A C ASE S ERIES A NALYSIS OF M ASS C ASUALTY I NCIDENTS

Introduction. Mass casualty incidents (MCIs) are infrequent but potentially overwhelming events that can stress the capabilities of even the most organized emergency medical services (EMS) system. The Maryland EMS system has been identified as a pioneer and leader in the field of prehospital emergency care and, as with many states, Maryland's regional preparation for MCIs has been integrated into its overall EMS systems planning. Objective. To determine how successful this integration has been by examining a three-year history of response to MCIs in Maryland. Methods. A three-year case series of MCIs in Maryland was obtained from a Nexis national news publications search. These MCIs were cross-referenced with U.S. postal ZIP codes and the U.S. Census Bureau's ZIP code files. They were then mapped and summary statistics were prepared for analysis. Data obtained through the Maryland Health Services Cost Review Commission for all severely injured patients discharged from Maryland hospitals were obtained over the same three-year period for comparison. Results. Eight MCIs occurred over a three-year period, resulting in a total of 203 injuries. An average of 25.4 ± 10.7 injuries occurred per MCI. A total of 158 (77.8%) of injuries necessitated ambulance transportation. An average of 3.1 ± 1.1 hospitals were involved per MCI. Conclusions. The Maryland EMS system was effective in responding to MCIs ranging in size from 10 to nearly 40 injuries. Analyzing MCIs that reoccur on a year-to-year basis should figure into the planning process for EMS systems.     

H OSPITAL F OLLOW - UP OF P ATIENTS C ATEGORIZED AS N OT N EEDING AN A MBULANCE U SING A S ET OF E MERGENCY M EDICAL T ECHNICIAN P ROTOCOLS

Objective. Using hospital outcomes, this study evaluated emergency medical technicians' (EMTs') ability to safely apply protocols to assign transport options. Methods. Protocols were developed that categorized patients as: 1) needs ambulance; 2) may go to emergency department (ED) by alternative means; 3) contact primary care provider (PCP); or 4) treat and release. After education on application of the protocols, EMTs categorized patients at the scene prior to transport but did not change current practice. Hospital charts were reviewed to determine outcome of patients whom EMTs categorized as not needing an ambulance. Category 2 patients were assumed to need the ambulance if they were admitted to a monitored bed or intensive care unit. Category 3 and 4 patients were assumed to need the ED if they were admitted. Results. The EMTs categorized 1,300 study patients: 1,023 (79%) ambulance transport, 200 (15%) alternative means, 63 (5%) contact PCP, and 14 (1%) treat and release. Hospital data were obtained for 140 (51%) patients categorized as not needing ambulance transport. Thirteen of 140 (9%) patients who transporting EMTs determined did not need the ambulance were considered to be undertriaged: five in category 2, six in category 3, and one in category 4. Six of 13 (46%) undertriaged patients had dementia or a psychiatric disorder as one of their presenting complaints. Conclusion. These protocols led to a 9% undertriage rate. Patients with psychiatric complaints and dementia were at high risk for undertriage.     

P REHOSPITAL C ARE R ESEARCH F ORUM /NAEMSE 2002

Objectives. Emergency medical dispatch (EMD) protocols are intended to match response resources with patient needs. In a small city that previously sent a first-responder basic life support (BLS) engine company lights-and-siren response to every emergency medical services (EMS) call, regardless of nature or severity, an EMD system was implemented in order to reduce the number of such responses. The study objectives were to determine the effects of the EMD system on first-responder call volume andto assess the safety of the system. Methods. This was a prospective, before–after trial. Using computer-assisted dispatch (CAD) records, all EMS calls in the 120 days before implementation of the EMD protocol andthe 120 days after implementation were identified (excluding a one-month wash-in period). In the “after” phase, patient care reports of a random sample of cases in which an ambulance was dispatched with no first responders was manually reviewed to assess whether there might have been any benefit to first-responder dispatch. Given the lack of accepted clinical criteria for need for first responders, the investigators' clinical judgment was used. Paired t-tests were used to compare groups. Results. There were 9,820 EMS calls in the “before” phase, with 8,278 first-responder engine runs (84.3%), and9,943 EMS calls in the “after” phase, with 3,804 first-responder engine runs (39.1%). The first-responder companies were dispatched to a median of 5.65 runs/day (range 1.1–12.7) in the “before” phase, and3.17 runs/day (range 0.6–5.0) in the “after” phase (p = 0.0008 by paired t-test). Review of 1,816 “after” phase ambulance-only patient care reports (PCRs) found ten (0.55%) in which first-responder dispatch might have been beneficial, but review of EMS andemergency department (ED) records found no adverse outcomes in these ten patients. Conclusions. This study suggests that a formal EMD system can reduce first-responder call volume by roughly one-half. The system appears to be safe for patients, with an undertriage rate of about one-half of one percent.     

