Does Single Dose Epinephrine Improve Outcomes for Patients with Out-of-Hospital Cardiac Arrest and Bystander CPR or a Shockable Rhythm?

BACKGROUND: A single dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) achieves similar survival to hospital discharge (SHD) rates as a multidose epinephrine protocol (MDEP). However, it is unknown if a SDEP improves SHD rates among patients with a shockable rhythm or those receiving bystander cardiopulmonary resuscitation (CPR). METHODS: This pre-post study, spanning 11/01/2016-10/29/2019 at 5 North Carolina EMS systems, compared pre-implementation MDEP and post-implementation SDEP in patients ≥18 years old with non-traumatic OHCA. Data on initial rhythm type, performance of bystander CPR, and the primary outcome of SHD were sourced from the Cardiac Arrest Registry to Enhance Survival. We compared SDEP vs MDEP performance in each rhythm (shockable and non-shockable) and CPR (bystander CPR or no bystander CPR) subgroup using Generalized Estimating Equations to account for clustering among EMS systems and to adjust for age, sex, race, witnessed arrest, arrest location, AED availability, EMS response interval, and presence of a shockable rhythm or receiving bystander CPR. The interaction of SDEP implementation with rhythm type and bystander CPR was evaluated. RESULTS: Of 1690 patients accrued (899 MDEP, 791 SDEP), 19.2% (324/1690) had shockable rhythms and 38.9% (658/1690) received bystander CPR. After adjusting for confounders, SHD was increased after SDEP implementation among patients with bystander CPR (aOR 1.61, 95%CI 1.03-2.53). However, SHD was similar in the SDEP cohort vs MDEP cohort among patients without bystander CPR (aOR 0.81, 95%CI 0.60-1.09), with a shockable rhythm (aOR 0.96, 95%CI 0.48-1.91), and with a non-shockable rhythm (aOR 1.26, 95%CI 0.89-1.77). In the adjusted model, the interaction between SDEP implementation and bystander CPR was significant for SHD (p = 0.002). CONCLUSION: Adjusting for confounders, the SDEP increased SHD in patients who received bystander CPR and there was a significant interaction between SDEP and bystander CPR. Single dose epinephrine protocol and MDEP had similar SHD rates regardless of rhythm type.

Performance of Prehospital Use of Chest Pain Risk Stratification Tools: The RESCUE Study.

BACKGROUND: Emergency medical services (EMS) assesses millions of patients with chest pain each year. However, tools validated to risk stratify patients for acute coronary syndrome (ACS) and pulmonary embolism (PE) have not been translated to the prehospital setting. The objective of this study is to assess the prehospital performance of risk stratification scores for 30-day major adverse cardiac events (MACE) and PE. METHODS: A prospective observational cohort study of patients ≥21 years of age with acute chest pain who were transported by EMS in two North Carolina (NC) counties was conducted from 18 April 2018-2 January 2019. In this convenience sample, paramedics completed HEAR (history, electrocardiogram, age, risk factor), ED Assessment of Chest Pain Score (EDACS), Revised Geneva Score (RGS), and pulmonary embolism rule-out criteria (PERC) assessments on each patient. MACE (all-cause death, myocardial infarction, and revascularization) and PE at 30 days were determined by hospital records and NC Death Index. The positive (+LR) and negative likelihood ratios (-LR) of the risk scores for 30-day MACE and PE were calculated. RESULTS: During the study period, 82.1% (687/837) patients had all four risk score assessments. The cohort was 51.1% (351/687) female, 49.5% (340/687) African American, and had a mean age of 55.0 years (SD 16.0). At 30 days, MACE occurred in 7.4% (51/687), PE occurred in 0.9% (6/687), and the combined outcome occurred in 8.2% (56/687). The HEAR score had a - LR of 0.46 (95% CI 0.27-0.78) and + LR of 1.48 (95% CI 1.26-1.74) for 30-day MACE. EDACS had a - LR of 0.61 (95% CI 0.46-0.81) and + LR of 2.53 (95% CI 1.86-3.46) for 30-day MACE. The PERC score had a - LR of 0 (95% CI 0.0-1.4) and a + LR of 1.38 (95% CI 1.32-1.45) for 30-day PE. The RGS score had a - LR of 0 (95% CI 0.0-0.65) and a + LR of 2.36 (95% CI 2.16-2.57) for 30-day PE. The combination of a low-risk HEAR score and negative PERC evaluation had a - LR of 0.25 (95% CI 0.08-0.76) and a + LR of 1.21 (95% CI 1.21-1.30) for 30-day MACE or PE. CONCLUSION: The combination of a paramedic-obtained HEAR score and PERC evaluation performed best to exclude 30-day MACE and PE but was not sufficient for directing prehospital decision making.

