in sex differences in time to treatment is unknown. We examined temporal trends in time to reperfusion therapy among men and women with STEMI. METHODS: the study includes 2 cohorts of STEMI patients presenting to a large metropolitan region during the periods August 24, 2000, to August 20, 2002 (Cohort1, n = 753), and August 25, 2006, to December 31, 2008 (Cohort2, n = 885). RESULTS: in both cohorts, compared with men, women were significantly older and had more comorbidities. Rate of emergency medical services use among women increased from 55% in Cohort1 to 66% in Cohort2 (P = .02). Median time from symptom onset to first medical contact was 84 minutes among men and 121 minutes among women (P < .01) in Cohort1 and 59 minutes among men and 81 minutes among women (P < .01) in Cohort2. Median door-to-balloon time was significantly longer among women compared with men in Cohort2. After multivariable adjustment, female sex was associated with a 34% (or 27-minute) increase in time from symptom onset to first medical contact and with a 23% (or 13-minute) increase in time from hospital arrival to reperfusion therapy. CONCLUSIONS: in the last decade, there have been significant reductions in patient and system delay, especially among women. However, women continue to have longer presentation and treatment times, suggesting that there continue to be opportunities for improvement.

Underuse of prehospital strategies to reduce time to reperfusion for ST-elevation myocardial infarction patients in 5 Canadian provinces.

OBJECTIVE: Timely reperfusion therapy for ST-elevation myocardial infarction (STEMI) is an important determinant of outcome, yet targets for time to treatment are frequently unmet in North America. Prehospital strategies can reduce time to reperfusion. We sought to determine the extent to which emergency medical services (EMS) use these strategies in Canada. METHODS: We carried out a cross-sectional survey in 2007 of ground EMS operators in British Columbia, Alberta, Ontario, Quebec and Nova Scotia. We focused on the use of 4 prehospital strategies: 1) 12-lead electrocardiogram (ECG), 2) routine expedited emergency department (ED) transfer of STEMI patients (from a referring ED to a percutaneous coronary intervention [PCI] centre), 3) prehospital bypass (ambulance bypass of local EDs to transport patients directly to PCI centres) and 4) prehospital fibrinolysis. RESULTS: Ninety-seven ambulance operators were surveyed, representing 15 681 paramedics serving 97% of the combined provincial populations. Of the operators surveyed, 68% (95% confidence interval [CI] 59%-77%) had ambulances equipped with 12-lead ECGs, ranging from 40% in Quebec to 100% in Alberta and Nova Scotia. Overall, 47% (95% CI 46%-48%) of paramedics were trained in ECG acquisition and 40% (95% CI 39%-41%) were trained in ECG interpretation. Only 18% (95% CI 10%-25%) of operators had prehospital bypass protocols; 45% (95% CI 35%-55%) had protocols for expedited ED transfer. Prehospital fibrinolysis was available only in Alberta. All EMS operators in British Columbia, Alberta and Nova Scotia used at least 1 of the 4 prehospital strategies, and one-third of operators in Ontario and Quebec used 0 of 4. In major urban centres, at least 1 of the 3 prehospital strategies 12-lead ECG acquisition, bypass or expedited transfer was used, but there was considerable variation within and across provinces. CONCLUSION: The implementation of widely recommended prehospital STEMI strategies varies substantially across the 5 provinces studied, and relatively simple existing technologies, such as prehospital ECGs, are underused in many regions. Substantial improvements in prehospital services and better integration with hospital-based care will be necessary in many regions of Canada if optimal times to reperfusion, and associated outcomes, are to be achieved.

Evaluating the views of paramedics, cardiologists, emergency department physicians and nurses on advanced prehospital management of acute ST elevation myocardial infarction.

