Vincent N. Mosesso

Use of Automated External Defibrillators by Police Officers for Treatment of Out-of-Hospital Cardiac Arrest

OBJECTIVE To determine the feasibility of police officers providing defibrillation with automated external defibrillators (AEDs) and to assess the effectiveness of this strategy in reducing time to defibrillation of victims of out-of-hospital sudden cardiac arrest. METHODS This was a prospective, interventional cohort study with historical controls conducted in 7 suburban communities in which police usually arrived at the scene of medical emergencies before EMS personnel. All adult patients who suffered cardiac arrest before EMS arrival and on whom EMS personnel attempted resuscitation were enrolled. Police officers who were trained to use and equipped with AEDs during the intervention phase were dispatched simultaneously with EMS to medical emergencies. Police were instructed to use the AED immediately on determination of pulselessness. Outcome measures were the difference between control and intervention phases in interval from the time the call was received at dispatch to the time of first defibrillation and in rate of survival to hospital discharge for patients initially in ventricular fibrillation. RESULTS EMS personnel attempted 183 resuscitations in the control phase and 283 during the intervention; of these, 80 (44%) and 127 (45%), respectively, involved patients with initial ventricular fibrillation rhythms. Mean time to defibrillation decreased from 11.8+/-4.7 minutes in the control phase to 8.7+/-3.7 minutes in the intervention phase (P<.0001). Survival to hospital discharge of patients in ventricular fibrillation did not differ between phases (6% control versus 14% intervention, P=.1). When police arrived before EMS personnel, shock administered by police compared with shock administered by EMS was associated with improved survival (26% [12/46] versus 3% [1/29], P=.01). Logistic regression analysis revealed AED use was an independent predictor of survival to hospital discharge. CONCLUSION In 7 suburban communities, police use of AEDs decreased time to defibrillation and was an independent predictor of survival to hospital discharge.

Importance and Implementation of Training in Cardiopulmonary Resuscitation and Automated External Defibrillation in Schools: A Science Advisory From the American Heart Association

In 2003, the International Liaison Committee on Resuscitation published a consensus document on education in resuscitation that strongly recommended that “…instruction in CPR [cardiopulmonary resuscitation] be incorporated as a standard part of the school curriculum.”1 The next year the American Heart Association (AHA) recommended that schools “…establish a goal to train every teacher in CPR and first aid and train all students in CPR” as part of their preparation for a response to medical emergencies on campus.2 Since that time, there has been an increased interest in legislation that would mandate that school curricula include training in CPR or CPR and automated external defibrillation. Laws or curriculum content standards in 36 states (as of the 2009–2010 school year) now encourage the inclusion of CPR training programs in school curricula. The language in those laws and standards varies greatly, ranging from a suggestion that students “recognize” the steps of CPR to a requirement for certification in CPR. Not surprisingly, then, implementation is not uniform among states, even those whose laws or standards encourage CPR training in schools in the strongest language. This statement recommends that training in CPR and familiarization with automated external defibrillators (AEDs) should be required elements of secondary school curricula and provides the rationale for implementation of CPR training, as well as guidance in overcoming barriers to implementation. Sudden cardiac arrest is a leading cause of death in the United States and Canada. It is estimated that each year emergency medical services (EMS) personnel assess 294 851 (quasi-confidence intervals, 236 063 to 325 007) out-of-hospital cardiac arrests (OHCAs) in the United States. Survival, which is defined as being discharged alive from the hospital, varies widely by region (3.0% to 16.3%; median, 8.4%), but the overall average rate of survival to discharge from the hospital is estimated …

Scaling Exponent Predicts Defibrillation Success for Out-of-Hospital Ventricular Fibrillation Cardiac Arrest