One and Done Epinephrine in Out-of-Hospital Cardiac Arrest? Outcomes in a Multiagency United States Study.

BACKGROUND: Cardiac arrest guidelines recommend epinephrine every 3-5 minutes during cardiac arrest resuscitation. However, it is unclear if multiple epinephrine doses are associated with improved outcomes. The objective of this study was to determine if a single-dose epinephrine protocol was associated with improved survival compared to traditional multidose protocols. METHODS: We conducted a pre-post study across five North Carolina EMS agencies from 11/1/2016 to 10/29/2019. Patients ≥18 years old with attempted resuscitation for non-traumatic prehospital cardiac arrest were included. Data were collected 1 year before and after implementation of the single-dose epinephrine protocol. Prior to implementation, all agencies used a multidose epinephrine protocol. The Cardiac Arrest Registry to Enhance Survival (CARES) was used to obtain patient outcomes. Study outcomes were survival to hospital discharge (primary) and return of spontaneous circulation (ROSC). Analysis was by intention to treat. Outcomes were compared pre- vs. post-implementation using generalized estimating equations to account for clustering within EMS agencies. Adjusted analyses included age, sex, race, shockable vs. non-shockable rhythm, witnessed arrest, automatic external defibrillator availability, EMS response interval, and bystander cardiopulmonary resuscitation. RESULTS: During the study period there were 1,690 encounters (899 pre- and 791 post-implementation). The population was 74.7% white, 61.1% male, and had a median age of 65 (IQR 53-76) years. Survival to hospital discharge was similar pre- vs. post-implementation [13.6% (122/899) vs. 15.4% (122/791); OR 1.19, 95%CI 0.89-1.59]. However, ROSC was more common post-implementation [42.3% (380/899) vs. 32.5% (257/791); OR 0.66, 95%CI 0.54-0.81]. After adjusting for covariates, the single-dose protocol was associated with similar survival to discharge rates (aOR 0.88, 95%CI 0.77-1.29), but with decreased ROSC rates (aOR 0.58, 95%CI 0.47-0.72). CONCLUSION: A prehospital single-dose epinephrine protocol was associated with similar survival to hospital discharge, but decreased ROSC rates compared to the traditional multidose epinephrine protocol.

EMS blood collection from patients with acute chest pain reduces emergency department length of stay.

BACKGROUND: Expediting the measurement of serum troponin by leveraging EMS blood collection could reduce the diagnostic time for patients with acute chest pain and help address Emergency Department (ED) overcrowding. However, this practice has not been examined among an ED chest pain patient population in the United States. METHODS: A prospective observational cohort study of adults with non-traumatic chest pain without ST-segment elevation myocardial infarction was conducted in three EMS agencies between 12/2016-4/2018. During transport, paramedics obtained a patient blood sample that was sent directly to the hospital core lab for troponin measurement. On ED arrival HEART Pathway assessments were completed by ED providers as part of standard care. ED providers were blinded to troponin results from EMS blood samples. To evaluate the potential impact on length of stay (LOS), the time difference between EMS blood draw and first clinical ED draw was calculated. To determine the safety of using troponin measures from EMS blood samples, the diagnostic performance of the HEART Pathway for 30-day major adverse cardiac events (MACE: composite of cardiac death, myocardial infarction (MI), coronary revascularization) was determined using EMS troponin plus arrival ED troponin and EMS troponin plus a serial 3-h ED troponin. RESULTS: The use of EMS blood samples for troponin measures among 401 patients presenting with acute chest pain resulted in a mean potential reduction in LOS of 72.5 ± SD 35.7 min. MACE at 30 days occurred in 21.0% (84/401), with 1 cardiac death, 78 MIs, and 5 revascularizations without MI. Use of the HEART Pathway with EMS and ED arrival troponin measures yielded a NPV of 98.0% (95% CI: 89.6-100). NPV improved to 100% (95% CI: 92.9-100) when using the EMS and 3-h ED troponin measures. CONCLUSIONS: EMS blood collection used for core lab ED troponin measures could significantly reduce ED LOS and appears safe when integrated into the HEART Pathway.

