Adenosine (Adenocard) is an endogenous purine nucleoside that has been approved recently for intravenous treatment of paroxysmal supraventricular tachycardia. With a serum half-life of 10 seconds, reported side effects including facial flushing, dyspnea, and chest pressure are common, but very transient. An elderly woman who received adenosine for paroxysmal supraventricular tachycardia had a prolonged anaphylactoid reaction that required pharmacological treatment. This is the first reported case of prolonged anaphylactoid reaction to adenosine.

Purpose: The wide spread use of orotracheal intubation with rapid sequence induction has made it difficult for EMS professionals to gain experience in nasotracheal intubation (NTI) in a controlled supervised setting. The purpose of this study was to determine if a training session on NTI with a breathing manikin can be used to improve skill and comfort of EMS professionals.

Methods: A prospective trial was conducted with a convenience sample of 16 emergency medical service professionals, previously trained in nasotracheal intubation techniques. For the training session a Laerdal airway manikin was modified by replacing the lungs with a bag-valve mask device, to simulate breathing with an inspiratory and expiratory phase. Following verbal instruction, and with direct supervision, each participant practiced NTI using the breathing manikin. Each participant completed a questionnaire, both before and after the training session, to determine self assessed comfort and skill level for both oral and nasal intubations (0 = lowest, 10 = highest). The pre and post intervention scores were compared using the Wilcoxon signed-rank test, £ = 0.01.

Objective: To determine the prevalence and outcome of out-of-hospital ventricular tachycardia (VT) cardiac arrest with a prolonged QT interval and to identify the subset with torsades de pointes (TdP).

Methods: Design: Retrospective review. Setting: Fire department-based paramedic system. Participants: Non-traumatic VT cardiac arrest (1/91-12/94) with a supraventricular perfusing rhythm (SVPR) and a measurable QT interval. Interventions: QT interval was measured from a SVPR and corrected QT interval (QTc) was calculated (prolonged if ≥0.45 sec). VT was classified as polymorphic or monomorphic.

Results: 190 patients met inclusion criteria. 51% of patients had a prolonged QTc (PQTc). The overall hospital discharge rate was 28.4%. No difference with respect to paramedic-witnessed arrests in each QTc group was found (25.8% normal QTc [NQTc] vs. 27.8% PQTc; p = 0.752). Patients with PQTc were less likely to be discharged from the hospital (19.6% vs. 37.6%; p = 0.01). Patients with PQTc were not more likely to have PVT (37% vs. 40%; p = 0.705). 16 (8.4%) patients had TdP. 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912).

Purpose: Because overall EMS system response depends on ambulance availability, we conducted a prospective study of the EMS turnaround interval. This interval consists of the delivery and recovery intervals as defined in Spaite's EMS time-interval model.

Methods: An on-site observer, while monitoring EMS radio traffic, recorded the delivery and recovery activities of personnel from a large urban EMS system at a university hospital ED. System policy permits a maximum 30 minute turnaround interval. Prospectively defined subintervals were analyzed.

Results: A convenience sample of 122 patient deliveries was collected. Observed and radio-reported arrival at the hospital differed by -1′24″; to +11′8″. Time from arrival to removal of the patient from the ambulance averaged 59″ (range 13″-2′53″), and time from patient removal to ED entry averaged 42″ (10″ - 5′22″). While the mean time for the verbal report to ED staff was 33″ (2″-5′20″), it was 0 = 15″ in 36% of cases. Time from ED entry to placement of the patient on an ED bed averaged 2′11″ (33″-9′35″). Writing the report averaged 17′12″ (5′20″-52′11″). The mean time off radio was 29′51″ (ll′43″-53′37″) and the mean time the ambulance was at the ED was 30′01″ (11′25″-1°17′53″). Observed and radio-reported ambulance departures differed by -4′31″ to +23′32″. In 22% of cases, departure was reported on radio more than 5′after actual departure.

Objective: Traditional EMS teaching identifies mechanism of injury as an important predictor of spine injury. Clinical criteria to select patients for immobilization are being studied in Michigan and have been implemented in Maine. Maine requires automatic immobilization of patients with “a positive mechanism” clearly capable of producing spine injury. The purpose of this study is to determine if mechanism of injury effects the ability of clinical criteria to select patients with spine injury.

