Cardiac arrest survival as a function of ambulance deployment strategy in a large urban emergency medical services system.

INTRODUCTION: This study examines the effect of paramedic deployment strategy on witnessed ventricular fibrillation (VF) cardiac arrest outcomes. Our null hypothesis was that there is no difference in survival between an EMS system using targeted response (TR) and one using a uniform or all advanced life support (ALS) response (UR) model. We define targeted response as a system where paramedics are sent to critical incidents while ambulances staffed with basic EMTs are sent to less critical incidents. A secondary outcome measure was paramedic skill proficiency between the systems. METHODS: We conducted a retrospective review of all 1997 VF arrests in a large urban EMS system. The majority of the city is a busy, urban area that uses TR. Outlying areas of the city are suburban and are served by a UR model. All areas have first responders equipped with automated external defibrillators. Outcomes are compared using Utstein criteria. RESULTS: Patient populations were well matched. There were 181 patients in the TR group and 24 in the UR group. Units in the TR area were able to demonstrate shorter response and time to defibrillation intervals than in the UR area. Rates for return of spontaneous circulation (ROSC), admission to the ward/intensive care unit (ICU), survival to discharge and survival to 1 year were all better in the cohort of patients cared for in the TR area than those in the UR area. Rates for successful intubation and IV initiation were also better in the TR areas than in the UR areas. CONCLUSION: This study shows improved outcomes for a subset of patients with cardiac arrest when they are cared for in an area that uses TR compared to an area that uses a UR EMS system.

Can first responders be sent to selected 9-1-1 emergency medical services calls without an ambulance?

OBJECTIVES: To evaluate the feasibility and safety of initially dispatching only first responders (FRs) to selected low-risk 9-1-1 requests for emergency medical services. First responders are rapidly-responding fire crews on apparatus without transport capabilities, with firefighters trained to at least a FR level and in most cases to the basic emergency medical technician (EMT) level. Low-risk 9-1-1 requests include automatic medical alerts (ALERTs), motor vehicle incidents (MVIs) for which the caller was unable to answer any medical dispatch questions designed to prioritize the call, and 9-1-1 call disconnects (D/Cs). METHODS: A before-and-after study of patient dispositions was conducted using historical controls for comparison. During the historical control phase of six months, one year prior to the study phase, basic life support ambulances (staffed with two basic EMTs) were dispatched to selected low-risk 9-1-1 incidents. During the six-month study phase, a fire FR crew equipped with automated external defibrillators (AEDs) was sent initially without an ambulance to these incidents. RESULTS: For ALERTs (n = 290 in historical group vs. 330 in study group), there was no statistical difference in the transport rate (7% vs 10%), but there was a statistically significant increase in the follow-up use of advanced life support (ALS) (1% vs 4%, p = 0.009). No patient in the ALERTs historical group required airway management, while one patient in the study group received endotracheal intubation. No patient required defibrillation in either group. Analysis of the MVIs showed a significant decrease (p < 0.0001) in the patient transport rate from 39% of controls to 33% of study patients, but no change in the follow-up use of ALS interventions (2% for each group). For both the ALERTs and MVIs, the FR's mean response time was faster than ambulances (p < 0.0001). Among the 9-1-1 D/Cs with FRs only (n = 1,028), 15% were transported and 43 (4%) received subsequent ALS care. Four of these patients (0.4%) received intubation and two (0.2%) required defibrillation. However, no patient was judged to have had adverse outcomes as a result of the dispatch protocol change. CONCLUSIONS: Fire apparatus crews trained in the use of AEDs can safely be used to initially respond alone (without ambulances) to selected, low-risk 9-1-1 calls. This tactic improves response intervals while reducing ambulance responses to these incidents.

Operational issues in EMS.

Improving outcomes for patients presenting to the EMS system relies on strong links at every level of the EMS system. Targeted deployment strategies that serve to limit the number of paramedics in each system foster a cadre of experienced paramedics that make a difference for seriously ill patients who present in the out-of-hospital setting. Dedicated physician directors who act as mentors at every level of the EMS system are essential elements of the successful EMS system.