Catheterization Laboratory Activation Time in Patients Transferred With ST-Segment-Elevation Myocardial Infarction: Insights From the Mission: Lifeline STEMI Accelerator-2 Project.

BACKGROUND: Catheterization laboratory (cath lab) activation time is a newly available process measure for patients with ST-segment-elevation myocardial infarction requiring inter-hospital transfers for primary percutaneous coronary intervention that reflects inter-facility communication and urgent mobilization of interventional laboratory resources. Our aim was to determine whether faster activation is associated with improved reperfusion time and outcomes in the American Heart Association Mission: Lifeline Accelerator-2 Project. METHODS AND RESULTS: From April 2015 to March 2017, treatment times of 2063 patients with ST-segment-elevation myocardial infarction requiring inter-hospital transfer for primary percutaneous coronary intervention from 12 regions around the United States were stratified by cath lab activation time (first hospital arrival to cath lab activation within [timely] or beyond 20 minutes [delayed]). Median cath lab activation time was 26 minutes, with a delayed activation observed in 1241 (60.2%) patients. Prior cardiovascular or cerebrovascular disease, arterial hypotension at admission, and black or Latino ethnicity were independent factors of delayed cath lab activation. Timely cath lab activation patients had shorter door-in door-out times (40 versus 68 minutes) and reperfusion times (98 versus 135 minutes) with 80.1% treated within the national goal of ≤120 minutes versus 39.0% in the delayed group. CONCLUSIONS: Cath lab activation within 20 minutes across a geographically diverse group of hospitals was associated with performing primary percutaneous coronary intervention within the national goal of ≤120 minutes in >75% of patients. While several confounding factors were associated with delayed activation, this work suggests that this process measure has the potential to direct resources and practices to more timely treatment of patients requiring inter-hospital transfer for primary percutaneous coronary intervention.

Care and outcomes of urban and non-urban out-of-hospital cardiac arrest patients during the HeartRescue Project in Washington state and North Carolina.

AIM: We examined overall and temporal differences in out-of-hospital cardiac arrest (OHCA) care and outcomes by urban versus non-urban setting separately for North Carolina (NC) and Washington State (WA) during HeartRescue initiatives and associations of urban/non-urban settings with outcome by state. METHODS: OHCAs of presumed cardiac etiology from counties with complete registry enrollment in NC during 2010-2014 (catchment population = 3,143,809) and WA during 2011-2014 (catchment population = 3,653,506) were identified. Geospatial arrest location data and US Census classification were used to categorize urban areas with ≥50,000 versus non-urban <50,000 people. RESULTS: Included were 7731 NC cases (78.9% urban) and 4472 WA cases (85.8% urban). Bystander cardiopulmonary resuscitation (CPR) increased from 36.9% (2010) to 50.3% (2014) in NC non-urban areas versus 58.2% (2011) to 69.2% (2014) in WA; and from 39.3% to 51.1% in NC urban areas versus 52.4% to 61.8% in WA. Crude discharge survival odds ratio (OR) was 2.49 (95%CI 1.96-3.16) for urban versus non-urban NC cases not declared dead in field (N = 4241). Adjusted for age, sex, public location, bystander-witness status, time between emergency call and emergency medical service (EMS) arrival, calendar-year, bystander and first-responder CPR and defibrillation and direct PCI-center transport, OR was 1.30 (95%CI 0.98-1.73). In WA, corresponding crude and adjusted ORs were 1.38 (95%CI 0.99-1.93) and 1.46 (95%CI 1.00-2.13). In both states, bystander and first-responder CPR and defibrillation and direct PCI-hospital transport were associated with increased survival. CONCLUSIONS: During HeartRescue initiatives, bystander CPR increased in urban and non-urban locations. Bystander and first-responder interventions and direct PCI-hospital transport were associated with improved outcomes, including in non-urban areas.

