Carol Conroy

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.

The influence of vehicle damage on injury severity of drivers in head-on motor vehicle crashes

Data from crashes investigated through the Crash Injury Research and Engineering Network (CIREN) Program were used to assess differences in injury patterns, severity, and sources for drivers, protected by safety belts and deploying steering wheel air bags, in head-on frontal impacts. We studied whether exterior vehicle damage with a different distribution (wide vs. narrow) across the front vehicle plane influenced injury characteristics. Drivers from both impact types were similar on the basis of demographic characteristics (except age), restraint use, and vehicle characteristics. There were significant differences in the type of object contacted and intrusion into the passenger compartment at the drivers seat location. The mean delta V (based on the kilometers per hour change in velocity during the impact) was similar for drivers in both (wide vs. narrow) impact types. There were no significant differences in injury patterns and sources except that drivers in wide impacts were almost 4 times more likely (odds ratio (OR)=3.81, 95% confidence limits (CL) 1.26, 11.5) to have an abbreviated injury scale (AIS) 3 serious or greater severity head injury. Adjusted odds ratios showed that drivers in wide impacts were less likely (OR=0.54, 95% CI 0.37, 0.79) to have severe injury (based on injury severity score (ISS)>25) when controlling for intrusion, vehicle body type, vehicle curb weight, age, proper safety belt use, and delta V. Drivers with intrusion into their position or who were driving a passenger vehicle were almost twice more likely to have severe injury, regardless of whether the frontal plane damage distribution was wide or narrow. Our study supports that the type of damage distribution across the frontal plane may be an important crash characteristic to consider when studying drivers injured in head-on motor vehicle crashes.

Continuous Intravenous Midazolam Infusion for Centruroides exilicauda Scorpion Envenomation

STUDY OBJECTIVE We sought to describe the effects of continuous intravenous midazolam infusion as therapy for severe bark scorpion (Centruroides exilicauda) envenomation. METHODS A retrospective chart review from July 1, 1993, through January 1, 1998, identified all patients treated at a university hospital with International Classification of Diseases, Ninth Revision, codes 989.5 (toxic effect of venom) or E905.2 (scorpion sting causing poisoning). By using standardized collection forms, data were extracted from the medical record of every patient who had a grade III or IV envenomation and was treated with a continuous intravenous midazolam infusion. RESULTS Our search identified 104 patients; 34 had grade III or IV envenomation. Of these, 33 were treated in the ICU with continuous intravenous midazolam infusion. Median patient age was 4 years (range, 1 to 68 years). Midazolam dosage was adjusted to induce a light sleep state to control agitation and involuntary motor activity. The median amount of midazolam resulting in the first recorded decrease in agitation and involuntary motor activity was 0.30 mg/kg (range, 0.03 to 1.76 mg/kg). This first evidence of clinical improvement was recorded as 1.00 hour (median), with a range of 0.00 to 3.75 hours. The initial midazolam infusion rate was 0.10 mg x kg(-1) x h(-1) (median), with a range of 0.01 to 0.31 mg x kg(-1) x h(-1). The maximal midazolam infusion rate was 0.30 mg x kg(-1) x h(-1) (median), with a range of 0.06 to 1.29 mg x kg(-1) x h(-1). The median time until the maximal midazolam infusion rate was 2.5 hours (range, 0.00 to 8.50 hours). The median duration of infusion was 9. 50 hours (range, 4.25 to 20.50 hours). The median length of stay in the ICU was 15.17 hours (range, 6.0 to 28.0 hours), and 85% of patients were discharged directly home. All patients had resolution of abnormal motor activity and agitation during their midazolam infusion. Transient hypoxemia without evidence of end-organ dysfunction was documented in 4 patients during midazolam therapy. CONCLUSION A continuous intravenous midazolam infusion can be a safe, effective, and readily available treatment option for patients with grade III or IV C exilicauda envenomation.

Fatal injury: characteristics and prevention of deaths at the scene

BACKGROUND Almost half of all trauma deaths occur at the scene. It is important to determine if these deaths can be prevented. METHODS Penetrating or blunt force trauma deaths were identified through the Office of the Medical Examiner during a 2-year period. Data were also obtained through review of these records. RESULTS There were 312 deaths at the scene that received no medical care. Almost 60% were firearm-related. About 80% of the victims were men, and 55% of these deaths occurred in people between 20 and 49 years old. Suicide accounted for nearly half of these deaths. Eighty percent of these injured people had Abbreviated Injury Scale scores of 5 or 6. CONCLUSION Almost 60% of deaths at the scene occurred at the same time as injury and reflect severe injury to vital regions of the body. These findings suggest that primary prevention of the initial event causing injury may be more important than definitive prehospital emergency medical care to prevent these deaths.

