Herbert G. Garrison

Study design and outcomes in out-of-hospital emergency medicine research: a ten-year analysis.

Objective. Lack of rigorous study design and failure to follow diverse patient outcomes have been identified as critical gaps in the medical research literature. This study sought to determine whether similar gaps exist in the literature for out-of-hospital interventions. Methods. A computerized MEDLINE search was conducted for the ten-year period 1985 through 1994 using the MeSH terms “emergency medical services,” “prehospital,” and “transportation of patients.” Using a standard abstraction form, two investigators independently analyzed articles meeting these inclusion criteria: original research evaluating an out-of-hospital intervention and measuring a patient outcome. Study design was categorized in order of scientific rigor, moving from case series to randomized trial. Measures of outcomes were classified into the six Ds: death, disease, discomfort, disability, dissatisfaction, and debt (cost). Results. Interobserver agreement was high (kappa = 0.80). For the ten-year period, 3,686 titles, 1,454 abstracts, and 373 articles were examined serially; all 285 studies meeting inclusion criteria were analyzed. Case series (44%) was the most frequently used design, while only 15% were randomized trials. The majority of the studies were retrospective (53%). A single outcome was assessed in 45% of the articles; 41% measured two outcomes, 13% three outcomes, and 1% four outcomes. Death and disease were the most common outcomes evaluated. Disability, debt, discomfort, and dissatisfaction were infrequently measured. Conclusion. Studies of out-of-hospital emergency medical interventions are limited in the scientific rigor of study design and the diversity of patient outcomes measured. To adequately assess the effectiveness of out-of-hospital care, efforts should be directed toward strengthening study designs and examining the full range of patient outcomes.

Data Elements for Emergency Department Systems, Release 1.0 (DEEDS): A Summary Report

See editorial, p 274. Variations in the way that data are entered in emergency department record systems impede the use of ED records for direct patient care and deter their reuse for many other legitimate purposes. To foster more uniform ED data, the Centers for Disease Control and Preventions National Center for Injury Prevention and Control is coordinating a public-private partnership that has developed recommended specifications for many observations, actions, instructions, conclusions, and identifiers that are entered in ED records. The partnerships initial product, Data Elements for Emergency Department Systems, Release 1.0 (DEEDS), is intended for use by individuals and organizations responsible for ED record systems. If the recommended specifications are widely adopted, then problems-such as data incompatibility and high costs of collecting, linking, and using data-can be substantially reduced. The collaborative effort that led to DEEDS, Release 1.0 sets a precedent for future review and revision of the initial recommendations. [DEEDS Writing Committee: Data Elements for Emergency Department Systems, Release 1.0 (DEEDS): A summary report. Ann Emerg Med February 1998;31:264-273.].

The Role of Emergency Medical Services in Primary Injury Prevention

Injury is a leading cause of death and disability. Preventing injuries from ever occurring is primary injury prevention (PIP). The objective of this statement is to present the consensus of a 16-member panel of leaders from the out-of-hospital emergency medical services (EMS) community on essential and desirable EMS PIP activities. Essential PIP activities for leaders and decision makers of every EMS system include: protecting individual EMS providers from injury; providing education to EMS providers in PIP fundamentals; supporting and promoting the collection and utilization of injury data; obtaining support for PIP activities; networking with other injury prevention organizations; empowering individual EMS providers to conduct PIP activities; interacting with the media to promote injury prevention; and participating in community injury prevention interventions. Essential PIP knowledge areas for EMS providers include: PIP principles; personal injury prevention and role modeling; safe emergency vehicle operation; injury risk identification; documentation of injury data; and one-on-one safety education.

Effect of ethanol on lactic acidosis in experimental hemorrhagic shock

Many trauma victims who have hemorrhagic shock are also intoxicated. Ethanol could worsen the severity of shock and decrease the amount of blood loss necessary to reach or maintain the shock state, perhaps by increasing lactic acidosis. We examined the effect of ethanol on lactic acidosis in a group of rats that were intoxicated, then put in a state of hemorrhagic shock (MAP = 40 mm Hg). These animals were compared to a control group that were in a similar state of hemorrhagic shock but not intoxicated. The volumes of blood necessary to reach and maintain the predetermined model state of shock for two hours in each group were also measured. The animals were paralyzed and placed on controlled ventilation. The ethanol produced an expected baseline lactic acidosis, and it took significantly less blood volume loss to keep the intoxicated group in shock. However, during shock there was no significant difference in the state of lactic acidosis. These results suggest that acute ethanol intoxication made the animals more sensitive to hemorrhage. This effect was not mediated by an increase in lactic acidosis in our model.

MOTOR VEHICLE-RELATED DROWNING DEATHS ASSOCIATED WITH INLAND FLOODING AFTER HURRICANE FLOYD: A FIELD INVESTIGATION

Drivers and passengers who drown while trapped in their vehicles or exiting from vehicles account for most flood-related deaths in the United States, yet little has been known about crash circumstances or risk factors for flood-related motor vehicle injury. We conducted a case-control study of all occupants of single-vehicle crashes in flood-affected North Carolina counties where drowning deaths occurred on 15, 16, and 17 September 1999 (the days before, during, and after landfall of Hurricane Floyd); a descriptive study of deaths using medical examiner records; and a survey of proxy respondents for persons who drowned. In 66 crashes vehicles hit puddles and went off the road, went off the road in rain, drove into water and stalled, hit trees in the road, or drove into collapsed sections of road; 19 of these vehicles were partially or fully submerged in water. Occupants of submerged vehicles were more likely to have drowned if their vehicles were fully submerged (14 of 19, 73.7%) than if their vehicles were partly submerged (0 of 8, 0%). According to proxy informants, most of the persons who drowned were familiar with the roads traveled during the study period, and all 16 had received severe weather warnings. Motor vehicle occupants in weather-related crashes are more likely to drown if their vehicles are submerged or swept away. Vehicle submersion may often be a consequence of deliberately driving into flooded roadways. However, in flood-affected areas, crashes and injuries may also occur when motorists encounter flooded roadways unexpectedly.