Prehospital Trauma Scene and Transport Times for Pediatric and Adult Patients.

INTRODUCTION: Increased out-of-hospital time is associated with worse outcomes in trauma. Sparse literature exists comparing prehospital scene and transport time management intervals between adult and pediatric trauma patients. National Emergency Medical Services guidelines recommend that trauma scene time be less than 10 minutes. The objective of this study was to examine prehospital time intervals in adult and pediatric trauma patients. METHODS: We performed a retrospective cohort study of blunt and penetrating trauma patients in a five-county region in North Carolina using prehospital records. We included patients who were transported emergency traffic directly from the scene by ground ambulance to a Level I or Level II trauma center between 2013-2018. We defined pediatric patients as those less than 16 years old. Urbanicity was controlled for using the Centers for Medicare and Medicaid's Ambulance Fee Schedule. We performed descriptive statistics and linear mixed-effects regression modeling. RESULTS: A total of 2179 records met the study criteria, of which 2077 were used in the analysis. Mean scene time was 14.2 minutes (95% confidence interval [CI], 13.9-14.5) and 35.3% (n = 733) of encounters had a scene time of 10 minutes or less. Mean transport time was 17.5 minutes (95% CI, 17.0-17.9). Linear mixed-effects regression revealed that scene times were shorter for pediatric patients (p<0.0001), males (p=0.0016), penetrating injury (p<0.0001), and patients with blunt trauma in rural settings (p=0.005), and that transport times were shorter for males (p = 0.02), non-White patients (p<0.0001), and patients in urban areas (p<0.0001). CONCLUSION: This study population largely missed the 10-minute scene time goal. Demographic and patient factors were associated with scene and transport times. Shorter scene times occurred with pediatric patients, males, and among those with penetrating trauma. Additionally, suffering blunt trauma while in a rural environment was associated with shorter scene time. Males, non-White patients, and patients in urban environments tended to have shorter transport times. Future studies with outcomes data are needed to identify factors that prolong out-of-hospital time and to assess the impact of out-of-hospital time on patient outcomes.

One-Year Mortality and Associated Factors in Patients Receiving Out-of-Hospital Naloxone for Presumed Opioid Overdose.

STUDY OBJECTIVE: Out-of-hospital naloxone has been championed as a lifesaving solution during the opioid epidemic. However, the long-term outcomes of out-of-hospital naloxone recipients are unknown. The objectives of this study are to describe the 1-year mortality of presumed opioid overdose victims identified by receiving out-of-hospital naloxone and to determine which patient factors are associated with subsequent mortality. METHODS: This was a regional retrospective cohort study of out-of-hospital records from 7 North Carolina counties from January 1, 2015 to February 28, 2017. Patients who received out-of-hospital naloxone were included. Out-of-hospital providers subjectively assessed patients for improvement after administering naloxone. Naloxone recipients were cross-referenced with the North Carolina death index to examine mortality at days 0, 1, 30, and 365. Naloxone recipient mortality was compared with the age-adjusted, at-large population's mortality rate in 2017. Generalized estimating equations and Cox proportional hazards models were used to assess for mortality-associated factors. RESULTS: Of 3,085 out-of-hospital naloxone encounters, 72.7% of patients (n=2,244) improved, whereas 27.3% (n=841) had no improvement with naloxone. At day 365, 12.0% (n=269) of the improved subgroup, 22.6% (n=190) of the no improvement subgroup, and 14.9% (n=459) of the whole population were dead. Naloxone recipients who improved were 13.2 times (95% confidence interval 13.0 to 13.3) more likely to be dead at 1 year than a member of the general populace after age adjusting of the at-large population to match this study population. Older age and being black were associated with 1-year mortality, whereas sex and multiple overdoses were not. CONCLUSION: Opioid overdose identified by receiving out-of-hospital naloxone with clinical improvement carries a 13-fold increase in mortality compared to the general population. This suggests that this is a high-risk population that deserves attention from public health officials, policymakers, and health care providers in regard to the development of long-term solutions.