BackgroundDefibrillator shocks often fail to terminate ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OOHCA), and repeated failed shocks can worsen the subsequent response to therapy. Because the VF waveform changes with increasing duration of VF, it is possible that ECG analyses could estimate the preshock likelihood of defibrillation success. This study examined whether an amplitude-independent measure of preshock VF waveform morphology predicts outcome after defibrillation. Methods and ResultsClinical data and ECG recordings from an automated external defibrillator were obtained for 75 subjects with OOHCA in a suburban community with police first responders and a paramedic-based emergency medical system. An estimate of the fractal self-similarity dimension, the scaling exponent, was calculated off-line for the VF waveform preceding shocks. Success of the first shock was determined from the recordings. Return of pulses and survival were determined by chart review. The first shock resulted in an organized rhythm in 43% of cases, and 17% of cases survived to hospital discharge. A lower mean value of the scaling exponent was observed for cases in which the first defibrillation resulted in an organized rhythm (P =0.004), for cases with return of pulses (P =0.049), and for cases surviving to hospital discharge (P <0.001). Receiver operator curves revealed the utility of the scaling exponent for predicting the probability of restoring an organized rhythm (area under the curve=0.70) and of survival (area under the curve=0.84). ConclusionsThe VF waveform in OOHCA can be quantified with the scaling exponent, which predicts the probability of first-shock defibrillation and survival to hospital discharge.

Development of systems of care for ST-Elevation myocardial infarction patients. The emergency medical services and emergency department perspective.

Central to the development of systems and centers of care for ST-elevation myocardial infarction (STEMI) patients will be the key role played by emergency medical services (EMS) at entry into the system and within the system when emergency interhospital transport is required. ### Emergency Medical Services System Design Prehospital EMS systems have 3 major components: emergency medical dispatch, public safety (fire and law enforcement) first response, and EMS ambulance response. Each of these operates within a broader emergency care system, which includes acute care facilities and regionalized healthcare services. In most states, an EMS regulatory entity within the state government oversees the emergency care system. Many states have regional EMS councils and advisory boards that function with varying levels of authority. #### Emergency Medical Dispatch Early access to EMS is promoted by a 9-1-1 system currently available to >95% of the US population. Enhanced 9-1-1 systems provide the caller’s location and number to the dispatcher, which permits rapid dispatch of prehospital personnel to locations even if the caller is not capable of verbalizing or the dispatcher cannot understand the location and telephone number of the emergency. Although cellular phones have been problematic because they do not stay in a fixed location, new technology exists that allows triangulation of a cellular phone caller’s location. This technology is being phased in throughout the country at a rapid pace. In most communities, law enforcement or public safety officials are responsible for operating 9-1-1 centers, because in most locations, 85% of calls are for police assistance, 10% are for EMS, and 5% are for fire-related emergencies. Dispatchers who staff 9-1-1 centers may have minimal medical training, be emergency medical technicians, or on occasion be paramedics trained and certified as emergency medical dispatchers. In any case, dispatchers operate under standardized, written (often computerized) protocols. Such protocols are developed nationally and then modified locally or nationally. …

Performance of police first responders in utilizing automated external defibrillation on victims of sudden cardiac arrest.

OBJECTIVE Rates of resuscitation from cardiac arrest are directly tied to time to defibrillation. To maximize results, the first arriving care provider should be equipped and trained to defibrillate. This would include police in those systems where they serve this function; to date, no training program has been examined for effectiveness in this group. The purpose of this study was to evaluate a training program designed to train police first responders in the use of an automated external defibrillator (AED). METHODS One hundred seventy police officers previously trained to the level of first responders underwent a four-hour course to teach incorporation of the AED in their practice. The evaluation of police performance was assessed by written tests prior to, immediately after, and six months post initial training. Actual field use was evaluated by using separate data collection forms filled out at the time of the resuscitation by both police and EMS providers. Each trip sheet was also reviewed. Cassette tapes from the AED were reviewed for continuous ECG tracings and audio recordings to validate and confirm the previous data. RESULTS One hundred twenty-eight police cases were reviewed. The officers performed with few errors in AED operation, with the only problem areas being incorrect airway management and delay in performance of CPR to use the AED to reanalyze a nonshockable rhythm. These results were compared with those of the only two other studies examining the performance of first responders, which were EMTs and firefighters. The police results compared favorably with, and in some instances exceeded, those results. CONCLUSION Police first responders trained in the use of AEDs performed at a level equivalent or superior to that in other reported studies. Future training strategies should stress proper integration of airway and CPR skills.

Use of therapeutic hypothermia after in-hospital cardiac arrest.