BACKGROUND: Although advanced prehospital management (PHM) in ST elevation myocardial infarction (STEMI) reduces reperfusion delay and improves patient outcomes, its use in North America remains uncommon. Understanding perceived barriers to and facilitators of PHM implementation may support the expansion of programs, with associated patient benefit. OBJECTIVE: To explore the attitudes and beliefs of paramedics, cardiologists, emergency physicians and nurses regarding these issues. METHODS: To maximize the potential to identify unpredictable issues within each of the four groups, focus group sessions were recorded, transcribed and analyzed for themes using the constant comparative method. RESULTS: All 18 participants believed that PHM of STEMI decreased time to treatment and improved health outcomes. Despite agreeing that most paramedics were capable of providing PHM, regular maintenance of competence and medical overview were emphasized. Significant variations in perceptions were revealed regarding practical aspects of the PHM process and protocol, as well as ownership and responsibility of the patient. Success and failures of technology were also expressed. Varying arguments against a signed 'informed consent' were presented by the majority. CONCLUSIONS: Focus group discussions provided key insights into potential barriers to and facilitators of PHM in STEMI. Although all groups were supportive of the concept and its benefits, concerns were expressed and potential barriers identified. This novel body of knowledge will help elucidate future educational programs and protocol development, and identify future challenges to ensure successful PHM of STEMI, thereby reducing reperfusion delay and improving patient outcomes.

Time from first medical contact to reperfusion in ST elevation myocardial infarction: a Which Early ST Elevation Myocardial Infarction Therapy (WEST) substudy.

BACKGROUND: Recent research and contemporary ST elevation myocardial infarction guidelines emphasize the importance of prompt reperfusion and have redefined the traditional time to treatment metric to include prehospital paramedical staff as the point of first medical contact. However, an important knowledge gap exists relating to data systematically addressing the impact of arrival at the hospital by ambulance and the delays inherent in transfer from a community hospital to tertiary centres for percutaneous coronary intervention (PCI). METHODS: The Which Early ST Elevation Myocardial Infarction Therapy (WEST) study initiated treatment at the point of first medical contact, including prehospital contact. Patients were randomly assigned to receive fibrinolysis with usual care or coupled with mechanical cointervention, or primary PCI. To assess the impact of this strategy on time to treatment, the following randomly assigned patient groups were compared: prehospital versus in-hospital; those arriving at the hospital by ambulance versus ambulatory self transport; and those whose initial hospital care was a community versus PCI centre. RESULTS: Of the 328 patients enrolled in the study, 221 received fibrinolysis and 107 received primary PCI. Compared with the in-hospital group, patients who underwent prehospital random assignment (44%, n=145) experienced a 48 min reduction in median (interquartile range) time from symptom onset to first study medication (87 min [65 min to 147 min] versus 135 min [95 min to 186 min]; P<0.001) and a 56 min reduction in time to first balloon inflation (148 min [117 min to 214 min] versus 204 min [166 min to 290 min]; P<0.001). Arrival by ambulance without prehospital random assignment (n=90) incurred a substantial delay from first medical contact to reperfusion (fibrinolysis 76 min [63 min to 105 min] and PCI 160 min [141 min to 212 min]) compared with prehospital random assignment (n=145; fibrinolysis 43 min [33 min to 54 min] and PCI 105 min [90 min to 127 min]) or ambulatory patients (n=93; fibrinolysis 47 min [32 min to 68 min] and PCI 108 min [85 min to 150 min]). Community (n=165) versus PCI hospital (n=163) random assignment was associated with a longer delay from first medical contact to reperfusion: fibrinolysis, 56 min versus 47 min (P=0.008) and primary PCI, 139 min versus 105 min (P=0.001). DISCUSSION: Prehospital diagnosis, random assignment and treatment substantially reduced treatment delay with both pharmacological and mechanical reperfusion. Those activating the prehospital medical response system without receiving prehospital random assignment experienced the longest delay from first medical contact to reperfusion, indicating a lost opportunity to enhance ST elevation myocardial infarction patient outcomes.

The development of a national emergency medical services curriculum framework for physicians in Canada.

