Comparative anatomy of the porcine and human thoracic spines with reference to thoracoscopic surgical techniques.

BACKGROUND: This study compared porcine and human thoracic spine anatomies for a better understanding of how structures encountered during thoracoscopy differ between training with a porcine model and actual surgery in humans. METHODS: Parameters were measured including vertebral body height, width, and depth; disc height; rib spacing; spinal canal depth and width; and pedicle height and width. RESULTS: Although most porcine vertebral structures were smaller, porcine pedicle height was significantly greater than that of humans because the porcine pedicle houses a unique transverse foramen. The longus colli and psoas attach, respectively, to T5 and T13 in swine and to T3 and T12 in humans. In swine, the azygos vein generally was absent. The intercostal veins drained into the hemiazygos vein. CONCLUSIONS: Several thoracoscopically relevant anatomic differences between human and porcine spinal anatomies were identified. A thoracoscopic approach in a porcine model probably is best performed from the right side. The best general working area is between T6 and T10.

Factors associated with CPR certification within an elderly community.

OBJECTIVE: To determine the frequency of CPR certification amongst residents living within a predominantly elderly community and examine the perceived barriers to learning basic CPR and factors associated with intent to become certified. METHODS: A household survey was sent with a community newsletter to each home of a non-gated elderly community that requires one member of each household to be at least 55 years of age. The community consists of 2488 homes (approximately 4000 residents). Thirteen Yes/No questions were asked in a skip-pattern based upon the question: "Are you CPR certified?" Data analysis included univariate, bivariate, and logistic regression. RESULTS: 947 participants with a mean age of 69 completed and returned the survey. Forty-eight percent of the participants had received prior training in CPR. Eighty-four percent were not currently certified in CPR, and top reasons cited were: 'don't know why' (36%), 'lack of interest' (20%), 'concerned about health risks' (17%). Forty-six percent of those not certified desired certification. Increasing age was inversely associated with CPR certification status and the desire to be certified. CONCLUSION: Almost half of the residents in this predominantly elderly community had received prior training in CPR, although most were not currently certified and cite significant specific and non-specific reasons and obstacles. Improved survival requires targeted interventions to achieve higher proportions of CPR-competent individuals in such high-risk communities.

Increasing paramedics' comfort and knowledge about children with special health care needs.

This study evaluated a continuing education program for paramedics about children with special health care needs (CSHCN). Pretraining, posttraining, and follow-up surveys containing two scales (comfort with CSHCN management skills and comfort with Pediatric Advanced Life Support [PALS] skills) were administered. Objective measures of knowledge were obtained from pre- and posttraining tests. Differences in average scores were assessed using t-tests. Response rates for paramedics completing the program ranged from 94% for the posttraining survey, 81% for the initial comfort survey, 56% for the knowledge pretest, and 56% for the follow-up survey. PALS comfort scores were significantly higher than CSHCN comfort scores both before and after training, both P < .01. Posttraining surveys showed an increase in CSHCN comfort, P < .01. The follow-up surveys showed a significant decline in CSHCN comfort, P = .05. Scores on the tests showed a similar pattern, with a significant increase in knowledge from pre- to posttraining (P = .02) and a significant decrease in knowledge from posttraining to follow-up (P < .01). Comfort was significantly higher for standard pediatric skills than for specialized management skills. Completion of the self-study program was associated with an increase in comfort and knowledge, but there was some decay over time.

Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos.

BACKGROUND: The use of automated external defibrillators by persons other than paramedics and emergency medical technicians is advocated by the American Heart Association and other organizations. However, there are few data on the outcomes when the devices are used by nonmedical personnel for out-of-hospital cardiac arrest. METHODS: We studied a prospective series of cases of sudden cardiac arrest in casinos. Casino security officers were instructed in the use of automated external defibrillators. The locations where the defibrillators were stored in the casinos were chosen to make possible a target interval of three minutes or less from collapse to the first defibrillation. Our protocol called for a defibrillation first (if feasible), followed by manual cardiopulmonary resuscitation. The primary outcome was survival to discharge from the hospital. RESULTS: Automated external defibrillators were used, 105 patients whose initial cardiac rhythm was ventricular fibrillation. Fifty-six of the patients 153 percent) survived to discharge from the hospital. Among the 90 patients whose collapse was witnessed (86 percent), the clinically relevant time intervals were a mean (+/-SD) of 3.5+/-2.9 minutes from collapse to attachment of the defibrillator, 4.4+/-2.9 minutes from collapse to the delivery of the first defibrillation shock, and 9.8+/-4.3 minutes from collapse to The arrival of the paramedics. The survival rate was 74 percent for those who received their first defibrillation no later than three minutes after a witnessed collapse and 49 percent for those who received their first defibrillation after more than three minutes. CONCLUSIONS: Rapid defibrillation by nonmedical personnel using an automated external defibrillator can improve survival after out-of-hospital cardiac arrest due to ventricular fibrillation. Intervals of no more than three minutes from collapse to defibrillation are necessary to achieve the highest survival rates.

