Brian S. Zachariah

Cardiac arrest presenting with rhythms other than ventricular fibrillation: contribution of resuscitative efforts toward total survivorship.

The medical literature portrays a bleak prognosis for out-of-hospital cardiac arrest cases presenting with asystole, idioventricular rhythms with pulselessness, or primary electromechanical dissociation. In view of evolving philosophies to waive resuscitation attempts in such cases, we sought to delineate the actual contribution toward overall survivorship that is provided by resuscitation efforts for patients who have these electrocardiographic presentations. Design:A prospective outcome study which analyzed all out-of-hospital cardiac arrest cases in a large city for a 2-yr period in terms of presenting electrocardiogram, age, sex, presence and status of witnesses, performance of bystander cardiopulmonary resuscitation, and survival to successful hospital discharge. Setting:A large urban municipality (population, two million) served by a single, centralized emergency medical services program. Patients:Excluding cases associated with trauma, drugs, airway obstruction, submersion or primary respiratory illness, 2,404 consecutive adult out-of-hospital cardiac arrest patients were studied. Interventions:Standard advanced cardiac life support. Measurements and Main Results:Although survival “rates” of patients with asystole, idio-ventricular rhythms with pulselessness, and electromechanical dissociation were low (1.6%, 4.7% and 6.9%, respectively), 22.2% of the 193 total survivors (confidence interval: +5.9%) initially presented with one of these electrocardiographic rhythms (14 asystole, 18 idioventricular rhythms with pulselessness, 10 electromechanical dissociation, plus one other). Conclusions:Despite poor survival “rates,” resuscitative efforts forpatients presenting with asystole, electromechanical dissociation, and idioventricular rhythms with pulselessness all contribute significantly toward a communitys total survivorship from out-of-hospital cardiac arrest. Initial, aggressive attempts at resuscitation still should be emphasized in such patients. (Crit Care Med 1993; 21:1838–1843)

Invasive airway techniques in resuscitation

Although endotracheal intubation is still the most definitive technique for airway management in patients with cardiac or respiratory arrest, in some emergency care systems, use of endotracheal intubation by prehospital care personnel has been restricted by policy or statute. Therefore, alternative airway devices have been developed. These alternative airway devices include the Esophageal Obturator Airway (EOA) and Esophageal Gastric Tube Airway (EGTA), the Pharyngeotracheal Lumen Airway (PTL), and the Esophageal-Tracheal Combitube (ETC). By examining the available literature concerning these alternative airway devices, we sought to determine 1) if these devices are superior to basic, noninvasive airway techniques (eg, bag-valve-mask ventilation); 2) if they are comparable to endotracheal intubation in terms of ventilation, oxygenation, and potential complications; 3) what the role of these devices should be in prehospital care; and 4) what the best recommendations should be regarding these devices in terms of resuscitation training and future areas for research. The review involved a total of 837 EOA/EGTA, 304 PTL, and 159 ETC study patients. Although ventilation and oxygenation can, in some circumstances, be as good with the EOA/EGTA devices as it is with the endotracheal intubation, in some cases they can be inadequate, and the complication rate is relatively high. Preliminarily, the PTL and the ETC seem to provide adequate ventilation and oxygenation with few complications. However, for both devices, published clinical experience, especially in the prehospital setting, is still limited. Therefore, their use should be left to the discretion of accountable physician directors of applicable resuscitation teams. Regardless of the device used, recognition of proper placement remains the most important aspect of using any invasive airway device. Therefore, proper training and expert medical supervision probably have more influence on the successful use and impact of these devices than any other factors related to the devices themselves. Future training efforts would be most useful if directed at proper endotracheal intubation training and development of improved basic ventilatory skills. Nevertheless, additional controlled, direct-comparison studies of the PTL and ETC devices are recommended and should be conducted in properly supervised emergency medical services systems.

Emergency medical services priority dispatch

STUDY OBJECTIVE To test the ability of a locally designed priority dispatch system to safely exclude the need for advanced life support (ALS). DESIGN Retrospective review of emergency medical services (EMS) incident records to determine how often the lone dispatch of basic life support (BLS) units, staffed with basic emergency medical technicians, subsequently required or involved ALS care. SETTING A large centralized municipal EMS system with a tiered ALS/BLS ambulance response. All BLS units carry automated defibrillators. MEASUREMENTS Consecutive EMS records (35,075) were reviewed by computerized search for ALS procedures. Records indicating ALS procedures were tabulated and then manually reviewed for the nature of and probable indication for the ALS intervention. INTERVENTION Brief sequences of computer-stored questions that help dispatchers identify (or exclude) signs and symptoms indicating the need for ALS. RESULTS The dispatch triage system spared ALS units from initial dispatch in 14,100 of the EMS incidents (40.2%), increasing their availability and use for more serious calls. Among these 14,100 cases, only 41 patients (0.3%) later received drugs such as nitroglycerin and naloxone; another 27 patients (0.2%) received resuscitative interventions such as epinephrine or defibrillation. Furthermore, on closer analysis, the immediate presence of a paramedic might have provided a true potential for advantage in outcome for only five or six patients (less than 0.04 of the 14,100 BLS dispatches). Meanwhile, many important operational, fiscal, and cost-effective patient care benefits were realized with this system. CONCLUSION A computer-aided dispatch triage algorithm can facilitate improvements in both EMS system operations and prehospital patient care by safely and reliably identifying EMS incidents requiring only BLS.

The development of emergency medical dispatch in the USA: a historical perspective.