Prehospital asthma management.

The treatment of acute asthma exacerbation consumes a significant portion of emergency medical services (EMS) system resources. Because few studies have addressed EMS treatment of asthma, most EMS providers model their approach to treatment on strategies thought to be effective in the emergency department. During the treatment of asthma, a patient's history and current airway and respiratory status are important components of the initial assessment. Although the general evaluation may address a patient's appearance, vital signs, mental status, level of fatigue, and ability to speak normally, the initial assessment of an asthmatic patient must focus specifically on his or her respiratory effort and quality and on objective measurement of the patient's blood oxygenation. Inhaled beta-agonist therapy is the widely recommended first choice of treatment, but anticholinergic agents and steroids may also have roles. Although not routine treatments, parenteral magnesium and epinephrine may also be beneficial for certain patients. Endotracheal intubation is a procedure of last resort and should be reserved for patients at immediate risk of respiratory arrest. Finally, EMS providers must be alert to the danger of using a "treat and release" approach, as recommended by some protocols, in the treatment of acute asthma. The quick results and benefit that short-acting treatments provide can easily and erroneously lead a provider to believe that an attack has been adequately controlled when, in fact, a more serious exacerbation may be imminent. Treatment protocols, therefore, should discourage EMS personnel from this practice and advise them to always transport asthmatic patients they have treated to the hospital to undergo more extended care and monitoring.

The effect of a quality improvement feedback loop on paramedic-initiated nontransport of elderly patients.

OBJECTIVE: To examine the effect of a paramedic educational program and quality improvement feedback loop on paramedic-initiated nontransport of patients 65 years of age and older. METHODS: Prospective observational study. Patients 65 years of age and older who were evaluated but not transported by paramedics were contacted by telephone within two weeks of emergency medical services (EMS) contact and asked: 1) whether the patient sought medical help within 24 hours after contact; 2) whether the patient was admitted to a hospital and, if so, what was the diagnosis; 3) who was responsible for the nontransport decision (patient, paramedic, or mutual); and 4) how satisfied the patient was with the EMS service. After six weeks of data collection, the results were presented in a nonjudgmental fashion to the paramedics. After this intervention, the data collection continued for another five weeks without the paramedics' knowledge. RESULTS: After the intervention, the overall nontransport rate remained constant (11.5% vs. 10.7%). The percentage of patients seeking further medical attention within 24 hours also remained constant (37.1% vs. 33.9%). The percentage of patients who required hospitalization within 24 hours of the nontransport declined from 12.6% to 6.4%. The percentage of patients who refused ambulance transportation by paramedics declined from 9.3% to 3.7%. Overall satisfaction level rose from 94.7% to 100%. CONCLUSION: When paramedics were provided with objective feedback regarding outcome of patients not transported, the paramedic-initiated nontransportation and delayed hospitalization rates decreased, and the patient satisfaction level rose to 100%.

Stroke: from recognition by the public to management by emergency medical services.

To improve the outcomes of stroke patients, public awareness of stroke must be increased and emergency medical services (EMS) response to stroke calls optimized. Rapid response to stroke is key, as emphasized in the American Stroke Association's "Stroke Chain of Survival," which consists of four components--rapid recognition of and reaction to stroke warning signs through immediate use of the 9-1-1 system; rapid EMS assessment; priority transport with prenotification of the receiving hospital; and rapid and accurate diagnosis and treatment at the hospital. Neither the risk factors for stroke nor the most common warning signs are adequately known to the public in general, and in particular, to the groups at highest risk for stroke. Effective education through mass media and health care professionals is paramount in increasing the public's awareness of stroke. Whether tools to aid dispatchers and paramedics in stroke diagnosis, assessment, and management can improve stroke patients' outcomes requires further study, as does the value of designated stroke centers. Overall, according stroke the same urgency as acute myocardial infarction, from both the public and the prehospital provider perspectives, might improve stroke patient outcomes.