Association of Public Health Initiatives With Outcomes for Out-of-Hospital Cardiac Arrest at Home and in Public Locations.

Importance: Little is known about the influence of comprehensive public health initiatives according to out-of-hospital cardiac arrest (OHCA) location, particularly at home, where resuscitation efforts and outcomes have historically been poor. Objective: To describe temporal trends in bystander cardiopulmonary resuscitation (CPR) and first-responder defibrillation for OHCAs stratified by home vs public location and their association with survival and neurological outcomes. Design, Setting, and Participants: This observational study reviewed 8269 patients with OHCAs (5602 [67.7%] at home and 2667 [32.3%] in public) for whom resuscitation was attempted using data from the Cardiac Arrest Registry to Enhance Survival (CARES) from January 1, 2010, through December 31, 2014. The setting was 16 counties in North Carolina. Exposures: Patients were stratified by home vs public OHCA. Public health initiatives to improve bystander and first-responder interventions included training members of the general population in CPR and in the use of automated external defibrillators, teaching first responders about team-based CPR (eg, automated external defibrillator use and high-performance CPR), and instructing dispatch centers on recognition of cardiac arrest. Main Outcomes and Measures: Association of resuscitation efforts with survival and neurological outcomes from 2010 through 2014. Results: Among home OHCA patients (n = 5602), the median age was 64 years, and 62.2% were male; among public OHCA patients (n = 2667), the median age was 68 years, and 61.5% were male. After comprehensive public health initiatives, the proportion of patients receiving bystander CPR increased at home (from 28.3% [275 of 973] to 41.3% [498 of 1206], P < .001) and in public (from 61.0% [275 of 451] to 70.5% [424 of 601], P = .01), while first-responder defibrillation increased at home (from 42.2% [132 of 313] to 50.8% [212 of 417], P = .02) but not significantly in public (from 33.1% [58 of 175] to 37.8% [93 of 246], P = .17). Survival to discharge improved for arrests at home (from 5.7% [60 of 1057] to 8.1% [100 of 1238], P = .047) and in public (from 10.8% [50 of 464] to 16.2% [98 of 604], P = .04). Compared with emergency medical services-initiated CPR and resuscitation, patients with home OHCA were significantly more likely to survive to hospital discharge if they received bystander-initiated CPR and first-responder defibrillation (odds ratio, 1.55; 95% CI, 1.01-2.38). Patients with arrests in public were most likely to survive if they received both bystander-initiated CPR and defibrillation (odds ratio, 4.33; 95% CI, 2.11-8.87). Conclusions and Relevance: After coordinated and comprehensive public health initiatives, more patients received bystander CPR and first-responder defibrillation at home and in public, which was associated with improved survival.

Therapeutic Hypothermia for Patients with Out-of-Hospital Cardiac Arrest in North Carolina.