Use of emergency medical services by children with special health care needs.

OBJECTIVE: This study describes emergency medical services (EMS) responses for children with special health care needs (CSHCN) in an urban area over a one-year period. METHODS: A prospective surveillance system was established to identify EMS responses for children, 21 years of age or younger, with a congenital or acquired condition or a chronic physical or mental illness. Responses related to the special health care needs of the child were compared with unrelated responses. RESULTS: During a one-year period, 924 responses were identified. Fewer than half of the responses were related to the child's special health care need. Younger children were significantly more likely to have a response related to their special needs than older children. Among related responses, seizure disorder was the most common diagnosis, while asthma was more common for unrelated responses. Almost 58% of the responses resulted in transport of the child to a hospital. CONCLUSIONS: Emergency medical services responses related to a child's special health care needs differ from unrelated responses. The most common special health care needs of children did not require treatment beyond the prehospital care provider's usual standard of care. These results are relevant for communities providing EMS services for CSHCN.

Development of an electronic emergency medical services patient care record.

OBJECTIVE: The need for valid and reliable emergency medical services (EMS) data has long been recognized. EMS data are useful for monitoring resources and operations, documenting patient care and outcome, and evaluating injury prevention strategies. The goal of this project was to develop a computerized data set with the capability to generate a patient care record (PCR) to overcome some of the current EMS data limitations. METHODS: The authors discuss developing an electronic PCR and analysis data set containing 233 variables. Data are collected for the following: incident, response, scene, patient, history, primary survey (including vital signs), physical examination, physiologic scores, diagnostics, plan (medications and procedures), assessment, and reevaluation. Software on a portable computer installed in an EMS response unit utilizes a graphical user interface for data collection by prehospital emergency care providers. A data set stores codes corresponding to user's selections. This data set supports data storage and analysis. The electronic PCR and data set can be useful to EMS agencies for collecting, storing, reporting, and analyzing information. RESULTS: Variables are categorized into 12 main categories to categorize the variables and to drive data collection. The system provides the user with the ability to print out a record (using a portable printer installed in an ambulance) and analyze data stored in the data set. CONCLUSION: This computerized approach overcomes many limitations inherent with using paper-based systems for research. Linked with emergency department, hospital discharge, and mortality data, EMS data can be used in systems analyses related to patient outcome.

Prehospital advanced life support for major trauma: critical need for clinical trials.

A widely diverse body of information exists on the use of Advanced Life Support procedures by prehospital personnel. We compared and contrasted the literature that currently exists on this topic. We examined methodologies, results, and conclusions for each article. We also stress the need for critical clinical evaluations in this arena.

Development of new methods to assess the outcomes of emergency care.

This article provides information supporting the need for new outcome measures in emergency care. It also addresses the use of these measures in emergency care, the impact of emergency care, identification of at-risk groups, new approaches to measuring patient satisfaction, quality of life, and cost-effectiveness, and the related unique implications for emergency medicine.

Development of new methods to assess the outcomes of emergency care.

This article provides information supporting the need for new outcome measures in emergency care. It also addresses the use of outcome measures in emergency care, the impact of emergency care, identification of at-risk groups, new approaches to measuring patient satisfaction, quality of life and cost-effectiveness, and the unique related implications for emergency medicine.

Developing a foundation for the evaluation of expanded-scope EMS: a window of opportunity that cannot be ignored.