J USTIFICATION OF P ULSE O XIMETER C OSTS FOR P ARAMEDIC P REHOSPITAL P ROVIDERS

Objective. To assess the potential cost savings of decreasing prehospital oxygen utilization by using pulse oximetry to identify those patients who do not require supplemental oxygen. Methods. A prospective, controlled trial was performed comparing rates of oxygen utilization by paramedics with and without access to pulse oximetry. Consecutive patient encounters over a ten-week period were randomized by day of presentation. Pulse oximeters were made available on alternate days. On those days, patients whose oxygen saturations were less than 95% were treated with supplemental oxygen. Results. The use of pulse oximeters incurred a saving of 0.14 “D”-size oxygen cylinders per call. For the authors' service, this translates to a potential saving of $2,324 (C)/vehicle/year. Conclusion. For regions with patient demographics similar to the authors', the initial cost of providing paramedics with pulse oximeters may be offset by savings in oxygen consumption. A formula is provided to allow individual ambulance services to calculate the potential savings for their service.     

A N E MERGENCY M EDICAL S ERVICES P ROGRAM OF A LTERNATE D ESTINATION OF P ATIENT C ARE

Objective: The emergency department (ED) is ideally reserved for urgent health needs. The ED, however, is often the site of care for nonurgent conditions. The authors investigated whether emergency medical technicians could decrease ED use by patients with nonurgent concerns who use 911 by appropriately identifying and triaging them to alternate care destinations. Methods: From August 2000 through January 2001, two King County fire-based emergency medical services (EMS) agencies participated in an alternate care destination program for patients with specific low-acuity diagnosis codes (intervention group). Eligible patients were offered care at a clinic-based destination as an alternate to the ED (n = 1,016). The frequency of the destination of care (ED, clinic, or home) for the intervention group was compared with a matched control group that was comprised of a preintervention historical cohort of EMS encounters from the same two fire-based agencies and with the same acuity and diagnosis criteria and seasonal interval (n = 2,617). Results: Compared with the preintervention group, a smaller proportion of patients in the intervention group received care in the ED (44.6% vs. 51.8%, p = 0.001), while a greater proportion of patients in the intervention group received clinic care (8.0% vs. 4.5%, p = 0.001) or home care (no transport) (47.4 vs. 43.7%, p = 0.043). Results were comparable when adjusted for other patient characteristics. Similar relationships were not evident among nonparticipating King County EMS agencies. Based on physician review and patient interview, the alternate care intervention appeared to be safe and satisfactory. Conclusion: An EMS-based program may represent one approach to limiting nonurgent ED use.     