Design: Multicenter Prospective Cohort.

Methods: EMS personnel completed a check-off data sheet on out-of-hospital spine immobilized patients. Data included mechanism of injury and yes/no determinations of the clinical criteria: altered mental status, neurologic deficit, evidence of intoxication, spinal pain or tenderness, and suspected extremity fracture. Hospital outcome data included confirmation of spine injury and treatment required. Mechanisms of injury were tabulated and rates of spine injury for each mechanism was calculated. The patients were divided into high-risk and low-risk groups.

Results: Data was collected on 6,500 patients. There were 213 (3.3%) patients with spine injuries identified. There were 1,065 patients with 100 (9.4%) injuries in the high-risk mechanism group, and 5435 patients with 113 (2%) injuries in the low-risk group. Clinical criteria identified 96 of 100 (96%) injuries in the high risk mechanism group and 106 of 113 (94%) in the low-risk group.

Purpose: To determine the most frequent sources of injuries from the interior of motor vehicles involved in crashes.

Methods: We searched the National Highway Traffic Safety Administration's National Accident Sampling System to determine the most frequent sources of injuries. This database includes sources of injuries resulting from crashes from January 1, 1991 to December 31, 1992.

Purpose: Standard prehospital practice includes frequent immobilization of blunt trauma patients, some 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. 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. We designed a prospective, randomized, simulated trial to determine the level of agreement between paramedic and EP assessment of clinical indicators of cervical spine injury. We hypothesized that there would be substantial agreement between paramedic and EP evaluation of standardized patients.

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, which were: 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, that was considered an immobilization decision. The kappa statistic was utilized to determine level of agreement between the two groups for each individual criterion and for the immobilization decision. A kappa of 0.40 to 0.75 denotes good reproducibility and >0.75 denotes excellent reproducibility.

Objective: Determine whether radio alerts to paramedics after 7 minutes of on-scene time reduces total on-scene time for trauma patients.

Methods: Paramedics radio base once they determine ACS criteria were met. Paramedics were informed by radio when 7 minutes lapsed on-scene. Dispatch times were recorded.

Results: The control group (Nov. 1-30, 1995) of 135 consecutive patients were reviewed without a radio alert. The test group (Dec. 1-31, 1995) of 103 consecutive patients, with a radio alert message 7 minutes after scene arrival were also reviewed. Groups were matched for extrication times, blunt versus penetrating trauma, age, etc. We analyzed both groups for the interval of time from announcement of “trauma alert,” (when paramedics determined the patient met ACS criteria or from the time extrication was complete (if applicable) to the time en route to the hospital. Average on-scene time for the control group was 13.7 minutes [range 4-35] versus test group 9.3 minutes [range 2-26] (p <0.001).

Purpose: The purpose of this study was to determine if there were differences in tidal volume (Vt), minute volume (MV), average mask leak per breath (ML), gastric insufflation (GI), and peak airway pressure (PAP) when ventilating a non-intubated mannikin with a bag-valve (BV), manually triggered ventilator (MTV) and automated ventilator (AV). Our hypothesis was that there would be no differences among devices for any of these variables.

Methods: This was a prospective in vitro experimental model. A convenience sample of 19 emergency medical technicians (EMTs) ventilated a non-intubated mannikin-mechanical test lung model with BV, MTV (flow rate 40 L/min; pressure relief 55 cm H2O), and AV (800 ml/breath; rate 12). Each subject, blinded to volume and pressure gauges, used each device for two minutes at both normal (0.1 cm H2O) and poor (0.04 cm H2O) compliances. Vt, MV, GI, and PAP were measured directly and ML was calculated. Data were analyzed with repeated measures ANOVA and Bonferoni-Dunn multiple comparison test with alpha set at 0.05.