EMS systems are about to undergo a major transformation. Not only will the scope of EMS change, but many experts believe that it will dramatically expand. Some see the "expanded scope" as entailing relatively limited changes, whereas others consider them to be more broad. Although no agreement is evident about the definition for expanded-scope EMS, it is hoped that all EMS professionals can agree that it must be implemented in a manner that can be carefully evaluated to determine its effects on patients and EMS systems. We present a framework for evaluating the effect of expanded-scope EMS in the various types of systems that currently exist. Special consideration must be given to the indirect effects that system changes may have on survival from out-of-hospital cardiac arrest. Numerous issues will affect our ability to properly assess expanded-scope EMS. The basic research models necessary to assess the impact of system change are lacking. Few EMS systems consistently produce significant volumes of good systems research ... that is, there are few "EMS laboratories." Cost-effectiveness and issues surrounding the "societal value" of EMS remain essentially unstudied. Reliable scoring methods, severity scales, and outcome measures are lacking: and, it is ethically and logistically difficult to justify withholding the "standard of care" in an effort to understand the impact of EMS interventions. Despite all of these barriers, it is time to pay the price of doing methodologically sound evaluations that ensure the most optimal societal impact by the EMS systems of the future.

Estimating effectiveness of cardiac arrest interventions: a logistic regression survival model.

BACKGROUND: The study objective was to develop a simple, generalizable predictive model for survival after out-of-hospital cardiac arrest due to ventricular fibrillation. METHODS AND RESULTS: Logistic regression analysis of two retrospective series (n=205 and n=1667, respectively) of out-of-hospital cardiac arrests was performed on data sets from a Southwestern city (population, 415,000; area, 406 km2) and a Northwestern county (population, 1,038,000; area, 1399 km2). Both are served by similar two-tiered emergency response systems. All arrests were witnessed and occurred before the arrival of emergency responders, and the initial cardiac rhythm observed was ventricular fibrillation. The main outcome measure was survival to hospital discharge. Patient age, initiation of CPR by bystanders, interval from collapse to CPR, interval from collapse to defibrillation, bystander CPR/collapse-to-CPR interval interaction, and collapse-to-CPR/collapse-to-defibrillation interval interaction were significantly associated with survival. There was not a significant difference between observed survival rates at the two sites after control for significant predictors. A simplified predictive model retaining only collapse to CPR and collapse to defibrillation intervals performed comparably to the more complicated explanatory model. CONCLUSIONS: The effectiveness of prehospital interventions for out-of-hospital cardiac arrest may be estimated from their influence on collapse to CPR and collapse to defibrillation intervals. A model derived from combined data from two geographically distinct populations did not identify site as a predictor of survival if clinically relevant predictor variables were controlled for. This model can be generalized to other US populations and used to project the local effectiveness of interventions to improve cardiac arrest survival.

Fatal trauma: the modal distribution of time to death is a function of patient demographics and regional resources.

BACKGROUND: Unlike previous studies in an urban environment, this study examines traumatic death in a geographically diverse county in the southwestern United States. METHODS: All deaths from blunt and penetrating trauma between November 15, 1991, and November 14, 1993, were included. As many as 150 variables were collected on each patient, including time of injury and time of death. Initial identification of cases was through manual review of death records. Information was supplemented by review of hospital records, case reports, and prehospital encounter forms. RESULTS: A total of 710 traumatic deaths were analyzed. Approximately half of the victims, 52%, were pronounced dead at the scene. Of the 48% who were hospitalized, the most frequent mechanism of injury was a fall. Neurologic dysfunction was the most common cause of death. Two distinct peaks of time were found on analysis: 23% of patients died within the first 60 minutes, and 35% of patients died at 24 to 48 hours after injury. CONCLUSIONS: Although there appears to continue to be a trimodal distribution of trauma deaths in urban environments, we found the distribution to be bimodal in an environment with a higher ratio of blunt to penetrating trauma.

Observational evaluation of compliance with traffic regulations among helmeted and nonhelmeted bicyclists.