Objectives:Formal guidelines recommend that therapeutic hypothermia be considered after in-hospital cardiac arrest. The rate of therapeutic hypothermia use after in-hospital cardiac arrest and details about its implementation are unknown. We aimed to determine the use of therapeutic hypothermia for adult in-hospital cardiac arrest, whether use has increased over time, and to identify factors associated with its use. Design:Multicenter, prospective cohort study. Setting:A total of 538 hospitals participating in the Get With the Guidelines-Resuscitation database (2003–2009). Patients:A total of 67,498 patients who had return of spontaneous circulation after in-hospital cardiac arrest. Interventions:None. Measurements and Main Results:The primary outcome was the initiation of therapeutic hypothermia. We measured the proportion of therapeutic hypothermia patients who achieved target temperature (32–34°C) and were overcooled. Of 67,498 patients, therapeutic hypothermia was initiated in 1,367 patients (2.0%). The target temperature (32–34°C) was not achieved in 44.3% of therapeutic hypothermia patients within 24 hours and 17.6% were overcooled. The use of therapeutic hypothermia increased from 0.7% in 2003 to 3.3% in 2009 (p < 0.001). We found that younger age (p < 0.001) and occurrence in a non-ICU location (p < 0.001), on a weekday (p = 0.005), and in a teaching hospital (p = 0.001) were associated with an increased likelihood of therapeutic hypothermia being initiated. Conclusions:After in-hospital cardiac arrest, therapeutic hypothermia was used rarely. Once initiated, the target temperature was commonly not achieved. The frequency of use increased over time but remained low. Factors associated with therapeutic hypothermia use included patient age, time and location of occurrence, and type of hospital.

P REHOSPITAL T HERAPY FOR A CUTE C ONGESTIVE H EART F AILURE : S TATE OF THE A RT

Acute congestive heart failure (CHF) is one of the most common syndromes encountered in emergency care settings. Correct diagnosis and treatment for pulmonary edema, the most common acute manifestation of CHF, are of primary importance as misdiagnosis can result in deleterious consequences to patients. The pathogenesis of acute pulmonary edema (APE) is currently believed to arise primarily from the redistribution of intravascular fluid to the lungs secondary to acutely elevated left ventricular (LV) filling pressures. This understanding has provided a basis for the management of acute APE, which entails reduction of LV preload, reduction of LV afterload, ventilatory support, inotropic support as needed, and identification and treatment of other underlying factors contributing to elevated LV filling pressures. The agent most applicable and effective for field treatment is nitroglycerin. Diuretics and morphine should be used with caution, as they carry higher risks, especially in misdiagnosed patients. The role of angiotensin-converting enzyme (ACE) inhibitors has yet to be demonstrated in a prehospital setting. Noninvasive positive pressure ventilation methods are effective adjuncts to current treatment, but their mode of delivery presents technical challenges. The development of novel rapid diagnostic tools, currently in progress, might prove valuable for emergency medical services (EMS) personnel in the future. But for now, EMS personnel must rely on their fundamental skills of history taking and physical examination for accurate diagnosis of CHF.

A LL –A DVANCED L IFE S UPPORT VS T IERED -R ESPONSE A MBULANCE S YSTEMS

In this discussion, two principal types of ambulance deployment systems were compared and contrasted: 1) the multipurpose, sole-provider all-advanced life support (all-ALS) ambulance system in which all ambulance-related services (emergent and nonemergent) for a city or region are provided by one fleet of ambulances, each of which is staffed by ALS providers (paramedics); and 2) the tiered ambulance system (tiered) in which some 911 ambulances are staffed by paramedics and others are staffed by basic emergency medical technicians (EMT-Bs) who provide basic life support (BLS) care. When managed with advanced system status management (SSM) techniques, the multipurpose, sole-provider all-ALS ambulance system can significantly reduce response intervals while simultaneously providing both fiscal and operational efficiencies. It can also be used to readily integrate and expand the scope of services for the ambulance provider service, such as interfacility transfers, thus increasing revenues. On the other hand, in large urban centers, the tiered ambulance system can be used to reduce response intervals to critical calls, primarily through the use of sophisticated dispatch triage protocols. This approach requires fewer paramedics in the system and appears, in some systems, to also provide medical care advantages in terms of skills utilization for individual ALS providers as well as a more concentrated focus for medical supervision. Therefore, both of these deployment systems can offer certain advantages depending on local emergency medical services (EMS) system needs as well as the local philosophy of health care delivery. Applicability must therefore be considered in terms of local service demands and other factors that affect the EMS system, including catchment population, statutory and jurisdictional issues, available funding, accessibility of receiving facilities, and medical quality concerns.