Determination of prehospital blood glucose: A prospective, controlled study

STUDY OBJECTIVE To determine if emergency medical personnel can effectively rule out hypoglycemia in the prehospital setting. DESIGN During a 10-week period, emergency medical personnel determined the fingerstick glucose on all prehospital patients with altered mental status using the Chemstrip bG. Statistical comparisons were made to serum glucose levels performed by hospital laboratory personnel on blood samples obtained prior to glucose administration. A serum glucose level less than 60 mg/dL was considered a positive test for hypoglycemia. PARTICIPANTS 170 consecutive patients with altered mental status (AMS) ranging in age from 13 to 90 years were enrolled. MEASUREMENTS AND MAIN RESULTS Of these patients, 158 were normal or hyperglycemic, 12 were hypoglycemic, and one patient was hypoglycemic but had only a borderline negative fingerstick test. Thus, a sensitivity of 91.7% and a negative predictive value of 99.3% were obtained. The specificity was 92.4%, and positive predictive value was 47.8%. CONCLUSION The Chemstrip bG may be used safely in the prehospital setting to rule out hypoglycemia.

Research directions in emergency medicine

Abstract The goal of emergency medicine is to improve health while preventing and treating disease and illness in patients seeking emergency medical care. Improvements in emergency medical care and the delivery of this care can be achieved through credible and meaningful research efforts. Improved delivery of emergency medical care through research requires careful planning and the wise use of limited resources. To achieve this goal, emergency medicine must provide appropriate training of young investigators and attract support for their work. Promotion of multidisciplinary research teams will help the specialty fulfill its goals. The result will be the improvement of emergency medical care which will benefit not only the patients emergency physicians serve but also, ultimately, the nations health.

Helicopter use by rural emergency departments to transfer trauma victims: A study of time-to-request intervals

To assess how soon rural emergency departments (EDs) call for helicopters to transport seriously injured patients, the records of all trauma victims (excluding isolated CNS trauma) transported by an emergency helicopter service from referring hospitals to a trauma center over an 18-month period were studied. Admission time to the referring ED was compared with the exact time a call for the helicopter was received and a time-to-request interval (TTR) was calculated. A total of 64 cases were studied. Fifty (78%) of the patients had blunt trauma; 14 (22%) had penetrating trauma. The average TTR for the helicopter was 69.8 minutes, with a range from 17 minutes before arrival at the referring ED to 337 minutes after arrival. Children (aged less than or equal to 16 years) had an average TTR of 34.1 minutes compared with 76.4 minutes for adults (aged greater than 16 years). Of the variables examined, patient age was the only factor significantly associated with TTR. These observations suggest that, except in children, there frequently is a lengthy time interval between the time trauma patients arrive at EDs in rural eastern North Carolina and the time an emergency helicopter service is called to transport them to a trauma center.

Factors associated with prolongation of transport times of emergency pediatric patients requiring transfer to a tertiary care center

Purpose: The purpose of this study was to determine factors associated with longer times to transport of emergency pediatric patients requiring tertiary care. Design: Retrospective case series. Setting: Emergency pediatric transport service. Participants: Infants and children transported by the transport service at the University of North Carolina Hospitals at Chapel Hill from January 1, 1988, to December 31, 1990. Main measurements: The time-to-request, the time from patient arrival at the referring hospital to the time when the request for transfer was received, and the ground time, defined as the time between the transport teams arrival at the referring hospital and their departure, were recorded for each transported patient. Results: Three hundred consecutive children 0 to 16 years (61 % male) were transferred. Time-to-request was shorter for trauma patients (median 62 minutes, quartiles 29 and 153 minutes) than for medical patients (median 172 minutes, quartiles 83 and 508 minutes) (P=0.0001). Infants, children, and adolescents had similar times-to-request of 147 minutes, 129 minutes, and 128 minutes, respectively (P=0.91). Increased ground times were associated with diagnosis category (median of 40 minutes for medical patients vs 29 minutes for trauma patients) (P=0.0001), with younger age (median of 46 minutes for infants, 35 minutes for children, and 28 minutes for adolescents) (P=0.0001), and with the performance of major procedures (median of 35 minutes if no procedures were performed, 38 minutes if one procedure was performed, and 54 minutes if two procedures were performed) (P=0.039). After the transport team arrived, 13% (40/300) of patients required at least one major procedure prior to transport. Conclusions: Increased time-to-request for patients with medical diagnoses, increased ground times for younger patients and patients with medical diagnoses, and failure to perform necessary procedures contribute to a prolongation of the time-to-transport of emergency pediatric patients. The magnitude of the impact of these longer transport times on outcome is unknown.

Injury prevention and emergency medical services for children in a managed care environment

Each year, 1 in 5 US children receives medical care as a result of injury. Injuries are the leading cause of medical spending for children ages 5 to 21 years, accounting for more than 20% of hospital admissions and days spent in the hospital. Pediatric injuries become an important issue for managed care organizations because of concern for member safety and increasing medical costs related to treatment. Because effective prevention decreases health care consumption, injury prevention often costs less than treating injuries. Simple devices, such as bicycle helmets, smoke detectors, and child safety seats, help keep children safe and save money. Appropriate emergency care at the scene of an injury, poison control centers that dispense expert advice over the telephone, and triaged regional trauma systems improve the outcome and save money at the same time. This article continues the white paper series by the Emergency Medical Services for Children Managed Care Task Force.