INTRODUCTION: While therapeutic hypothermia has been the standard of care for patients who suffer out-of-hospital cardiac arrest (OHCA), recent trials have led to an advisory statement recommending a focus on targeted in-hospital temperature management and against initiation of prehospital hypothermia with rapid infusion of cooled saline. The aim of this study is to review the experience with therapeutic hypothermia in North Carolina. METHODS: We studied patients who suffered OHCA in North Carolina in 2012 captured in the CARES database as part of the Heart Rescue Project. We excluded patients without return of spontaneous circulation and patients without an advanced airway placed in the field to reduce selection bias. Bivariate distributions and multivariate logistic regression models were used to examine differences in survival to discharge and positive neurological outcome. RESULTS: 847 patients were included in the analysis of pre-hospital hypothermia. Of these patients, 55% received prehospital hypothermia. Prehospital initiation of hypothermia was associated with higher survival to hospital discharge (OR 1.55, 95% CI 1.03-2.32) and improved neurologic outcome at discharge (OR 1.56 95% CI 1.01-2.40). In patients who survived to hospital admission (n = 537), in-hospital hypothermia was associated with a non-significant trend toward better survival to discharge (p = 0.18). CONCLUSION: We found that patients who received prehospital hypothermia had improved outcomes, a finding that may be due to a greater likelihood of receiving in-hospital hypothermia or a reflection of higher quality of pre-hospital care. These findings support ongoing efforts to improve all aspects of the chain of survival after cardiac arrest.

The role of bystanders, first responders, and emergency medical service providers in timely defibrillation and related outcomes after out-of-hospital cardiac arrest: Results from a statewide registry.

AIM: Defibrillation by bystanders and first responders has been associated with increased survival, but limited data are available from non-metropolitan areas. We examined time from 911-call to defibrillation (according to who defibrillated patients) and survival in North Carolina. METHODS: Through the Cardiac Arrest Registry to Enhance Survival, we identified 1732 defibrillated out-of-hospital cardiac arrests from counties with complete case capture (population 2.7 million) from 2010 to 2013. RESULTS: Most patients (60.9%) were defibrillated in > 10 min. A minority (8.0%) was defibrillated < 5 min; most of these patients were defibrillated by first responders (51.8%) and bystanders (33.1%), independent of location of arrest (residential or public). Bystanders initiated cardiopulmonary resuscitation (CPR) in 49.0% of cases and defibrillated 13.4% of those. Survival decreased with increasing time to defibrillation (< 2 min: 59.1%; 2 to < 5 min: 38.5%; 5-10 min: 33.1%; > 10 min: 13.2%). Odds of survival with favorable neurologic outcome adjusted for age, sex, and bystander CPR improved with faster defibrillation (<2 min: OR 7.73 [95% CI 3.19-18.73]; 2 to < 5 min: 3.78 [2.45-5.84]; 5-10 min: 3.16 [2.42-4.12]; > 10 min: reference). CONCLUSION: Bystanders and first responders were mainly responsible for defibrillation within 5 min, independent of location of arrest. Bystanders initiated CPR in half of the cardiac arrest cases but only defibrillated a minority of those. Timely defibrillation and defibrillation by bystanders and/or first responders were strongly associated with increased survival. Strategic efforts to increase bystander and first-responder defibrillation are warranted to increase survival after out-of-hospital cardiac arrest.

Prehospital care of traumatic brain injury in North Carolina.

Traumatic brain injury results in more than 140,000 visits to North Carolina emergency departments annually. North Carolina first implemented a systematically organized approach to brain injury management in 1967, and the state's emergency medical services community continues to optimize patient care by incorporating evolving knowledge into protocols and procedures.

Mobile Versus Fixed Deployment of Automated External Defibrillators in Rural EMS.

INTRODUCTION: There is no consensus on where automated external defibrillators (AEDs) should be placed in rural communities to maximize impact on survival from cardiac arrest. In the community of Stokes County, North Carolina (USA) the Emergency Medical Services (EMS) system promotes cardiopulmonary resuscitation (CPR) public education and AED use with public access defibrillators (PADs) placed mainly in public schools, churches, and government buildings. HYPOTHESIS/PROBLEM: This study tested the utilization of AEDs assigned to first responders (FRs) in their private-owned-vehicle (POV) compared to AEDs in fixed locations. METHODS: The authors performed a prospective, observational study measuring utilization of AEDs carried by FRs in their POV compared to utilization of AEDs in fixed locations. Automated external defibrillator utilization is activation with pads placed on the patient and analysis of heart rhythm to determine if shock/no-shock is indicated. The Institutional Review Board of Wake Forest University Baptist Health System approved the study and written informed consent was waived. The study began on December 01, 2012 at midnight and ended on December 01, 2013 at midnight. RESULTS: During the 12-month study period, 81 community AEDs were in place, 66 in fixed locations and 15 assigned to FRs in their POVs. No utilizations of the 66 fixed location AEDs were reported (0.0 utilizations/AED/year) while 19 utilizations occurred in the FR POV AED study group (1.27 utilizations/AED/year; P<.0001). Odds ratio of using a FR POV located AED was 172 times more likely than using a community fixed-location AED in this rural community. Discussion Placing AEDs in a rural community poses many challenges for optimal utilization in terms of cardiac arrest occurrences. Few studies exist to direct rural community efforts in placing AEDs where they can be most effective, and it has been postulated that placing them directly with FRs may be advantageous. CONCLUSIONS: In this rural community, the authors found that placing AED devices with FRs in their POVs resulted in a statistically significant increase in utilizations over AED fixed locations.