S UCCESSFUL P REHOSPITAL A IRWAY M ANAGEMENT BY EMT-D S U SING THE C OMBITUBE

Objective. To evaluate the ability to train emergency medical technicians-defibrillation (EMT-Ds) to effectively use the Combitube for intubations in the prehospital environment. Methods. This was an 18-month prospective field study in which EMT-Ds were trained how and in what situations to use the Combitube. Data were then obtained for all patients in whom Combitube insertion was attempted. Indications for use of the Combitube included: unconsciousness without a purposeful response, absence of the gag reflex, apnea or respiratory rate less than 6 breaths/min, age more than 16 years, and height at least 5 feet tall. Contraindications were: obvious signs of death, intact gag reflex, inability to advance the device due to resistance, or known esophageal pathology. Data were entered prospectively from the San Diego County EMS QANet database for prehospital providers. Results. Twenty-two EMT-D provider agencies, involving approximately 500 EMT-Ds, were included as study participants. Combitube insertions were attempted in 195 prehospital patients in cardiorespiratory arrest, with appropriate indication for Combitube use. An overall successful intubation rate (defined as the ability to successfully ventilate) of 79% was observed. Identical success rates for medical and trauma patients were noted. The device was placed in the esophagus 91% of the time. Resistance during insertion was the major reason for unsuccessful Combitube intubations. An overall hospital admission rate of 19% was observed. No complications were reported. Conclusion. EMT-Ds can be trained to use the Combitube as a means of establishing an airway in the pre-hospital setting. Future studies will need to further evaluate its effect on patient outcome.     

T HE D EVELOPMENT OF A R EGISTER OF R ANDOMIZED C ONTROLLED T RIALS IN P REHOSPITAL T RAUMA C ARE

Objectives. To establish a register of randomized controlled trials of interventions in the prehospital care of trauma patients. Methods. A systematic search was conducted for all randomized controlled trials of interventions in the prehospital care of trauma patients. The search included the Cochrane Controlled Trial Register, the Cochrane Injuries Group Specialised Register, Medline, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), Science Citation Index, National Research Register, Dissertation Abstracts, and PubMed for the time period 1966–2000. There were no language restrictions. In addition, full-text hand searching of a range of relevant journals was done, and the authors of included trials were contacted. Results. The combined search strategy identified 16,037 potentially eligible records, of which 28 were reports of randomized controlled trials evaluating prehospital trauma care interventions. After excluding duplicate reports, there were 24 separate randomized controlled trials including 6,806 patients. The largest and smallest trials involved 1,309 and 30 trauma patients, respectively. Conclusions. This register will facilitate the conduct of systematic reviews of the effectiveness of interventions in prehospital trauma care. However, despite the extensive searching, very few randomized trials in this area were found. In view of the absence of evidence for the effectiveness of many of the interventions that are used in the prehospital care of trauma patients, further randomized controlled trials are required.     

P REHOSPITAL R APID-SEQUENCE I NTUBATION : A P ILOT T RAINING P ROGRAM

Objective. To develop a training program enabling paramedics to use sedation and paralytic medications to facilitate endotracheal intubation in patients who otherwise could not be successfully intubated. Methods. Paramedics underwent a training program consisting of six hours of didactic education, two four-hour mannequin labs, one four-hour animal intubation lab, and operating room experience. Rapid-sequence intubation (RSI) runs were reviewed for appropriateness in patient selection and medication use. Non-RSI runs were reviewed to determine whether appropriate patients were being missed. Intubation success rates continue to be followed. Long-term quality assurance includes monthly run reviews, periodic quizzes, and unannounced on-site practical tests. Results. 101 patients have been intubated using RSI, including medical, trauma, pediatric, and adult cases. Of all patients receiving RSI drugs, 100 of 101 were successfully intubated. There were no undetected esophageal intubations. Paramedics were able to demonstrate proper patient selection and appropriately administer RSI medications. The use of sheep labs was a critical component of this training because it permitted multiple intubations in a live model possessing an airway quite similar to that of the human. The gum elastic bougie was felt to be critical in the intubation of three patients. Conclusion. This RSI training model can serve as a template for other agencies seeking to implement RSI. Limitations of this model include the availability of live animal labs and the expense of conducting the training. Intense medical director involvement has been key to the success of this prehospital RSI program.     