Introduction: Monophasic defibrillation waveforms are presently the standard of care in clinical use for trans-thoracic defibrillation. Recently, there has been renewed interest in biphasic waveforms. This interest reflects the superior performance demonstrated with biphasic waveforms in implantable defibrillators (ICD). External defibrillation research on two biphasic truncated exponential waveforms has been reported in which the waveforms were compared clinically to a damped sine waveform. A limitation of these transthoracic waveforms is the insufficiency of fundamental design principles used to determine the waveform characteristics.

Methods: We developed design principles to determine the optimal waveform characteristics of an external biphasic truncated exponential waveform based on myocardial cell response model. The cell response model incorporates critical transthoracic elements into a recently published and experimentally validated intracardiac model used to design ICD waveforms. We determined the optimal leading-edge voltage (LEV), phase durations (in milliseconds, Ph1 D, Ph2 D), and delivered energies (ED) for the reported external biphasic waveforms (WF) using the model with 78 W for trans-chest resistance. We compared our results against those reported for the biphasic waveforms.

Purpose: The practice of helicopter emergency medical services is variable in its mission profile, crew configuration, and transport capabilities. We sought to describe the characteristics of physician air medical directors in the United States.

Methods: We surveyed medical directors concerning their education, training, transport experience, and roles/responsibilities in critical care air transport programs.

Results: Two page surveys were mailed to 281 air medical services. Three programs merged or were dissolved. Data from 122/278 (43.9%) air medical directors were analyzed. One-hundred eleven respondents reported residency training in: Emergency Medicine (EM) 44 (39.6%), Internal Medicine (IM) 18 (16.2%), General Surgery (GS) 18 (16.2%), Family Practice (FP) 12 (10.8%), dual-trained (EM/IM, EM/FP, IM/FP) 11 (9.9%) and others 8 (7.2%). Medical directors’ roles/responsibilities consist, most frequently of: drafting protocols 108 (88.5%), QA/CQI activities 104 (85.3%), crew training 98 (80.3%), and administrative negotiations 95 (77.7%).

Aeromedical navigation to the scene of an accident using navigational assistance computer mapping software (NACM) can be difficult in rural areas due to the lack of topographic landmarks. In these instances, navigation is made easier using the Global Positioning Satellite (GPS) system to determine latitude and longitude.

Purpose: To determine the reliability and feasibility of portable GPS receivers compared with our current system of NACM (MAP EXPERT®) in the navigation of aeromedical transport flights.

Design: A non-randomized prospective trial comparing flights using either GPS or NACM. Setting: Flight program at a Level I trauma center.

Methods: GPS receivers (for transmitting location) were carried by half the helicopters and ground EMS units. The NACM system was used to transmit the location of the accident to the other flights. Data on flight time, distance, and accident location were collected. Pilots and EMS personnel using the portable GPS system completed a questionnaire regarding accuracy, reliability, and ease of use.

Results: This study included 51 flights; GPS (n = 26) and NACM (n = 25). There was no difference in the miles flown per minute in the NACM group (1.69 miles/minute) compared with the GPS group (1.70 miles/minute). Pilots and EMS personnel rated the GPS reliable, accurate, and easy to use for navigation.

Purpose: Treatment and prevention strategies regarding people who jump from medium height bridges over water could be optimized by an improved understanding of patient demographics and injury spectra. Currently, little is known about this EMS patient population. We sought to describe the demographics and injuries sustained by those who jumped or fell from medium height bridges.

Methods: We searched the River Rescue and EMS reports of a medium size city for the ten year period 1986–1995 to identify cases involving a person who jumped/fell from a bridge into water. Additional cases were identified by searching coroner and trauma center registries. For each case, we reviewed applicable EMS, hospital, and coroner records to determine patient demographics, treatment provided, and injuries sustained.

Results: We identified 76 cases of individuals who jumped/fell from bridges into water. Eighteen of the region's 24 bridges (40 to 100 feet high) were involved. Average patient age was 34.8 years, 87% were male, and 29% jumped during July. These jumps/falls resulted in 25 (33%) deaths and 22 (29%) uninjured persons. Of those who died, 18 (72%) drowned, sustaining no other detectable injuries. Hospitalized survivors and injured coroner cases suffered predominantly extremity and rib fractures, pneumo/hemothoraces, and closed head injuries. No neck injuries were identified. No patient whose advanced level EMS treatment exceeded basic monitoring and IV access survived.