Association of body mass index with increased cost of care and length of stay for emergency department patients with chest pain and dyspnea.

BACKGROUND: High body mass index (BMI) increases the probability of indeterminate findings on diagnostic studies, length of stay, and cost of care for hospitalized patients. No study has examined the economic and operational impact of BMI in patients with chest complaints presenting to the emergency department (ED). The objective was to measure the association of BMI with the main outcomes of cost of care, length of stay (including time in the ED and time in the wards if admitted), and radiation exposure in patients presenting to the ED with chest pain and dyspnea. METHODS AND RESULTS: This was a prospective, 4-center, outcomes study. Patients were adults with dyspnea and chest pain, nondiagnostic electrocardiograms, and no obvious diagnosis. Patients were followed for the main outcomes for 90 days. Outcomes that were stratified by BMI in 5 categories, underweight, normal weight, overweight, obese, and morbidly obese, were compared using the Kruskall-Wallis rank test, and the independent predictive value of BMI was tested with multivariate regressions. Compared with medical costs for normal weight patients, costs were 22% higher for overweight patients (P=0.077), 28% higher for obese patients (P=0.020), and 41% higher for morbidly obese patients (P=0.015). Morbidly obese patients without computerized tomographic scanning stayed in the hospital 34% longer than normal weight patients (P=0.073), and morbidly obese patients with computerized tomographic scanning stayed in the hospital 44% longer than normal weight patients (P=0.083). BMI was not a significant predictor of radiation exposure. Morbidly obese patients had the highest proportion (87%) of no significant cardiopulmonary diagnosis for 90 days after computerized tomographic pulmonary angiography. CONCLUSIONS: BMI was associated with increases in cost of care and length of hospital stay for patients with chest pain and dyspnea. These results emphasize a need for specific protocols to manage morbidly obese patients presenting to the ED with chest pain and dyspnea. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT01059500.

Outcomes and radiation exposure of emergency department patients with chest pain and shortness of breath and ultralow pretest probability: a multicenter study.

STUDY OBJECTIVE: Excessive radiation exposure remains a concern for patients with symptoms suggesting acute coronary syndrome and pulmonary embolism but must be judged in the perspective of pretest probability and outcomes. We quantify and qualify the pretest probability, outcomes, and radiation exposure of adults with both chest pain and dyspnea. METHODS: This was a prospective, 4-center, outcomes study. Patients were adults with dyspnea and chest pain, nondiagnostic ECGs, and no obvious diagnosis. Pretest probability for both acute coronary syndrome and pulmonary embolism was assessed with a validated method; ultralow risk was defined as pretest probability less than 2.5% for both acute coronary syndrome and pulmonary embolism. Patients were followed for diagnosis and total medical radiation exposure for 90 days. RESULTS: Eight hundred forty patients had complete data; 23 (3%) had acute coronary syndrome and 15 (2%) had pulmonary embolism. The cohort received an average of 4.9 mSv radiation to the chest, 48% from computed tomography pulmonary angiography. The pretest probability estimates for acute coronary syndrome and pulmonary embolism were less than 2.5% in 227 patients (27%), of whom 0 of 277 (0%; 95% confidence interval 0% to 1.7%) had acute coronary syndrome or pulmonary embolism and 7 of 227 (3%) had any significant cardiopulmonary diagnosis. The estimated chest radiation exposure per patient in this ultralow-risk group was 3.5 mSv, including 26 (3%) with greater than 5 mSv radiation to the chest and no significant cardiopulmonary diagnosis. CONCLUSION: One quarter of patients with chest pain and dyspnea had ultralow risk and no acute coronary syndrome or pulmonary embolism but were exposed to an average of 3.5 mSv radiation to the chest. These data can be used in a clinical guideline to reduce radiation exposure.