T RAINING P REHOSPITAL P ERSONNEL IN S APHENOUS V EIN C UTDOWN AND A DULT I NTRAOSSEOUS A CCESS T ECHNIQUES

Objective. To compare the success rates, complication rates, and times required for paramedic students to perform saphenous vein cutdown and adult intraosseous infusion using the bone injection gun (BIG). Methods. This was a prospective, randomized crossover study of 13 senior-level students in a baccalaureate degree paramedic program. Study subjects were instructed in adult intraosseous and saphenous vein cutdown techniques through lecture and laboratory exercises and then randomized into two groups. Group 1 performed saphenous vein cutdown at the ankle, followed by intraosseous infusion using the BIG. Group 2 performed the same procedures but in reverse order. All procedures were performed on preserved cadavers and videotaped. Using a standardized scoring sheet, the authors evaluated the study subjects at the time of the procedures to determine success rates, errors, and complications. Videotapes were later reviewed to verify the time required to complete the procedures. Results. The normalized mean procedure scores were 96.15 (SD 4.28) and 83.83 (SD 15.52) for the intraosseous infusion and saphenous vein cutdown procedures, respectively (95% CI for difference in means, ?12.34 to ?1.3; p = 0.020). Success rates for establishing venous access were higher for the intraosseous route (92.3%) than the cutdown technique (69.2%), but did not achieve statistical significance (p = 0.250). The times required to initiate fluid flow were 3.91 minutes (SD 0.82) by the intraosseous route and 7.57 minutes (SD 1.80) by venous cutdown (95% CI for difference in means, 2.43 to 5.55; p = 0.000). One critical error and 11 noncritical errors were encountered during the intraosseous procedure, compared with ten critical errors and 29 noncritical errors during the cutdown procedure ( p = 0.195). Conclusion. In a group of inexperienced paramedic students working on a preserved human cadaver model, intravenous access was gained more rapidly, with a higher success rate, and with fewer complications using the bone injection gun than by the saphenous vein cutdown procedure. Further study is needed to evaluate these procedures in the field setting and to compare their feasibility with other alternative venous access techniques such as femoral, external jugular, and central venous cannulation.     

P REHOSPITAL S EDATION WITH I NTRAMUSCULAR D ROPERIDOL : A O NE - YEAR P ILOT

Objective. Combative patients pose a threat to themselves and prehospital personnel, and are at risk for sudden death. Droperidol is an antipsychotic and sedative agent that might be effectively utilized by paramedics to assist in the management of uncontrollably violent patients. Methods. A prospective observational study of patients requiring sedation was conducted in an urban third-service emergency medical services system (55,000 calls per year). Patients were scored by paramedics on a five-point agitation scale with 5 being extremely combative (continuous, vigorous fighting against restraints) and 1 being somnolent (sleeping or sleepy). Eligible (score 4–5) patients received 5?mg of intramuscular droperidol on direct physician order. Data including vital signs and agitation scores were recorded at 5-minute intervals until hospital arrival. Adverse effects were also recorded. Results. Fifty-three patients received droperidol (51 patients received 5?mg; two received 2.5?mg) during the study period. The average predrug agitation score was 4.7 (±0.1 SD). The average 5-minute postdrug score was 3.9 (±0.1 SD, 95% CI 3.7–4.1). The average 10-minute postdrug score was 3.3 (±0.1 SD, 95% CI 3.1–3.6). The average hospital arrival score was 2.8 (±0.1 SD, 95% CI 2.5–3.1). One patient became obtunded and required supplemental oxygen; no other patient experienced an adverse event after receiving droperidol. Sedation was ineffective in seven patients, three of whom had head injuries, and one of whom received 2.5?mg of droperidol per physician order. Paramedics sustained no needlestick exposures. Conclusion. Intramuscular droperidol contributed to effective and rapid prehospital sedation in this observational series of 53 combative patients.     

