Emergency physician interpretation of prehospital, paramedic-acquired, electrocardiograms (ECG) is accurate judged by comparison with that of a reference cardiologist.

Twelve-lead ECGs were obtained by paramedics in the field from 150 patients with acute chest pain. The ECGs were transmitted by cellular telephone to a central location. Each ECG was assessed for evidence of acute myocardial infarction (AMI) by: 1) a third-year, emergency medicine resident (EMP-R); 2) a residency-trained, board-certified, emergency physician (EMP-RT); 3) an emergency physician board certified under the practice option (EMP-PT); and 4) a board-certified cardiologist. Agreement between each emergency physician and the cardiologist was assessed by the kappa statistic. Hospital records were reviewed for final diagnosis of each patient.

Sixteen of 150 (10.7%) patients received a hospital discharge diagnosis of AMI. Sensitivity of physician interpretation ranged from 0.31 to 0.56. All physicians achieved specificity of 0.99. False-positive rates for the physicians ranged from 0.18–0.29. The mean positive predictive value for the four physicians was 0.77±0.05; the mean negative predictive value was 0.94±0.01. The total agreements between the EMP-R, EMP-RT, and EMP-PT and the cardiologists were 0.97, 0.96, and 0.97, respectively. Kappa values for agreement between the emergency physicians and the cardiologist ranged from 0.65–0.79.

Residency-trained or board-certified emergency physician interpretations of prehospital, paramedic-acquired 12-lead ECGs show a high degree of agreement with reference cardiologist interpretations.

The interaction patterns that result from the role performance of nurses and paramedics as they care for patients conveyed to the Emergency Department could impact substantially on outcome. The nature of this interaction was studied.

Structured interviews were conducted with 35 persons: 21 paramedics, 12 full-time emergency department nurses, and two ED physicians.

Open conflicts in the ED are not a common occurrence. The reports given by paramedics and the assessments of patients by the nurse at transfer seem to represent “flash points” of conflict. The characteristics of some of the hostile behaviors which do occur are defined.

Conflict does exist and the application of suggested interventions may serve to lessen such conflict.

To evaluate the seroconversion rate of EMS personnel given the hepatitis B virus (HBV) recombinant deoxyribonucleic acid (DNA) vaccine series.

Retrospective review of paramedics and firefighters consecutively completing the HBV recombinant DNA vaccine program.

Urban, non-prof it, private, regional EMS Resource Hospital. The Chicago North EMS System is under contract with the Chicago Fire Department. This contract allows for the voluntary vaccination of EMS personnel with recombinant DNA-HBV vaccine and treatment and follow-up of paramedics and firefighters possibly exposed to HBV.

Initial 68 EMS personnel completing HBV recombinant DNA vaccine program (48 primary prophylaxis and 20 post-exposure prophylaxis).

HBV recombinant DNA vaccine series was administered voluntarily to Chicago EMS System paramedics and firefighters per manufacturers recommendations. Two weeks after completion of the vaccination series, blood samples for HBV antibody titres were drawn to determine reactivity and the need for further immunization.

Of the 68 vaccinated individuals, only two had negative titres (3%). These two individuals were given a fourth dose of vaccine with successful seroconversion.

Prehospital care personnel are known highrisk, health-care workers for acquiring HBV and should be vaccinated prophylactically. There is a high seroconversion rate (97%) utilizing HBV recombinant DNA vaccine. However, post-vaccination antibody titres must be performed to identify those rare individuals that do not seroconvert.

A national survey was conducted to determine the sponsorship of emergency medical services (EMS) projects, composition of EMS advanced life support (ALS) teams, types of medications and equipment carried, and procedures approved for use by EMS systems in the United States.

A mail survey was sent to 211 training supervisors of EMS services across the United States in 1989. The survey requested demographic and service-related information, including types of EMS sponsorship, composition of ALS teams, medications and equipment carried, and procedures which personnel have been trained to use. Medications carried were correlated with advanced cardiac life support (ACLS), the American College of Emergency Physicians (ACEP) recommended drug lists, and with the sponsoring agency.

One-hundred seventy (70%) survey forms were returned. The major providers of ALS in the United States are fire departments (36%), followed by private providers (26%), hospitals (22%), and local governments (16%). The most common ALS team composition was two paramedics followed by one paramedic and one emergency medical technician (EMT). Most ALS services carry all of the recommended ACLS medications; a much smaller percentage carry all of the drugs recommended by ACEP. Fire department based ALS units carried the least number of medications; hospital-based ALS units carried the highest number of medications. Combined, over 80 different medications were carried by the services responding to the survey.