BACKGROUND: As the role of emergency medical services (EMS) continues to expand, EMS physicians and medical directors require special skills and training to keep pace with the rapidly evolving subspecialty of EMS. In Canada, subspecialty training in EMS is still relatively new, and a standard national curriculum for physician EMS training does not exist. OBJECTIVE: To develop a national EMS curriculum for emergency medicine (EM) residents and fellows and an abbreviated curriculum for non-EM trainees and community physicians. METHODS: The authors obtained EMS curricula and opportunities from Canadian EM and EMS training programs and a sample of U.S. programs to determine existing curricula, and developed a framework for a national EMS curriculum using an expert working group of EMS medical directors and EMS leaders in Canada. RESULTS: Canadian EM residency training programs included an EMS rotation, but their content and depth of training were not uniform. The expert working group proposed a comprehensive set of training objectives, grouped into 16 categories, stratified by level of training. CONCLUSION: The proposed framework and objectives are suitable for training medical students, family medicine trainees, community physicians, EM residents, and EMS fellows in Canada. The authors hope this article will serve as a guideline for residency and fellowship directors to develop their EMS training programs in a consistent manner, promote formal training for physicians involved in EMS, and help define the specific knowledge and expertise required of physicians who provide EMS medical direction in Canada.

BIPHASIC Trial: a randomized comparison of fixed lower versus escalating higher energy levels for defibrillation in out-of-hospital cardiac arrest.

BACKGROUND: There is little clear evidence as to the optimal energy levels for initial and subsequent shocks in biphasic waveform defibrillation. The present study compared fixed lower- and escalating higher-energy regimens for out-of-hospital cardiac arrest. METHODS AND RESULTS: The Randomized Controlled Trial to Compare Fixed Versus Escalating Energy Regimens for Biphasic Waveform Defibrillation (BIPHASIC Trial) was a multicenter, randomized controlled trial of 221 out-of-hospital cardiac arrest patients who received > or = 1 shock given by biphasic automated external defibrillator devices that were randomly programmed to provide, blindly, fixed lower-energy (150-150-150 J) or escalating higher-energy (200-300-360 J) regimens. Patient mean age was 66.0 years; 79.6% were male. The cardiac arrest was witnessed in 63.8%; a bystander performed cardiopulmonary resuscitation in 23.5%; and initial rhythm was ventricular fibrillation/ventricular tachycardia in 92.3%. The fixed lower- and escalating higher-energy regimen cases were similar for the 106 multishock patients and for all 221 patients. In the primary analysis in multishock patients, conversion rates differed significantly (fixed lower, 24.7%, versus escalating higher, 36.6%; P=0.035; absolute difference, 11.9%; 95% CI, 1.2 to 24.4). Ventricular fibrillation termination rates also were significantly different between groups (71.2% versus 82.5%; P=0.027; absolute difference, 11.3%; 95% CI, 1.6 to 20.9). For the secondary analysis of first shock success, conversion rates were similar between the fixed lower and escalating higher study groups (38.4% versus 36.7%; P=0.92), as were ventricular fibrillation termination rates (86.8% versus 88.8%; P=0.81). There were no distinguishable differences between regimens for survival outcomes or adverse effects. CONCLUSIONS: This is the first randomized trial to compare fixed lower and escalating higher biphasic energy regimens in out-of-hospital cardiac arrest, and it demonstrated higher rates of ventricular fibrillation conversion and termination with an escalating higher-energy regimen for patients requiring multiple shocks. These results suggest that patients in ventricular fibrillation benefit from higher biphasic energy levels if multiple defibrillation shocks are required.

Can body temperature be maintained during aeromedical transport?

BACKGROUND: Aeromedical transport in northern areas may be associated with hypothermia. The objective of this study was to determine whether significant hypothermia (core temperature <35 masculineC) occurs in severely injured or ill intubated patients during transport by rotary wing aircraft. METHODS: In this prospective cohort study, all intubated patients over 16 years of age who were transported by rotary wing aircraft from rural hospitals or trauma scenes in northern Alberta to regional hospitals in Edmonton were eligible for study. Esophageal thermometers were used to measure core temperature at 10-minute intervals during transport. RESULTS: Of 133 potentially eligible patients, 116 were enrolled; 69 (59%) had esophageal thermometers inserted, and 47 (41%) had other temperature measurements. Severe hypothermia occurred in only 1% to 2% of cases, but 28% to 39% of patients met criteria for mild hypothermia prior to transport. Core temperatures did not fall during transport, despite the fact that warming techniques were documented in only 38% of cases. CONCLUSIONS: During brief (<225 km) rotary wing aeromedical transport of severely injured or ill patients, significant hypothermia is uncommon and body temperature is generally well maintained with the use of simple passive measures. These findings do not justify recommendations for more aggressive core temperature monitoring during this type of aeromedical transport.