P REHOSPITAL R APID-SEQUENCE I NTUBATION

Prehospital pain management has become an important emergency medical services (EMS) patient care issue. Objectives. To describe the frequency of EMS andemergency department (ED) analgesic administration to injured children; to describe factors associated with the administration of analgesia by EMS; andto assess whether children with lower-extremity fractures receive analgesia as frequently as do adults with similar injuries. Methods. This was a retrospective study of children (age < 21 years) who were transported by EMS between January 2000 andJune 2002 andhad a final hospital diagnosis of extremity fractures or burns. Secondarily, children with lower-extremity fractures were compared with a cohort of EMS-transported adults with similar injuries andtransported during the same study period. Receipt of andtime of parenteral analgesia were recorded. Results. Seventy-three children met the inclusion criteria. The mean (range) age of this sample was 12.4 (0.9–21) years, with only four patients aged < 5 years. A majority of the patients were male (49/73, 67.1%) andsustained femur (20/73, 27.4%) or tibia/fibula (26/73, 35.6%) fractures. Few pediatric patients received prehospital analgesia (16/73, 21.9%), while a majority received analgesia in the ED (58/73, 79.4%). Prehospital analgesia was associated with earlier patient treatment than that administered in the ED (22.3 ± 5.9 min vs. 88.3 ± 38.2 min). Comparing children (n = 33) with adults (n = 76) with similar lower-extremity fractures, a small insignificant difference was found in the rate of prehospital analgesia between children andadults (7/33, 21.2%, vs. 20/56, 26.3%). Conclusion. Few pediatric patients receive prehospital analgesia, although most ultimately received ED analgesia. Few factors were identified that could be associated with EMS oligoanalgesia. No difference was found between children andadults in the rates of EMS analgesia.     

P REHOSPITAL M ANAGEMENT OF A CUTE T ACHYARRHYTHMIAS

Arrhythmias are commonly encountered by emergency medical services (EMS) personnel. The potential seriousness of acute symptomatic arrhythmias necessitates thorough up-to-date training of EMS personnel. The three most common acute tachyarrhythmias, not linked to cardiac arrest, that are observed outside the hospital are paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation with rapid ventricular response (RAF), and perfusing ventricular tachycardia (VT). Ideally, these tachyarrhythmias should be operationally defined in a manner that simplifies, particularly for EMS providers, their diagnosis and treatment. The authors recommend referring to these rhythms as regular narrow-complex tachycardia (presumed PSVT), irregularly irregular narrow-complex tachycardia (presumed RAF), or regular wide-complex tachycardia (presumed VT or aberrantly conducted PSVT). Although the value of treatments such as cardioversion is widely understood, the benefit from others, such as lidocaine, is unclear. Current preferences, recommendations, and concerns regarding the treatment of most arrhythmias outside the hospital reflect the dichotomy that sometimes exists between available evidence and actual practice.     

C ONCEPTS AND A PPLICATION OF P REHOSPITAL V ENTILATION

Airway management and optimal ventilation are crucial aspects of managing out-of-hospital medical emergencies. The goals in these situations are controlled ventilation and optimized inspiratory time, expiratory time, and airflow. Numerous techniques and devices are available to deliver oxygen-enriched air to patients during resuscitation. The bag-valve-mask (BVM) is one of the most common devices used to provide ventilation, although the American Heart Association ranks BVM devices lower in preference than other ventilation adjuncts, such as emergency and transport ventilators (ETVs) and pocket masks. The clearly documented limitations of BVM ventilation and its widespread use in the United States underscore the need to improve ventilation practices during care provided by emergency medical services (EMS) personnel. As part of that improvement, ETVs clearly have a role in the prehospital setting. These devices should be available on every ambulance, and the ability to use ETVs should be part of each EMS provider's skill set. Furthermore, all patients requiring emergency ventilation must be adequately monitored, including continuous monitoring of end-tidal carbon dioxide concentrations. As with any other skill, ventilation requires attention during initial training, continuing education and skill reinforcement, and quality review.     