The use of ACLS drugs and procedures are well-established nation-wide; less accepted are the medications recommended by ACEP. While over 80 different medications are carried by the EMS systems that responded to this survey, only a small fraction have been investigated in the prehospital setting.

To determine if intravenous (IV) glucose boluses cause significant alterations of serum potassium ([K+]) levels.

A prospective, descriptive study of patients ≥18 years of age presenting with altered levels of consciousness (ALOC) to paramedics in the prehospital setting or to the emergency department (ED) of a community teaching hospital and who received 50% Dextrose (D50) intravenously (IV). At presentation, a blood sample (PRE) was obtained prior to D50 therapy. For patients treated by paramedics, a second blood sample (POST) was obtained upon arrival at the ED. For patients who initially were seen in the ED, the POST sample was obtained one hour after D50 therapy. Both samples were analyzed to determine [K+] and glucose levels.

Over a seven-month period, 40 patients met study criteria. The average age was 46±20 years. Sixty percent of patients (24/40) had PRE blood sugars (BS) <80 mg/dl (mean PRE BS = 37±12 mg/dl; mean POST BS = 140±45 mg/dl) and 40% (16/40) had a PRE BS >80 mg/dl, (mean PRE BS = 241±255 mg/dl; mean POST BS = 274±237 mg/dl). The mean PRE [K+] was 4.1±0.8 mEq/L and the mean POST [K+] was 4.2±0.7 mEq/L. Forty-two percent of patients (17/40) had a <5% change in [K+], 33% (13/40) had a >5% increase in [K+], and 25% (10/40) had a >5% decrease in [K+]. Ten percent of patients (4/40) had a >20% increase in [K+], and 3% (1/40) had a ≥20% decrease in [K+]. No patient was treated for symptoms of either hyperkalemia or hypokalemia.

Boluses of IV glucose produce unpredictable changes in [K+]. The majority of these changes probably are insignificant clinically.

This study describes the epidemiology of hazardous materials (hazmat) incidents in Fresno County, California, and analyzes the emergency medical services (EMS) response to these incidents.

The study area has a population of 635,000 people living in an area of 6,004 square miles.

All Hazmat Emergency Response Team (HERT) reports and related prehospital, emergency department, and inpatient records from ljuly 1988 through 30 June 1989 were reviewed retrospectively.

There were 107 hazmat incidents involving 156 materials consisting of pesticides (24.4%), miscellaneous chemicals (17.3%), corrosives (16.7%), petroleum products (13.5%), airborne toxins (10.2%), organic solvents (7.7%), unidentified chemicals (5.1%), infectious medical waste (1.9%), empty containers with radioactive warning symbols but without detectable radiation (1.3%), heavy metals (1.3%), and alkali metals (0.6%). In ten (9%) of the 107 incidents, 68 patients required on-scene evaluation and 26 patients were transported to emergency departments. Four of these patients required admission, three because of injuries due to vehicular accidents, and one because of a coincidental cere-brovascular accident. Five incidents produced multiple victims from exposures to airborne toxins, accounting for 63 (93%) of 68 patients. Spills of solid or liquid pesticides occurred in four incidents involving patients. Ambulance personnel and/or equipment became contaminated in three of these four incidents.

1) Ambulances should be dispatched selectively to hazmat incidents because only 9% of incidents involved patients. 2) training should emphasize personnel protection and proper patient decontamination to help prevent contamination of EMS personnel and equipment. 3) Preparation of EMS personnel should emphasize exposure to airborne toxins because these produced 93% of patients.

In a single-tier, advanced-life-support (ALS) emergency medical service (EMS) system, ALS-trained staff in ALS-equipped vehicles respond to all ambulance calls. In some two-tier systems, basic life support (BLS) vehicles respond to calls which are determined initially to be non-emergency based on dispatcher triage. I emergency requiring ALS is discovered (or recognized) by BLS personnel, then a subsequent ALS response can be requested.

The purpose of this study was to determine the frequency of ALS care provided on ambulance calls initially dispatched as non-emergency.

A single-tier, all-ALS provider, EMS system, serving an urban population of 475,000 with an annual response volume of 45,000 calls.

A retrospective review of all prehospital transports initially dispatched as non-emergency from 1 January 1989 to 1 January 1990 that resulted in an ALS intervention being performed was conducted. An ALS intervention was defined as, “administration of a medication, endotracheal intubation, attempted IV insertion, and/or ECG monitoring.”