Introduction: Prior studies have documented less than 3% survival for out-of-hospital cardiac arrest (CA) in D.C. EMS intubation has failed to improve extremely poor survival rates for out of hospital CA. This study will investigate whether the addition of automatic external defibrillator (AED) use will improve the negligible survival rate experienced in a system that transports 80,000 pts/yr; Thus replicating success with AED for CA in other centers.

Methods: Retrospective review of all CA data from D.C. EMS system from 1-12/91 (no AED) vs. 1-12/93 (AED in use). Supporting data from run sheets and hospital records was compared for years with and without the AED using student's t test, chi-square with p <0.05.

Results: In 1991 there were 414 out of hospital CAs arrests with an overall survival rate of 2.3% with a mean EMS arrival time of 10 minutes. There were no significant differences with respect to CA patients’ age, bystander CPR or BLS/ALS response times between two years (1991 and 1993) p = NS. In VF patients who comprised 26% and 24% of presenting rhythms for ’91 and ’93 respectively, the use of AEDs improved survival 3.8% vs. 29% with AEDs in ’93 (p <0.05). There was no difference in percentage of non-VF presenting rhythms or patient outcomes between the two groups.

Objective: The objective of this study is to identify potential problems associated with prehospital advanced airways by assessing the utilization, complications, and education associated with the use of portable suction equipment.

Methods: Fifty-one paramedics serving a university medical center were anonymously surveyed. The survey consisted of questions regarding: utilization, difficulties, bad outcomes, and training associated with portable suction equipment.

Results: Six of the paramedics set up and check suction equip ment for every airway procedure. The rest perform daily checks or rarely test equipment. Twenty-three medics reported equipment malfunctions: dead battery (12), improper set-up (5), clogged tubing (6). Twenty-six of the paramedics reported having at least one bad outcome due to malfunction of suction equipment. These were cases of failed intubation following at least one attempt. Seven bad outcomes were attributed to lack of suction equipment at scene. Paramedics carry suction equipment to the scene for less than twenty-five percent of calls. Three suction units were in use: S-SCORT (32), S-SCORT Jr. (11), and Impact (8). There was no difference in utilization or bad outcomes by unit type. Ninety-eight percent of the paramedics reported some type of formal training on use of suction equipment during airway procedures.

Purpose: To determine the reasons why patients with potentially serious complaints present to the Emergency Department by a non-EMS mode of transportation.

Methods: Prospective patient survey distributed during a one-month period to patients presenting to a military emergency department. Surveys were entered into a data base program and descriptive, parametric and non-parametric statistical tests utilized to examine characteristics of the two groups.

Results: The only significant difference between the ambulance and non-ambulance groups of the 158 participants was patient sex.

Statement of Purpose: Prehospital death pronouncement policies are common among ground ambulances. No previous report has addressed such policies among Air Medical (AM) programs.

Statement of Methods: Statement of Methods: Structured telephone interviews of 125 of 143 (87%) AM programs (14 fixed wing, 68 rotor wing, 43 both) were conducted by research staff from 6 to 8/95.

Summary of Results: Summary of Results: Only fifty percent of AM crews are permitted to pronounce death in the field. Of those AM programs which permit pronouncement, direct medical command physician contact is required in 35% of pronouncements while 25% of programs utilize protocols. Of those AM programs which permit pronouncement, 77% of flight nurses can pronounce while only 33% of paramedics. Most programs (95%) conduct QA reviews of all deaths.

Statement of Conclusions: Prehospital death pronouncement is permitted in only 50% of AM programs. Since prehospital death pronouncement may obviate the need for AM transport, AM programs may be transporting clinically dead but unpronounced patients wasting scarce medical resources. This differs greatly from ground EMS programs where death protocols are common. Particularly puzzling is the small percentage of flight paramedics who are allowed to pronounce when compared to flight nurses since ground EMS pronouncements are performed by paramedics. AM programs should review their prehospital pronouncement protocols since managed care initiatives will drive health care organizations to abandon the wasteful practice of transporting clinically dead, but unpronounced, patients.