P REHOSPITAL U SE OF A NALGESIA FOR S USPECTED E XTREMITY F RACTURES

Introduction. Pain and its control have been studied extensively in the emergency department. Numerous studies indicate that inadequate treatment of pain is common, despite the availability of myriad analgesics. It has been suggested that oligoanesthesia is also a common practice in the prehospital setting. Objective. To assess the use of prehospital analgesia in patients with suspected extremity fracture. Methods. Emergency medical services (EMS) call reports were reviewed for all patients with suspected extremity fractures treated from June 1997 to July 1998 in a midwestern community with a population base of 223,000. Data collected included demographic information, mechanism of injury, medications given, and field treatment. Standing orders for administration of analgesia were available and permitted paramedics to give either morphine sulfate or nitrous oxide per protocol. Results. The EMS call reports were analyzed for 1,073 patients with suspected extremity fractures. The mean patient age was 47 years. Accidental injuries comprised 86.5% of those reviewed. Suspected leg fractures were most common (20%), followed by hips (18%), arms (11%), knees (10%), ankles (9%), shoulders (7.2%), hands (5.5%), and wrists (5.3%). Multiple trauma and assorted broken digits accounted for the remaining 14%. The most common mechanisms of injury were: fall (43%), motor vehicle collision (21%), and human assault (10%). Intravenous lines were placed in 9.4% of patients; 17% received ice packs; 16% received bandage/dressings; 25% received air splints; and 19% were fully immobilized. Analgesia was administered to 18 patients (1.8%): 16 patients received nitrous oxide and two received morphine. Conclusion. Administration of analgesics to prehospital patients with suspected fractures was rare. Prehospital identification and treatment of pain for patients with musculoskeletal trauma could be improved.     

U SE OF E MERGENCY M EDICAL S ERVICES FOR S USPECTED A CUTE C ARDIAC I SCHEMIA AMONG D EMOGRAPHIC AND C LINICAL P ATIENT S UBGROUPS : T HE REACT T RIAL

Objective. Barriers to the use of emergency medical services (EMS) and patient delay in seeking care can limit the receipt or effectiveness of reperfusion therapies and the availability of prehospital emergency cardiac care. The Rapid Early Action for Coronary Treatment (REACT) trial was designed to determine the impact of a community intervention on use of EMS among demographic and clinical subgroups of patients with suspected acute cardiac ischemia. Methods. A randomized controlled community trial was conducted in 20 pair-matched communities in the United States. One community from each pair received an 18-month, multicomponent community education program. Data were collected at 44 participating hospitals during a four-month baseline period and throughout the 18-month trial, using medical record abstracts to collect information on mode of transport to the hospital and other sociodemographic and clinical variables. Eligible patients were persons aged ≥30 years presenting with chest pain or discomfort to emergency departments (EDs) who were admitted and discharged with a cardiac-related diagnoses (ICD 410-414, 427-429, 440, 786.9). Results. The net change in the odds of EMS use was an increase of 34% in intervention compared with control communities [adjusted odds ratio (OR) 1.34, 95% CI 1.07–1.67]. We observed greater increases in the odds of EMS use among patients who had chronic or other cardiac diagnoses (adjusted OR 1.53, 95% CI 1.18–1.99, and adjusted OR 1.52, 95% CI 1.17–1.97, respectively) than in those diagnosed as having acute ischemia (adjusted OR 1.14, 95% CI 0.91-1.44). We observed greater increases in odds of EMS use in those who were retired (adjusted OR 1.62, 95% CI 1.29–2.04) or had systolic blood pressure (SBP) at or below 160?mm Hg upon presentation to the ED (adjusted OR 1.55, 95% CI 1.26–1.91 for SBP 100-160 mm Hg; 1.61, 95% CI 0.88–2.97 for SBP <100?mm Hg). Conclusions. The REACT trial demonstrated a significant impact on the use of EMS among patients admitted to the hospital for suspected acute myocardial infarction, with greater increases among patients with chronic or other cardiac ICD-9 discharge diagnoses, those presenting with lower SBP, and retired persons.     