Emergency medical dispatch has evolved over the last 25 years from a system designed to limit abuse of the emergency medical services (EMS) to a sophisticated part of the total EMS response. Its current goal is to send the right thing to the right person at the right time in the right way and to do the right thing until help arrives. The historical development of emergency medical dispatch in the USA is outlined decade by decade. In addition, the current state of emergency medical dispatch is reviewed and future directions are discussed.

Emergency medical vehicle collisions in an urban system

INTRODUCTION Emergency medical services collisions (EMVCs) are a largely unexplored area of emergency medical services (EMS) research. Factors that might contribute to an EMVC are numerous and include use of warning lights and siren (WL&S). Few of these factors have been evaluated scientifically. Similarly, the incidence and severity of EMVCs is poorly documented in the literature. This study sought to define the incidence and severity of, and where possible, identify any contributing factors to EMVCs in a large urban system. METHODS Retrospective study of all collisions involving vehicles assigned to the EMS Division of the Houston Fire Department in calendar year 1993. Fifty-one ambulances were operational 24 hours per day during calendar year 1993. Houston EMS received 150,000 requests for assistance, made 180,000 vehicular responses, and accrued 2,651,760 miles in 1993. RESULTS Eighty-six EMVCs were identified during the study period. The gross incidence rate was therefore 3.2 EMVC/100,000 miles driven or 4.8 collisions/10,000 responses. Of the 86 EMVCs, 74 (86%) files were complete and available for evaluation. Major collisions, determined according to injuries or vehicular damage, accounted for 10.8% of all EMVCs. There were 17 persons transported to hospitals from EMS collisions, yielding an injury incidence of 0.64 injuries/100,000 miles driven or 0.94 injuries/10,000 responses. There were no fatalities. The majority of collisions (85.1%) occurred at some site other than an intersection. There was no statistical association between occurrence at an intersection and severity, day versus night, weekend versus weekday, presence or absence of precipitation, or use of WL & S versus severity of collision. Drivers with a history of previous EMVCs were involved in 33% of all collisions. The presence of prior EMVCs was associated (p < 0.001) with the number of persons transported from the collision to a local hospital. Five drivers, all with previous EMVCs, accounted for 88.2% (15/17) of all injuries. CONCLUSIONS A few drivers with previous EMVCs account for a disproportionate number of EMVCs and nearly 90% of all injuries. This risk factor--history of previous EMVC--has not been reported in the EMS literature. It is postulated that this factor ultimately will prove to be the major determinant of EMVCs. Data collection of EMS collisions needs to be standardized and a proposed collection tool is provided.

74. Location of Cardiac Arrests: Implications for AED Placement

Hypothesis : First responder organizations with automated external defibrillators (AEDs) can have a larger impact on survival of out-of-hospital cardiac arrest than placing AEDs in large buildings. Methods : To evaluate the impact, all cardiac arrests handled by a large urban fire department for 1994 were analyzed. Each 5.6 square mile area of the city was defined as business (Bus), high (HilRes), middle (MilRes), or low income (LoIRes) residential. For each area, the CPR rates were calculated for the number of arrests/100 ambulance dispatches, and were stratified by percent of adults over age 65. Results : Of the 1,222 cardiac arrests, only 85 occurred in business and industrial areas, 1,041 occurred in residential areas. The downtown business district had only 77 arrests with half of those being outside of buildings or in shelters.

Acute coronary syndrome: Pharmacotherapy ☆ ☆☆

Acute coronary syndrome (ACS) refers to the spectrum of cardiac disease, from unstable angina to ST-segment-elevation myocardial infarction. In the emergency medical services (EMS) setting, ACS may be more broadly thought to include patients with chest pain or other symptoms believed to have a cardiac origin who have evidence of ischemia or acute myocardial infarction on a 12-lead electrocardiogram, or symptomatic patients with a previous cardiac event or known cardiac disease. Pharmacologic management of these patients is based on the use of three primary classes of drugs: those that affect clotting, those that establish and maintain hemodynamic control, and those that relieve pain. Many of these agents have been evaluated in large clinical trials for in-hospital use, and a number of ongoing studies are assessing their efficacy in the prehospital setting. The appropriateness of prehospital use of specific agents within each class depends on proper patient selection, the necessity of immediate intervention, ease of use in the field, expertise of EMS personnel, and cost-effectiveness of therapy. This consensus group reviewed agents from all three classes (including aspirin, GPIIb/IIIa inhibitors, unfractionated and low-molecular-weight heparins, fibrinolytics, beta-adrenergic blockers, calcium antagonists, nitrates, and morphine) for their overall indication, applicability to the prehospital setting, and current prehospital use.

Ems systems and managed care integration

Emergency medical services systems and MCOs must cooperate and educate each other in order to effect delivery of reliable, high-quality emergency health care to the entire community. Shared goals are rapid access, medically appropriate care, and operational efficiency. An integrated approach is necessary in order to maintain the integrity of EMS systems. EMS systems serve as a safety net for patients with perceived emergencies. Changes in form and function should be guided by outcome studies that ensure the continued delivery of quality emergency health care services.

How to monitor the effectiveness of an emergency medical dispatch system: the Houston model.

The use of priority dispatch systems for emergency medical services (EMS) is widespread throughout the United States and in several other countries. It is essential that any such system be monitored to prove that it is safe and effective. A study of the EMS system in Houston, Texas, USA, has previously reported that the priority dispatch system can safely and reliably identify EMS incidents requiring only basic life support; the methods by which this was achieved are outlined here. In addition, the current and pending revisions to the Houston Fire Department Dispatch Quality Management Programme are discussed.

Conducting Retrospective Emergency Medical Services Research

ors.