STUDY OBJECTIVE: To evaluate whether helmeted bicyclists are more compliant with traffic regulations than nonhelmeted bicyclists. METHODS: This prospective observational study, using a convenience sample, was conducted during daylight hours at three separate intersections, marked with legal stop signs, near the campus of a major university. Data collected included helmet use, legal hand signal use to indicate a turn or stop, and whether the bicyclist came to a complete stop before proceeding through the intersection. RESULTS: A total of 1,793 bicyclists were evaluated. Only 8.8% of the bicycle riders were wearing helmets. Helmeted bicyclists were 2.6 times more likely than nonhelmeted bicyclists to make legal stops (P < .000001; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.1 to 4.6). They were also 7.1 times more likely to use hand signals (P < .000001; OR, 7.2; 95% CI, 2.8 to 18.2). CONCLUSION: Helmeted bicycle riders showed a significantly greater compliance with two traffic laws than nonhelmeted bicyclists. They were 2.6 times more likely to stop at stop signs and 7.1 times more likely to use legal hand signals. This very strong association of helmet use with safer riding habits has implications for injury-control efforts aimed at preventing bicycle-related injuries.

Emergency medical service systems research: problems of the past, challenges of the future.

Out-of-hospital emergency care was designed around the concept of a system of interrelated events that combine to offer a patient the best care possible outside the hospital. However, in contrast to the actual operations of emergency medical service (EMS) systems, research has not typically used systems-based models as the method for evaluation. In this discussion we outline the weaknesses of component-based research models in EMS evaluation and attempt to provide a "systems-analysis" framework that can be used for future research. Incorporation of this multidiscipline approach into EMS research is essential if there is to be any hope of finding answers to many of the important questions that remain in the arena of out-of-hospital health care.

Comparison of clinically significant infection rates among prehospital-versus in-hospital-initiated i.v. lines.

STUDY OBJECTIVE: To compare the risk of infection for i.v. lines placed in the prehospital versus in the in-hospital setting in a midsized emergency medical service system. DESIGN: A retrospective analysis was made of all i.v. line site infections among patients admitted to ward beds from a university hospital emergency department in 1992. METHODS: The hospital's infection control team conducted daily ward rounds and a surveillance of all wound and blood cultures. Patients with signs and/or symptoms consistent with Centers for Disease Control and Prevention guidelines for skin and soft tissue infection were reported to the responsible medical team. Infections were documented based on consensus opinion between the infection control team and the physicians responsible for the care of the patient. IV lines placed in the prehospital phase of care were identified by electronic retrieval from the prehospital database. RESULTS: Three thousand one hundred eighty-five patients who had a prehospital or an in-hospital i.v. line placed were admitted from the ED. Eight hundred fifty-nine i.v. lines were prehospital placed (27%), and 2,326 were in-hospital placed (73%). There was one infection in the prehospital group and four in the in-hospital group (infection rate: .0012 for prehospital patients and .0017 for in-hospital patients; P = .591 by Fisher's exact test). CONCLUSION: Both cohorts had exceptionally low infection rates. No clinically or statistically significant increase in the risk of infection among prehospital- or in-hospital-initiated i.v. lines was identified.

A prospective investigation of the impact of alcohol consumption on helmet use, injury severity, medical resource utilization, and health care costs in bicycle-related trauma.

STUDY OBJECTIVE: To examine if a relationship exists between bicycle-related injuries, consumption of alcohol, helmet use, and medical resource utilization. DESIGN: A prospective cohort study with data from emergency department, operating room, and inpatient records. SETTING: University-based trauma center in a medium-sized metropolitan area. TYPE OF PARTICIPANTS: Adult victims (age > or = 18 years) of bicycle-related injury presenting to the emergency department. A total of 350 patients made up the study population. RESULTS: Group 1 consisted of 29 patients (8.3%) with detectable blood alcohol levels at the time of the incident. Group 2 (321 patients) had a measured blood alcohol level of 0 or no clinical indication of alcohol consumption. Group 1 mean Injury Severity Score was 10.3, with six (20.7%) sustaining at least one severe anatomic injury. Group 2 had an Injury Severity Score of 3.3 (p < 0.0001), with only 4.4% (p = 0.0013) sustaining severe anatomic injury. Mean length of hospitalization for group 1 was 3.5 days, including a mean of 1.4 intensive care unit days. Mean hospitalization (0.5 days, p < 0.0001) and intensive care unit (0.1 days, p < 0.0001) were significantly lower in group 2. Mean combined hospital and physician charges were more than six times greater for group 1 ($7,206) than group 2 patients ($1170, p < 0.0001). CONCLUSION: In patients presenting with bicycle-related injuries, prior consumption of alcohol is highly associated with greater injury severity, longer hospitalization, and higher health care costs. This information is useful in the development of injury prevention strategies to decrease incidence and severity of adult bicycle injuries.