T HE L AY P UBLIC ' S E XPECTATIONS OF P REARRIVAL I NSTRUCTIONS W HEN D IALING 9-1-1

Objective. To determine whether the lay public expects public safety answering points (PSAPs) to provide prearrival instructions. Methods. Two thousand telephone numbers were randomly generated from all listed residential numbers in a county containing urban, suburban, and rural communities served by 26 enhanced 9-1-1 PSAPs. Only a minority of the PSAPs provided prearrival instructions. Research assistants made two attempts to contact an individual at each telephone number. A survey was administered to any person who answered the telephone provided the person was at least 18 years of age and gave verbal consent. The respondents were asked their age, level of education, and gender. They were also asked what number they would call for first aid or an ambulance and whether they would expect telephone instructions from the dispatcher if a close relative was choking, not breathing, bleeding, or giving birth. Results. One thousand twenty-four individuals were successfully contacted; and 524 (51%) were at least 18 years of age and agreed to participate. The respondents' mean age was 50 (standard deviation 19 years). Sixty-five percent of the respondents were female; and 90% had at least a high school diploma. Only 37% had previously called 9-1-1 (nine-one-one) for an emergency. Ninety-seven percent said they would dial either 9-1-1 (85%) or 9–11 (nine-eleven) (12%) in an emergency. Seventy-six percent (95% CI: 73%–80%) expected prearrival instructions for all four medical conditions. Specifically, prearrival instructions were expected by: 88% for choking (95% CI: 85%–90%), 87% for not breathing (95% CI: 84%–90%), 89% for bleeding (95% CI: 86%–91%), and 88% for childbirth (95% CI: 86%–91%). Ninety-nine of 117 respondents (81%) served by a PSAP that did not provide prearrival instructions expected to receive phone instructions for all four emergencies. Logistic regression revealed that knowing to dial 9-1-1 or 9–11 in an emergency was the only significant predictor of prearrival instruction expectation [p < 0.03, odds ratio 3.4 (95% CI: 1.16–9.78)]. Age, gender, service by a PSAP providing prearrival instructions, and level of education were not predictive. Conclusion. The lay public expects prearrival instructions when calling 9-1-1, although they may not currently receive this service.     

T HE U SE OF E TOMIDATE FOR P REHOSPITAL R APID-SEQUENCE I NTUBATION

Prehospital hypoxia and hypotension increase morbidity and mortality in head-injured patients. Etomidate is a sedative agent with increasing use for emergent rapid-sequence intubation (RSI) because of its favorable hemodynamic profile. This prospective, observational study documents the authors' preliminary experience with etomidate as part of an aeromedical RSI protocol. Major trauma victims received etomidate 0.1 to 0.3?mg/kg intravenously (IV) before administration of a neuromuscular-blocking agent. After confirmation of endotracheal tube position, 1 to 2?mg midazolam IV was administered. The main outcome measure was systolic blood pressure (SBP) before and after the RSI procedure and the incidence of hypotension after RSI; individual patient plots of SBP versus time were also included for graphic analysis. An improvement in SBP after RSI with etomidate was observed (123?mm Hg to 136?mm Hg, p = 0.011) with a 9% incidence of hypotension, defined as a decrease in SBP to 90?mm Hg or less. Graphic analysis of individual SBP-time plots reveals hemodynamic stability, especially in patients with lower initial SBP values. These data suggest that the use of etomidate as part of a prehospital RSI protocol is associated with hemodynamic stability and a low incidence of hypotension.     

H ELICOPTER T RANSPORT OF P EDIATRIC VERSUS A DULT T RAUMA P ATIENTS

Objective: Conflicting reports exist regarding the appropriate utilization of helicopter transport for victims of trauma. It has been suggested that adult patients are more severely injured compared with pediatric patients when transported by helicopter. The purpose of this study was to determine whether injury severity and survival probability in pediatric trauma patients were similar to those for adults when helicopter transport was utilized at a suburban trauma center. Methods: The authors conducted a retrospective review of all trauma patients transported by helicopter from the accident scene. Patients were identified from the Christiana Care Health System trauma registry from January 1995 to November 1999. Pediatric patients were defined as those aged 15 years and younger. Data collected were utilized to determine injury severity score (ISS), revised trauma score (RTS), and survival probability. Results: Nine hundred sixty-nine patients were transported; 143 were pediatric. There was no statistical difference noted in ISS (14.21 adult, 12.76 pediatric; p = 0.1506) and RTS (7.23 adult, 7.31 pediatric; p = 0.1832). Mean length of stay was less for the pediatric group (7.5 days adult, 5.2 days pediatric; p = 0.008). Survival probabilities were likewise similar for the two groups, yet the difference met statistical significance (0.92 adult, 0.95 pediatric; p = 0.03). Conclusion: Pediatric patients transported from the accident scene by helicopter have similar ISSs and RTSs compared with adults. These data suggest that prehospital selection criteria for the two groups are similar.     