Paramedic evaluation of clinical indicators of cervical spinal injury

PURPOSE Standard prehospital practice includes frequent immobilization of blunt trauma patients, oftentimes based solely on mechanism. Unnecessary cervical spine (c-spine) immobilization does have disadvantages, including morbidity such as low back pain and splinting, increased scene time and costs, and patient-paramedic conflict. Some emergency physicians (EPs) use clinical criteria to clear trauma patients of c-spine injury. If paramedics were able to apply clinical criteria in the out-of-hospital setting, then unnecessary c-spine immobilization could be safely avoided. The authors designed a prospective, randomized, simulated trial to determine the level of agreement between paramedic and EP assessments of clinical indicators of c-spine injury, hypothesizing that there would be substantial agreement between them. METHODS A convenience sample of ten paramedics and ten attending EPs participated. Ten standardized patients, with various combinations of positive and negative findings, were examined simultaneously by EP-paramedic pairs. Each pair evaluated five randomly assigned patients for six clinical criteria: 1) alteration in consciousness, 2) evidence of intoxication, 3) complaint of neck pain, 4) cervical tenderness, 5) neurologic deficit or complaint, and 6) distracting injury. If any criterion was positive, clinical clearance was considered to have failed, and the simulated patient would have been immobilized. Fifty pairs of examinations were performed. The kappa statistic was utilized to determine level of agreement between the two groups for each criterion and for the immobilization decision. A kappa of 0.40 to 0.75 denotes good agreement and > 0.75 denotes excellent agreement. RESULTS The kappas for the six criteria were: 1) 0.77; 2) 0.68; 3) 0.62; 4) 0.73; 5) 0.68; and 6) 0.62. The kappa statistic for the immobilization decision was 0.90. In only one case did the immobilization decisions differ; the paramedic indicated immobilization, whereas the physician did not. CONCLUSION In this model, there was excellent agreement between paramedics and physicians when evaluating simulated patients for possible c-spine injury. No patient requiring immobilization would have been clinically cleared by paramedics. These data support the progression to a prospective field trial evaluating the use of these criteria by paramedics.

Law enforcement agencies and out-of-hospital emergency care.

STUDY OBJECTIVE We sought to assess the involvement of law enforcement agencies in out-of-hospital emergency medical care and their attitudes toward expanded roles in emergency medical services (EMS) systems. METHODS We mailed a 20-question survey to 800 police chiefs and sheriffs randomly selected from a list of all law enforcement agencies in the United States. The questions focused on the characteristics of each law enforcement agency, its current level of involvement in providing out-of-hospital emergency medical care, and the characteristics of its associated community and local EMS system. The survey concluded with four statements to assess officer attitudes toward an expanded role in EMS-related activities. We used the chi 2 or Fisher exact test to analyze differences in proportions. The alpha-error rate was set at .05. RESULTS Seventeen surveys were returned as undeliverable. Of the remaining 783 surveys, we received 602 responses (77%). Five hundred forty-nine (70.1%) of the respondents were the primary law enforcement agencies in their communities; they make up the final sample. The median number of officers per agency was 12 (range, 1 to 2,623), and the median population served was 6,936 (range, 150 to 1,500,000). Responses indicated that 442 (80.7%) agencies responded to one or more specific types of medical emergencies and 263 (50.3%) provided some level of patient care. Law enforcement officers frequently arrived at the scene of medical emergencies before EMS personnel (81.5%), with a roll-time interval of less than 8 minutes (87.2%). Only 14 agencies (2.6%) used automatic external defibrillators. Fifty-three percent agreed with the statement that EMS-related activities would interfere with their law enforcement duties. However, more than 60% of respondents agreed that law enforcement agencies should be involved in providing emergency medical services for life-threatening emergencies, that their officers would be willing to undertake extra medical training and that EMS-related activities would improve their public images. CONCLUSION Many law enforcement agencies are involved to some extent in providing out-of-hospital emergency medical care, and most of the agencies we surveyed would support additional medical training and new or expanded roles for themselves in EMS systems.