A prospective in-field comparison of intravenous line placement by urban and nonurban emergency medical services personnel.

STUDY HYPOTHESIS: Emergency medical services personnel are highly proficient at rapid i.v. line placement in the prehospital setting, with little difference between urban and nonurban areas in a geographically diverse state. DESIGN: Prospective evaluation by an in-field observer of timing, sequence, success rates, and patient characteristics for IV line placement by prehospital personnel for 1 year. SETTING: Twenty advanced life support agencies from all four emergency medical service regions of Arizona. PARTICIPANTS: Fifty-eight patients encountered by participating emergency medical service agencies who had at least one i.v. line placement attempt in the prehospital setting. RESULTS: Urban agencies encountered 24 patients (41.4%), and nonurban agencies encountered 34 (58.6%). Fifty-seven of 58 patients (98.3%) had at least one successful i.v. line started before arrival at a hospital. All 24 urban patients and 33 of 34 nonurban patients (97.1%) had a successful i.v. line attempt (P = .586, power = .09). In the urban setting, 24 of 31 attempts (77.4%) were successful, and in the nonurban setting 35 of 52 attempts (67.3%) were successful (P = .464, power = .28). Mean i.v. line procedure intervals were 1.6 minutes in urban and 1.4 minutes in nonurban settings (P = .408, power = .7). Thirty of 31 i.v. line attempts (96.7%) were completed in less than 4 minutes in urban systems, and 49 of 52 IV line attempts (94.2%) were completed in less than 4 minutes in nonurban systems (P = .520, power = .13). Mean i.v. line procedure intervals were 1.3 minutes for successful attempts and 2.1 minutes for unsuccessful ones (P = .015). Mean i.v. line procedure intervals for on-scene attempts were 1.3 minutes compared with 2.0 minutes for attempts during transport (P = .005). On average, i.v. line attempts in trauma patients took only 1.0 minutes compared with 1.7 in medical patients (P = .017). CONCLUSION: Personnel in the 20 advanced life support agencies studied were extremely adept (rate of 98.3%) at obtaining i.v. line access in the prehospital setting. The time required to complete i.v. line placement was very short, and little difference was noted between urban and nonurban providers. I.v. procedure intervals were shorter for successful attempts, on-scene attempts, and attempts in trauma patients compared with their counterparts.

Emergency vehicle intervals versus collapse-to-CPR and collapse-to-defibrillation intervals: monitoring emergency medical services system performance in sudden cardiac arrest.

STUDY OBJECTIVE: To compare emergency vehicle response intervals with collapse-to-intervention intervals to determine which of these system data better correlated with survival after prehospital sudden cardiac arrest. STUDY DESIGN: A 22-month case series, collected prospectively, of out-of-hospital cardiac arrests. Times of collapse, dispatch, scene arrival, CPR, and initial defibrillation were determined from dispatch records, recordings of arrest events, interviews with bystanders, and hospital records. SETTING: Southwestern city (population, 400,000; area, 390 km2) with a two-tiered basic life support-advanced life support emergency medical services system. Emergency medical technician-firefighters without electrical defibrillation capability comprised the first response tier; firefighter-paramedics were the second tier. PATIENTS: One hundred eighteen cases of witnessed, out-of-hospital cardiac arrest in adults with initial ventricular fibrillation. MAIN OUTCOME MEASURES: Survival was defined as a patient who was discharged alive from the hospital. RESULTS: Eighteen of 118 patients (15%) survived. Survivors did not differ significantly from nonsurvivors in age, sex, or basic life support or advanced life support response intervals. Survivors had significantly (P < .05) shorter intervals from collapse to CPR (1.7 versus 5.2 minutes) and to defibrillation (7.4 versus 9.5 minutes). CONCLUSION: Collapse-to-intervention intervals, not emergency vehicle response intervals, should be used to characterize emergency medical services system performance in the treatment of sudden cardiac death.