P ARAMEDIC U SE OF E NDOTRACHEAL T UBE I NTRODUCERS FOR THE D IFFICULT A IRWAY

Objective. To evaluate the ability of paramedics to learn and apply the skill of introducer-aided oral intubation in the setting of the simulated “difficult airway.” The authors hypothesized that, following a brief introduction to the device, intubation success rates would not differ for traditional and introducer-aided intubations of an immobilized airway mannequin. Methods. During a paramedic recertification class, experienced paramedics were given a brief didactic introduction to the “bougie-like” Flex Guide endotracheal tube introducer (ETTI). The participants were then asked to intubate adult mannequins immobilized in the head-neutral position, with and without the ETTI. “Successful placement” was defined as completion of the procedure within 30 seconds and endotracheal tube position confirmed by the investigator with direct visualization. Results. For both traditional and ETTI intubations, 34 (97%) of the 35 paramedics successfully intubated within 30 seconds. The two unsuccessful intubation attempts were recognized by the paramedic as esophageal intubations, and correct tube placement was obtained within an additional 30 seconds. Conclusion. In this study, use of the ETTI was mastered by the participants after only a brief didactic introduction to the device, with their ability to intubate an immobilized mannequin using the ETTI being equal to their ability to perform traditional intubation. These results suggest that use of the ETTI is easily learned, and may support the device's role in the prehospital management of the difficult airway.     

T HE U SE OF P REHOSPITAL C ONTINUOUS P OSITIVE A IRWAY P RESSURE T REATMENT IN P RESUMED A CUTE S EVERE P ULMONARY E DEMA

Objective. To describe the prehospital use of a continuous positive airway pressure (CPAP) system for the treatment of presumed acute severe pulmonary edema (ASPE). Methods. The efficacy of prehospital CPAP treatment was analyzed in terms of changes in oxygen saturation, need for intubation or ventilatory support, and possible morbidity associated with the CPAP therapy. This was a retrospective cohort study conducted in the mobile intensive care unit of a university hospital. Participants included all consecutive patients with a clinical picture of ASPE treated by a mobile intensive care unit between January 1, 1998, and December 31, 1999. Results. 121 patients were included in this study. 116 patients received prehospital CPAP therapy. Two patients (1.7%) from the CPAP-treated patients were intubated in the field. A total of six patients required endotracheal intubation before hospital, and six other patients after that. After the beginning of CPAP treatment, there was statistically significant elevation in blood oxygen saturation (mean and standard deviation [SD] before CPAP 77% ± 11% and after CPAP 90% ± 7%) (p < 0.0001) as well as reductions in the respiratory rate (mean and SD before CPAP 34 ± 8 breaths/min and after CPAP 28 ± 8 breaths/min) (p < 0.0001), systolic blood pressure (mean and SD before CPAP 173 ± 39 mm Hg and after CPAP 166 ± 37 mm Hg) (p = 0.0002), and heart rate (mean and SD before CPAP 108 ± 25 beats/min and after CPAP 100 ± 20 beats/min) (p = 0.0017). The main reason for in-hospital death (8%) was myocardial infarction. No technical problems or complications occurred during CPAP treatment. Conclusions. Prehospital CPAP treatment in patients with ASPE improved oxygenation significantly and lowered respiratory rate, heart rate, and systolic blood pressure. Because of the retrospective nature of this study, the hemodynamic effects of nitroglycerine and morphine cannot be excluded. The mortality rate was low, which needs to be confirmed in a controlled, prospective study.