The Haddon Matrix: Applying an Epidemiologic Research Tool as a Framework for Death Investigation

The Haddon matrix is a research tool used by injury epidemiologists. Although this matrix has typically been used only in epidemiologic studies, it may serve as a framework to investigate the circumstances of traumatic deaths. This matrix consists of three rows representing time phases (before the injury incident, during the incident, and after the incident) and four columns representing the energy agent, characteristics of the deceased person, the environment, and the vehicle or vector resulting in the abnormal energy exchange, which are considered in the context of the three time phases. The authors present four cases illustrating how this epidemiologic tool can be useful during death investigations. Although the objectives for epidemiologic studies and medicolegal death investigations differ, this approach can be used to describe the circumstances surrounding an injury-related death.

Emergency medical service agency definitions of response intervals.

STUDY OBJECTIVE There is a time continuum from emergency medical services (EMS) dispatch, response, scene, transport, and arrival at the hospital. Previous research has documented favorable patient outcome with short response intervals; however, these studies revealed the documentation of EMS time intervals is not always consistent. This study evaluates how agencies estimate these times and factors that may affect the length of response intervals. METHODS The study used a mail questionnaire to assess factors related to response intervals and to determine how agencies define and record response intervals. All ground-based EMS agencies in a southwestern state were invited to participate in the survey. Univariate and stratified data analyses compared definitions of response intervals. RESULTS Agencies varied as to how they defined the start and end of the response. Fifty-six percent stated that their response started when the responding unit was notified of the call. However, almost 23% defined response interval as starting when dispatch received the call, and 11% defined it as starting with the initial 911 call. A factor that affected response intervals was routing of the 911 call. Less than 6% of agencies had only 1-call routing. CONCLUSION Agencies use different time points as the start and end of their response interval, which makes comparison of results directly related to response intervals across agencies or regions difficult. To maintain an appropriate standard of prehospital emergency medical care throughout the state, the use of consistent standard terminology defining response intervals will help reach that goal.

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 childs 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 childs 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 providers usual standard of care. These results are relevant for communities providing EMS services for CSHCN.

Rib and sternum fractures in the elderly and extreme elderly following motor vehicle crashes

As the population ages, the need to protect the elderly during motor vehicle crashes becomes increasingly critical. This study focuses on causation of elderly rib and sternum fractures in seriously injured elderly occupants involved in motor vehicle crashes. We used data from the Crash Injury Research and Engineering Network (CIREN) database (1997-2009). Study case criteria included occupant (≥ 65 years old) drivers (sitting in the left outboard position of the first row) or passengers (sitting in the first row right outboard position) who were in frontal or side impacts. To avoid selection bias, only occupants with a Maximum Abbreviated Injury Scale (MAIS) 3 (serious) or greater severity injury were included in this study. Odds ratios were used as a descriptive measure of the strength of association between variables and Chi square tests were used to determine if there was a statistically significant relationship between categorical variables. Of the 211 elderly (65-79 years old) occupants with thoracic injury, 92.0% had rib fractures and 19.6% had sternum fractures. For the 76 extreme elderly (80 years or older) with thoracic injury, 90.4% had rib fractures and 27.7% had sternum fractures. Except for greater mortality and more rib fractures caused by safety belts, there were no differences between the extreme elderly and the elderly occupants. Current safety systems may need to be redesigned to prevent rib and sternum fractures in occupants 80 years and older.

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 users 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.

Injury patterns in frontal crashes: The association between knee-thigh-hip (KTH) and serious intra-abdominal injury

Safety belts protect occupants in frontal impacts by reducing occupant deceleration and preventing the occupant from hitting interior vehicle components likely to cause injury. However, occupants moving forward during the impact may contact the safety belt webbing across their chest and abdomen. We hypothesized that if the occupant loaded their knee-thigh-hip (KTH) region with enough force to result in injury to this region-it might prevent compression (and injury) of their abdomen by the safety belt. Crash Injury Research and Engineering Network (CIREN) data were used to test the association between KTH and intra-abdominal injury related to safety belts. Odds ratios with 95% confidence limits (CL) and logistic regression models were used to assess statistical significance. Analyses were based on 706 CIREN adult, front seat occupants using their safety belt and injured in frontal crashes. Occupants with KTH injury were four times less likely (adjusted odds ratio=0.25, 95% CL 0.10, 0.62) to have concomitant serious intra-abdominal injury caused by the safety belt. Although safety belts save lives and prevent serious injury, some occupants may sustain serious intra-abdominal injury when the abdomen is loaded by the safety belt during a frontal impact. These results may be useful to motor vehicle manufacturers and others who design and test motor vehicle safety systems.