A total of 6,362 non-emergency calls were identified; of these 309 (5%) were upgraded to emergency while the responding unit was in route. Of 6,053 non-emergency calls remaining, 710 (11.7%) involved the provision of one or more ALS interventions. Of these, 296 (42%) received an IV, 24 (3%) a medication, and three (0.4%) were intubated. Calls that were upgraded by dispatchers required one or more interventions in 144/309 calls (46.6%). This was statistically significantly different than for the non-upgraded calls.

Despite the use of strict dispatching protocols, 11.7% of patients prioritized as non-emergent unexpectedly received ALS care after evaluation by ALS personnel. These results add support for the use of a single-tier, ALS ambulance system.

The effectiveness and safety of thrombolytic treatment (TT) for acute myocardial infarction (AMI) in the prehospital setting have not been defined. Therefore, its use on a mobile coronary care unit (MCCU) was studied.

A MCCU was provided with the equipment and supplies necessary for the administration TT and its personnel were trained in the indications for TT and in its administration. When an emergency medical team physician suspected the diagnosis from the presence of chest pain typical of an AMI, the patient's ECG was transmitted to the Cardiological Consulting Center. If the S-T segments were elevated and the patient met all of the screening criteria, the cardiologist ordered the MCCU personnel to carry out TT. Streptokinase (Avelyzin, Germed, GDR) was administered intravenously at a dose of 500,000 UE.

Sixty-seven patients with AMI were included in the trial. The mean interval between the onset of the symptoms and the beginning of the TT was 156±77 minutes; it was less than 3 hours for 54 patients. Thirty-four patients (50.7%) had non-invasive markers of successful reperfusion, while 33 (49.3%) did not. Three patients had non-fatal ventricular fibrillation (VF), ventricular tachycardia (VT) and/or ventricular premature beats of high grades (Lown classes 3–5) developed in six and 22 patients respectively. Five patients had conduction disturbances, and 40 had symptomatic hypotension. None of the patients died before arrival at the hospital. Four suffered reinfarction, and one died of VF during the in-hospital phase of care. Post-discharge follow-up (17.5±5.0 months) demonstrated a positive exercise test in 23 (43%), and a left ventricular ejection fraction >80% in 29 (85.2%) and <40% in five (14.8%) of the patients. The in-hospital and post-discharge mortalities were 1.5 and 4.8% respectively. There was not a single case of bleeding sufficient to require a transfusion.

The study indicates that the administration of TT for AMI in the prehospital setting is both safe and effective.

This study is an evaluation of the ability of medically trained and controlled emergency medical dispatchers to use telephone triage techniques to direct the appropriate prehospital unit to an emergency scene.

Emergency dispatchers, educated in a formal emergency medical dispatch program, were assigned one of four triage priorities to incoming 9-1-1 calls. The actual field management delivered for each patient was compared with the dispatcher's triage to determine the appropriateness of triage.

A total of 1,045 consecutive calls were reviewed with 74.4% sorted as needing advanced life support (ALS) units on scene; 65.3% (95% CI, 61.9 to 68.6%) of these calls required ALS intervention. A total of 3.4% of the runs sorted to the non-ALS response groups were identified to have required ALS intervention. Comparing the need for ALS intervention, a significant difference was found between the triage groups.

Emergency medical dispatchers, using a formal system for telephone triage, are able to direct appropriate prehospital resources to the emergency scene.

In Part I of the study, the collar and a short spine board were applied to 25 adult volunteers in a sitting position, using standard methods. Each subject then exerted maximal force inflexion, extension, rotation, and abduction. Degrees of head motion from neutral position were measured in each direction. Mean values were compared using Student's t-test. For Part II, 10 EMS personnel were asked to apply the collar to volunteers. Each rated the performance of the collar on a scale of 1 (poor) to 4 (excellent) regarding: ease of application (sitting and supine), ease of extrication (lifting, logrolling, transfer), access to patient (chest auscultation, CPR, airway management), storage, and overall utility.

The collar was significantly better than the short spine board in both lateral and rotational immobilization (p<0.001). There was no significant difference for flexion or extension (p>0.05). The Red E.M. limited motion to a mean of 15° or less in any direction. Ratings by EMS personnel for the device (meant±standard error) were: ease of application (sitting) 3.5±0.2, (supine) 2.7±0.2; ease of extrication 3.1±0.2; access to patient 3.4±0.2; storage 3.1±0.3; and overall utility 3.1±0.2.

This study indicates that the Philadelphia Red E.M. Collar with Head Immobilizer/Stabilizer is an effective and practical adjunct to stabilization and extrication of potentially neck-injured patients.