Turbidimetric D-dimer test in the diagnosis of pulmonary embolism: a metaanalysis.

BACKGROUND: Clinicians in outpatient clinics and emergency departments desire an accurate quantitative D-dimer assay. The study objective was to evaluate the diagnostic performance characteristics of the latex turbidimetric D-dimer test in the diagnosis of pulmonary embolism (PE) in the emergency department population. METHODS: We conducted a search of MEDLINE, EMBASE, and bibliographies of previous systematic reviews with no language restriction. Experts in the field of PE research were contacted to identify unpublished studies. Prospective investigations involving predominately outpatient populations with suspected PE that used a turbidimetric D-dimer test were included. Two authors extracted data independently and assessed study quality based on the composition of the patient spectrum and the reference standard used. Consensus was reached by conference. The analysis was based on a summary ROC curve and combining sensitivity and specificity independently across studies using a random-effects model. RESULTS: The search yielded 264 publications and 2 unpublished studies. Nine studies met the inclusion criteria and provided a sample of 1901 individuals. Eight of the nine studies were homogeneous in terms of both sensitivity and specificity. One study had similar sensitivity but higher specificity. Combining the studies yielded an overall sensitivity of 0.93 (95% confidence interval, 0.89-0.96) and an overall specificity of 0.51 (95% confidence interval, 0.42-0.59). CONCLUSIONS: The turbidimetric D-dimer test is sensitive but nonspecific for the detection of PE in the emergency department setting. D-Dimer tests using latex turbidimetric methods appear to have test characteristics comparable to those for ELISA methods.

Criteria for the safe use of D-dimer testing in emergency department patients with suspected pulmonary embolism: a multicenter US study.

STUDY OBJECTIVE: We derive a decision rule to partition emergency department patients with suspected pulmonary embolism (PE) into a small, high-risk group (>40% pretest probability) that is unsafe for D -dimer testing and a larger group that is safe to have PE ruled out with either a whole-blood D -dimer plus alveolar deadspace measurement or a quantitative D -dimer assay. METHODS: Nine hundred thirty-four patients with suspected PE were studied at 7 urban EDs in the United States. Patients were prospectively interviewed and examined for recognized symptoms, signs, and risk factors associated with PE. These data were collected before standard objective imaging for PE. Selected variables were analyzed by multivariate logistic analysis to determine factors associated with PE (P <.05). A decision rule was then constructed to categorize approximately 80% of ED patients as safe for D -dimer testing. RESULTS: Pretest prevalence of PE was 19.4% (181/934; 95% confidence interval [CI] 16.3% to 21.7%). Six variables found to be significant on multivariate analysis were used to construct the decision rule. Unsafe patients had either a shock index (heart rate/systolic blood pressure) more than 1.0 or age older than 50 years, together with any one of the following conditions: unexplained hypoxemia (SaO (2) <95%; no prior lung disease), unilateral leg swelling, recent major surgery, or hemoptysis. These criteria were met by 197 (21.0%) of 934 patients, and 83 of 197 (42.1%; 95% CI 35.3% to 49.6%) patients had PE. Exclusion of these 197 unsafe patients significantly decreased the probability of PE in the remaining 737 (79.0%) safe patients to 13.3% (95% CI 10.9% to 15.9%). CONCLUSION: Simple clinical criteria can permit safe D -dimer testing in the majority of ED patients with suspected PE. These criteria warrant prospective validation.